Issuu on Google+


Practical CakePHP Projects

Kai Chan and John Omokore with Richard K. Miller


Practical CakePHP Projects Copyright © 2009 by Kai Chan and John Omokore with Richard K. Miller All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the prior written permission of the copyright owner and the publisher. ISBN-13 (pbk): 978-1-4302-1578-3 ISBN-13 (electronic): 978-1-4302-1579-0 Printed and bound in the United States of America 9 8 7 6 5 4 3 2 1 Trademarked names may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, we use the names only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. Java™ and all Java-based marks are trademarks or registered trademarks of Sun Microsystems, Inc., in the US and other countries. Apress, Inc., is not affiliated with Sun Microsystems, Inc., and this book was written without endorsement from Sun Microsystems, Inc. Lead Editor: Steve Anglin Technical Reviewer: David Golding Editorial Board: Clay Andres, Steve Anglin, Mark Beckner, Ewan Buckingham, Tony Campbell, Gary Cornell, Jonathan Gennick, Michelle Lowman, Matthew Moodie, Jeffrey Pepper, Frank Pohlmann, Ben Renow-Clarke, Dominic Shakeshaft, Matt Wade, Tom Welsh Project Manager: Richard Dal Porto Copy Editor: Marilyn Smith Associate Production Director: Kari Brooks-Copony Production Editor: Candace English Compositor: Patrick Cunningham Proofreader: Martha Whitt Indexer: Brenda Miller Artist: April Milne Cover Designer: Kurt Krames Manufacturing Director: Tom Debolski Distributed to the book trade worldwide by Springer-Verlag New York, Inc., 233 Spring Street, 6th Floor, New York, NY 10013. Phone 1-800-SPRINGER, fax 201-348-4505, e-mail kn`ano)ju<olnejcan)o^i*_ki, or visit dppl6++sss*olnejcankjheja*_ki. For information on translations, please contact Apress directly at 2855 Telegraph Avenue, Suite 600, Berkeley, CA 94705. Phone 510-549-5930, fax 510-549-5939, e-mail ejbk<]lnaoo*_ki, or visit dppl6++sss* ]lnaoo*_ki. Apress and friends of ED books may be purchased in bulk for academic, corporate, or promotional use. eBook versions and licenses are also available for most titles. For more information, reference our Special Bulk Sales–eBook Licensing web page at dppl6++sss*]lnaoo*_ki+ejbk+^qhgo]hao. The information in this book is distributed on an “as is” basis, without warranty. Although every precaution has been taken in the preparation of this work, neither the author(s) nor Apress shall have any liability to any person or entity with respect to any loss or damage caused or alleged to be caused directly or indirectly by the information contained in this work. The source code for this book is available to readers at dppl6++sss*]lnaoo*_ki.


For Rita —Kai Chan For Comfort —John Omokore For Marian —Richard K. Miller


Contents at a Glance About the Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii About the Technical Reviewer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii

CHAPTER 1

Cake Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

CHAPTER 2

Blogging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

CHAPTER 3

E-Commerce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

CHAPTER 4

A Message Forum Web Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

CHAPTER 5

Google Maps and the Traveling Salesman . . . . . . . . . . . . . . . . . . . . . . 131

CHAPTER 6

Mashing Twitter with the Google Translator . . . . . . . . . . . . . . . . . . . . 173

CHAPTER 7

Unit Testing and Web Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213

CHAPTER 8

A Cake Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237

CHAPTER 9

Translating Stories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271

CHAPTER 10

Adding Automagic Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307

CHAPTER 11

Cake Tags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317

CHAPTER 12

Dynamic Data Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329

CHAPTER 13

Captcha . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371

v


Contents About the Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii About the Technical Reviewer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii

CHAPTER 1

Cake Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Cake Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 The Ingredients of Cake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 The Model-View-Controller Design Pattern . . . . . . . . . . . . . . . . . . . . . . 2 Rapid Application Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 PHP 4+. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Object-Oriented Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Dissecting Cake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Cakeâ&#x20AC;&#x2122;s Directory Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 The Cake Naming Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Model Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Data Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Cake Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Helpers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Plugins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Vendors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

CHAPTER 2

Blogging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Creating the Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Reviewing the Application Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Creating the Post Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

vii


viii

NCONT ENTS

Creating the Posts Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Listing the Posts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Adding a Post . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Updating a Post . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Unpublishing a Post . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Publishing a Post . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Deleting a Post . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Creating an RSS Feed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

CHAPTER 3

E-Commerce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 The Online Shop Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Two Site Layouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Layout of the Main Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 The User Journey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Setting Up the Shop Database. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Interacting with the Online Shop Database . . . . . . . . . . . . . . . . . . . . . . . . . . 52 The Category Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 The Categories Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 The Product Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 The Products Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 The Cart Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Handling User Requests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 The AppController Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 The Home Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 The Carts Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 The Order Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 The Google Checkout Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 The PayPal Submit Button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

CHAPTER 4

A Message Forum Web Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Our Take on Web Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Web Service Elements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 REST and HTTP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Result Return Formats. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Application Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Threads and Posts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Web Service Requests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91


NC O N T E N T S

Application Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 JSON Web Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Our Application Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 Fetch a Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Fetch Several Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Fetch the Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 Post Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 Process a Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Process a Search Request . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 Writing the API Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

CHAPTER 5

Google Maps and the Traveling Salesman . . . . . . . . . . . . . . . 131 Hello Map! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 Google Maps Explained . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Geocoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Google Map Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 Map Interface Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 Overlays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 Driving Directions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Application Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 Application Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 Cake Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 The Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 The Global Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 Home Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 Travel Mappr Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Finding Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 The Traveling Salesman Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 Plotting the Journey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 Journey Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Saving a Journey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Saving Tags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 Retrieving and Editing a Journey. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 Viewing a Journey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

ix


x

NCONT ENTS

CHAPTER 6

Mashing Twitter with the Google Translator . . . . . . . . . . . . . 173 The Twitter API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 The Google Ajax Language API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 Application Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 Application Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 Cake Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 Internationalization and Localization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 Web Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 Caching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Caching Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 Caching Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 Caching Twitter and Google Translations . . . . . . . . . . . . . . . . . . . . . 189 Caching and the Application Layout . . . . . . . . . . . . . . . . . . . . . . . . . . 190 Changing Languages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 Changing Locales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 The Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 The Twittertwister Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 The TwitterRequest Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 The TwitterStatus Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 The AppController . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

CHAPTER 7

Unit Testing and Web Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Getting Programming Done . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Our Case Study: An App Like In/Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 Creating the Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 Adding Username Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 Using Cakeâ&#x20AC;&#x2122;s Unit Testing Framework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 Installing SimpleTest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 Creating Your Own Unit Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 Using Assert Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 Testing the Entire MVC System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 Web Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 Creating Web Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 Web Testing Any Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234 Test-Driven Development. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235


NC O N T E N T S

CHAPTER 8

A Cake Control Panel

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237

Application Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 The Authentication and ACL Components . . . . . . . . . . . . . . . . . . . . . . . . . . 238 The Authentication Component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 The Access Control List Component . . . . . . . . . . . . . . . . . . . . . . . . . . 238 Component Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 Control Panel Application Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 The Control Panel Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 The Actions Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 The Groups Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 The Users Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 Testing the Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270

CHAPTER 9

Translating Stories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 Application Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 The Translate Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 Stories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 Baking Cake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 Adding Stories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 Administering Stories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 Translating Stories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 Viewing Stories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282 Deleting Stories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 Listing Stories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 Translation Pagination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288 Locale and Language Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 Setting Locale by Browser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 Setting Locale by Language Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 Setting Locale by Hand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 User Authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 Logging In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 Logging Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 Baked Code. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306

xi


xii

NCONT ENTS

CHAPTER 10

Adding Automagic Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307 Cakeâ&#x20AC;&#x2122;s Built-in Magic Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307 Writing a Custom Behavior. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308 Building Custom Magic Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 Access Data Field. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 Record Order Data Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311 Locking Data Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315

CHAPTER 11

Cake Tags

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317

Content and Data Separation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317 View Template . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 Cake View Class Extension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 Cake Plugins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323 Yahoo! Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328

CHAPTER 12

Dynamic Data Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 Traditional Product Searching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 The Dynamic Data Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330 Considerations for Using the Dynamic Data Approach . . . . . . . . . . 331 The Product Database Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 Baking for This Application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337 Building the Product Search Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338 Creating the Product Search Form . . . . . . . . . . . . . . . . . . . . . . . . . . . 338 Processing the Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 Adding a Product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 Creating Table Entries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 Entering Product Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358

CHAPTER 13

Captcha . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 Captcha Implementations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 Captcha Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 ASCII Art Captcha . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 A Captcha Component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 The ASCII Art Component Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 The Captcha Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371


About the Authors NKAI CHAN started his computing career in the late 1980s. His current interests include programming methodology, the Semantic Web, data visualization, and enterprise systems. Kai holds a Computer Science bachelor’s degree and a master’s degree in Computer Graphics. He is a cofounder of the Azzian MVC CMS framework. Together with John Omokore and others, he runs a software and training company in London, specializing in various large-scale projects, from SAP to e-commerce web sites. When he has a spare moment, he likes tennis, squash, and long-distance running. NJOHN OMOKORE is a developer, technical consultant, writer, and trainer. John has programming experience in many technologies, including Linux, PHP, MySQL, and Ajax. He has worked on market research data analysis, database development, and related systems. He received his bachelor’s degree in Mathematics and is pursuing a postgraduate degree in software engineering at Oxford University in England. John provides consulting and web development services to corporate organizations around the world. He’s a cofounder of AlternativeBrains and the Azzian MVC CMS framework and sits on the board of many companies. John lives outside London with his wife, two children, and some animals. His career interests include open source scripting languages, OOP programming, and the use of SAP in large-scale industries (chiefly oil and gas). When not scripting, he enjoys playing chess and squash, visiting the gym, and a bit of socializing. NRICHARD K. MILLER graduated from Brigham Young University with a degree in Business Management but has been interested in technology since he began computer programming at age 10. His experience includes web programming, Internet marketing, and new media strategies. He is the developer of several MediaWiki extensions and WordPress plugins, including the widely used What Would Seth Godin Do plugin.

xiii


About the Technical Reviewer NDAVID GOLDING began developing web sites in 1999 and first started using CakePHP on a bet he couldnâ&#x20AC;&#x2122;t complete a web application in five minutes. He is the author of Beginning CakePHP: From Novice to Professional (Apress, 2008) and has taught CakePHP even while it was still in early stages of development. David has a degree in European Studies from Brigham Young University and continues work in religious studies and history as a graduate student at Claremont Graduate University. He lives with his wife, Camille, and his son, Kenny, in Southern California.

xiv


Acknowledgments W

hen we first decided to write this book, we really didn’t think it would be that difficult a task. After all, we’ve been coding and writing documentation for years and years. Now having written the book, we can honestly say it has been one of the hardest projects we’ve done since we wrote our first-ever Hello World program. As such, with tears streaming from our eyes, we would wholeheartedly like to thank all the people involved. It all sounds like a cliché, but it’s all true. Thank you to the team at Apress, the Cake Software Foundation, colleagues, friends, families, and neighbors. In no particular order, we would like to thank them individually. They are Steve Anglin, Richard Dal Porto, Matt Wade, Marilyn Smith, Joohn Choe, David Golding, Nancy Wright, Richard K. Miller, Rita Woo, Terry Wells, Dan Jackson, Candace English, and God. Kai Chan and John Omokore

Thank you to Kai Chan and John Omokore for allowing me to take part in this book. I’ve enjoyed working with them and the entire Apress team. Thanks to David Golding for getting me involved. I’m thankful for good parents, family, friends, and colleagues, and to God. Richard K. Miller

xv


Introduction F

irst off, thank you for picking up this book. Whether you are standing in a bookshop or reading this at home, we assume you probably have a strong interest in developing web sites. In the past few years, the number of web site frameworks has increased dramatically. This is especially true for PHP-based frameworks. Many people have chosen to adopt CakePHP (Cake, for short) for various reasons, such as these: Ê

UÊ **Ê«Àœ}À>““iÀÃÊ>ÀiÊ܈`iÞÊ>Û>ˆ>Li°ÊœÃÌÊ«ÀœiVÌÃʅ>ÛiÊ̈}…ÌÊ`i>`ˆ˜iÃ]Ê>˜`ÊޜÕÊ want team members who can quickly pick up a new piece of technology.

Ê

UÊ >Ži**ʈÃÊi>ÃÞÊ̜ʏi>À˜°Ê9œÕÊÜ>˜ÌÊ>Ê«œÜiÀvՏÊ̜œÊ̅>ÌÊޜÕÊV>˜Êi>ȏÞʓ>ÃÌiÀ°

Ê

UÊ >Ži**ʅ>ÃÊ}œœ`ÊÃÕ««œÀÌ°Ê iÛiœ«iÀÃÊvÀiµÕi˜ÌÞÊ«œÃÌÊ>˜`ÊÀi«ÞÊ̜ʓiÃÃ>}iÃʜ˜Ê̅iÊ Cake forum. And there are always some good discussions happening on the Cake IRC. (To see for yourself, simply download mIRC from dppl6++sss*ien_*_ki+, connect to the server en_*bnaajk`a*jap, and join the _]galdl channel.)

When you are developing a site using Cake, you often find yourself trawling through tutorials online to see how things are done. We’ve done that ourselves many times. However, despite the power of the Internet, we still like to look through books. And we think you will find this book a great help in your Cake development endeavors, in addition to all of the material available online. Most of the applications in this book have been written as a result of some real-world development we have done in the past. We focus on projects that we think are relevant to the future of web development. Let’s take mashups, for example. We should all take an interest in this ever-expanding area of web development. We can honestly say that any successful online web site in the future will need to easily communicate with other applications. Application designers will need to bear this in mind. Matters such as search engine optimization need to be built into the application itself. Cake allows us to think in terms of the high-level architecture instead of the nuts and bolts of a web application.

Who Should Read This Book Practical CakePHP is a book mainly for developers. To get the most from it, you should be comfortable with a number of web technologies and programming concepts. These include PHP, SQL, HTML, JavaScript, object-oriented programming, and design patterns, as well as the general principles of web development. If you are at the forefront of web development, then this book is for you!

xvii


xviii

NINTRO DUCT ION

If our book sounds a little too advanced for you, we recommend that you do some preliminary reading. We suggest the following books: Ê

UÊ Beginning PHP and MySQL: From Novice to Professional, Third Edition, by W. Jason Gilmore (Apress, 2008)

Ê

UÊ Beginning CakePHP: From Novice to Professional by David Golding (Apress, 2008)

How This Book Is Organized Each chapter in this book has been chosen so it will cover the core features in Cake, plus some of the minor features as well. The following is a rough breakdown of what each chapter includes. Ê

UÊ …>«ÌiÀÊ£]ʺ >ŽiÊ՘`>“i˜Ì>Ã]»Ê}ˆÛiÃÊޜÕÊ>˜Êˆ˜ÌÀœ`ÕV̈œ˜ÊÌœÊ >Ži°ÊvÊޜÕÊ>ÀiʘiÜÊÌœÊ the CakePHP framework, this is the place to start.

Ê

UÊ …>«ÌiÀÊÓ]ʺ œ}}ˆ˜}]»Ê«ÀœÛˆ`iÃÊޜÕÊ܈̅Ê>Êȓ«iÊLœ}}ˆ˜}Ê>««ˆV>̈œ˜°Ê̽ÃÊ«iÀviVÌÊvœÀÊ beginners who want to know what a Cake application looks like. If there are two chapters in the book that need to be read in sequence, they are Chapters 1 and 2.

Ê

UÊ …>«ÌiÀÊÎ]ʺ ‡ œ““iÀVi]»Ê}ˆÛiÃÊޜÕÊ}Ài>ÌiÀʈ˜Ãˆ}…Ìʈ˜ÌœÊ̅iÊÜ>ÞÊ >ŽiʈÃÊÕÃi`ʈ˜Ê>Ê common application. We walk through implementing an online shop using the Cake framework.

Ê

UÊ …>«ÌiÀÊ{]ʺÊiÃÃ>}iÊœÀՓÊ7iLÊ-iÀۈVi]»ÊVœÛiÀÃÊ̅iÊ`iÛiœ«“i˜ÌʜvÊ>ÊÜiLÊÃiÀۈViÃÊ API. We guide you through creating a clean API, so any third party can access your application using standard protocols.

Ê

UÊ …>«ÌiÀÊx]ʺœœ}iÊ>«ÃÊ>˜`Ê̅iÊ/À>Ûiˆ˜}Ê->iÓ>˜]»ÊŜÜÃÊޜÕʅœÜÊ̅iÊœœ}iÊ Maps API is used with Cake. One of the main features of this chapter’s application relates to the classic traveling salesman problem: a salesman needs to visit a number of cities only once and return to where he started.

Ê

UÊ …>«ÌiÀÊÈ]ʺ>ň˜}Ê/܈ÌÌiÀÊ܈̅Ê̅iÊœœ}iÊ/À>˜Ã>̜À]»Êi“«…>ÈâiÃÊ̅iʈ“«œÀÌ>˜ViÊ of web services in modern web application development. In true Web 2.0 and Cake fashion, this chapter’s application mashes the Google Ajax Language API with the Twitter API to provide automatic translation of Twitter messages.

Ê

UÊ …>«ÌiÀÊÇ]ʺ1˜ˆÌÊ/iÃ̈˜}Ê>˜`Ê7iLÊ/iÃ̈˜}]»ÊVœÛiÀÃʜ˜iʜvÊ̅iʅœÌÌiÃÌÊ̜«ˆVÃÊ>“œ˜}ÊÜiLÊ professionals. Cake 1.2 devotes a large section to testing, and this chapter shows you how to take advantage of Cake’s integrated unit testing features.

Ê

UÊ …>«ÌiÀÊn]ʺÊ >ŽiÊ œ˜ÌÀœÊ*>˜i]»ÊVœÛiÀÃÊ >Ži½ÃÊ>VViÃÃÊVœ˜ÌÀœÊˆÃÌÃÊ>˜`ÊÃiVÕÀˆÌÞÊ features. We develop a web-based front end that allows administrators to manage user security.


NI N T R O D U C T I O N

Ă&#x160;

UĂ&#x160; Â&#x2026;>ÂŤĂ&#x152;iĂ&#x20AC;Ă&#x160;Â&#x2122;]Ă&#x160;Âş/Ă&#x20AC;>Â&#x2DC;Ă&#x192;Â?>Ă&#x152;Â&#x2C6;Â&#x2DC;}Ă&#x160;-Ă&#x152;Â&#x153;Ă&#x20AC;Â&#x2C6;iĂ&#x192;]ÂťĂ&#x160;ÂŤĂ&#x20AC;Â&#x153;Ă&#x203A;Â&#x2C6;`iĂ&#x192;Ă&#x160;Ă&#x17E;Â&#x153;Ă&#x2022;Ă&#x160;Ă&#x153;Â&#x2C6;Ă&#x152;Â&#x2026;Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;Â&#x17D;Â&#x2DC;Â&#x153;Ă&#x153;Â?i`}iĂ&#x160;Ă&#x152;Â&#x153;Ă&#x160;Ă&#x152;>VÂ&#x17D;Â?iĂ&#x160; >Â&#x17D;i½Ă&#x192;Ă&#x160; internationalization and localization features. We develop an application in which news stories are available in other languages, with an administration area where translators can translate stories from a base language to another language.

Ă&#x160;

UĂ&#x160; Â&#x2026;>ÂŤĂ&#x152;iĂ&#x20AC;Ă&#x160;£ä]Ă&#x160;Âş``Â&#x2C6;Â&#x2DC;}Ă&#x160;Ă&#x2022;Ă&#x152;Â&#x153;Â&#x201C;>}Â&#x2C6;VĂ&#x160;Â&#x2C6;iÂ?`Ă&#x192;]ÂťĂ&#x160;`iÂ&#x201C;Â&#x153;Â&#x2DC;Ă&#x192;Ă&#x152;Ă&#x20AC;>Ă&#x152;iĂ&#x192;Ă&#x160;iĂ?Ă&#x152;iÂ&#x2DC;`Â&#x2C6;Â&#x2DC;}Ă&#x160; >Â&#x17D;i½Ă&#x192;Ă&#x160;Ă&#x2022;Ă&#x192;iĂ&#x160;Â&#x153;vĂ&#x160;>Ă&#x2022;Ă&#x152;Â&#x153;Â&#x2021; magic fields like _na]pa`, ik`ebea`, and pepha. We create three new automagic fields.

Ă&#x160;

UĂ&#x160; Â&#x2026;>ÂŤĂ&#x152;iĂ&#x20AC;Ă&#x160;ÂŁÂŁ]Ă&#x160;Âş >Â&#x17D;iĂ&#x160;/>}Ă&#x192;]ÂťĂ&#x160;Ă&#x192;Â&#x2026;Â&#x153;Ă&#x153;Ă&#x192;Ă&#x160;Ă&#x17E;Â&#x153;Ă&#x2022;Ă&#x160;Â&#x153;Ă&#x2022;Ă&#x20AC;Ă&#x160;Ă&#x152;>Â&#x17D;iĂ&#x160;Â&#x153;Â&#x2DC;Ă&#x160;>Â&#x2DC;Ă&#x160;iĂ&#x192;Ă&#x152;>LÂ?Â&#x2C6;Ă&#x192;Â&#x2026;i`Ă&#x160;Ă&#x152;iVÂ&#x2026;Â&#x2DC;Â&#x153;Â?Â&#x153;}Ă&#x17E;Ă&#x160;Ă&#x153;Â&#x2026;iĂ&#x20AC;iĂ&#x160; XML tags are used as a wrapper to coding logic. Using Cake, we develop our own HTML-based tags to display two Yahoo maps.

Ă&#x160;

UĂ&#x160; Â&#x2026;>ÂŤĂ&#x152;iĂ&#x20AC;Ă&#x160;ÂŁĂ&#x201C;]Ă&#x160;Âş Ă&#x17E;Â&#x2DC;>Â&#x201C;Â&#x2C6;VĂ&#x160; >Ă&#x152;>Ă&#x160;Â&#x2C6;iÂ?`Ă&#x192;]ÂťĂ&#x160;iĂ?Ă&#x152;iÂ&#x2DC;`Ă&#x192;Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;iÂ&#x2021;VÂ&#x153;Â&#x201C;Â&#x201C;iĂ&#x20AC;ViĂ&#x160;VÂ&#x2026;>ÂŤĂ&#x152;iĂ&#x20AC;Ă&#x160;Ă&#x153;Â&#x2C6;Ă&#x152;Â&#x2026;Ă&#x160;>Ă&#x160;Ă&#x192;ÂŤiVÂ&#x2C6;>Â?Ă&#x160; product-filtering technique. We take a dynamic data approach to product searches.

Ă&#x160;

UĂ&#x160; Â&#x2026;>ÂŤĂ&#x152;iĂ&#x20AC;Ă&#x160;ÂŁĂ&#x17D;]Ă&#x160;Âş >ÂŤĂ&#x152;VÂ&#x2026;>]ÂťĂ&#x160;Ă&#x192;Â&#x2026;Â&#x153;Ă&#x153;Ă&#x192;Ă&#x160;Â&#x2026;Â&#x153;Ă&#x153;Ă&#x160;- Ă&#x160;Ă&#x20AC;Ă&#x152;Ă&#x160;V>Â&#x2DC;Ă&#x160;LiĂ&#x160;Ă&#x2022;Ă&#x192;i`Ă&#x160;>Ă&#x192;Ă&#x160;>Ă&#x160; >ÂŤĂ&#x152;VÂ&#x2026;>Ă&#x160;Ă&#x152;iĂ&#x192;Ă&#x152;°Ă&#x160;Â&#x2DC;Ă&#x160;Ă&#x152;Â&#x2026;Â&#x2C6;Ă&#x192;Ă&#x160; chapterâ&#x20AC;&#x2122;s project, the Captcha test is housed in a Cake component so it can be used by other applications.

How to Contact the Authors The authors can be contacted as follows: Ă&#x160;

UĂ&#x160; >Â&#x2C6;Ă&#x160; Â&#x2026;>Â&#x2DC;Ă&#x160;V>Â&#x2DC;Ă&#x160;LiĂ&#x160;VÂ&#x153;Â&#x2DC;Ă&#x152;>VĂ&#x152;i`Ă&#x160;>Ă&#x152;Ă&#x160;g]e*_d]j<a`ca]^ha*_ki.

Ă&#x160;

UĂ&#x160; Â&#x153;Â&#x2026;Â&#x2DC;Ă&#x160;"Â&#x201C;Â&#x153;Â&#x17D;Â&#x153;Ă&#x20AC;iĂ&#x160;V>Â&#x2DC;Ă&#x160;LiĂ&#x160;VÂ&#x153;Â&#x2DC;Ă&#x152;>VĂ&#x152;i`Ă&#x160;>Ă&#x152;Ă&#x160;fkdj<kikgkna*_ki.

Ă&#x160;

UĂ&#x160; ,Â&#x2C6;VÂ&#x2026;>Ă&#x20AC;`Ă&#x160;°Ă&#x160;Â&#x2C6;Â?Â?iĂ&#x20AC;Ă&#x160;V>Â&#x2DC;Ă&#x160;LiĂ&#x160;VÂ&#x153;Â&#x2DC;Ă&#x152;>VĂ&#x152;i`Ă&#x160;>Ă&#x152;Ă&#x160;ne_d]n`<ne_d]n`giehhan*_ki.

xix


C HAPTER

1

Cake Fundamentals U

sing a framework of some sort has now become the order of the day for building large-scale web applications. Organizations have found that using an in-house framework for web projects enhances code reuse, scalability, quick project turnarounds, and security. New and evolving frameworks provide rapid application development tools to promote the adoption of particular programming languages. Many frameworks derived from PHP have been popular with programmers in the open source community. CakePHP—Cake for short—is currently one of the fastest-growing rapid application development frameworks. When you are developing large web applications or creating components that you will reuse in many applications, you’ll find Cake to be a great help. In this chapter, we’ll highlight some of the concepts, technologies, and tools that Cake relies on, including the PHP scripting language, the Model-View-Controller design pattern, and object-oriented programming techniques. We will also outline the default folder structures and naming conventions and introduce some Cake best practices. And, of course, we’ll demonstrate how to write some Cake code. This chapter will serve as a quick reference that will provide you with a solid foundation on which to build your knowledge of the framework throughout the rest of the book.

Cake Features Why should you use Cake when there are so many other frameworks in town? There is a number of good reasons for the popularity of Cake PHP. It has a short learning curve in comparison to other frameworks, because Cake is easy to use and understand. Also, because there are so many PHP programmers, Cake has a large community. New users can find many projects to refer to and use. Here are some features of Cake that make web application development with it easy and fast: Ê

UÊ ÌÊÕÃiÃÊ̅iÊÊœ`i‡6ˆiÜ‡Ê œ˜ÌÀœiÀÊ­6 ®ÊvÀ>“iܜÀŽÊvœÀÊ**°

Ê

UÊ ÌÃÊ`>Ì>L>ÃiÊVœ˜˜iV̈ۈÌÞÊÃÕ««œÀÌʈ˜VÕ`iÃÊÞ-+Ê>˜`Ê*œÃÌ}Ài-+]Ê>ÃÊÜiÊ>Ãʓ>˜ÞÊ other database platforms.

Ê

UÊ >ŽiʈÃÊi>ÃÞÊ̜ʈ˜ÃÌ>Êœ˜Ê“œÃÌÊ«>ÌvœÀ“Ã]ʈ˜VÕ`ˆ˜}Ê1˜ˆÝÊ>˜`Ê7ˆ˜`œÜð

Ê

UÊ ÌÃÊ/ʏˆVi˜ÃiʈÃʓœÀiÊvi݈LiÊ̅>˜ÊœÌ…iÀʏˆVi˜Ãið

Ê

UÊ ÌÊÕÃiÃÊi>ÃÞÊ>˜`Êvi݈LiÊÌi“«>̈˜}ʭ܅ˆV…Ê>œÜÃÊ**ÊÃޘÌ>Ý]Ê܈̅ʅi«iÀî° 1


2

CH APT ER 1 N CAK E FU NDA MENTA L S

Ă&#x160;

UĂ&#x160; >Â&#x17D;iĂ&#x160;Â&#x2026;>Ă&#x192;Ă&#x160;Ă&#x203A;Â&#x2C6;iĂ&#x153;Ă&#x160;Â&#x2026;iÂ?ÂŤiĂ&#x20AC;Ă&#x192;Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;>Ă&#x192;Ă&#x192;Â&#x2C6;Ă&#x192;Ă&#x152;Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;Â&#x2C6;Â&#x2DC;Ă&#x192;iĂ&#x20AC;Ă&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;Ă&#x160;Â&#x153;vĂ&#x160;Ă&#x160;Â&#x153;vĂ&#x152;iÂ&#x2DC;Â&#x2021;Ă&#x160;Ă&#x20AC;iÂŤi>Ă&#x152;i`Ă&#x160;Ă&#x192;Â&#x2DC;Â&#x2C6;ÂŤÂŤiĂ&#x152;Ă&#x192;Ă&#x160;Â&#x153;vĂ&#x160;/Ă&#x160;>Â&#x2DC;`Ă&#x160; vÂ&#x153;Ă&#x20AC;Â&#x201C;Ă&#x192;Ă&#x160;VÂ&#x153;`i]Ă&#x160;Â?>Ă?]Ă&#x160;>Ă&#x203A;>-VĂ&#x20AC;Â&#x2C6;ÂŤĂ&#x152;]Ă&#x160;>Â&#x2DC;`Ă&#x160;Ă&#x192;Â&#x153;Ă&#x160;Â&#x153;Â&#x2DC;°

Ă&#x160;

UĂ&#x160; Ă&#x152;Ă&#x160;Â&#x2026;>Ă&#x192;Ă&#x160;VÂ&#x153;Â&#x201C;ÂŤÂ&#x153;Â&#x2DC;iÂ&#x2DC;Ă&#x152;Ă&#x192;Ă&#x160;vÂ&#x153;Ă&#x20AC;Ă&#x160;Â&#x2026;>Â&#x2DC;`Â?Â&#x2C6;Â&#x2DC;}Ă&#x160;Ă&#x160;iÂ&#x2021;Â&#x201C;>Â&#x2C6;Â?]Ă&#x160;>Ă&#x2022;Ă&#x152;Â&#x2026;iÂ&#x2DC;Ă&#x152;Â&#x2C6;V>Ă&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;]Ă&#x160;>VViĂ&#x192;Ă&#x192;Ă&#x160;VÂ&#x153;Â&#x2DC;Ă&#x152;Ă&#x20AC;Â&#x153;Â?]Ă&#x160;Â?Â&#x153;V>Â?Â&#x2C6;â>Ă&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;]Ă&#x160; security, sessions, and request handling.

Ă&#x160;

UĂ&#x160; >Â&#x17D;iĂ&#x160;ÂŤĂ&#x20AC;Â&#x153;Ă&#x203A;Â&#x2C6;`iĂ&#x192;Ă&#x160;Ă&#x2022;Ă&#x152;Â&#x2C6;Â?Â&#x2C6;Ă&#x152;Ă&#x17E;Ă&#x160;VÂ?>Ă&#x192;Ă&#x192;iĂ&#x192;Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;Â&#x201C;>Â&#x2DC;Â&#x2C6;ÂŤĂ&#x2022;Â?>Ă&#x152;iĂ&#x160;Ă&#x20AC;iĂ&#x192;Â&#x153;Ă&#x2022;Ă&#x20AC;ViĂ&#x192;Ă&#x160;Ă&#x192;Ă&#x2022;VÂ&#x2026;Ă&#x160;>Ă&#x192;Ă&#x160;Ă&#x192;iĂ&#x152;Ă&#x192;]Ă&#x160;vÂ&#x2C6;Â?iĂ&#x192;]Ă&#x160;vÂ&#x153;Â?`iĂ&#x20AC;Ă&#x192;]Ă&#x160;8]Ă&#x160; and many others.

Ă&#x160;

UĂ&#x160; 9Â&#x153;Ă&#x2022;Ă&#x20AC;Ă&#x160;1,Ă&#x192;Ă&#x160;>Ă&#x20AC;iĂ&#x160;Â&#x153;ÂŤĂ&#x152;Â&#x2C6;Â&#x201C;Â&#x2C6;âi`Ă&#x160;vÂ&#x153;Ă&#x20AC;Ă&#x160;Ă&#x192;i>Ă&#x20AC;VÂ&#x2026;Ă&#x160;iÂ&#x2DC;}Â&#x2C6;Â&#x2DC;iĂ&#x192;°

NNote For a complete and up-to-date list of Cake features; see the official web site at dppl6++ _]galdl*knc. You can also find many discussions regarding how Cake compares with other frameworks, such as Ruby on Rails, symfony, Zend Framework, and CodeIgniter. For a comparison of Cake with the aforementioned frameworks, check dppl6++bnejepu*^hkcolkp*_ki+.,,4+,2+sdu)_dkkoa)_]galdl) kran)kpdan*dpih.

The Ingredients of Cake In this section, weâ&#x20AC;&#x2122;ll delve into the core concepts and technologies employed by Cake, starting with the MVC design pattern.

The Model-View-Controller Design Pattern Cake supports the MVC design pattern, which aims to modularize an application into three parts: Ă&#x160;

UĂ&#x160; /Â&#x2026;iĂ&#x160;model represents the data for the application.

Ă&#x160;

UĂ&#x160; /Â&#x2026;iĂ&#x160;view represents the presentation.

Ă&#x160;

UĂ&#x160; /Â&#x2026;iĂ&#x160;controller ties the model and view together and deals with user input.

Familiarity with the MVC pattern is a plus, but this book does not assume you have any prior knowledge of MVC. This chapter covers how Cake employs the MVC concept.

Rapid Application Development Along with MVC, Cake took on the philosophy of Ă&#x20AC;>ÂŤÂ&#x2C6;`Ă&#x160;>ÂŤÂŤÂ?Â&#x2C6;V>Ă&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;Ă&#x160;`iĂ&#x203A;iÂ?Â&#x153;ÂŤÂ&#x201C;iÂ&#x2DC;Ă&#x152;Ă&#x160;­, ÂŽ]Ă&#x160; Ă&#x192;Â&#x153;Â&#x201C;iĂ&#x152;Â&#x2C6;Â&#x201C;iĂ&#x192;Ă&#x160;>Â?Ă&#x192;Â&#x153;Ă&#x160;Â&#x17D;Â&#x2DC;Â&#x153;Ă&#x153;Â&#x2DC;Ă&#x160;>Ă&#x192;Ă&#x160;Ă&#x20AC;>ÂŤÂ&#x2C6;`Ă&#x160;ÂŤĂ&#x20AC;Â&#x153;Ă&#x152;Â&#x153;Ă&#x152;Ă&#x17E;ÂŤÂ&#x2C6;Â&#x2DC;}°Ă&#x160;, Ă&#x160;Â&#x2C6;Ă&#x192;Ă&#x160;L>Ă&#x192;Â&#x2C6;V>Â?Â?Ă&#x17E;Ă&#x160;>Ă&#x160;Â&#x201C;iĂ&#x152;Â&#x2026;Â&#x153;`Ă&#x160;Â&#x153;vĂ&#x160;`iVĂ&#x20AC;i>Ă&#x192;Â&#x2C6;Â&#x2DC;}Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;Ă&#x152;Â&#x2C6;Â&#x201C;iĂ&#x160; taken to design software systems by using many prebuilt skeleton structures. This provides developers with many advantages, including easier maintenance, code reuse, more efficient Ă&#x152;i>Â&#x201C;Ă&#x153;Â&#x153;Ă&#x20AC;Â&#x17D;]Ă&#x160;>Â&#x2DC;`Ă&#x160;ÂľĂ&#x2022;Â&#x2C6;VÂ&#x17D;Ă&#x160;ÂŤĂ&#x20AC;Â&#x153;Â?iVĂ&#x152;Ă&#x160;Ă&#x152;Ă&#x2022;Ă&#x20AC;Â&#x2DC;>Ă&#x20AC;Â&#x153;Ă&#x2022;Â&#x2DC;`°Ă&#x160;, Ă&#x160;>Â?Ă&#x192;Â&#x153;Ă&#x160;ÂŤĂ&#x20AC;Â&#x153;Ă&#x203A;Â&#x2C6;`iĂ&#x192;Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;>LÂ&#x2C6;Â?Â&#x2C6;Ă&#x152;Ă&#x17E;Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;Â&#x201C;>Â&#x17D;iĂ&#x160;Ă&#x20AC;>ÂŤÂ&#x2C6;`Ă&#x160;VÂ&#x2026;>Â&#x2DC;}iĂ&#x192;Ă&#x160; based on client feedback, decreasing the dangers of feature creep. Additionally, you can find a lot of off-the-shelf open source code, which you can easily plug into your Cake applications. A great place to start is dppl6++^]ganu*_]galdl*knc.


C H A P T E R 1 N C A K E F U N D A M E N T A LS

PHP 4+ PHP 4+ refers to PHP version 4 and above. PHP has become one of the most important server-side scripting languages on the Web. It is currently a predominant language for the development of web applications. It provides web developers the functionalities to quickly create dynamic web applications. PHP has come a long way since PHP 3 was first introduced more than a decade ago. The adoption of the Cake framework assumes knowledge of PHP 4. The official PHP manual, at dppl6++sss*ldl*jap, provides a complete reference on PHP.

NNote A common problem faced in life with a new adventure is where to go for the right information in order to avoid the mistakes of predecessors. If you are just starting out with PHP, you can refer to the many online PHP forums and repositories, such as the popular PEAR library and the ever-growing dppl6++sss* ldl_h]ooao*knc web site.

Object-Oriented Programming Object-oriented «Àœ}À>““ˆ˜}Ê­""*®ÊV>˜ÊLiÊ`iÃVÀˆLi`Ê>ÃÊ>ʓi̅œ`ʜvʈ“«i“i˜Ì>̈œ˜Êˆ˜Ê which the parts of a program are organized as a collection of objects, each of which represents an instance of a class, and whose classes are all members of a hierarchy of classes united via ˆ˜…iÀˆÌ>˜ViÊÀi>̈œ˜Ã…ˆ«Ã°ÊœÀÊiÝ>“«i]Ê>Ê@kc object o]uo$% #skkbskkb#, while a ?]p object o]uo$%#iaksiaks#, and they both inherit o]uo$% from the Lapo class. The Cake framework supports the three key principles of object-oriented development: encapsulation, inheritance, and polymorphism. For the simple magic called encapsulation, Cake’s implementation of one object is protected, or hidden away, from another object to eliminate interference. However, there must be some interaction with other objects in the application, or the object is useless. As in most OOP applications, an object in the Cake framework provides an interface to another object to enable this interaction. ʈÃ̈˜}Ê£‡£ÊŜÜÃÊ̅iÊ`iv>ՏÌÊ`>Ì>L>ÃiÊVœ˜vˆ}ÕÀ>̈œ˜ÊV>ÃÃ]Ê called @=P=>=OA[?KJBEC, which encapsulates `ab]qhp and odkl database connection arrays. Listing 1-1. The Cake Database Configuration Class _h]oo@=P=>=OA[?KJBECw r]n `ab]qhp9]nn]u$ #`neran#9:#iuomh#( #lanoeopajp#9:#pnqa#( #dkop#9:#hk_]hdkop#( #hkcej#9:#]`iej#( #l]ooskn`#9:#oqlan]`iej#( #`]p]^]oa#9:#qoan`^#( #lnabet#9:##

3


4

CH APT ER 1 N CAK E FU NDA MENTA L S

r]n odkl9]nn]u$ #`neran#9:#iuomh#( #lanoeopajp#9:#pnqa#( #dkop#9:#hk_]hdkop#( #hkcej#9:#qoan#( #l]ooskn`#9:#qoania#( #`]p]^]oa#9:#odkl`^#( #lnabet#9:#ol# %7 By default, Cake internally interfaces with the `ab]qhp connection database. It uses its >ÀÀ>ÞÊ«>À>“iÌiÀÃÊvœÀʈÌÃÊ`iv>ՏÌÊ`>Ì>L>ÃiÊVœ˜˜iV̈œ˜Ê՘iÃÃÊޜÕÊiÝ«ˆVˆÌÞÊëiVˆvÞÊ>Ê`ˆvviÀi˜ÌÊ database connection by assigning the qoa@^?kjbec9# odkl# property in a model class. This iÝ«ˆVˆÌʈ˜ÌiÀv>ViÊ܈Êi˜>LiÊܓiʈ˜ÌiÀ>V̈œ˜Ê܈̅Ê̅iÊÌ>LiÃʈ˜Ê̅iÊodkl database. Cake’s support for inheritance cannot be overemphasized. It wraps a lot of database manipulation and other utility functions in its default classes in a manner that enables an œLiVÌÊ̜ÊÌ>Žiʜ˜Ê̅iÊv՘V̈œ˜ÃʜvÊ>˜œÌ…iÀʜLiVÌÊ>˜`ÊiÝÌi˜`ʜÀÊÌ>ˆœÀÊ̅œÃiÊv՘V̈œ˜ÃÊÜÊޜÕÊ don’t repeat the same code. We consider this act of charity as one of the greatest benefits to developers, as it undoubtedly ensures fast application development. Therefore, you need to spend some time sharpening your knives by reading a Cake cheat map or its online API ­dppl6++]le*_]galdl*knc®Ê̜Ê՘`iÀÃÌ>˜`Ê܅>ÌÊޜÕÀʜLiVÌÃÊ܈Êˆ˜…iÀˆÌ°Ê In a controller genealogy, user-defined controller objects inherit from the =ll?kjpnkhhan object. The =ll?kjpnkhhan inherits from ?kjpnkhhanʜLiVÌ]Ê܅ˆV…ÊiÝÌi˜`ÃÊ̅iÊK^fa_p class. A controller class can be derived from the =ll?kjpnkhhan class, as shown in  Ê ˆÃ̈˜}Ê£‡Ó°Ê ­ œ˜ÌÀœiÀÃÊ>ÀiÊ`ˆÃVÕÃÃi`ʈ˜Ê“œÀiÊ`iÌ>ˆÊˆ˜Ê̅iÊÕ«Vœ“ˆ˜}ÊÃiV̈œ˜ÃÊ>LœÕÌÊ >Žiʓœ`iÃ]ÊۈiÜÃ]Ê >˜`ÊVœ˜ÌÀœiÀð® Listing 1-2. The Application Controller Class _h]ooLnk`q_po?kjpnkhhanatpaj`o=ll?kjpnkhhanw bqj_pekj^abknaBehpan$%w y y This default class contains the ^abknaBehpan$% method, which can be overridden in >˜ÞÊV>ÃÃÊ̅>ÌÊiÝÌi˜`ÃÊ̅iÊ=ll?kjpnkhhan class, such as a user-defined controller class. In ʈÃ̈˜}Ê£‡Ó]ÊLnk`q_po?kjpnkhhanÊiÝÌi˜`ÃÊ̅iÊ=ll?kjpnkhhan class. And lastly, Cake implements polymorphism and ensures that functions within an object can behave differently depending on the input. It basically creates the ability to respond to the same function call in many different ways. /…iÊ >ŽiÊvÀ>“iܜÀŽÊVÀi>ÌiÃʓ>˜ÞÊÀiÕÃ>LiʜLiVÌðÊ9œÕÊV>˜ÊÕÃiÊ̅iÃiʜLiVÌÃÊ܈̅œÕÌÊ knowing their internal workings. This is one of the key benefits of using Cake.

NNote For more information about OOP in relation to PHP, refer to the PHP manual at dppl6++sss*ldl* jap+kkl1.


C H A P T E R 1 N C A K E F U N D A M E N T A LS

Dissecting Cake Before you start baking a Cake application, you will need to download the Cake framework from _]galdl*kncÊ>˜`ʈ˜ÃÌ>ÊˆÌʜ˜ÊޜÕÀÊVœ“«ÕÌiÀ°Ê,i“i“LiÀÊ̅>ÌÊ >ŽiʈÃÊL>Ãi`ʜ˜Ê̅iÊ**Ê scripting language, so you need to have PHP up and running first. If you will be using inform䜘ÊÃ̜Ài`ʈ˜Ê>Ê`>Ì>L>Ãi]ÊޜÕÊ܈Ê˜ii`Ê̜ʈ˜ÃÌ>Ê̅iÊ`>Ì>L>ÃiÊi˜}ˆ˜i°ÊÊœÕÀÊiÝ>“«iÃÊ>ÃÃՓiÊ the Þ-+Ê`>Ì>L>Ãi°

Cake’s Directory Structure When you unpack Cake, you will find the following main folder structures: Ê

UÊ ]ll: Contains files and folders for your application. The ]ll folder is your development folder, where your application-specific folders and files reside.

Ê

UÊ _]ga: Contains core Cake libraries. The _]ga folder contains the core libraries for

>Ži**°Ê9œÕÊŜՏ`ʘœÌÊ̜ÕV…Ê̅iÃiʏˆLÀ>ÀˆiÃÊ՘iÃÃÊޜÕÊÀi>Þʎ˜œÜÊ܅>ÌÊޜÕÊ>ÀiÊ doing.

Ê

UÊ `k_o: Contains Cake document files such as the read me, copyright, and change log ÌiÝÌÊvˆiðÊ9œÕÊV>˜ÊÃ̜ÀiÊޜÕÀʜܘÊ`œVՓi˜Ì>̈œ˜Êˆ˜Ê̅ˆÃÊvœ`iÀ°

Ê

UÊ raj`kno: Contains third-party code. The raj`kno folder can contain third-party ˆLÀ>ÀˆiÃ]ÊÃÕV…Ê>ÃÊ̅iÊ-܈vÌÊ>ˆiÀÊ«>VŽ>}iÊvœÀÊÃi˜`ˆ˜}ÊÊi‡“>ˆÊ“iÃÃ>}ið

-i«>À>̈˜}Ê̅iÊ`iv>ՏÌÊ >ŽiÊVœÀiʏˆLÀ>ÀÞÊvœ`iÀÊvÀœ“Ê̅iÊ>««ˆV>̈œ˜Êvœ`iÀʓ>ŽiÃʈÌÊ«œÃsible for you to have many different applications sharing a single Cake installation. With this vœ`iÀÊÃÌÀÕVÌÕÀi]ÊޜÕÊV>˜Êi>ȏÞÊÕ«}À>`iÊޜÕÀÊi݈Ã̈˜}ÊÛiÀȜ˜ÊœvÊ >ŽiÊ܈̅œÕÌÊ>vviV̈˜}Ê>˜ÞÊ >««ˆV>̈œ˜ÃÊޜÕʅ>ÛiÊÜÀˆÌÌi˜°ÊÊ/>LiÊ£‡£Ê`iÌ>ˆÃÊ >Ži½ÃÊ`iv>ՏÌÊvœ`iÀÊÃÌÀÕVÌÕÀi° Table 1-1. The Cake Default Folder Structure

Directory

Description

]ll+

The parent folder for your application

_kjbec+ _kjpnkhhano+

Contains configuration files for global structures such database connections, security, and access control

œ˜Ì>ˆ˜ÃÊޜÕÀÊ>««ˆV>̈œ˜ÊVœ˜ÌÀœiÀÃÊvˆiÃÊ­i°}°]Êqoan[

_kjpnkhhan*ldl® _kilkjajpo+ Contains your user-defined component files +ej`at*ldl

Allows you to deploy Cake with +]ll as the @k_qiajpNkkp

hk_]ha+

Contains locale files that deal with internationalization

ik`aho+

Contains the model files

lhqcejo+

Contains the plugin files

paopo+

Contains the test folders and files

pil+

1Ãi`ÊvœÀÊV>V…iÃÊ>˜`ʏœ}Ã

raj`kno+

Contains third-party libraries Continued

5


6

CH APT ER 1 N CAK E FU NDA MENTA L S

Table 1-1. Continued

Directory

Description reaso+

Contains view folders and files for presentation ­i°}°]Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;*_plĂ&#x160;vÂ&#x2C6;Â?iĂ&#x192;ÂŽ

ahaiajpo+

Elements, which are bits of views, go here

annkno+

Custom error pages

dahlano+

Helpers

h]ukqpo+

Application layout files

sa^nkkp+

The @k_qiajpNkkp for the application

_oo+

Contains the application style sheet files

behao+

Contains any files

eic+

Contains graphics

fo+

Â&#x153;Â&#x2DC;Ă&#x152;>Â&#x2C6;Â&#x2DC;Ă&#x192;Ă&#x160;>Ă&#x203A;>-VĂ&#x20AC;Â&#x2C6;ÂŤĂ&#x152;Ă&#x160;vÂ&#x2C6;Â?iĂ&#x192;

_]ga+

Contains Cake core libraries

raj`kno+

Contains third-party libraries for all applications

The Cake Naming Conventions Â&#x2C6;Â&#x17D;iĂ&#x160;Ă&#x192;Â&#x2C6;Â&#x201C;Â&#x2C6;Â?>Ă&#x20AC;Ă&#x160;frameworks, Cake employs naming conventions instead of configuration files for many of its workings, such as for its MVC structure. It is good practice to understand and iÂ&#x201C;ÂŤÂ?Â&#x153;Ă&#x17E;Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160; >Â&#x17D;iĂ&#x160;VÂ&#x153;Â&#x2DC;Ă&#x203A;iÂ&#x2DC;Ă&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;Ă&#x192;°Ă&#x160;9Â&#x153;Ă&#x2022;Ă&#x160;V>Â&#x2DC;Ă&#x160;Â&#x153;Ă&#x203A;iĂ&#x20AC;Ă&#x20AC;Â&#x2C6;`iĂ&#x160;Ă&#x192;Â&#x153;Â&#x201C;iĂ&#x160;Â&#x153;vĂ&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;Ă&#x20AC;Ă&#x2022;Â?iĂ&#x192;Ă&#x160;Â?>Ă&#x152;iĂ&#x20AC;]Ă&#x160;Ă&#x153;Â&#x2026;iÂ&#x2DC;Ă&#x160;Ă&#x17E;Â&#x153;Ă&#x2022;Ă&#x160;LiVÂ&#x153;Â&#x201C;iĂ&#x160; a proficient Cake baker. Cake has naming conventions for the four core objects: controllers, models, views, and tables. It also provides global constants and functions.

Controller Naming Controller class names must be plural and must have ?kjpnkhhan appended, as in Lnk`q_po?kjpnkhhan. If the object has more than one word, the second word must also begin with an uppercase letter, as in KjhejaLnk`q_po?kjpnkhhan°Ă&#x160; Â&#x153;Ă&#x160;Â&#x2DC;Â&#x153;Ă&#x152;Ă&#x160;Ă&#x2022;Ă&#x192;iĂ&#x160;Ă&#x2022;Â&#x2DC;`iĂ&#x20AC;Ă&#x192;VÂ&#x153;Ă&#x20AC;iĂ&#x192;Ă&#x160; to separate words. File names must be plural, with [_kjpnkhhan appended and the *ldlĂ&#x160;iĂ?Ă&#x152;iÂ&#x2DC;Ă&#x192;Â&#x2C6;Â&#x153;Â&#x2DC;]Ă&#x160;>Ă&#x192;Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x160; lnk`q_po[_kjpnkhhan*ldl. If the object has more than one word, the subsequent words must be delimited with underscores, as in kjheja[lnk`q_po[_kjpnkhhan*ldl.

Model Naming Model class names are singular, as in Lnk`q_p. If the object has more than one word, the Ă&#x192;iVÂ&#x153;Â&#x2DC;`Ă&#x160;Ă&#x153;Â&#x153;Ă&#x20AC;`Ă&#x160;Â&#x201C;Ă&#x2022;Ă&#x192;Ă&#x152;Ă&#x160;>Â?Ă&#x192;Â&#x153;Ă&#x160;Li}Â&#x2C6;Â&#x2DC;Ă&#x160;Ă&#x153;Â&#x2C6;Ă&#x152;Â&#x2026;Ă&#x160;>Â&#x2DC;Ă&#x160;Ă&#x2022;ÂŤÂŤiĂ&#x20AC;V>Ă&#x192;iĂ&#x160;Â?iĂ&#x152;Ă&#x152;iĂ&#x20AC;Ă&#x160;­V>Â&#x201C;iÂ?Ă&#x160;V>Ă&#x192;iÂŽ]Ă&#x160;>Ă&#x192;Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x160;KjhejaLnk`q_p. File names are singular, with the *ldlĂ&#x160;iĂ?Ă&#x152;iÂ&#x2DC;Ă&#x192;Â&#x2C6;Â&#x153;Â&#x2DC;]Ă&#x160;>Ă&#x192;Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x160;lnk`q_p*ldl. If the object has more than one word, the subsequent words are delimited with underscores, as in kjheja[lnk`q_p*ldl.


C H A P T E R 1 N C A K E F U N D A M E N T A LS

View Naming View file ˜>“iÃÊÌ>Žiʜ˜Ê̅iÊ>V̈œ˜Ê˜>“iʈ˜Ê̅iÊVœ˜ÌÀœiÀ°ÊœÀÊiÝ>“«i]ʈvÊ̅iʜLiVÌʅ>ÃÊ a method Lnk`q_po?kjpnkhhan66qlcn]`a$%, the path is ]ll+reaso+lnk`q_po+qlcn]`a*_pl.

Table Naming

>Ì>L>ÃiÊÌ>LiÊnames should be plural, with words delimited with underscores, as in _kqjpnu[ _k`ao°Ê9œÕÊV>˜ÊœÛiÀÀˆ`iÊ̅ˆÃʘ>“ˆ˜}ÊVœ˜Ûi˜Ìˆœ˜ÊLÞÊÃiÌ̈˜}Ê̅iÊ qoaP]^ha property to your «ÀiviÀÀi`ÊÌ>Liʘ>“i°ÊœÀÊiÝ>“«i]ÊޜÕÊVœÕ`ÊÃiÌÊ̅iÊvœœÜˆ˜}\ qoaP]^ha9#iup]^ha#7 where #iup]^ha# is the name of a table in a database.

Global Constants The global constants are categorized into three major parts: Ê

UÊ Core defines: For iÝ>“«i]Ê?=GA[OAOOEKJ[OPNEJC defines the Cake application session value.

Ê

UÊ Web root configurable paths: For iÝ>“«i]ÊSA>NKKP[@EN defines the web root folder ܅iÀiÊÀiÜÕÀViÃÊÃÕV…Ê>Ãʈ“>}iÊ>˜`Ê --ÊvˆiÃÊ>ÀiÊÃ̜Ài`°Ê

Ê

UÊ Paths: For iÝ>“«i]ÊREASOÊ`ivˆ˜iÃÊ̅iÊ«>Ài˜ÌÊvœ`iÀÊvœÀÊ̅iÊ«ÀiÃi˜Ì>̈œ˜ÊvˆiÃʭۈiÜî°Ê

œÀÊiÝ>“«i]ÊޜÕÊV>˜Ê…>ÛiÊ̅iÊvœœÜˆ˜}ÊVœ`iÊ؈««iÌÊ̜ÊÀi>`Ê̅iÊat]ilha*_pl page as an array from the REASO folder:  l]ca9REASO*#at]ilha*_pl#7  beha9beha$ l]ca%7

Global Functions The global v՘V̈œ˜ÃÊÃiÀÛiÊ>ÃÊÜÀ>««iÀÃÊvœÀÊܓiÊṎˆÌÞÊv՘V̈œ˜Ã°ÊœÀÊiÝ>“«i]Ê̅iÊvœœÜˆ˜}Ê function code snippet performs a simple search and replace operation to add style to patp.  skn`9osaap7++oa]n_dopnejc)Pdajaa`ha  patp9Pdeo?]gaeo]oosaap]odkjau7++Pdad]uop]_g ++n$***%eopdachk^]hbqj_pekj n$# skn`#(8`er_h]oo9#na`#: skn`8+`er:(#patp#%7 The controller should contain most of the business logic, like this:  odkllejc[^]ogap[^]h]j_a9 jap[lne_a' p]t7 +ՈÌiʜvÌi˜Êˆ˜ÊÀi>Ê>««ˆV>̈œ˜Ã]Ê̅iÊLÕȘiÃÃʏœ}ˆVʈÃÊ돈Ìʈ˜ÌœÊÃi«>À>ÌiÊ«>ÀÌðÊœÜiÛiÀ]ʈ˜Ê Cake, the business logic is often separated into components or vendors, as discussed later in this chapter.

7


8

CH APT ER 1 N CAK E FU NDA MENTA L S

NNote It is advisable to familiarize yourself with the global constants and functions to avoid reinventing the wheel. To see a complete list of Cakeâ&#x20AC;&#x2122;s various classes and functions, visit dppl6++]le*_]galdl*knc.

Models The model is the first of the MVC concepts. Communicating with data stores such as tables, Â&#x2C6; >Â?Ă&#x160;iĂ&#x203A;iÂ&#x2DC;Ă&#x152;Ă&#x192;]Ă&#x160;Ă&#x192;Ă&#x152;Ă&#x20AC;Ă&#x2022;VĂ&#x152;Ă&#x2022;Ă&#x20AC;i`Ă&#x160;vÂ&#x2C6;Â?iĂ&#x192;]Ă&#x160; *Ă&#x160;Ă&#x20AC;iVÂ&#x153;Ă&#x20AC;`Ă&#x192;]Ă&#x160;>Â&#x2DC;`Ă&#x160;Ă&#x192;Â&#x153;Ă&#x160;Â&#x153;Â&#x2DC;Ă&#x160;Â&#x2C6;Ă&#x192;Ă&#x160;>Â&#x2DC;Ă&#x160;Â&#x2C6;Â&#x2DC;iĂ&#x203A;Â&#x2C6;Ă&#x152;>LÂ?iĂ&#x160;>Ă&#x192;ÂŤiVĂ&#x152;Ă&#x160;Â&#x153;vĂ&#x160;>Â&#x2DC;Ă&#x17E;Ă&#x160;Ă&#x160;Â?>Ă&#x20AC;}iÂ&#x2021;Ă&#x160;Ă&#x192;V>Â?iĂ&#x160; web application, especially when it involves a large number of users. The actions of manipulating data stored in a data store are best done within a model. The model should be involved Ă&#x153;Â&#x2C6;Ă&#x152;Â&#x2026;Ă&#x160;Â?Ă&#x2022;Ă&#x192;Ă&#x152;Ă&#x160;viĂ&#x152;VÂ&#x2026;Â&#x2C6;Â&#x2DC;}Ă&#x160;>Â&#x2DC;`Ă&#x160;Ă&#x192;>Ă&#x203A;Â&#x2C6;Â&#x2DC;}Ă&#x160;`>Ă&#x152;>Ă&#x160;vĂ&#x20AC;Â&#x153;Â&#x201C;Ă&#x160;`>Ă&#x152;>Ă&#x160;Ă&#x192;Ă&#x152;Â&#x153;Ă&#x20AC;iĂ&#x192;°Ă&#x160;Â&#x153;Ă&#x20AC;Ă&#x160;iĂ?>Â&#x201C;ÂŤÂ?i]Ă&#x160;Ă&#x152;>LÂ?iĂ&#x160;ÂľĂ&#x2022;iĂ&#x20AC;Â&#x2C6;iĂ&#x192;Ă&#x160;Ă&#x192;Â&#x2026;Â&#x153;Ă&#x2022;Â?`Ă&#x160;LiĂ&#x160; placed in the model.

Model Creation Models are declared using the keyword _h]oo, followed by the name you wish to give to the Â&#x201C;Â&#x153;`iÂ?°Ă&#x160;Ă&#x2022;Ă&#x192;Ă&#x152;Ă&#x160;Â?Â&#x2C6;Â&#x17D;iĂ&#x160;>Â&#x2DC;Ă&#x17E;Ă&#x160;**Ă&#x160;VÂ?>Ă&#x192;Ă&#x192;]Ă&#x160;>Ă&#x160;Ă&#x160;Ă&#x2022;Ă&#x192;iĂ&#x20AC;Â&#x2021;Ă&#x160;`ivÂ&#x2C6;Â&#x2DC;i`Ă&#x160;Â&#x201C;Â&#x153;`iÂ?Ă&#x160;Â&#x201C;>Ă&#x17E;Ă&#x160;VÂ&#x153;Â&#x2DC;Ă&#x152;>Â&#x2C6;Â&#x2DC;Ă&#x160;Ă&#x192;Â&#x153;Â&#x201C;iĂ&#x160;ÂŤĂ&#x20AC;Â&#x153;ÂŤiĂ&#x20AC;Ă&#x152;Â&#x2C6;iĂ&#x192;Ă&#x160;>Â&#x2DC;`Ă&#x160;Â&#x201C;iĂ&#x152;Â&#x2026;ods specific to the implementation of that model as determined by the business requirement. A user-defined model class should follow the Cake naming convention and predefined Ă&#x20AC;Ă&#x2022;Â?iĂ&#x192;Ă&#x2020;Ă&#x160;vÂ&#x153;Ă&#x20AC;Ă&#x160;iĂ?>Â&#x201C;ÂŤÂ?i]Ă&#x160;>Ă&#x160;Lnk`q_pĂ&#x160;Â&#x201C;Â&#x153;`iÂ?Ă&#x160;VÂ?>Ă&#x192;Ă&#x192;Ă&#x160;Ă&#x192;Â&#x2026;Â&#x153;Ă&#x2022;Â?`Ă&#x160;iĂ?Ă&#x152;iÂ&#x2DC;`Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;=llIk`ah class. The =llIk`ah class iĂ?Ă&#x152;iÂ&#x2DC;`Ă&#x192;Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;Ik`ahĂ&#x160;VÂ?>Ă&#x192;Ă&#x192;]Ă&#x160;Ă&#x153;Â&#x2026;Â&#x2C6;VÂ&#x2026;Ă&#x160;`ivÂ&#x2C6;Â&#x2DC;iĂ&#x192;Ă&#x160; >Â&#x17D;i½Ă&#x192;Ă&#x160;Â&#x201C;Â&#x153;`iÂ?Ă&#x160;vĂ&#x2022;Â&#x2DC;VĂ&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;>Â?Â&#x2C6;Ă&#x152;Ă&#x17E;°Ă&#x160;Â&#x153;Ă&#x20AC;Ă&#x160;iĂ?>Â&#x201C;ÂŤÂ?i]Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;Lnk`q_p model class in Ă&#x160;Â&#x2C6;Ă&#x192;Ă&#x152;Â&#x2C6;Â&#x2DC;}Ă&#x160;ÂŁÂ&#x2021;Ă&#x17D;Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x203A;>Ă&#x20AC;Â&#x2C6;>LÂ?Ă&#x17E;Ă&#x160;Â&#x2C6;Â&#x2DC;Â&#x2026;iĂ&#x20AC;Â&#x2C6;Ă&#x152;Ă&#x192;Ă&#x160;>Â?Â?Ă&#x160;Â&#x153;vĂ&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;Ik`ah class properties and methods. Listing 1-3. A Sample Model Class _h]ooLnk`q_patpaj`o=llIk`ahw y Though the Lnk`q_pĂ&#x160;VÂ?>Ă&#x192;Ă&#x192;Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x160;Ă&#x160;Â&#x2C6;Ă&#x192;Ă&#x152;Â&#x2C6;Â&#x2DC;}Ă&#x160;ÂŁÂ&#x2021;Ă&#x17D;Ă&#x160;>ÂŤÂŤi>Ă&#x20AC;Ă&#x192;Ă&#x160;iÂ&#x201C;ÂŤĂ&#x152;Ă&#x17E;]Ă&#x160;Â&#x2C6;Ă&#x152;Ă&#x160;Â&#x2C6;Ă&#x192;Ă&#x160;Â&#x2026;i>Ă&#x203A;Â&#x2C6;Â?Ă&#x17E;Ă&#x160;Â?Â&#x153;>`i`Ă&#x160;Ă&#x153;Â&#x2C6;Ă&#x152;Â&#x2026;Ă&#x160;Ă&#x192;Â&#x153;Â&#x201C;iĂ&#x160;Â&#x153;vĂ&#x160; Cakeâ&#x20AC;&#x2122;s properties and methods. We will bring some of these useful properties and methods into the limelight throughout this book. The =llIk`ah class is originally defined in the _]ga+ directory. To create your own, place it in ]ll+]ll[ik`ah*ldl. This allows methods to be shared among the models. The Ik`ah class, which =llIk`ahĂ&#x160;iĂ?Ă&#x152;iÂ&#x2DC;`Ă&#x192;]Ă&#x160;Â&#x2C6;Ă&#x192;Ă&#x160;>Ă&#x160;Ă&#x192;Ă&#x152;>Â&#x2DC;`>Ă&#x20AC;`Ă&#x160; >Â&#x17D;iĂ&#x160;Â?Â&#x2C6;LĂ&#x20AC;>Ă&#x20AC;Ă&#x17E;Ă&#x160;`ivÂ&#x2C6;Â&#x2DC;i`Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x160;_]ga+he^o+ik`ah*ldl. Model default methods such as the bej`$% method are defined in the Ik`ah class stored in _]ga+he^o+ik`ah+ik`ah*ldl°Ă&#x160; Â&#x153;Â&#x2DC;½Ă&#x152;Ă&#x160;Ă&#x192;Ă&#x152;>Ă&#x20AC;Ă&#x152;Ă&#x160;Ă&#x152;Ă&#x153;i>Â&#x17D;Â&#x2C6;Â&#x2DC;}Ă&#x160; >Â&#x17D;i½Ă&#x192;Ă&#x160;`iv>Ă&#x2022;Â?Ă&#x152;Ă&#x160;Ik`ah class until you become >Â&#x2DC;Ă&#x160;iĂ?ÂŤiĂ&#x20AC;Ă&#x152;Ă&#x160;L>Â&#x17D;iĂ&#x20AC;°


C H A P T E R 1 N C A K E F U N D A M E N T A LS

NNote Refer to the cheat sheet in at dppl6++_]galdl*knc+behao+_]gaodaap*l`b before writing a query method in your Ik`ah class definition. Alternatively, check the Cake API at dppl6++]le*_]galdl*knc. This effort will save you from rewriting existing functionalities and enhance rapid application development. For example, Cake provides a bej`$#]hh#% query to retrieve some or all information from a database table.

i̽ÃÊÕÃiÊ>˜ÊiÝ>“«iÊ̜Ê`i“œ˜ÃÌÀ>ÌiÊ̅iÊvœÕÀÊÊÜi‡ÊŽ˜œÜ˜ÊÌÞ«iÃʜvʜ«iÀ>̈œ˜ÃÊ̅>ÌÊޜÕÊ܈Ê ˜œÀ“>ÞÊ«iÀvœÀ“Êœ˜Ê>Ê`>Ì>L>ÃiÊ­VœiV̈ÛiÞʎ˜œÜ˜Ê>ÃÊ ,1 ®\ Ê

UÊ Ài>ÌiÊ>ÊÀiVœÀ`Ê>˜`ʈ˜ÃiÀÌʈÌʈ˜ÌœÊ>Ê`>Ì>L>ÃiÊÌ>Li°

Ê

UÊ ,iÌÀˆiÛiÊrecords from one or more database tables.

Ê

UÊ 1«`>ÌiÊtables.

Ê

UÊ iiÌiÊrecords.

First, we will create a table named `al]npiajpoÊ>˜`ʈ˜ÃiÀÌÊܓiÊÃ>“«iÊ`>Ì>Ê܈̅Ê̅iÊ-+Ê shown in ʈÃ̈˜}Ê£‡{° Listing 1-4. The Table Schema for departments ?NA=PAP=>HAEBJKPATEOPO\`al]npiajpo\$ \e`\ejp$-,%qjoecja`JKPJQHH]qpk[ej_naiajp( \j]ia\r]n_d]n$.11%`ab]qhpJQHH( \nacekj\r]n_d]n$.11%`ab]qhpJQHH( LNEI=NUGAU$\e`\% %7 EJOANPEJPK\`al]npiajpo\$\e`\(\j]ia\(\nacekj\%R=HQAO $-(#?qopkianOanre_ao#(#QG#%( $.(#O]hao#(#QG#%( $/(#LnaooKbbe_a#(#QG#%( $0(#EjraopknNah]pekjo#(#QO#%( $1(#Dqi]jNaokqn_ao#(JC%( $2(#L]npjanodelKllknpqjepeao#(#QO#%( $3(#I]ngapejc#(#QG#%( $4(#KjhejaI]ngapejc#(#QO#%7 ʈÃ̈˜}Ê£‡{ÊVœ˜Ì>ˆ˜ÃÊܓiÊÀiVœÀ`ÃÊ>LœÕÌÊ̅iʘ>“iÊ>˜`ÊÀi}ˆœ˜ÊœvÊ̅iÊ`i«>À̓i˜ÌÃ°Ê /…ˆÃÊÌ>LiʈÃÊȓ«iÊ>˜`ÊÊÃiv‡ÊiÝ«>˜>̜ÀÞ°Ê œÜÊ̅>ÌÊÜiʅ>ÛiÊ>Ê`>Ì>L>Ãi]ÊÜi½Ê«iÀvœÀ“Ê̅iÊvˆÀÃÌʜvÊ̅iÊ ,1 ʜ«iÀ>̈œ˜Ã°Ê7i½Ê create some records, by using the default o]ra$%ʓi̅œ`Ê«ÀœÛˆ`i`ʈ˜Ê>ʓœ`iÊV>ÃðÊ1Ș}Ê this method comes at the price of ensuring that the format of the data to be passed to it as >Ê«>À>“iÌiÀʓÕÃÌÊ>`…iÀiÊ̜Ê̅iÊ >ŽiÊ«ÀivœÀ“>ÌÌi`Ê>ÀÀ>ÞÊÃÌÀÕVÌÕÀi°Êi̽ÃÊÌ>ŽiÊ>ʏœœŽÊ>ÌÊ>Ê sample data structure in ʈÃ̈˜}Ê£‡x°

9


10

CH APT ER 1 N CAK E FU NDA MENTA L S

Listing 1-5. Cake’s Expected $this->data Format =nn]u $ W,Y9:=nn]u $ W@al]npiajpY9:=nn]u $ We`Y9:5 Wj]iaY9:S]nn]jpeao WnacekjY9:Nqooe] % % W-Y9:=nn]u $ W@al]npiajpY9:=nn]u $ We`Y9:-, Wj]iaY9:Sa^oepa WnacekjY9:QG % % % ˜ÊʈÃ̈˜}Ê£‡x]ÊÜi½ÛiÊ«ÀivœÀ“>ÌÌi`ÊÌܜÊ>``ˆÌˆœ˜>ÊÀiVœÀ`ÃÊ̜ÊLiÊ>``i`Ê̜ʜÕÀÊ`al]npiajpo database table. This structure, stored in a PHP variable such as `]p] or pdeo)`]ta, will save its values to matching fields in the `al]npiajpo database table. To commit the data in this structure into this table, the o]ra$% method is at your service, but the format of pdeo):`]p] argument is crucial to the success of the operation. œÜÊ̅>ÌÊÜi½ÛiÊVÀi>Ìi`Ê̅iÊiÝ«iVÌi`Ê`>Ì>ÊÃÌÀÕVÌÕÀi]ʏi̽ÃÊ`ivˆ˜iÊ̅iÊ@al]npiajp model class to use this preformatted data and commit the two additional records into the `al]npiajpo table. The @al]npiajp model class is shown in ʈÃ̈˜}Ê£‡È° Listing 1-6. The Department Model Class 8;ldl _h]oo@al]npiajpatpaj`o=llIk`ahw  r]n j]ia9#@al]npiajp#7 r]n qoaP]^ha9#`al]npiajpo#7 bqj_pekjo]raIaoo]ca$ `]p]%w eb$ pdeo):o]ra$ `]p]%%w napqnjpnqa7 yahoaw napqnjb]hoa7 y y ;:


C H A P T E R 1 N C A K E F U N D A M E N T A LS

˜ÊʈÃ̈˜}Ê£‡È]ÊvˆÀÃÌÊÜiÊ`iV>ÀiÊ̅iÊ@al]npiajpÊV>ÃÃÊ̅>ÌÊiÝÌi˜`ÃÊ=llIk`ah°Ê iÝÌÊ>ÀiÊ̅iÊ properties, starting with the j]ia property assigned the value @al]npiajp. This property is ˜iViÃÃ>ÀÞʈvÊޜÕÊ>ÀiÊÀ՘˜ˆ˜}ʜ˜Ê>˜Þ̅ˆ˜}ʏiÃÃÊ̅>˜Ê**Êx°Ê/…iÊ qoaP]^ha property specifies the name of the table required for data access or manipulation in the model. Although it isn’t ÀiµÕˆÀi`]ʈvʜ“ˆÌÌi`]Ê >ŽiÊ܈ÊÕÃiÊ>ÊÌ>LiÊ܈̅Ê̅iʘ>“iʜvÊ̅iʓœ`i°ÊœÀÊiÝ>“«i]ʈvÊ̅iÊ model name is `al]npiajp, Cake will use the `al]npiajpo table for the model by default. It is ˆ“«œÀÌ>˜ÌÊ̜ÊiÝ«ˆVˆÌÞÊëiVˆvÞÊ܅ˆV…Ê`>Ì>L>ÃiÊÌ>LiÊޜÕÊ>ÀiÊÕȘ}]ÊiëiVˆ>ÞʈvÊ >Ži½ÃÊÌ>LiÊ naming convention is not followed. The o]raIaoo]ca$% model function call should be done in a controller class. We’ll discuss the controller in more detail later in this chapter. In our imaginary controller class, to invoke the o]raIaoo]ca$%ʓi̅œ`Ê`ivˆ˜i`ʈ˜ÊʈÃ̈˜}Ê£‡È]ÊÜiʘii`Ê̅iÊvœœÜˆ˜}ÊÃÌ>Ìi“i˜Ì\ pdeo):@al]npiajp):o]raIaoo]ca$ `]p]%7 This method accepts as a parameter the preformatted array information called `]p], as `ivˆ˜i`ʈ˜ÊʈÃ̈˜}Ê£‡x°Ê1Ș}Ê>˜ÊEb statement, if the `]p] passed to Cake’s o]ra$% model function is committed to the `al]npiajpo database table, a Boolean pnqa value is returned; if not, b]hoaʈÃÊÀiÌÕÀ˜i`°Ê9œÕÊV>˜Ê>ÃœÊÃ>ÛiÊ`>Ì>ʈ˜ÌœÊ>Ê`>Ì>L>ÃiÊÌ>Liʈ˜Ê̅ˆÃʓ>˜˜iÀÊLÞÊÕȘ}Ê >Ži½ÃÊ _na]pa$% model function. 7…i˜ÊÃÕL“ˆÌ̈˜}Ê>˜Ê/Êform created using the bkni object in a view, Cake automatically structures the form fields data submitted to a controller in a format that is similar to that Ŝܘʈ˜ÊʈÃ̈˜}Ê£‡x° iÝÌ]ʏi̽ÃÊ`iÛiʈ˜ÌœÊ̅iÊÀiÌÀˆiÛiÊ«>ÀÌʜvÊ ,1 ʜ«iÀ>̈œ˜Ã]ʜÀÊ`>Ì>Ê>VViÃðÊ/œÊLiʓi>˜ingful, most data-access operations are filtered using some criteria. We’re going to add a cap@al]npiajp$% method to the @al]npiajpʓœ`iÊV>ÃÃ]Ê>ÃÊŜܘʈ˜ÊʈÃ̈˜}Ê£‡Ç° Listing 1-7. Retrieving Records Using $region=‘US’ Criteria with the find() Method bqj_pekjcap@al]npiajp$ nacekj9jqhh%w  napqnjpdeo):bej`$#]hh#(]nn]u$#_kj`epekjo#9:]nn]u$#nacekj#9: nacekj%%%7 y ˜ÊʈÃ̈˜}Ê£‡Ç]ÊÜiÊ`ivˆ˜iÊ>Êcap@al]npiajp$% method that accepts nacekj as its parameter. This method employs the service of the Cake’s bej`$% method to retrieve some department information based on nacekjÊ>ÃʈÌÃÊ«>À>“iÌiÀ°Ê/œÊÃi>ÀV…ÊvœÀÊ>Ê`i«>À̓i˜Ìʈ˜Ê̅iÊ1˜ˆÌi`Ê -Ì>ÌiÃ]ÊÜi½ÊVÀi>ÌiÊ̅iÊvœœÜˆ˜}ʈ˜Ê>ÊVœ˜ÌÀœiÀÊV>ÃÃ\ pdeo):@al]npiajp):cap@al]npiajp$#QO#%7 /…ˆÃÊÃÌ>Ìi“i˜ÌÊ܈ÊÀiÌÀˆiÛiÊ>˜`ÊvœÀ“>ÌÊ>Ê̅iÊ`i«>À̓i˜ÌÃʈ˜Ê̅iÊ1-ÊÀi}ˆœ˜]Ê>ÃÊŜܘʈ˜Ê ʈÃ̈˜}Ê£‡n°

11


12

CH APT ER 1 N CAK E FU NDA MENTA L S

Listing 1-8. Structure of the Return Department Data Where Region Equals US =nn]u $ W,Y9:=nn]u $ W@al]npiajpY9:=nn]u $ We`Y9:0 Wj]iaY9:EjraopknNah]pekjo WnacekjY9:QO % % W-Y9:=nn]u $ W@al]npiajpY9:=nn]u $ We`Y9:2 Wj]iaY9:L]npjanodelKllknpqjepeao WnacekjY9:QO % % W.Y9:=nn]u $ W@al]npiajpY9:=nn]u $ We`Y9:4 Wj]iaY9:KjhejaI]ngapejc WnacekjY9:QO % % %

NNote The formatted array data in Listing 1-8 might appear completely different when there are associations between the @al]npiajp model class and other model classes that are connected to database tables. In case of associations, the array will include array data from tables of associated models. You will come across preformatted associated data in Chapter 3.


C H A P T E R 1 N C A K E F U N D A M E N T A LS

The bej`$% function is one of the most useful Cake functions for data access. It has the following format: bej`$_kj`epekjoW]nn]uY(beah`oW]nn]uY(kn`anWopnejcY(na_qnoeraWejpY% /…ˆÃʓi̅œ`Ê>ÃœÊ>VVi«ÌÃÊ̅iÊ«>À>“iÌiÀÃ]ʈ˜Ê̅iʜÀ`iÀʏˆÃÌi`ʈ˜ÊÊ/>LiÊ£‡Ó° Table 1-2. The find() Function Parameters

Name

Description

Default Value

pula

Can be set to ]hh, benop, _kqjp, jaecd^kno, or heop to determine what type of data-access operation to carry out

benop

_kj`epekjo

An array of conditions specified as key and value

jqhh

beah`o

An array of fields of key and value to retrieve

jqhh

kn`an

/œÊëiVˆvÞÊ܅i̅iÀÊ̜ʜÀ`iÀÊvˆi`Ãʈ˜Ê>ÃVi˜`ˆ˜}Ê­=O?®ÊœÀÊ `iÃVi˜`ˆ˜}Ê­@AO?®ÊœÀ`iÀ

jqhhÊ­˜œÊ-+ÊKN@AN>U clause will be used if no kn`anÊvˆi`ʈÃÊëiVˆvˆi`®

l]ca

To determine the page number

jqhh

heiep

To limit the page result

jqhh

kbboap

/…iÊ-+ʜvvÃiÌÊÛ>Õi

jqhh

na_qnoera

Whether to include the associated model

-

9œÕÊV>˜ÊÕÃiʓ>˜Þʜ̅iÀÊ >ŽiÊ«Ài`ivˆ˜i`ʓœ`iÊ“i̅œ`Ã]ÊÃÕV…Ê>ÃÊ̅iÊmqanu$% method or the na]`$% method, which returns a list of fields from the database and sets the current model `>Ì>Ê­Ik`ah66 `]p]®Ê܈̅Ê̅iÊÀiVœÀ`ÊvœÕ˜`°Ê"ÀÊޜÕÊV>˜ÊVÀi>ÌiÊޜÕÀʜܘÊÊÕÃiÀ‡Ê`ivˆ˜i`ʓi̅œ`ÃÊ to manipulate data specific to the table a model object uses. ʈÃ̈˜}Ê£‡™ÊŜÜÃÊ>˜Ê>ÌiÀ˜>̈ÛiÊÜ>ÞʜvÊÀiÌÀˆiۈ˜}ʈ˜vœÀ“>̈œ˜Ê>LœÕÌÊ̅iÊ`i«>À̓i˜ÌÃ* /…ˆÃʏˆÃ̈˜}Ê܈ÊÀiÌÕÀ˜ÊiÝ>V̏ÞÊ̅iÊÃ>“iÊÀiVœÀ`ÃÊvÀœ“Ê̅iÊ`al]npiajpo table as the one shown ˆ˜ÊʈÃ̈˜}Ê£‡nÊ܅i˜ÊÕÃi`ʈ˜ÊœÕÀʈ“>}ˆ˜>ÀÞÊVœ˜ÌÀœiÀ°Ê/…iÊ`ˆvviÀi˜ViʈÃÊ̅>ÌÊʈÃ̈˜}Ê£‡nÊÕÃiÃÊ̅iÊ bej`$%ʓi̅œ`]Ê܅ˆiÊʈÃ̈˜}Ê£‡™ÊÕÃiÃÊ̅iÊmqanu$% method to access data. Listing 1-9. Retrieving Records with the query() Method bqj_pekjcap@al]npiajp$ nacekj9jqhh%w   omh9OAHA?P&BNKI\`al]npiajpo\SDANA\nacekj\9 nacekj7 napqnjpdeo):mqanu$ omh%7 y One advantage of using the mqanu$%ʓi̅œ`ʈÃÊ̅>ÌÊޜÕÊV>˜Ê«ÕÌÊ>˜Ê>Ài>`ÞÊ`ivˆ˜i`Ê-+Ê statement, from a legacy system, into this method without going through the trouble of dividing the query parameters into parts, as you would need to do to use the bej`$% method.

Data Validation

>Ì>ÊÛ>ˆ`>̈œ˜Êis an essential part of ensuring integrity and accuracy of data submitted by the ÕÃiÀ]ÊÃÕV…Ê>ÃÊۈ>Ê>ÊÜiLÊvœÀ“°Ê >Žiʅ>ÃÊÊLՈÌ‡Êˆ˜ÊÛ>ˆ`>̈œ˜Ê“iV…>˜ˆÃ“ðÊ9œÕÊëiVˆvÞÊ̅iÊÛ>ˆ`>tion rules in a model, and Cake automatically applies the rules when a web form is connected ̜Ê̅>Ìʓœ`i°Ê/…iÃiÊÀՏiÃÊV>˜Ê>ÃœÊLiÊ>««ˆi`Ê̜Ê8Ê`>Ì>°

13


14

CH APT ER 1 N CAK E FU NDA MENTA L S

First, let’s add a simple validation rule to our @al]npiajp model using the r]he`]pa array, >ÃÊŜܘʈ˜ÊʈÃ̈˜}Ê£‡£ä°Ê/…iÊÛ>ˆ`>̈œ˜ÊÀՏiÊ>ÀÀ>ÞʈÃÊL>ÈV>ÞÊ>˜Ê>ÃÜVˆ>̈ÛiÊ>ÀÀ>Þ°Ê/…iʎiÞÃÊ are the names of the form fields to validate, and the corresponding values represent the rules attached to the form fields. We’ll make use of this rule later, in the “Views” section. Listing 1-10. The Validation Rule for the Department Model r]n r]he`]pa9]nn]u$#nacekj#9:]nn]u$ #]hld]Jqiane_#9:]nn]u$ #nqha#9:#]hld]Jqiane_#( #namqena`#9:pnqa( #iaoo]ca#9:#Ajpan]nacekj*# % % %7 A field can have multiple validation rules. The r]he`]paÊ>ÀÀ>Þʈ˜ÊʈÃ̈˜}Ê£‡£äÊ`ivˆ˜iÃÊ a rule for the nacekj field in our @al]npiajp model. If a user does not submit a valid nacekj field, the model will return an error to the controller and quit committing the data to the `al]npiajpo database table. The iaoo]ca key deals with the error messages during validation. To display the error message on a form, use the form helper’s annkn function: 8;ldla_dkbkni):annkn$#nacekj#%7;: This will display the error message “Enter a region” if a user enters a nonalphanumeric value in the nacekj input field. «>ÀÌÊvÀœ“Ê̅iÊÀՏiÃÊi“«œÞi`ʈ˜ÊʈÃ̈˜}Ê£‡£ä]Ê >ŽiÊ«ÀœÛˆ`iÃÊ>ʘՓLiÀʜvÊÊLՈÌ‡Êˆ˜Ê validation rules to check the validity of form inputs and ensure the integrity of information ޜÕÊÜ>˜ÌÊ̜ÊÃ̜Ài°ÊÊ/>LiÊ£‡ÎʏˆÃÌÃÊ>ÊviÜʜvÊ̅iÊÊLՈÌ‡Êˆ˜ÊÀՏiÃÊ«ÀœÛˆ`i`ÊLÞÊ >Ži° Table 1-3. Some of Cake’s Built-in Validation Rules

Rule

Description

Example

__

Checks for a valid credit card number

#nqha#9:]nn]u$#__#(#b]op#%

`]pa

Checks for a valid date

#nqha#9:#`]pa#

ai]eh

Checks for a valid e-mail address

#nqha#9:#ai]eh#

el

Checks for a valid IP address

#nqha#9:#el#

ldkja

Checks for a valid phone number

#nqha#9:]nn]u$#ldkja#(jqhh(#qg#%

For a complete list of the validation constants in your Cake build, see the predefined rules in the _]ga+he^o+r]he`]pekj*ldl file. 9œÕÊV>˜ÊiÝÌi˜`Ê̅iʏˆÃÌʜvÊ̅iÊÀՏiÃÊLÞÊ>``ˆ˜}ÊޜÕÀʜܘÊÊÕÃiÀ‡Ê`ivˆ˜i`ÊÀՏiðʘÊʈÃ̈˜}Ê£‡££]Ê we define a simple custom rule to check if a value is a string.


C H A P T E R 1 N C A K E F U N D A M E N T A LS

Listing 1-11. A Custom Rule Called String bqj_pekjopnejc$ _da_g%w  napqnjeo[opnejc$ _da_g%7 y Before you apply a custom rule, such as the opnejcÊÀՏiÊŜܘʈ˜ÊʈÃ̈˜}Ê£‡££]Ê>``ʈÌÊ̜Ê̅iÊ _]ga+he^o+r]he`]pekj*ldl file, and then simply add the rule to your model r]he`]pa array: r]n r]he`]pa9]nn]u$#j]ia#9:#opnejc#%7 This will ensure that the j]ia field is a valid string. In upcoming chapters, you will come across more validation rules. The model object is robust and provides a lot of functionality for database manipulation. However, part of the data retrieved by a model is required for web surfers’ consumption. When >ÊÕÃiÀʓ>ŽiÃÊ>Ê1,ÊÀiµÕiÃÌ]ÊܓiÊÀi뜘ÃiʈÃÊiÝ«iVÌi`Ê̜ÊLiÊ`ˆÃ«>Þi`ʈ˜Ê>ÊۈiÜ]Ê܅ˆV…ÊÜi½Ê look at in the following section.

Views Now that Üiʅ>ÛiÊܓiÊÛ>ˆ`>̈œ˜ÊÀՏiÃ]ʏi̽ÃÊLՈ`Ê>˜Ê/Êform to ask users to enter department information. The task of building a web form is done in a view. 6ˆiÜÃÊ>ÀiÊ«ÀiÃi˜Ì>̈œ˜Ê«>}iðÊ/…iÊ/ʜÀÊ8Ê`œVՓi˜ÌÃʜ˜Ê̅iÊ7iLÊ>ÀiÊۈiÜÃÊÌœÊ the users. However, views can be anything, especially if Cake is used to output other formats ˆŽiÊ,--]Ê* ]Ê>˜`ÊÜʜ˜Ê­Ü…ˆV…ʈÃÊViÀÌ>ˆ˜ÞÊ«œÃÈLiÊ܈̅Ê̅iÊNamqaopD]j`han component and «>ÀȘ}ÊiÝÌi˜Ãˆœ˜Ãʈ˜Ê̅iÊÀœÕÌiÀ®°Ê6ˆiÜÃÊÀi˜`iÀʈ˜vœÀ“>̈œ˜Ê̜Ê̅iÊÕÃiÀðÊ6ˆiÜÃÊ>ÀiÊVœ“«œÃi`Ê œvÊ>ʓˆÝÌÕÀiʜvÊ/Ê>˜`Ê**ÊVœ`i°Ê ÞÊ`iv>ՏÌ]Ê>ÊۈiÜÊŜՏ`ÊLiÊÃ̜Ài`Ê՘`iÀÊ̅iÊVœ˜ÌÀœiÀʘ>“iÊvœ`iÀ°ÊœÀÊiÝ>“«i]Ê̅iÊ view for the ]``$% method in the @al]npiajpo?kjpnkhhan is stored as ]ll+reaso+`al]npiajpo+ ]``*ldl.

>Ì>ÊvÀœ“Ê̅iÊVœ˜ÌÀœiÀʈÃÊ«>ÃÃi`Ê̜Ê̅iÊۈiÜÊLÞÊÕȘ}Ê̅iÊoap$% method in a controller.

NNote Views should be involved only with displaying output. For example, this is where you will see HTML tags and XML tags. Business logic, such as odkllejc[^]ogap[^]h]j_a9 jap[lne_a' p]t7, should not be in the view. However, the following is OK in a view: Eb$ odkllejc[^]ogap[^]h]j_a:-,,,%w a_dk#Ukq]naahece^habkn]`eo_kqjp#7y*

i̽ÃÊLՈ`Ê̅iÊۈiÜÊ̜Ê>``ʈ˜vœÀ“>̈œ˜Ê̜ʜÕÀÊ`al]npiajpo database table. We are going to use another utility provided by Cake to build forms: the bkni object. ʈÃ̈˜}Ê£‡£ÓÊŜÜÃÊ̅iÊ add view.

15


16

CH APT ER 1 N CAK E FU NDA MENTA L S

Listing 1-12. The Add View for the departments Table 8d-:=``@al]npiajp8+d-: 8;9 bkni):_na]pa$#`al]npiajp#(]nn]u$#]_pekj#9:#]``#%%7;: 8l:J]ia6 8;9 bkni):ejlqp$#@al]npiajp*j]ia#(]nn]u$#oeva#9:#-.,#%%7;: 8;9 bkni):annkn$#j]ia#%7;:8+l: 8l:Nacekj6 8;9 bkni):ejlqp$#@al]npiajp*nacekj#(]nn]u$#oeva#9:#0,#%%7;: 8;9 bkni):annkn$#nacekj#%7;:8+l: 8;9 bkni):aj`$#O]ra#%;: The view code created using the bkni object is stored in +]ll+reaso+`al]npiajp+]``*_pl. ,i“i“LiÀÊ̅>ÌÊ̅iÊÛ>ˆ`>̈œ˜ÊÀՏiÊvœÀÊ̅ˆÃÊvœÀ“ʈÃÊVÀi>Ìi`Ê>ÌÊʈÃ̈˜}Ê£‡£ä° To display the add view to a user, we need a controller object with a function called ]``$%, ܅ˆV…ÊÌÀˆiÃÊ̜Ê`œÊiÝ>V̏ÞÊ܅>ÌʈÌÊÃ>ÞÃ\Ê>``Ê̅iÊvœÀ“Ê`>Ì>Ê̜ʜÕÀÊ`al]npiajpo database table. ʈÃ̈˜}Ê£‡£ÎÊshows the action ]``$% method of the @al]npiajpo?kjpnkhhan. Listing 1-13. The add() Action in the Departments Controller 8;ldl _h]oo@al]npiajpo?kjpnkhhanatpaj`o=ll?kjpnkhhanw  bqj_pekj]``$%w  eb$ailpu$ pdeo):`]p]%%w  pdeo):@al]npiajp):_na]pa$%7 eb$ pdeo):@al]npiajp):o]ra$ pdeo):`]p]%%w pdeo):Oaooekj):oapBh]od$£ [[$#Pda@al]npiajp`]p]d]o^aajo]ra`#(pnqa%%7 pdeo):na`ena_p$]nn]u$#]_pekj#9:#]``#%%7 yahoaw pdeo):Oaooekj):oapBh]od$£ [[$#Pda@al]npiajp`]p]_kqh`jkp^ao]ra`*Lha]oa(pnu]c]ej*#(pnqa%%7 y y y ;: Now that we’ve built a web form using the /ʅi«iÀÊ>˜`ÊVÀi>Ìi`Ê>ÊVœ˜ÌÀœiÀÊÌœÊ handle the ]``$% action, let’s demonstrate how data is passed to a view. We’ll start by creating a show action in our @al]npiajpo controller class. The action method is shown in  Ê ˆÃ̈˜}Ê£‡£{°


C H A P T E R 1 N C A K E F U N D A M E N T A LS

Listing 1-14. The show() action in the Departments Controller bqj_pekjodks$ nacekj%w  pdeo):oap$#`]p]#(pdeo):@al]npiajp):cap@al]npiajp$ nacekj%%7 y ˜ÊʈÃ̈˜}Ê£‡£{]Ê̅iÊodks$% method accepts the nacekj data as a parameter, and then retrieves departmental data and uses the oap$% method to prepare the data for the view in ʈÃ̈˜}Ê£‡£x°ÊÊۈiÜʈÃÊ>Ü>ÞÃʘ>“i`Ê>vÌiÀÊ>˜Ê>V̈œ˜°ÊœÀÊiÝ>“«i]Ê̅iÊodks$% action in the @al]npiajpo?kjpnkhhanʜvÊʈÃ̈˜}Ê£‡£{Ê܈Ê…>ÛiÊ>ÊۈiÜÊvˆiÊÃ̜Ài`ʈ˜Ê]ll+reaso+`al]npiajp+ odks*_pl. Listing 1-15. A View for the Action show($region) of DepartmentsController 8d-_h]oo9benop:  Kqn@al]npiajp6)  8;ldl bkna]_d$ `]p]]o `al]npiajp%w a_dk `al]npiajpW#@al]npiajp#YW#j]ia#Y7 y ;: 8+d-: 8l:Kqn@al]npiajpo]naha`^u@n*?]ga*8+l: /…iÊۈiÜʈ˜ÊʈÃ̈˜}Ê£‡£xÊ܈Ê`ˆÃ«>ÞÊ̅iʘ>“iʜvÊ̅iÊ`i«>À̓i˜ÌÊ­vœÀÊiÝ>“«i]Ê->iîʈ˜Ê the header section of the web page presented to the user.

NTip If you have a number of data items to display in a view, such as

pepha9Ln]_pe_]h?]ga Lnkfa_po7 `al]npiajp9O]hao7]j` nacekj9QG7, using pdeo):oap$_kil]_p$#pepha #(#`al]npiajp#(#nacekj#%%7 will enable you to use only one oap$% function in your controller class to

pass all the information to your view. You can then access the individual variable in your view; for example, 8;ldlln$ pepha%7;:.

An essential part of any framework is the part that handles requests. In the MVC structure, this is handled by the controller.

17


18

CH APT ER 1 N CAK E FU NDA MENTA L S

Controllers As you’ve seen, a controller is a class with methods called actions. These actions or methods Vœ˜Ì>ˆ˜Ê“œÃÌʜvÊ̅iʏœ}ˆVÊ̅>ÌÊÀi뜘`ÃÊ̜ÊÕÃiÀÊÀiµÕiÃÌÃʈ˜Ê>˜Ê>««ˆV>̈œ˜°ÊœÀÊiÝ>“«i]ʈvÊ a user wants to know the number of departments in a particular region, the user needs to access the odks$% method of @al]npiajpo?kjpnkhhanÊ`ivˆ˜i`ʈ˜ÊʈÃ̈˜}Ê£‡£ä]ÊLÞÊÌÞ«ˆ˜}Ê̅iÊ vœœÜˆ˜}Ê1,ʈ˜Ê>ÊLÀœÜÃiÀÊ>``ÀiÃÃÊL>À\ hk_]hdkop+`al]npiajpo+odks+QO /…iÊ`iv>ՏÌÊÃÌÀÕVÌÕÀiÊvœÀÊ>VViÃȘ}Ê>Ê >ŽiÊ1,ʈÃÊ̜ÊvˆÀÃÌÊëiVˆvÞÊ̅iÊVœ˜ÌÀœiÀÊ>˜`Ê̅i˜Ê ̅iÊ>V̈œ˜°Ê˜Ê̅iÊ«ÀiVi`ˆ˜}Ê1,]Ê`al]npiajpo is the controller, odks is the action, and QO is a parameter. By convention, a Cake request should be structured in the following manner: dppl6++Wiu`ki]ej*_kiY+W=llhe_]pekjY+W?kjpnkhhanY+W=_pekjY+WL]n]i-Y+ÅWL]n]iJY

NNote The ej`at$%method is the default access point to a controller when a method is not explicitly specified in a user’s request. For example, you can load the ej`at$% method with codes that will invoke the welcome page of your application. However, do not forget to create a view, or you will get a warning from Cake stating that you should create a view for the action.

9œÕÀÊ>««ˆV>̈œ˜½ÃÊVœ˜ÌÀœiÀÊV>ÃÃiÃÊ>ÀiÊiÝ«iVÌi`Ê̜ÊiÝÌi˜`Ê̅iÊ=ll?kjpnkhhan class, ܅ˆV…ʈ˜ÊÌÕÀ˜ÊiÝÌi˜`ÃÊ>ÊVœÀiÊ?kjpnkhhan class, which is a standard Cake library. The =ll?kjpnkhhan class is defined in +]ll+]ll[_kjpnkhhan*ldl, and it should contain methods that are shared between two or more controllers. These controllers can include any number of actions. The =ll?kjpnkhhan serves as a global class that can contain properties and methods common to all the user-defined conÌÀœiÀÃʈ˜Ê>˜Ê>««ˆV>̈œ˜°ÊœÀÊiÝ>“«i]ÊޜÕÊV>˜Ê…>ÛiÊ>ʓi̅œ`Ê̜Ê`iÌiVÌÊ>˜`ÊiÝÌÀ>VÌÊ̅iÊ*Ê address of a user, and then use the value of this address to determine the flow of the applic䜘°Ê >ÀˆiÀ]ʈ˜ÊʈÃ̈˜}Ê£‡Ó]ÊÜiÊÕÃi`Ê̅iÊ`iv>ՏÌÊVœ˜ÌÀœiÀʓi̅œ`ÊV>i`Ê^abknaBehpan$% in our controller class to reference the method defined in the =ll?kjpnkhhan class stored in ]ll+ ]ll[_kjpnkhhan*ldl°Ê˜œÌ…iÀÊȓ«iÊiÝ>“«iʈÃÊ̜ÊÃiÌÊ>Êdefault page title for an application, >Ãʈ˜Ê̅ˆÃÊiÝ>“«i\ 8;ldl _h]oo=ll?kjpnkhhanatpaj`o?kjpnkhhanw r]n l]caPepha9#?d]lpan-Ì=>]ganu=llhe_]pekj#7 -ˆ˜ViʜÕÀÊÊÕÃiÀ‡Ê`ivˆ˜i`ÊVœ˜ÌÀœiÀÊiÝÌi˜`ÃÊ̅iÊ=ll?kjpnkhhan, using the statement pdeo):L]caPepha within our controller gives us access to the string #?d]lpan-Ì=>]ganu =llhe_]pekj# assigned to the l]caPepha property in the =ll?kjpnkhhan class.


C H A P T E R 1 N C A K E F U N D A M E N T A LS

The qoao property is an important property within the controller. It works similarly to the namqena[kj_aÊÃÌ>Ìi“i˜Ìʈ˜Ê**°Ê >ÈV>Þ]ʜ˜ViÊޜÕʅ>ÛiÊVÀi>Ìi`Ê>ʓœ`iÊ­ÃÕV…Ê>ÃÊ@al]npiajp®Ê and you want to use the model in a controller, you need to include it in the qoao array. For iÝ>“«i]Ê܅iÀiÊ@al]npiajp and Pn]`aÊ>ÀiÊi݈Ã̈˜}ʓœ`iÃ]ÊޜÕÊV>˜Ê…>ÛiÊ̅iÊvœœÜˆ˜}ÊÃÌ>Ìiment in your controller: qoao9]nn]u$#@al]npiajp#(#Pn]`a#%7*

Cake Components Components are classes defined to carry out specific application tasks to support the controller. Cake comes with many built-in components, such as =_hÊ­vœÀÊÕÃiÀÊ>˜`Ê}ÀœÕ«Ê>VViÃÃÊ Vœ˜ÌÀœ®]Ê=qpdÊ­vœÀÊÕÃiÀÊ>˜`Ê}ÀœÕ«Ê>Õ̅i˜ÌˆV>̈œ˜®]ÊAi]eh, Oaooekj, and NamqaopD]j`han. Components can also be user-defined. In fact, in large web applications, you will most likely need to build some of your own components to be used by several controllers. All the components that you develop should be stored in the folder ]ll+_kjpnkhhano+_kilkjajpo. Components follow the same Cake conventions as controllers. Àœ“Ê>Ê«Àœ}À>““iÀ½ÃÊ«œˆ˜ÌʜvÊۈiÜ]ÊVœ“«œ˜i˜ÌÃÊi˜>LiÊޜÕÊ̜ÊiÝÌi˜`Ê̅iÊv՘V̈œ˜>ˆÌÞÊ of Cake. If you find that your component is quite useful and you possess the free open source spirit, you can and should post it on the Cake web site, where there is a public repository of components. To demonstrate, we’ll dive straight in and create our own simple component—a utility to convert an array to an object. ʈÃ̈˜}Ê£‡£ÈÊŜÜÃÊ̅iÊVœ`iÊ̜ÊVÀi>ÌiÊ̅ˆÃÊVœ“«œ˜i˜Ì° Listing 1-16. A Component to Convert an Array to an Object 8;ldl _h]oo=nn]uPkK^fa_p?kilkjajpatpaj`oK^fa_pw bqj_pekjop]npql$" _kjpnkhhan%w pdeo):?kjpnkhhan9 _kjpnkhhan7 y bqj_pekj_kjranp$ ]nn]u(" k^f%w bkna]_d$ ]nn]u]o gau9: r]hqa%w eb$eo[]nn]u$ r]hqa%%w k^f): gau9jasop`?h]oo$%7 pdeo):]nn]u[pk[k^f$ r]hqa(k^f): gau%7 yahoaw k^f): gau9 r]hqa7 y y  napqnj k^f7 y y ;:

19


20

CH APT ER 1 N CAK E FU NDA MENTA L S

The =nn]uPkK^fa_p?kilkjajpÊV>ÃÃʈ˜ÊʈÃ̈˜}Ê£‡£ÈÊVœ˜Ì>ˆ˜ÃÊÌܜÊL>ÈVÊv՘V̈œ˜Ã]Ê܅ˆV…Ê>ÀiÊ stored in ]ll+_kjpnkhhano+_kilkjajpo+]nn]u[pk[k^fa_p*ldl: Ê

UÊ /…iÊvˆÀÃÌÊv՘V̈œ˜]ÊV>i`Êop]npql$%, is used to instantiate the controller object. This enables all other functions within the component to access information contained in the parent controller. It’s basically a callback method used to bring the controller object into the component.

Ê

UÊ /…iÊÃiVœ˜`Êv՘V̈œ˜]Ê_kjranp$%, is our user-defined function. It does the work of >VVi«Ìˆ˜}Ê>˜Ê>ÀÀ>ÞʜvÊ`>Ì>Ê>˜`ÊÀiÌÕÀ˜ˆ˜}Ê̅iÊ>ÀÀ>ÞÊ>ÃÊ>˜ÊœLiVÌ°Ê9œÕÊV>˜ÊÕÃiÊ̅ˆÃÊVœ“ponent whenever you want to convert an array to an object.

ÛiÀÞ̅ˆ˜}ʈ˜Ãˆ`iÊ>ÊVœ“«œ˜i˜ÌÊŜՏ`ÊLiÊ}i˜iÀˆV°Ê œÊ˜œÌÊ«ÕÌÊÊVœ˜ÌÀœiÀ‡ÊëiVˆvˆVÊVœ`i]Ê such as a database table name, into components. 9œÕÊV>˜ÊÕÃiÊVœ“«œ˜i˜ÌÃÊ܈̅ˆ˜Êcontrollers or other components. To use a component— whether it is a built-in one or one you have created—you need to first declare the component within the _kilkjajpo array in a user-defined controller, another component, or in the =ll?kjpnkhhanÊV>ÃðÊœÀÊiÝ>“«i]Ê̜ÊÕÃiÊ̅iÊVœ“«œ˜i˜Ìʈ˜ÊʈÃ̈˜}Ê£‡£È]ʈ˜VÕ`iÊ̅iÊvœœÜˆ˜}Ê statement: r]n _kilkjajpo9]nn]u$#=nn]uPkK^fa_p#% ˜ÊʈÃ̈˜}Ê£‡£Ç]ÊÜiʓ>ŽiÊÀiviÀi˜ViÃÊ̜Ê̅iÊÊLՈÌ‡Êˆ˜ÊOaooekj component and our =nn]uPkK^fa_p component in the @al]npiajpo?kjpnkhhan class. Listing 1-17. Using Components in DepartmentsController 8;ldl _h]oo@al]npiajpo?kjpnkhhanatpaj`o=ll?kjpnkhhan w r]n qoao9]nn]u$#@al]npiajp#%7 r]n _kilkjajpo9]nn]u$#Oaooekj#(#=nn]uPkK^fa_p#%7 bqj_pekj`eolh]u$%w  ]nn@]p]9]nn]u$%7  ]nn@]p]9pdeo):bej`$#]hh#%7 ln$ pdeo):=nn]uPkK^fa_p):_kjranp$]nn@]p](" k^f%%7 y y ;: ˜ÊʈÃ̈˜}Ê£‡£Ç]ÊÜiÊVœ˜ÛiÀÌÊ̅iÊÀiÃՏÌʜvÊ̅iÊ`>Ì>ÊÀiÌÀˆiÛi`ÊvÀœ“ÊœÕÀÊ`al]npiajpo database table from an array to an object. First, we use the qoao array to reference the @al]npiajp model. We then use the _kilkjajp array to reference the Oaooekj component, which is a built-in Cake component, and the =nn]uPkK^fa_p component, which is our user-defined Vœ“«œ˜i˜Ì°Ê iÝÌ]ÊÜiÊVÀi>ÌiÊ>Ê`eolh]u$% function that contains a declaration of an array variable called ]nn@]p]. We retrieve the department data using the default bej`$% function, store the result in the array, and then pass the array to the _kjranp$% method of the =nn]uPkK^fa_p component. Finally, we use the Cake ln$% global function to print the resulting object.


C H A P T E R 1 N C A K E F U N D A M E N T A LS

Helpers Cake helpers are classes that help to decrease development time by providing shortcuts to generate presentational elements. Earlier, we used the Cake form helper, which helps with form element creation and data handling. Helper files should be stored in the ]ll+reaso+dahlano vÂ&#x153;Â?`iĂ&#x20AC;°Ă&#x160;Ă&#x160;/>LÂ?iĂ&#x160;ÂŁÂ&#x2021;{Ă&#x160;LĂ&#x20AC;Â&#x2C6;ivÂ?Ă&#x17E;Ă&#x160;`iĂ&#x192;VĂ&#x20AC;Â&#x2C6;LiĂ&#x192;Ă&#x160;Ă&#x192;Â&#x153;Â&#x201C;iĂ&#x160;Â&#x153;vĂ&#x160; >Â&#x17D;i½Ă&#x192;Ă&#x160;Ă&#x160;LĂ&#x2022;Â&#x2C6;Â?Ă&#x152;Â&#x2021;Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x160;Â&#x2026;iÂ?ÂŤiĂ&#x20AC;Ă&#x192;°Ă&#x160;Â&#x153;Ă&#x20AC;Ă&#x160;vĂ&#x2022;Â?Â?Ă&#x160;documentation of the Cake helpers, check the Cake API at dppl6++]le*_]galdl*knc. Table 1-4. Some of Cakeâ&#x20AC;&#x2122;s Built-in Helpers

Helper

Description

/

Helps >Ă&#x2022;Ă&#x152;Â&#x153;Â&#x201C;>Ă&#x152;iĂ&#x160;VĂ&#x20AC;i>Ă&#x152;Â&#x2C6;Â&#x2DC;}Ă&#x160;/Ă&#x160;iÂ?iÂ&#x201C;iÂ&#x2DC;Ă&#x152;Ă&#x192;Ă&#x160;>Â&#x2DC;`Ă&#x160;>Â?Ă&#x192;Â&#x153;Ă&#x160;iÂ&#x2DC;>LÂ?iĂ&#x192;Ă&#x160;`Ă&#x17E;Â&#x2DC;>Â&#x201C;Â&#x2C6;VĂ&#x160;}iÂ&#x2DC;iĂ&#x20AC;>Ă&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;Ă&#x160;Â&#x153;vĂ&#x160; /Ă&#x160;Ă&#x152;>}Ă&#x192;Ă&#x160;LĂ&#x17E;Ă&#x160;>VViÂŤĂ&#x152;Â&#x2C6;Â&#x2DC;}Ă&#x160;>Â&#x2DC;`Ă&#x160;ÂŤ>Ă&#x20AC;Ă&#x192;Â&#x2C6;Â&#x2DC;}Ă&#x160;Ă&#x203A;>Ă&#x20AC;Â&#x2C6;>LÂ?iĂ&#x192;°Ă&#x160;/Â&#x2026;Â&#x2C6;Ă&#x192;Ă&#x160;Â&#x2026;iÂ?ÂŤiĂ&#x20AC;Ă&#x160;Â&#x2C6;Ă&#x192;Ă&#x160;V>Â?Â?i`Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x160;>Ă&#x160;Ă&#x203A;Â&#x2C6;iĂ&#x153;Ă&#x160;LĂ&#x17E;Ă&#x160;Ă&#x2022;Ă&#x192;Â&#x2C6;Â&#x2DC;}Ă&#x160; the dpihĂ&#x160;Â&#x153;LÂ?iVĂ&#x152;°Ă&#x160;/Â&#x153;Ă&#x160;Â&#x2C6;Â&#x2DC;VÂ?Ă&#x2022;`iĂ&#x160;>Ă&#x160;Ă&#x20AC;iviĂ&#x20AC;iÂ&#x2DC;ViĂ&#x160;Ă&#x152;Â&#x153;Ă&#x160;/Ă&#x160;Â&#x2026;iÂ?ÂŤiĂ&#x20AC;]Ă&#x160;Ă&#x2022;Ă&#x192;iĂ&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;Ă&#x203A;>Ă&#x20AC;Â&#x2C6;>LÂ?iĂ&#x160; dahlano 9]nn]u$#Dpih#%7°Ă&#x160;/Ă&#x160;Â&#x2026;iÂ?ÂŤiĂ&#x20AC;Ă&#x160;vĂ&#x2022;Â&#x2DC;VĂ&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;Ă&#x192;Ă&#x160;Â&#x153;Ă&#x2022;Ă&#x152;ÂŤĂ&#x2022;Ă&#x152;Ă&#x160;/Ă&#x160;iÂ?iÂ&#x201C;iÂ&#x2DC;Ă&#x152;Ă&#x192;Ă&#x160;Ă&#x192;Ă&#x2022;VÂ&#x2026;Ă&#x160;>Ă&#x192;Ă&#x160;_d]noap, _oo, `er, `k_Pula, ei]ca, hejg, iap], jaopa`Heop, l]n], opuha, p]^haDa]`ano, p]^ha?ahho, and so on.

Form

Helps Â&#x2C6;Â&#x2DC;Ă&#x160;vÂ&#x153;Ă&#x20AC;Â&#x201C;Ă&#x160;VĂ&#x20AC;i>Ă&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;Ă&#x160;>Â&#x2DC;`Ă&#x160;ÂŤĂ&#x20AC;Â&#x153;ViĂ&#x192;Ă&#x192;Â&#x2C6;Â&#x2DC;}°Ă&#x160;1Ă&#x192;iĂ&#x160;Ă&#x152;Â&#x2026;iĂ&#x160; bkni object together with its funcĂ&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;Ă&#x192;Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;VĂ&#x20AC;i>Ă&#x152;iĂ&#x160;vÂ&#x153;Ă&#x20AC;Â&#x201C;Ă&#x160;iÂ?iÂ&#x201C;iÂ&#x2DC;Ă&#x152;Ă&#x192;°Ă&#x160;Â&#x153;Ă&#x20AC;Ă&#x160;iĂ?>Â&#x201C;ÂŤÂ?i]Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;VĂ&#x20AC;i>Ă&#x152;iĂ&#x160;>Ă&#x160;vÂ&#x153;Ă&#x20AC;Â&#x201C;Ă&#x160;Â&#x2C6;Â&#x2DC;ÂŤĂ&#x2022;Ă&#x152;Ă&#x160;iÂ?iÂ&#x201C;iÂ&#x2DC;Ă&#x152;]Ă&#x160;Ă&#x2022;Ă&#x192;iĂ&#x160;Ă&#x152;Â&#x2026;iĂ&#x160; bkni):ejlqp$% function. To start the form tag, use the bkni):_na]pa$% function. Other form input element functions include h]^ah, _da_g^kt, `]paPeia, de``aj, n]`ek, patp]na], and so on. There are many options that can be used in form element functions, such as i]tHajcpd]Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;Ă&#x192;iĂ&#x152;Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;Â&#x201C;>Ă?Â&#x2C6;Â&#x201C;Ă&#x2022;Â&#x201C;Ă&#x160;Â?iÂ&#x2DC;}Ă&#x152;Â&#x2026;Ă&#x160;Â&#x153;vĂ&#x160;>Â&#x2DC;Ă&#x160;/Ă&#x160;>Ă&#x152;Ă&#x152;Ă&#x20AC;Â&#x2C6;LĂ&#x2022;Ă&#x152;i°

Â?>Ă?

:hejg$]nn]u$# Helps Ă&#x152;Â&#x153;Ă&#x160;Ă&#x192;Â&#x2C6;Â&#x201C;ÂŤÂ?Â&#x2C6;vĂ&#x17E;Ă&#x160;Â?>Ă?Ă&#x160;Ă&#x152;>Ă&#x192;Â&#x17D;Ă&#x192;°Ă&#x160;Ă&#x152;Ă&#x160;Ă&#x20AC;iÂľĂ&#x2022;Â&#x2C6;Ă&#x20AC;iĂ&#x192;Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;Ă&#x192;Ă&#x152;>Ă&#x152;iÂ&#x201C;iÂ&#x2DC;Ă&#x152;Ă&#x160;f]r]o_nelp) lnkpkpula#%%Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;Ă&#x203A;Â&#x2C6;iĂ&#x153;]Ă&#x160;Ă&#x153;Â&#x2026;Â&#x2C6;VÂ&#x2026;Ă&#x160;Ă&#x20AC;iviĂ&#x20AC;iÂ&#x2DC;ViĂ&#x192;Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;*Ă&#x20AC;Â&#x153;Ă&#x152;Â&#x153;Ă&#x152;Ă&#x17E;ÂŤiĂ&#x160;>Ă&#x203A;>-VĂ&#x20AC;Â&#x2C6;ÂŤĂ&#x152;Ă&#x160;vĂ&#x20AC;>Â&#x201C;iĂ&#x153;Â&#x153;Ă&#x20AC;Â&#x17D;]Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x160; Â&#x153;Ă&#x20AC;`iĂ&#x20AC;Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;Ă&#x153;Â&#x153;Ă&#x20AC;Â&#x17D;Ă&#x160;ÂŤĂ&#x20AC;Â&#x153;ÂŤiĂ&#x20AC;Â?Ă&#x17E;Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x160;>Ă&#x160;Ă&#x203A;Â&#x2C6;iĂ&#x153;°Ă&#x160;9Â&#x153;Ă&#x2022;Ă&#x160;V>Â&#x2DC;Ă&#x160;}iĂ&#x152;Ă&#x160;>Ă&#x160;VÂ&#x153;ÂŤĂ&#x17E;Ă&#x160;Â&#x153;vĂ&#x160;*Ă&#x20AC;Â&#x153;Ă&#x152;Â&#x153;Ă&#x152;Ă&#x17E;ÂŤiĂ&#x160;vĂ&#x20AC;Â&#x153;Â&#x201C;Ă&#x160;dppl6++sss* lnkpkpulafo*knc+`ksjhk]`.

>Ă&#x203A;>-VĂ&#x20AC;Â&#x2C6;ÂŤĂ&#x152;

Helps Ă&#x152;Â&#x153;Ă&#x160;Ă&#x192;Â&#x2C6;Â&#x201C;ÂŤÂ?Â&#x2C6;vĂ&#x17E;Ă&#x160;>Ă&#x203A;>-VĂ&#x20AC;Â&#x2C6;ÂŤĂ&#x152;Ă&#x160;Ă&#x152;>Ă&#x192;Â&#x17D;Ă&#x192;]Ă&#x160;Ă&#x192;Ă&#x2022;VÂ&#x2026;Ă&#x160;>Ă&#x192;Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;VĂ&#x20AC;i>Ă&#x152;iĂ&#x160;>Ă&#x160;>Ă&#x203A;>-VĂ&#x20AC;Â&#x2C6;ÂŤĂ&#x152;Ă&#x160;"LÂ?iVĂ&#x152;Ă&#x160; Â&#x153;Ă&#x152;>Ă&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;Ă&#x160; :k^fa_p­Ž°Ă&#x160;/Â&#x153;Ă&#x160;>Ă&#x152;Ă&#x152;>VÂ&#x2026;Ă&#x160;>Â&#x2DC;Ă&#x160;iĂ&#x203A;iÂ&#x2DC;Ă&#x152;Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;>Â&#x2DC;Ă&#x160; ­-" ÂŽĂ&#x160;Â&#x153;LÂ?iVĂ&#x152;Ă&#x160;vĂ&#x20AC;Â&#x153;Â&#x201C;Ă&#x160;>Â&#x2DC;Ă&#x160;>Ă&#x20AC;Ă&#x20AC;>Ă&#x17E;]Ă&#x160;Ă&#x2022;Ă&#x192;Â&#x2C6;Â&#x2DC;}Ă&#x160;f]r]o_nelp) :arajp­Ž° element, use f]r]o_nelp)

Paginator

Helps to format data into multiple pages or to sort data based on some parameters. Â&#x153;Ă&#x20AC;Ă&#x160;iĂ?>Â&#x201C;ÂŤÂ?i]Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;VĂ&#x20AC;i>Ă&#x152;iĂ&#x160;>Ă&#x160;Â?Â&#x2C6;Â&#x2DC;Â&#x17D;Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;Â&#x2DC;iĂ?Ă&#x152;Ă&#x160;Ă&#x192;iĂ&#x152;Ă&#x160;Â&#x153;vĂ&#x160;ÂŤ>}Â&#x2C6;Â&#x2DC;>Ă&#x152;i`Ă&#x160;Ă&#x20AC;iĂ&#x192;Ă&#x2022;Â?Ă&#x152;Ă&#x192;]Ă&#x160;Ă&#x2022;Ă&#x192;iĂ&#x160;Ă&#x152;Â&#x2026;iĂ&#x160; l]cej]pkn):jatp$% function.

-iĂ&#x192;Ă&#x192;Â&#x2C6;Â&#x153;Â&#x2DC;

Provides vĂ&#x2022;Â&#x2DC;VĂ&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;Ă&#x192;Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;`i>Â?Ă&#x160;Ă&#x153;Â&#x2C6;Ă&#x152;Â&#x2026;Ă&#x160;Ă&#x192;iĂ&#x192;Ă&#x192;Â&#x2C6;Â&#x153;Â&#x2DC;Ă&#x160;Â&#x201C;>Â&#x2DC;>}iÂ&#x201C;iÂ&#x2DC;Ă&#x152;°Ă&#x160;Â&#x153;Ă&#x20AC;Ă&#x160;iĂ?>Â&#x201C;ÂŤÂ?i]Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;Ă&#x20AC;iÂ&#x2DC;`iĂ&#x20AC;Ă&#x160; :bh]od­Ž°Ă&#x160;/Â&#x153;Ă&#x160;Ă&#x20AC;i>`Ă&#x160;>Â?Â?Ă&#x160;Ă&#x203A;>Â?Ă&#x2022;iĂ&#x192;Ă&#x160;Ă&#x192;Ă&#x152;Â&#x153;Ă&#x20AC;i`Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x160;>Ă&#x160;}Â&#x2C6;Ă&#x203A;iÂ&#x2DC;Ă&#x160;Ă&#x192;iĂ&#x192;Ă&#x192;Â&#x2C6;Â&#x153;Â&#x2DC;]Ă&#x160;Ă&#x2022;Ă&#x192;iĂ&#x160; messages, use oaooekj) oaooekj):na]`­Ž°

/iĂ?Ă&#x152;

Provides vĂ&#x2022;Â&#x2DC;VĂ&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;Ă&#x192;Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;`i>Â?Ă&#x160;Ă&#x153;Â&#x2C6;Ă&#x152;Â&#x2026;Ă&#x160;Ă&#x152;iĂ?Ă&#x152;Ă&#x160;Â&#x153;Ă&#x20AC;Ă&#x160;Ă&#x192;Ă&#x152;Ă&#x20AC;Â&#x2C6;Â&#x2DC;}Ă&#x160;Â&#x2026;>Â&#x2DC;`Â?Â&#x2C6;Â&#x2DC;}°Ă&#x160;Â&#x153;Ă&#x20AC;Ă&#x160;iĂ?>Â&#x201C;ÂŤÂ?i]Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;Ă&#x20AC;iÂ&#x201C;Â&#x153;Ă&#x203A;iĂ&#x160; :pnei$% function. Ă&#x153;Â&#x2026;Â&#x2C6;Ă&#x152;iĂ&#x192;ÂŤ>ViĂ&#x160;vĂ&#x20AC;Â&#x153;Â&#x201C;Ă&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;Li}Â&#x2C6;Â&#x2DC;Â&#x2DC;Â&#x2C6;Â&#x2DC;}Ă&#x160;>Â&#x2DC;`Ă&#x2030;Â&#x153;Ă&#x20AC;Ă&#x160;iÂ&#x2DC;`Ă&#x160;Â&#x153;vĂ&#x160;Ă&#x152;iĂ?Ă&#x152;]Ă&#x160;Ă&#x2022;Ă&#x192;iĂ&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;patp)

Time

Helps Â&#x201C;>Â&#x2DC;>}iĂ&#x160;`>Ă&#x152;iĂ&#x192;Ă&#x160;>Â&#x2DC;`Ă&#x160;Ă&#x152;Â&#x2C6;Â&#x201C;iĂ&#x192;°Ă&#x160;Â&#x153;Ă&#x20AC;Ă&#x160;iĂ?>Â&#x201C;ÂŤÂ?i]Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;VÂ&#x2026;iVÂ&#x17D;Ă&#x160;Â&#x2C6;vĂ&#x160;>Ă&#x160;}Â&#x2C6;Ă&#x203A;iÂ&#x2DC;Ă&#x160;`>Ă&#x152;iĂ&#x2030;Ă&#x152;Â&#x2C6;Â&#x201C;iĂ&#x160;Ă&#x192;Ă&#x152;Ă&#x20AC;Â&#x2C6;Â&#x2DC;}Ă&#x160;Â&#x2C6;Ă&#x192;Ă&#x160; :eoPk`]u$% function. today, use the peia)

8

:ahai$% Helps Ă&#x153;Â&#x2C6;Ă&#x152;Â&#x2026;Ă&#x160;8Ă&#x160;Â&#x201C;>Â&#x2DC;Â&#x2C6;ÂŤĂ&#x2022;Â?>Ă&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;°Ă&#x160;/Â&#x153;Ă&#x160;VĂ&#x20AC;i>Ă&#x152;iĂ&#x160;8Ă&#x160;iÂ?iÂ&#x201C;iÂ&#x2DC;Ă&#x152;Ă&#x192;]Ă&#x160;Ă&#x2022;Ă&#x192;iĂ&#x160;Ă&#x152;Â&#x2026;iĂ&#x160;tih) vĂ&#x2022;Â&#x2DC;VĂ&#x152;Â&#x2C6;Â&#x153;Â&#x2DC;°Ă&#x160;/Â&#x2026;Â&#x2C6;Ă&#x192;Ă&#x160;Â&#x2026;iÂ?ÂŤiĂ&#x20AC;Ă&#x160;V>Â&#x2DC;Ă&#x160;>Â?Ă&#x192;Â&#x153;Ă&#x160;LiĂ&#x160;Ă&#x2022;Ă&#x192;i`Ă&#x160;Ă&#x152;Â&#x153;Ă&#x160;VÂ&#x153;Â&#x2DC;Ă&#x203A;iĂ&#x20AC;Ă&#x152;Ă&#x160;>Ă&#x160;Ă&#x20AC;iĂ&#x192;Ă&#x2022;Â?Ă&#x152;Ă&#x160;Ă&#x192;iĂ&#x152;Ă&#x160;Â&#x2C6;Â&#x2DC;Ă&#x152;Â&#x153;Ă&#x160;8°

To reference the common helpers that you need in your application, you can specify the following statement in your =ll?kjpnkhhan class: r]n dahlano9]nn]u$#Dpih#(#Bkni#(#=f]t#(#F]r]O_nelp#%7

21


22

CH APT ER 1 N CAK E FU NDA MENTA L S

This will ensure that the f]r]o_nelp):hejg$% function in a layout works properly. 9œÕʓ>Þʘii`Ê̜ÊVÀi>ÌiÊޜÕÀʜܘʅi«iÀʜÀÊÌÜi>ŽÊ>˜Êi݈Ã̈˜}ʅi«iÀÊV>ÃÃÊ̜ʫÀœÛˆ`iÊ >``ˆÌˆœ˜>Êv՘V̈œ˜>ˆÌÞÊ̅>ÌʈÃʘœÌÊÞiÌÊÃÕ««ˆi`ÊLÞÊ >Ži°ÊÃÊ>˜ÊiÝ>“«i]ÊʈÃ̈˜}Ê£‡£nÊVÀi>ÌiÃÊ a simple helper called /]ll+reaso+dahlano+^na]g*ldl. This helper will print a variable and insert a new break after printing. Listing 1-18. A Sample Custom Break Helper _h]oo>na]gDahlanatpaj`o=llDahlanw bqj_pekjjasheja$ r]h%w napqnjpdeo):kqplqp$ r]h8^n+:%7 y y We can use this helper in our @al]npiajpo controller object to insert a break whenever we use the controller’s lnejp$%Êv՘V̈œ˜]Ê>ÃÊŜܘʈ˜ÊʈÃ̈˜}Ê£‡£™°Ê Listing 1-19. Using the Sample Break Helper 8;ldl _h]oo@al]npiajpo?kjpnkhhanatpaj`o=ll?kjpnkhhanw r]n j]ia9#@al]npiajpo#7 r]n dahlano9]nn]u$#>na]g#%7 bqj_pekjlnejp$ r]h%w napqnjpdeo):>na]g):jasheja$ r]h%7 y y ;: ˆÀÃÌ]ʈ˜ÊʈÃ̈˜}Ê£‡£™]ÊÜiÊÀiviÀi˜ViÊ̅iÊLÀi>ŽÊ…i«iÀÊLÞÊ`iV>Àˆ˜}Êr]n dahlano9 ]nn]u$#>na]g#%7°Ê iÝÌ]ÊÜiÊ`ivˆ˜iÊ>Êlnejp$% function that accepts a r]h parameter. This function contains the statement that invokes the break helper’s jasheja$ r]h% method, and consequently returns the result with a newline after it.

Plugins With Cake, you can create a complete MVC package called a plugin, which you can integrate into other Cake applications. A plugin is a mini-application with its own controllers, modiÃ]ÊۈiÜÃ]Ê>˜`ʜ̅iÀÊ >ŽiÊÀiÜÕÀViÃ°Ê >ŽiÊ`œiÃʘœÌʅ>ÛiÊ>˜ÞÊÊLՈÌ‡Êˆ˜Ê«Õ}ˆ˜Ã°Ê9œÕÊV>˜ÊÕÃiÊ third-party plugins, or better still, build your own.


C H A P T E R 1 N C A K E F U N D A M E N T A LS

Here, we will create a basic feedback plugin that will provide mailing facility. It will have the following directory structure: +]ll +lhqcejo +baa`^]_g +_kjpnkhhano +ik`aho +reaso +baa`^]_g[]ll[_kjpnkhhan*ldl +baa`^]_g[]ll[ik`ah*ldl where Ê

UÊ +_kjpnkhhano contains plugin controllers.

Ê

UÊ +ik`aho contains plugin models.

Ê

UÊ +reaso contains plugin views.

Ê

UÊ +baa`^]_g[]ll[_kjpnkhhan*ldl is the plugin’s =ll?kjpnkhhan, named after the plugin.

Ê

UÊ +baa`^]_g[]ll[ik`ah*ldl is the plugin’s =llIk`ah, named after the plugin.

NNote You must create both an =ll?kjpnkhhan and an =llIk`ah for a plugin to work properly. If you forget to define the Baa`^]_g=ll?kjpnkhhan class and the Baa`^]_g=llIk`ah, Cake will throw a “Missing Controller” error.

The feedback plugin’s =ll?kjpnkhhan is stored in ]ll+lhqcejo+baa`^]_g[]ll[_kjpnkhhan* ldl, and its corresponding =llIk`ah class is stored in ]ll+lhqcejo+baa`^]_g[]ll[ik`ah*ldl( as shown in ʈÃ̈˜}Ê£‡Óä° Listing 1-20. Feedback App Classes for the Feedback Plugin 8;ldl _h]ooBaa`^]_g=ll?kjpnkhhanatpaj`o=ll?kjpnkhhanw ++** y ;: 8;ldl _h]ooBaa`^]_g=llIk`ahatpaj`o=llIk`ahw ++** y ;:

23


24

CH APT ER 1 N CAK E FU NDA MENTA L S

Now, let’s create the Baa`^]_gOaj`?kjpnkhhan for our feedback plugin. The code in ʈÃ̈˜}Ê£‡Ó£ÊˆÃÊÃ̜Ài`ʈ˜Ê]ll+lhqcejo+baa`^]_g+_kjpnkhhano+baa`^]_g[oaj`[_kjpnkhhan*ldl. Listing 1-21. The FeedbackSendController to Invoke the send() Method 8;ldl _h]ooBaa`^]_gOaj`?kjpnkhhanatpaj`oBaa`^]_g=ll?kjpnkhhanw r]n j]ia9#Baa`^]_g#7 r]n qoao9]nn]u$#Baa`^]_g#%7 bqj_pekjoaj`$ pkAi]eh%w pdeo):oap$naoqhp(b]hoa%7 eb$pdeo):Baa`^]_g):oaj`Ai]eh$ pkAi]eh%%w pdeo):oap$naoqhp(pnqa%7 y y y ;: iÝÌ]ÊÜi½ÊVÀi>ÌiÊ>˜`ÊÃ̜ÀiÊ̅iÊBaa`^]_gOaj`Ik`ah class in the ]ll+lhqcejo+baa`^]_g+ ik`aho+baa`^]_g[oaj`[ik`ah*ldlÊvˆi]Ê>ÃÊŜܘʈ˜ÊʈÃ̈˜}Ê£‡ÓÓ° Listing 1-22. The FeedbackSendModel That Uses the PHP mail() Function to Send a Message 8;ldl _h]ooBaa`^]_gOaj`Ik`ahatpaj`oBaa`^]_g=llIk`ah w bqj_pekjoaj`Ai]eh$ na_eleajp%w ++Dana#osdanasapnupkoaj`]jai]ehiaoo]ca* eb$i]eh$ na_eleajp(#De#(#Sd]peo^]gejc#(#Bnki6oqc]n<?]ga*_ki#%%w napqnjpnqa7 y napqnjb]hoa7 y y ;: iÝÌ]ʏi̽ÃÊVÀi>ÌiÊ>Êȓ«iÊvii`L>VŽÊ«Õ}ˆ˜ÊۈiÜÊÃ̜Ài`ʈ˜Ê̅iÊ]ll+lhqcejo+baa`^]_g+ reaso+baa`^]_g[oaj`+oaj`*_plÊvˆi]Ê>ÃÊŜܘʈ˜ÊʈÃ̈˜}Ê£‡Óΰ


C H A P T E R 1 N C A K E F U N D A M E N T A LS

Listing 1-23. The Feedback Email View 8d-:Baa`^]_gAi]eh8+d-: 8;ldl eb$ naoqhp%w a_dk#Pd]jgukqbknukqnbaa`^]_g*#7 yahoaw a_dk#OknnuKqnouopaieo`ksj]ppdaikiajp*Lha]oapnu]c]ejh]pan*#7 y ;: y ;: Now that we have installed the feedback plugin, we can use it. To access the plugin within a Cake application, you can add name of the plugin, then the action, then the parameter to the 1,]Ê>ÃÊvœœÜÃ\ dppl6++hk_]hdkop+baa`^]_g+baa`^]_gOaj`+baa`^]_gOaj`+oaj`+Wai]ehl]n]iY 9œÕÊV>˜Ê…>ÛiÊ>Ê`iv>ՏÌÊVœ˜ÌÀœiÀÊ܈̅Ê̅iʘ>“iʜvÊޜÕÀÊ«Õ}ˆ˜°ÊvÊޜÕÊ`œÊ̅>Ì]ÊޜÕÊV>˜Ê access it via +WlhqcejY+]_pekj°ÊœÀÊiÝ>“«i]Ê>Ê«Õ}ˆ˜Ê˜>“i`Êqoano with a controller named Qoano?kjpnkhhan can be accessed at dppl6++Wukqn`ki]ejY+qoano+]`` if there is no plugin called =``?kjpnkhhan in your WlhqcejY+_kjpnkhhano folder. Plugins will use the layouts from the ]ll+reaso+h]ukqpoÊvœ`iÀÊLÞÊ`iv>Տ̰Ê9œÕÊ܈ÊÃiiʅœÜÊ to override layouts in Chapter 3. 9œÕÊV>˜Ê>VViÃÃÊ>Ê«Õ}ˆ˜Ê܈̅ˆ˜ÊVœ˜ÌÀœiÀÃʈ˜ÊޜÕÀÊ >ŽiÊ>««ˆV>̈œ˜ÊLÞÊÕȘ}Ê̅iÊ namqaop=_pekj$% function: oajp9pdeo):namqaop=_pekj$]nn]u$#_kjpnkhhan#9:#Baa`^]_gOaj`#(#]_pekj#9:#oaj`#%%7

Vendors Many modern frameworks adopt the œ˜½ÌÊ,i«i>ÌÊ9œÕÀÃivÊ­ ,9®Ê«Àˆ˜Vˆ«i°Ê>âÞÊ­œÀʓ>ÞLiÊ ivvˆVˆi˜Ì®Ê«Àœ}À>““iÀÃÊ`œ˜½ÌʏˆŽiÊ̜ÊÀiˆ˜Ûi˜ÌÊ̅iÊ܅iitÊ/œÊ>œÜÊÕÃÊ̜ÊÏii«Êˆ˜Ê>ʏˆÌ̏iʏœ˜}iÀ]Ê Cake has provided a raj`kno folder. This is where we store third-party applications that don’t …>ÛiÊ>˜ÞÊÀi>̈œ˜Ã…ˆ«ÊÜˆÌ…Ê >Ži]ÊÃÕV…Ê>ÃÊ̅iÊ«…« ʓiÃÃ>}iÊLœ>À`Ê>««ˆV>̈œ˜Ê>˜`Ê̅iÊ-܈vÌÊ Mailer mailing application. This comes in handy, considering the number of utility scripts and programs available in various PHP repositories such as dppl6++sss*ldl_h]ooao*knc.

>Ži½ÃÊÌiV…˜ˆµÕiʜvʈ˜VÕ`ˆ˜}ÊiÝÌiÀ˜>Êscripts is as simple as using the following function: =ll66eilknp$#Raj`kn#(#beha#(]nn]u$#beha#9:#behaJ]ia*ldl#%%7 /…iÊ̅ˆÀ`Ê«>À>“iÌiÀʜvÊ̅iÊv՘V̈œ˜Ê>VVi«ÌÃÊ>˜Ê>ÀÀ>ÞʜvÊvˆiʘ>“iðÊ1ÃÕ>Þ]ÊbehaJ]ia*ldl is the startup file of the third-party application. The =ll66eilknp$% function can be used in controllers, models, and views of Cake applications. However, it is important that the call is made before any class definition. The raj`kno folder provides a standard way to include third-party applications.

25


26

CH APT ER 1 N CAK E FU NDA MENTA L S

ÃÊ>˜ÊiÝ>“«i]ʏi̽ÃÊVÀi>ÌiÊ>Êolehhkqp*ldlÊÃVÀˆ«Ì]Ê>ÃÊŜܘʈ˜ÊʈÃ̈˜}Ê£‡Ó{°Ê/…ˆÃÊÃVÀˆ«ÌÊ܈Ê serve as our third-party script that we’ll use in our O_naaj?kjpnkhhan later. This script should be stored in the ]ll+raj`kno folder. Listing 1-24. A Script to Display the Content of a File on the Screen 8;ldl _h]ooNa]`Behaw lnkpa_pa` beha7  lq^he_bqj_pekj[[_kjopnq_p$ behaJ]ia%w pdeo):beha9 behaJ]ia7 y lner]pabqj_pekjolehh$%w napqnjna]`beha$ pdeo):beha%7 y y ;: ʈÃ̈˜}Ê£‡Ó{Ê܈Êȓ«ÞÊÀi>`Ê̅iÊVœ˜Ìi˜ÌʜvÊ̅iÊsah_kia*dpih file and send it to the screen for a user’s consumption. We can import this script into our O_naaj?kjpnkhhan as shown in ʈÃ̈˜}Ê£‡Óx° Listing 1-25. The ScreenController to Use a Script as a Vendor 8;ldl =ll66eilknp$#Raj`kn#(#beha#(]nn]u$#beha#9:#olehhkqp*ldl#%%7 _h]ooO_naaj?kjpnkhhanatpaj`o=ll?kjpnkhhanw bqj_pekjej`at$%w  kqplqp9jasNa]`Beha$#sah_kia*dpih#%7 kqplqp):olehh$%7 y y ;: ˜ÊʈÃ̈˜}Ê£‡Óx]ÊÜiÊÕÃiÊ̅iÊeilknp$% function to load the content of the olehhkqp*ldl file, and then we create an instance of the Na]`Beha class using the sah_kia*dpih file as its parameter and store it in kqplqp. Finally, we send the content of the file to the screen using kqplqp):olehh$®Æ°


C H A P T E R 1 N C A K E F U N D A M E N T A LS

Summary ˜Ê̅ˆÃÊV…>«ÌiÀ]ÊÜiÊLÀˆivÞʈ˜ÌÀœ`ÕVi`ÊޜÕÊ̜Ê̅iʓ>ˆ˜Êvi>ÌÕÀiÃʜvÊ >Ži°Ê7iÊiÝ«>ˆ˜i`ʅœÜʈÌʈÃÊ >Ê, Ê«>ÌvœÀ“]Ê܈̅Ê̅iÊ6 Ê`iÈ}˜Ê«>ÌÌiÀ˜ÊvœÀ“ˆ˜}Ê̅iÊL>ÃiÊvœÕ˜`>̈œ˜°Ê7iÊVœÛiÀi`ʅœÜÊ the Cake MVC structure works, with business logic stored in controllers and components, data access in models, and presentational markup in the view. Additionally, we showed how Cake reduces development time with helpers, plugins, and vendors. After reading this chapter, you should have an overview of how Cake structures a web >««ˆV>̈œ˜°Ê9œÕÊŜՏ`ÊviiÊVœ˜vˆ`i˜ÌÊ̅>Ìʏi>À˜ˆ˜}Ê >ŽiʈÃʜ˜iʜvÊ̅iÊLiÃÌÊ`iVˆÃˆœ˜ÃÊvœÀÊ>˜Þone interested in PHP programming and with a need to write rapid web applications. But do note, sometimes it may be better to write basic methods like “Hello World” in a simple PHP script, rather than using Cake, so that you don’t end up killing an ant with a sledge hammer. In the following chapters, we’ll present full-fledged Cake applications, beginning with a simple blogging application.

27


C HAPTER

2

Blogging T

he Web has revolutionized the way we communicate with friends and strangers. We now freely exchange media content, such as textual information, graphics, audio, and video. One of the ways to exchange such information is known as blogging. Blogging uses HTML forms for tasks such as submitting posts, uploading content, and so on. In the 1990s, blogging started like a kiddie joke, with individuals posting their personal stuff online. Since then, there has been an explosion of blogging web sites. Nowadays, movie stars, politicians, and corporate organizations such as Microsoft host their own blogging sites to communicate their ideas. This chapter describes how to build your own blogging application. But why would you bother to develop such an application when you can use one of the many free or low-cost solutions, such as Blogger, Movable Type, Textpattern, WordPress, TypePad, or LiveJournal (to name a few)? The ready-made blogger solutions have common interface design features. Developing your own blogging application allows you to customize the site, giving it a unique look, excluding unnecessary features, and adding features that are not supplied with the prebuilt sites. In this chapter, we’ll build our own blog application, which will enable us to list, add, edit, delete, publish, and unpublish posts. We will use Cake’s form helper to automate some tasks, such as to generate form elements, validate user-submitted data, and repopulate invalid form elements with submitted data. We will insert the post data into an XML file to provide RSS service to those with an RSS reader (or aggregator). To create this blog application, you need a web server that supports PHP and a database server to store some information. If you are new to the concepts and the workings of Cake, read Chapter 1 before continuing with this chapter.

Creating the Database Building web sites that allow user interactivity sometimes requires working with persistent data, which can be stored in relational databases or local file systems. This requirement applies to building our blog application, as we need to manage the post records. As mentioned in the previous chapter, we’ll use the MySQL database server for the examples in this book. We’ll use Cake’s objects and their methods that allow us to store and retrieve data from a database. For information about how to configure Cake’s database connection parameters and connect to a database, see Chapter 1.

29


30

CH APT ER 2 N BLOG G ING

Our >hkc database will contain a single table named lkopo. This table will store records of posts. The records include fields for an ID to provide a unique reference for each post, the title of a post, the post’s content, the dates that a post was created and modified, and whether or not a post should be published (displayed to the public). Listing 2-1 shows the SQL to create the lkopo table. Listing 2-1. The SQL Statement to Create the posts Table ?NA=PAP=>HAEBJKPATEOPO\lkopo\$ \e`\ejp$--%JKPJQHH]qpk[ej_naiajp( \pepha\r]n_d]n$1,%`ab]qhpJQHH( \_kjpajp\patp( \_na]pa`\`]papeia`ab]qhpJQHH( \ik`ebea`\`]papeia`ab]qhpJQHH( \lq^heoda`\pejuejp$-%JKPJQHH`ab]qhp#-#( LNEI=NUGAU$\e`\% %7 The SQL schema shown in Listing 2-1 will handle basic post information. If you like, you can add more fields, such as a oqii]nu field to store summaries of posts. Now, let’s insert some sample post information into our lkopo table, using the following SQL statements: EJOANPEJPK\lkopo\£ $\e`\(\pepha\(\_kjpajp\(\_na]pa`\(\ik`ebea`\(\lq^heoda`\%R=HQAO $-(#=jkpdan`]uOpehhHkkgejc#(#IuHekjn]jkbb#(£ #.,,4),2)-5-46.26--#(#.,,4),2)-5-46.26--#(-%( $.(#=ckk``]u#(#PdaHekjeo^]_gejkjalea_a*#(£ #.,,4),2)-5-46/-61,#(#.,,4),2)-5-46/-61,#(-%( $/(#Pd]jgCK@#(#Aranupdejc^ahkjcopkiub]pdan#(£ #.,,4),2).,-460.6--#(#.,,4),2).,-460.6--#(-%7 If you added other fields, be sure to insert their corresponding values with SQL EJOANP statements.

NTip Cake will automatically populate the _na]pa` and ik`ebea` fields in a table with the current date information (in our example, the dates when saving and updating posts). In Cake, these fields are called automagic model fields.


C H A P T E R 2 N B LO G G I N G

Reviewing the Application Structure Before we start to build the blog application, let’s take a brief look at the folder structure and files that will form part of the application. Table 2-1 assumes that other default Cake folders and files also exist in the same environment. Table 2-1. The Blog Application Structure

Directory

Description

]ll+

The parent folder for the blog application

_kjbec+

Amended `]p]^]oa*ldl file to include our blog database parameters

_kjpnkhhano+

lkopo[_kjpnkhhan*ldl file, which contains all the actions, such as add post

ik`aho+

lkop*ldl file to deal with our blog application data

reaso+lkopo

ej`at*_pl, ]``*_pl, a`ep*_pl, and `ahapa*_pl files

We’ll create these files and explain their contents in upcoming sections. For details on Cake’s complete file system structure, refer to Chapter 1.

Creating the Post Model The Lkop object manages the post data. By using Cake’s naming convention, we’ll be able to take advantage of the functionality inherently provided by Cake. We’ll use that functionality to interact with the lkopo database table, and access and manipulate the post records. The Lkop model class, shown in Listing 2-2, is stored in ]ll+ik`aho+lkop*ldl. Listing 2-2. The Post Object That Handles the Post Data (app/models/post.php) 8;ldl _h]ooLkopatpaj`o=llIk`ah w r]n j]ia9#Lkop#7 r]n r]he`]pa9]nn]u$#pepha#9:]nn]u$ #]hld]Jqiane_#9:]nn]u$ #nqha#9:#]hld]Jqiane_#( #namqena`#9:pnqa( #iaoo]ca#9:#Ajpan]pephabknpdeolkop#( % %( #_kjpajp#9:]nn]u$ #]hld]Jqiane_#9:]nn]u$ #nqha#9:#]hld]Jqiane_#( #namqena`#9:pnqa( #iaoo]ca#9:#Ajpanokia_kjpajpbknukqnlkop#( % % %7 y;:

31


32

CH APT ER 2 N BLOG G ING

The Lkop model class consists of the j]ia property, used to handle PHP 4 backwardcompatibility, and the r]he`]pa array property, which contains the validation rules. In the r]he`]pa array, each element’s key corresponds to the name of the input element to be validated (for example, pepha), and its value defines the rules to apply against the input before the post data is saved to the lkopo table—when the post form is submitted. Listing 2-2 shows the validation rules. We check that the pepha and the _kjpajp fields of the form are not empty when the form is submitted. We also check whether the values submitted are alphanumeric. If not, the corresponding error messages set in the validation array against the #iaoo]ca# keys will be displayed. The Lkopo?kjpnkhhan object, which we will create next, will use the Lkop model object to access information from the lkopo table, ensure the integrity of the submitted post information, and then commit the post into the lkopo database table.

Creating the Posts Controller Now that the Lkop model class is created, we need a Lkopo?kjpnkhhan object to manage all the post actions. These actions include listing all the posts and providing the user interfaces for adding and editing post data. The controller calls the Lkop model object created in Listing 2-2 to handle the post data as required. The Lkopo?kjpnkhhan class will contain the methods listed in Table 2-2. Table 2-2. The PostsController Class Actions

Method

Description

ej`at$%

Lists all the posts from the lkopo table and handles the RSS feed for posts

]``$%

Invokes the add post page and saves validated posts to the lkopo table

a`ep$%

Invokes the edit post page

`eo]^ha$%

Disables a published post

aj]^ha$%

Enables a disabled post so it’s published

`ahapa$%

Removes a post record from the lkopo table

Listing the Posts The Lkopo?kjpnkhhan class, shown in Listing 2-3, extends the =ll?kjpnkhhan class. This file is stored in ]ll+_kjpnkhhano+lkopo[_kjpnkhhan*ldl.


C H A P T E R 2 N B LO G G I N G

Listing 2-3. The PostsController to Define Post Actions (app/controllers/posts_controller.php) 8;ldl _h]ooLkopo?kjpnkhhanatpaj`o=ll?kjpnkhhan w r]n j]ia9#Lkopo#7 bqj_pekjej`at$%w  lkopo9pdeo):Lkop):bej`$#]hh#%7 pdeo):oap$_kil]_p$#lkopo#%%7 y First, we add the ej`at method, which displays the list of posts. By default, this method is called if no other action is called explicitly during a URL request. Along with showing all the published posts, the index page contains links that will enable users to perform operations such as edit, publish, unpublish, and delete a post record. In Listing 2-3, the ej`at method contains two simple statements. The first uses the Lkop model object with its default bej` method to pull all the posts from the lkopo database table and then store the results in an array called lkopo. The second prepares and sets the lkopo records so that the reaso+lkopo+ej`at*_pl file, shown in Listing 2-4, can display the list of all the posts from the lkopo variable. Listing 2-4. The View for the Post List (views/posts/index.ctp) 8`ere`9_ajpan[_kjpajp: 8d.:LkopHeopejco8+d.: 8l:Danaeo]heopkbpdaateopejclkopo*8+l: 8`er: 8+`er: 8;ldl eb$eooap$ lkopo%""eo[]nn]u$ lkopo%%w ;: 8p]^ha: 8pn: 8p`: 8^:E@8+^: 8+p`: 8p`: 8^:pepha8+^: 8+p`: 8p`: 8^:_kjpajp8+^: 8+p`: 8p`: 8^:H]opIk`ebea`8+^: 8+p`: 8p`: 8^:lq^heoda`8+^: 8+p`: 8p`_khol]j9.:8^:"j^ol7"j^ol7=_pekj8+^:8+p`: 8+pn: 

33


34

CH APT ER 2 N BLOG G ING

8;ldlbkna]_d$ lkopo]o lkop%6;: 8pn: 8p`:8;ldla_dk lkopW#Lkop#YW#e`#Y7;:8+p`: 8p`:8;ldla_dk lkopW#Lkop#YW#pepha#Y7;:8+p`: 8p`:8;ldla_dk lkopW#Lkop#YW#_kjpajp#Y7;:8+p`: 8p`:8;ldla_dk lkopW#Lkop#YW#ik`ebea`#Y7;:8+p`: 8p`: 8;ldla_dkdpih):hejg$eba$ # lkopW#Lkop#YW#lq^heoda`#Y99-#( #Lq^heoda`#( #Qjlq^heoda`#%( #+lkopo+#*eba$# lkopW#Lkop#YW#lq^heoda`#Y99-#( #`eo]^ha#(#aj]^ha#%*#+#* lkopW#Lkop#YW#e`#Y %7 ;: 8+p`: 8p`: 8;ldla_dkdpih):hejg$ #A`ep#( #+lkopo+a`ep+#* lkopW#Lkop#YW#e`#Y%7;: 8+p`: 8p`: 8;ldla_dkdpih):hejg$ #@ahapa#( #+lkopo+`ahapa+#* lkopW#Lkop#YW#e`#Y%7;: 8+p`: 8+pn: 8;aj`bkna]_d7;: 8;ldl eb$oevakb$ lkopo%99,%w ;: 8pnopuha9^]_gcnkqj`)_khkn6______7: 8p`_khol]j92: 8ol]jopuha9bkjp)oeva6-3lt7: Jklkopbkqj`* 8+ol]j: 8+p`: 8+pn: 8;ldl y ;: 8+p]^ha:  8^n+:  8;ldl y ;: 8+`er:


C H A P T E R 2 N B LO G G I N G

The ej`at*_pl file in Listing 2-4 starts with the headings of the web page that displays the posts list. We then insert a section of PHP code immediately after these headings. If the lkopo variable set by the Lkopo?kjpnkhhan object contains some post records, we first display the headings for the individual elements in the variable. Next, using a bkna]_d loop statement to loop through the lkopo variable, we display a list item for each post. Finally, if the lkop variable is empty, we simply display the message Jklkopbkqj`. Figure 2-1 shows an example of a post listing.

Figure 2-1. Viewing the post listings page This list provides an interface to directly manage individual posts. As shown on the right side of Figure 2-1, the page has links to trigger the publish, edit, and delete actions.

Adding a Post The next method we need to implement in the Lkopo?kjpnkhhan class is the ]`` method, as shown in Listing 2-5. This method, as the name implies, handles adding post data.

35


36

CH APT ER 2 N BLOG G ING

Listing 2-5. The add Method for Adding Post Data bqj_pekj]``$%w   ]_pekjDa]`ejc9#=``]Lkop#7  ]_pekjOhkc]j9#Lha]oabehhej]hhbeah`o*Baahbnaapk]``ukqn£ lkop]j`atlnaooukqnklejekj*#7 pdeo):oap$_kil]_p$#]_pekjDa]`ejc#(#]_pekjOhkc]j#%%7  eb$ailpu$ pdeo):`]p]%%w pdeo):Lkop):_na]pa$%7 eb$ pdeo):Lkop):o]ra$ pdeo):`]p]%%w pdeo):Oaooekj):oapBh]od$[[$#PdaLkopd]o^aajo]ra`#(pnqa%%7 pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 yahoaw pdeo):Oaooekj):oapBh]od$£ [[$#PdaLkop_kqh`jkp^ao]ra`*Lha]oapnu]c]ej*#(pnqa%%7 y y y In the ]`` method, the first two statements set the heading and slogan for the add view page. This is necessary because we are going to use a single element view to display the forms to add and edit posts. Elements in Cake enable you to reuse views. Next, we check if the add post form has been submitted. If the form has not been submitted, the add view is displayed. If the submitted data $ pdeo):`]ta) is not empty, using the o]ra method of the Lkop model object, the application will attempt to create a new post record. The o]ra method automatically uses the validation rules defined in Listing 2-2 to check the integrity of the submitted post. If the post does not pass the validation rules, the error message is set, using the oapBh]od method of the Oaooekj object. Otherwise, the post is saved to the database table, and the success message is set for display in the view. Next, we’ll create the add view and store the codes in reaso+lkopo+]``*_pl file. The content of the ]``*_pl file is simply the following code snippet: 8;ldla_dkpdeo):ahaiajp$#]``[kn[a`ep#%7;: The pdeo):ahaiajp$% method accepts the name of a file stored in the reaso+ahaiajpo folder (]``[kn[a`ep in this case), without the file extension (without *_pl). It simply transfers the content of ]``[kn[a`ep*_pl into the ]``*_pl file. The resulting source code for the add view is shown in Listing 2-6.


C H A P T E R 2 N B LO G G I N G

Listing 2-6. The Add View That Provides an Interface to Add a Post (app/views/posts/add.ctp) 8beah`oap: 8hacaj`:8;ldl[[$#=``]Lkop#%7;:8+hacaj`: Lha]oabehhej]hhbeah`o* 8;ldl a_dkbkni):_na]pa$#Lkop#%7 a_dkbkni):annkn$#Lkop*pepha#%7 a_dkbkni):ejlqp$#Lkop*pepha#( ]nn]u$#e`#9:#lkoppepha#(#h]^ah#9:#Pepha6#(£ #oeva#9:#1,#(#i]thajcpd#9:#.11#(#annkn#9:b]hoa%%7 a_dkbkni):annkn$#Lkop*_kjpajp#%7 a_dkbkni):ejlqp$#Lkop*_kjpajp#( ]nn]u$#e`#9:#lkop_kjpajp#(#pula#9:#patp]na]#(£ #h]^ah#9:#?kjpajp6#(#nkso#9:#-,#(#annkn#9:b]hoa%%7 a_dkbkni):aj`$]nn]u$#h]^ah#9:#Oq^iepLkop#%%7 ;: 8+beah`oap: In Listing 2-6, we start by displaying the heading of the interface for adding a post. We then insert a PHP opening code tag to house the creation of the form using Cake’s form helper functionality. First, the bkni):_na]pa$% method defines the start tag for our form. Its #Lkop# string argument represents the action that will be invoked, such as the URL to which the form data will be submitted. Note that if the method attribute is not specified, the LKOP method is the default request method. Next, we start to add the required form input elements using the bkni):annkn$% method, which deals with the error handling of the form. Its argument, Lkop*pepha, is a string that represents the name of the input element, where Lkop is the model name, followed by a dot (.), and pepha holds the value of the post’s title. Next is the bkni):ejlqp$% method to generate the text input element called pepha, whose first argument is in the same argument format as the error input element. The second argument of the text input element is an associative array of HTML text input element attributes. Following that is the code that generates the patp]na] input element called _kjpajp using an argument format similar to the pepha input element discussed previously. Finally, after we’ve added the form elements, we can add the form closing tag using the form helper method bkni):aj`(). It also accepts an associative array of HTML submit input element attributes. Figure 2-2 shows an example of an add post form when a user tries to submit a blank form. The error messages are displayed.

37


38

CH APT ER 2 N BLOG G ING

Figure 2-2. Error messages appear when you try to submit a blank add post form.

Updating a Post Sometimes, we are not completely satisfied with our posts and would like to make some amendments. We will create the a`ep action of the Lkopo?kjpnkhhan to handle this task. It uses a supplied post ID (in our case e`) to retrieve the details of a post from the lkopo database table and repopulates the edit form with the information. This a`ep method code snippet is shown in Listing 2-7.


C H A P T E R 2 N B LO G G I N G

Listing 2-7. The edit Action That Handles a Post Edit Request bqj_pekja`ep$ e`9jqhh%w  ]_pekjDa]`ejc9#A`ep]Lkop#7  ]_pekjOhkc]j9#Lha]oabehhej]hhbeah`o*Jksukq_]j]iaj`ukqnlkop*#7  pdeo):oap$_kil]_p$#]_pekjDa]`ejc#(#]_pekjOhkc]j#%%7  eb$ e`""ailpu$ pdeo):`]p]%%w pdeo):Oaooekj):oapBh]od$[[$#Ejr]he`Lkop#(pnqa%%7 pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 y eb$ailpu$ pdeo):`]p]%%w eb$ pdeo):Lkop):o]ra$ pdeo):`]p]%%w pdeo):Oaooekj):oapBh]od$[[$#PdaLkopd]o^aajo]ra`#(pnqa%%7 pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 yahoaw pdeo):Oaooekj):oapBh]od$[[£ $#PdaLkop_kqh`jkp^ao]ra`*Lha]oapnu]c]ej*#(pnqa%%7 y y eb$ailpu$ pdeo):`]p]%%w pdeo):`]p]9pdeo):Lkop):na]`$jqhh( e`%7 y y In Listing 2-7, we first set the heading and slogan for the edit view page. The next step we take is to check whether e` and pdeo):`]p] (form data) are empty. If so, an error message is stored in our Oaooekj object, and the request is redirected to the blog home page. If the submitted form data is not empty, Cake will try to commit the edited post information to the lkopo database table and then flash appropriate messages upon success or failure. Finally, if only the submitted data is empty, a post’s information is pulled with the Lkop model na]` method using the supplied e` as the criterion. Next, we’ll create the edit view and store the codes in the reaso+lkopo+a`ep*_pl file. The content of this file is exactly the same as that of the ]``*_pl file: 8;ldla_dkpdeo):ahaiajp$#]``[kn[a`ep#%7;: Here, we’ve reused the ]``[kn[a`ep*_pl element file again to produce the source code for the edit post view, taking advantage of the elements resource of Cake. In principle, the views for adding and editing posts are the same, except for their page headings. Figure 2-3 shows an example of the edit view for post ID 1.

39


40

CH APT ER 2 N BLOG G ING

Figure 2-3. The view to update post ID 1 We’ve built our post forms using one of the key features of Cake: form helpers. These helpers have automated the tasks of generating our form elements, validating the form input, and repopulating the submitted data.

Unpublishing a Post When you don’t want a post record to be displayed on the home page, you can disable the record. Given a post e`, the `eo]^ha method disables the appropriate post, as shown in Listing 2-8. Listing 2-8. The disable Action to Disable a Published Post bqj_pekj`eo]^ha$ e`9jqhh%w  lkop9pdeo):Lkop):na]`$jqhh( e`%7 eb$ e`""ailpu$ lkop%%w pdeo):Oaooekj):oapBh]od$£ [[$#Ukqiqoplnkre`a]r]he`E@jqi^anpk`eo]^ha]lkop*#(pnqa%%7 pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 y eb$ailpu$ lkop%%w  lkopW#Lkop#YW#lq^heoda`#Y9,7 eb$ pdeo):Lkop):o]ra$ lkop%%w pdeo):Oaooekj):oapBh]od$[[$#LkopE@#* e`*#d]o^aaj`eo]^ha`*#(pnqa%%7


C H A P T E R 2 N B LO G G I N G

yahoaw pdeo):Oaooekj):oapBh]od$[[$#LkopE@#* e`*#s]ojkpo]ra`*#(pnqa%%7 y pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 yahoaw pdeo):Oaooekj):oapBh]od$[[$#JkLkop^upd]pE@s]obkqj`*#(pnqa%%7 pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 y y In Listing 2-8, using the request e`, a post record is retrieved from the lkopo database table and stored in the lkop array variable. If the e` value is null or the lkop variable is empty, we use the Oaooekj object to set the appropriate message and redirect to the blog home page. If there is a valid e` and the lkop is not empty, we set the post published element to , and update the lkopo database table. Finally, the Oaooekj object sets the appropriate message, and then we redirect to the blog home page.

Publishing a Post The aj]^ha method does the opposite of the `eo]^ha method. It uses the supplied post ID ( e`) to determine which post record to enable, as shown in Listing 2-9. Listing 2-9. The enable Action to Enable (Publish) a Disabled Post bqj_pekjaj]^ha$ e`9jqhh%w  lkop9pdeo):Lkop):na]`$jqhh( e`%7 eb$ e`""ailpu$ lkop%%w pdeo):Oaooekj):oapBh]od$ÂŁ [[$#Ukqiqoplnkre`a]r]he`E@jqi^anpkaj]^ha]lkop*#(pnqa%%7 pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 y eb$ailpu$ lkop%%w  lkopW#Lkop#YW#lq^heoda`#Y9-7 eb$ pdeo):Lkop):o]ra$ lkop%%w pdeo):Oaooekj):oapBh]odÂŁ $[[$#LkopE@#* e`*#d]o^aajlq^heoda`*#(pnqa%%7 yahoaw pdeo):Oaooekj):oapBh]od$[[$#LkopE@#* e`*#s]ojkpo]ra`*#(pnqa%%7 y pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 yahoaw pdeo):Oaooekj):oapBh]od$[[$#JkLkop^upd]pE@s]obkqj`*#(pnqa%%7 pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 y y In Listing 2-9, the aj]^ha method contains the same code sections as that of the `eo]^ha method in Listing 2-8. The difference is in the aj]^ha method, the statement lkopW#Lkop#Y W#lq^heoda`#Y is set to -.

41


42

CH APT ER 2 N BLOG G ING

Deleting a Post We can do some housekeeping by removing posts that are no longer needed. Weâ&#x20AC;&#x2122;ll use the `ahapa method to remove posts from the lkopo database table. Listing 2-10 shows the code for the `ahapa method. Listing 2-10. The delete Action to Remove Posts bqj_pekj`ahapa$ e`9jqhh%w eb$ e`%w pdeo):Oaooekj):oapBh]od$[[$#Ejr]he`e`bknLkop#(pnqa%%7 pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 y eb$ pdeo):Lkop):`ah$ e`%%w pdeo):Oaooekj):oapBh]od$[[$#Lkop`ahapa`#(pnqa%%7 pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 y y ;: When the `ahapa action is invoked by requesting to delete a post, the dialog box shown in Figure 2-4 appears. Clicking the OK button will permanently remove the selected post record from the database table.

Figure 2-4. The delete confirmation dialog box


C H A P T E R 2 N B LO G G I N G

Creating an RSS Feed Since we’ve decided to share our posts with the rest of the world, we can reduce the stress on our blog database by creating an RSS feed—a static XML file that will be updated whenever the posts change. RSS is an abbreviation for Really Simple Syndication. It is an XML web content syndication format that can be read by using news reader software (or through some online sites and scripts). For the blog application, using an RSS feed means that people can get updated information about your blog without needing to visit your blogging web site. Scripts such as robots can fetch your RSS feed so that your users can be kept informed of changes to your posts. Essentially, what we’ll create is an XML file of the information stored in the lkopo database table. Remember that our code will be writing to a static file stored somewhere on your web site, so it is important to ensure read-write privileges for the document. You can generate an RSS feed in several ways, such as with the Document Object Model (DOM), XMLWriter, SimpleXML, and so on. However, Cake provides a helper to handle RSS feeds, so you don’t need to worry about how to micromanage them. The RSS helper creates standards-compliant RSS feeds. You invoke its functionality with r]n dahlano9 ]nn]u$#Noo#%7. For the RSS feed for our blog application, we first need to include the following in our ]ll+_kjbec+nkqpao*ldl file: Nkqpan66l]noaAtpajoekjo$#noo#%7 This informs the router to parse out file extensions from the URL. For example, dppl6++ hk_]hdkop+lkopo*noo would yield a file extension of noo. It is used by NamqaopD]j`han components to automatically switch to alternative layouts and templates in order to load the NooDahlan with *noo content.

NCaution Don’t forget to add Nkqpan66l]noaAtpajoekjo$#noo#%7 to your ]ll+_kjbec+nkqpao*ldl file and also ensure that you add NamqaopD]j`han to your Lkopo?kjpnkhhan’s _kilkjajp variable. Things will not go well if the two instructions are not added. However, if you already have Nkqpan66l]noaAtpajoekjo, just add the noo string argument. Nkqpan66l]noaAtpajoekjo accepts many arguments.

Now we need to perform the following tasks: Ê

UÊ iÌiÀ“ˆ˜iÊ̅iÊii“i˜ÌÃÊ­vœÀÊiÝ>“«i]Ê̅iÊ`>Ì>Êvˆi`îÊ̅>ÌÊÜiÊÜ>˜ÌÊ̜Ê>««i>Àʈ˜ÊœÕÀÊ RSS feed.

Ê

UÊ Ài>ÌiÊ̅iʏ>ޜÕÌÊvœÀʜÕÀÊ,--É8ÊۈiÜ°

Ê

UÊ Ài>ÌiÊ̅iÊ«œÃÌÊ,--ÊۈiÜ°

The first task requires that we tweak the ej`at method in the Lkopo?kjpnkhhan class by adding extra lines of code to it. In this case, we will add the channel array data and then fetch the ten most recent post records for public consumption. The content of our new ej`at method is shown in Listing 2-11.

43


44

CH APT ER 2 N BLOG G ING

Listing 2-11. The New index Method of the PostsController Modified for RSS bqj_pekjej`at$%w  lkopo9pdeo):Lkop):bej`$#]hh#%7  _d]jjah@]p]9]nn]u$ #pepha#9:#?qnnajplkopoxPda^hkccan#( #hejg#9:]nn]u$ #_kjpnkhhan#9:#lkopo#(#]_pekj#9:#ej`at#(#atp#9:#noo#%( #qnh#9:]nn]u$#_kjpnkhhan#9:#lkopo#(#]_pekj#9:#ej`at#(£ #atp#9:#noo#%( #`ao_nelpekj#9:#Pda_qnnajplkopoejkqn^hkc#( #h]jcq]ca#9:#aj)qg# %7  lkopo9pdeo):Lkop):bej`$#]hh#( ]nn]u$#heiep#9:-,(#kn`an#9:#Lkop*_na]pa`#%%7 pdeo):oap$_kil]_p$#_d]jjah@]p]#(#lkopo#%%7 y In Listing 2-11, the channel and posts information are set for the views and layouts, which we’ll create next. The layout file, ]ll+reaso+h]ukqpo+noo+`ab]qp*_pl, will contain the following code snippet: 8;ldl a_dknoo):da]`an$%7  _d]jjah9noo):_d]jjah$]nn]u$%( _d]jjah@]p]( epaio%7 a_dknoo):`k_qiajp$]nn]u$%( _d]jjah%7 ;: Since Cake allows views to pass variables to the layout, we’ve set the epaio variable in the layout, instead of following the normal convention of setting variables in a controller. Next, we will create the RSS view in ]ll+reaso+lkopo+noo+ej`at*_pl. This file will contain a function called noo[pn]jobkni, which accepts the epaio (for example, post data) as an argument, and as its name implies, returns a transformed array version of the post data. Listing 2-12 shows the content of the RSS view file. Listing 2-12. The Content of the RSS View (app/views/posts/rss/index.ctp) 8;ldl bqj_pekjnoo[pn]jobkni$ epai%w napqnj]nn]u$#pepha#9: epaiW#Lkop#YW#pepha#Y( #hejg#9:]nn]u$#_kjpnkhhan#9:#lkopo#(#]_pekj#9:#reas#(£ #atp#9:#noo#( epaiW#Lkop#YW#e`#Y%( #cqe`#9:]nn]u$#_kjpnkhhan#9:#lkopo#(#]_pekj#9:#reas#(£


C H A P T E R 2 N B LO G G I N G

#atp#9:#noo#( epaiW#Lkop#YW#e`#Y%( #`ao_nelpekj#9:opnel[p]co$ epaiW#Lkop#YW#_kjpajp#Y%( #lq^@]pa#9: epaiW#Lkop#YW#_na]pa`#Y( %7 y pdeo):oap$#epaio#(noo):epaio$ lkopo(#noo[pn]jobkni#%7 ;: In Listing 2-12, the noo):epaio helper method converts our post data into an XML format and uses the oap method to pass the converted XML to the RSS layout. Here, the layout is going to do the work of rendering the output when you make the URL request lkopo+ej`at*noo. Your request should display an XML version of the posts as fetched in the Lkopo?kjpnkhhan ej`at action. When you choose to view the posts, you can select whether to save a copy of the RSS feed file or display it on the screen. Figure 2-5 shows an example of how this looks in Firefox.

Figure 2-5. Fetching posts from an RSS feed

45


46

CH APT ER 2 N BLOG G ING

Summary This chapter described how to build a blogging application using Cake. We first created a lkopo database table and populated it with some sample posts. We took advantage of Cakeâ&#x20AC;&#x2122;s components by creating our posts controller and model classes to perform the necessary tasks: list, add, edit, delete, save, enable, disable, and access data. The corresponding action views were created using the bkni object methods. Finally, we created an RSS feed, with the help of the RSS helper, to present some of our posts to the public. The modularity of the blogging application allows it to be extended by adding more actions to the controller class. For example, you could add an action to upload images.


C HAPTER

3

E-Commerce T

he buzzword e-commerce, short for electronic commerce, simply refers to the processing and recording of online transactions. To boast a competitive edge and increase profit, businesses and individuals that peddle services or products must not just have a web presence but also endeavor to sell their merchandise online. There are numerous e-commerce applications based on the PHP scripting language, such as the free, open source osCommerce and Magento. Here, we’re going to implement an online shop using the Cake framework. First, we’ll design a skeletal look and feel for our shop, and then we’ll create our shop database in MySQL. Next, we’ll populate the database with some category and product information. We’ll then use Cake features to allow users to select categories and products, add selected products to their shopping cart, click to check out, and, finally, make payments using the popular Google Checkout or PayPal payment system. This chapter assumes that you’re familiar with PHP, MySQL, and Cake. It also assumes that you have set up a development environment that supports these technologies.

The Online Shop Layout A typical online shop layout is divided into five sections (elements). We’ll follow that design and use the Cake view elements listed in Table 3-1. We’ll use Cake’s features to help us develop these elements of our shop application before stitching them together into the standard layout. Table 3-1. View Elements of Online Shop Layout

Division Name

Description

[Header]

Contains header information, such as the logo and banner

[Left Column]

Displays an expandable category level, sublevel, and product lists

[Center Column]

The main content area of the web site; what it contains depends on the visitor action, so it might show a product description, best-selling products, and so on

[Right Column]

Contains the mini-basket or other elements

[Footer]

Displays summary information about a shop, such as the copyright, contact information, shortcut links, and so on

47


48

CH APT ER 3 N E-C OMMER C E

NTip To include the left navigation element stored in ]ll+reaso+ahaiajpo+iajq*ldl in a view, use the code pdeo):ahaiajpo$#iajq#);.

Two Site Layouts In this example, we’re going to use two different layouts: Ê

UÊ œÃÌʜvÊ̅iÊÜiLÊ«>}iÃÊ܈ÊŜÜÊ̅iÊvˆÛiÊÃiV̈œ˜ÃʜvÊ̅iÊÜiLÊÈÌiÊ>ÃʈÕÃÌÀ>Ìi`ʈ˜Ê Figure 3-1. This first layout is stored in the ]ll+reaso+h]ukqpo+`ab]qhp*_pl file as the application default layout.

Ê

UÊ /…iÊÃiVœ˜`ʏ>ޜÕÌÊ܈ÊiÝVÕ`iÊ̅iÊÀˆ}…ÌÊVœÕ“˜ÊLÞÊVœ>«Ãˆ˜}Ê̅iÊVi˜ÌiÀÊ>˜`Ê̅iÊÀˆ}…ÌÊ columns into one column. This layout stored in ]ll+reaso+h]ukqpo+_da_g^]oa*_pl. We’ll use this layout to display the _da_gkqp action of the orders controller.

Figure 3-1. The default layout

NNote One of the aims of this book is to show you how to properly organize elements (code snippets) of an application within the Cake’s structure in order to enjoy the benefit of Cake’s code reuse and ease of maintenance. However, in this chapter, we will not discuss how our online shop folders and files are organized, as this organization is identical to the structure explained in Chapter 1.

Layout of the Main Content When a user requests a web page, the `ab]qhp*_pl file takes care of the overall look and feel of the web site, which is shown in Figure 3-1. If you want to adapt the main layout of the shop application, just edit the file or create another layout, such as a _da_g^]oa*_pl file, to suit your needs. However, do not forget to include the h]ukqp9#_da_g^]oa#; statement in the method of your controller object that requires this new look.


CHAPTER 3 N E-COMMERCE

The following code displays only the main content area of the layout: 8`ere`9i]ej[_kjpajp[_kjp]ejan: 8`ere`9habpj]r:8;ldla_dkpdeo):ahaiajp$iajq#%7;:8+`er: 8`ere`9i]ej[^k`u[_kjp]ejan: 8;ldla_dk _kjpajp[bkn[h]ukqp7;: 8+`er: 8`ere`9necdp[j]r[_kjp]ejan: 8;ldla_dkpdeo):ahaiajp$#^]ogap#%7;: 8+`er: 8+`er: The pdeo):ahaiajp$iajq#% method is used to include the navigation view stored in the ]ll+reaso+ahaiajpo+iajq*_pl file. This file contains the view logic that generates the category tree menu that is displayed in the left column of the layout. This navigation section of the page is expected to display the product categories at all times. The _kjpajp[bkn[h]ukqp variable includes the view rendered in response to a user action. The pdeo):ahaiajp$#^]ogap#% method displays the mini-basket content in the right column of the layout.

The User Journey Like any successful dynamic web site, an online shop requires planning and a data store of some sort before jumping into the implementation of the application. These tasks include database design, program flow design, resource planning, and so on. Since we are fortunate to have an existing database schema to use for this example, we will skip the first step of categorizing and normalizing our shop data and move on to explaining the program flow, or user journey. The online shopping process starts with a customer surfing the Internet and ends with the customer parting with some cash, which ends up in some businessmanâ&#x20AC;&#x2122;s online account. This basic flow for our online shop example looks like this: 1. A user visits our shop. 2. The user browses the categories and products. 3. The user views the product details. 4. The user adds products to the shopping basket. 5. The user clicks to check out and pay. 6. The customer receives an e-mail confirmation notice. In our example, users do not need to register. They browse categories and products, pay for selected items, and leave the shop. During the user journey, some vital transaction information is collected and stored in database tables. Needless to say, the tracked data is used for transaction completion and for making other business decisions.

49


50

CH APT ER 3 N E-C OMMER C E

Setting Up the Shop Database First, we need to connect our application to a MySQL database server. Our configuration, stored in the ]ll+_kjbec+`]p]^]oa*ldl file, includes the following array definition: r]n `ab]qhp9]nn]u$#`neran#9:#iuomh#( #lanoeopajp#9:b]hoa( #dkop#9:#hk_]hdkop#( #hkcej#9:#qoan#( #l]ooskn`#9:#l]ooskn`#( #`]p]^]oa#9:#odkl#( #lnabet#9:##( %7 Do not forget to replace the current database access information with your local username and password. If you need more information about how to configure a database connection, see Chapter 1. We'll create three database tables for our online shop application: Ê

UÊ /…iÊ_]packneao table stores product categories.

Ê

UÊ /…iÊlnk`q_po table stores the product descriptions.

Ê

UÊ /…iÊ_]npo table stores selected product items.

NNote We’ve said that we are not going to collect personal user information in our online shop application. So how do we identify a user? We will create and use a session ID for every unique user request. For information about implementing authentication, see Chapter 8. Also, some common online shop tables, such as the kn`an and kn`an[epai tables, are left out of this example. Any table schema not presented in this section is skipped for the sample implementation of this application.

As indicated in Figure 3-1, the left column of our shop layout will present a navigation menu tree that is generated from the product categories data. The _]packneao table and data are created by the SQL statements shown in Listing 3-1. Listing 3-1. The categories Table Schema ?NA=PAP=>HAEBJKPATEOPO\_]packneao\$ \e`\ejp$-,%qjoecja`JKPJQHH]qpk[ej_naiajp( \l]najp[e`\ejp$--%JKPJQHH`ab]qhp#,#( \j]ia\r]n_d]n$1,%_d]n]_panJKPJQHH( \`ao_nelpekj\r]n_d]n$.,,%_d]n]_panJKPJQHH( \ei]ca\r]n_d]n$.11%_d]n]_panJKPJQHH( LNEI=NUGAU$\e`\%( GAU\_]p[l]najp[e`\$\l]najp[e`\%( GAU\_]p[j]ia\$\j]ia\% %7


CHAPTER 3 N E-COMMERCE

EJOANPEJPK\_]packneao\$\e`\(\l]najp[e`\(\j]ia\(\`ao_nelpekj\(\ei]ca\%R=HQAO $-3(,(#F]vv#(#Aranupdejcbnki-45,o#(##%( $-.(,(#?h]ooe_]h#(#BnkiIa`ear]hpk?kjpailkn]nu#(##%( $-/(-3(#@evvuCehhaolea#(#PdaPnqilapanI]opan#(##%( $-0(-.(#Ikv]np#(#PdaKh`B]rkqnepa#(##%7 Next, our categories need to relate to some product information, which we’ll put in a lnk`q_po table. Listing 3-2 presents the SQL statements to create this table and populate it with some sample data. Listing 3-2. The products Table Schema ?NA=PAP=>HAEBJKPATEOPO\lnk`q_po\$ \e`\ejp$-,%qjoecja`JKPJQHH]qpk[ej_naiajp( \_]packnu[e`\ejp$-,%qjoecja`JKPJQHH`ab]qhp#,#( \j]ia\r]n_d]n$-,,%_d]n]_panJKPJQHH`ab]qhp##( \`ao_nelpekj\patp_d]n]_panJKPJQHH( \lne_a\`a_ei]h$5(.%JKPJQHH`ab]qhp#,*,,#( \mpu\oi]hhejp$1%qjoecja`JKPJQHH`ab]qhp#,#( \ei]ca\r]n_d]n$.,,%_d]n]_pan`ab]qhpJQHH( \pdqi^j]eh\r]n_d]n$.,,%_d]n]_pan`ab]qhpJQHH( \_na]pa`\`]papeiaJKPJQHH`ab]qhp#,,,,),,),,,,6,,6,,#( \ik`ebea`\`]papeiaJKPJQHH`ab]qhp#,,,,),,),,,,6,,6,,#( LNEI=NUGAU$\e`\%( GAU\_]p[e`\$\_]packnu[e`\%( GAU\j]ia\$\j]ia\% %7 EJOANPEJPK\lnk`q_po\$\e`\(\_]packnu[e`\(\j]ia\(\`ao_nelpekj\(£ \lne_a\(\mpu\(\ei]ca\(\pdqi^j]eh\(\_na]pa`\(\ik`ebea`\%R=HQAO $-(-/(#@evvu-55,o#(#>aopkb@evvuCehhaoleaejpda-55,o#(-.*,,(£ -,(JQHH(#-*flc#(#,,,,),,),,,,6,,6,,#(#,,,,),,),,,,6,,6,,#%( $.(-0(#Ikv]npbknHkrano#(#Nah]tsepdukqnhkra`kjasepdpdeo£ `kq^ha?@*#(-1*,,(1(JQHH(JQHH(#,,,,),,),,,,6,,6,,#(#,,,,),,),,,,6,,6,,#%( $..(-/(#@evvu]j`Op]j#(#Herasepd@evvuCehhaolea]j`Op]jCapv*#(£ -/*,,(-,(JQHH(#-*flc#(#,,,,),,),,,,6,,6,,#(#,,,,),,),,,,6,,6,,#%7 When a user selects a category, the products linked to this category are displayed. For example, when you select the category called Jazz, you’ll see the Dizzy 1990s item and the Dizzy and Stan item listed as products under this category. Next on the user journey, when a user has selected the type of music she wants to buy and she is happy with the vibes, she adds her selections to a shopping basket. The user-selected items are stored in the _]npo database table. This table and some sample data are created using the SQL in Listing 3-3.

51


52

CH APT ER 3 N E-C OMMER C E

Listing 3-3. The carts Table Schema ?NA=PAP=>HAEBJKPATEOPO\_]npo\$ \e`\ejp$-,%qjoecja`JKPJQHH]qpk[ej_naiajp( \lnk`q_p[e`\ejp$-,%qjoecja`JKPJQHH`ab]qhp#,#( \mpu\ia`eqiejp$4%qjoecja`JKPJQHH`ab]qhp#-#( \_p[oaooekj[e`\_d]n$/.%JKPJQHH( \_na]pa`\`]papeiaJKPJQHH`ab]qhp#,,,,),,),,,,6,,6,,#( LNEI=NUGAU$\e`\%( GAU\l`[e`\$\lnk`q_p[e`\%( GAU\_p[oaooekj[e`\$\_p[oaooekj[e`\% %7 EJOANPEJPK\_]npo\$\e`\(\lnk`q_p[e`\(\mpu\(\_p[oaooekj[e`\(\_na]pa`\%R=HQAO $1.(-(.(#/._]^^5`2b^/-0,0]1^3/24/,a]_2]]/#(#.,,4),5).0-160261/#%( $1-(.(/(#/._]^^5`2b^/-0,0]1^3/24/,a]_2]]/#(#.,,4),5).0-16.56,-#%7

NTip Some online shops store configuration information in a table. Alternatively, this information can be stored using Cake’s configuration method—for example, ?kjbecqna66snepa$#Odkl* j]ia#(#Okqj`Ailena#%7. To access the shop name, use Cake’s configuration na]` method, as in ?kjbecqna66na]`$#Odkl*j]ia#%. As you can imagine, a shop administrator would find it more difficult to update these configuration parameters than to work with information stored in a database table. Modifying the parameters would require physical file system access and consequently some manipulation fuss.

Interacting with the Online Shop Database Now that we’re connected to the database, created the required tables, and populated them with some sample data, our application needs the information stored in the database in order to provide the initial content of the web pages. For example, the site navigation requires the category data stored in the _]packneao table to do its bit. So who handles the tasks of accessing and manipulating information stored in the database? You’ll be happy to learn that Cake provides default model functions that serve as shortcuts to database operations. These prebuilt functions allow for easy and fast application development. Now let’s start digging out some information. First, we’ll create our custom objects to handle the display of an expandable category level, sublevel, and product lists.


CHAPTER 3 N E-COMMERCE

The Category Model Let’s create the ?]packnu model class to interact with the _]packneao table data created in Listing 3-1. The beginning of this model is shown in Listing 3-4. Listing 3-4. The Beginning of the Category Model (app/models/category.php) 8;ldl _h]oo?]packnuatpaj`o=llIk`ahw r]n j]ia9#?]packnu#7 r]n d]oI]ju9]nn]u$#Lnk`q_p#%7 In this model, we have two important properties: Ê

UÊ /…iÊ j]ia property will serve as a reference to this model object within the controllers of this application when needed.

Ê

UÊ /…iÊ>ÃÜVˆ>̈œ˜Ê«Àœ«iÀÌÞÊ d]oI]ju simply defines the relationship between the _]packneao table and the lnk`q_po table. In this case, we define that a _]packneao record can relate to many lnk`q_po records. In our application, the category F]vv is associated with the products @evvu-55,o and @evvu]j`Op]j (see Listings 3-1 and 3-2). This property is required to ensure an association between the ?]packnu and Lnk`q_p model objects.

Now that the ?]packnu model class is attached to our _]packneao table data and it has established a relationship with the lnk`q_po table data, we can create some custom methods in the model class to interact with the _]packneao and lnk`q_po tables. These custom methods will internally use Cake’s default properties and methods, such as the bej` method for database create, read, update, and delete (CRUD) operations. The ?]packnu model class will contain three methods to provide information in the final format needed to generate the products category navigation: cap?]packneao, ^qeh`?]packneao, and cap?deh`?]packneao. The first method, cap?]packneao, returns the entire category list. This method is shown in Listing 3-5. Listing 3-5. The Category Model’s getCategories() Method bqj_pekjcap?]packneao$ beah`9#?]packnu*e`#( `ena_pekj9#=O?#%w napqnjpdeo):bej`$#]hh#(]nn]u$#kn`an#9: beah`*##* `ena_pekj%%7 y The method in Listing 3-5 is employed whenever we require the list of all the product categories from the _]packneao table, in ascending order of the category IDs. We’ve provided some parameters, beah` and `ena_pekj, so that it’s possible to use this function in more than one way elsewhere in the application. Next in this model class is the ^qeh`?]packneao method, which returns the currently selected category and its children categories. This method is shown in Listing 3-6.

53


54

CH APT ER 3 N E-C OMMER C E

Listing 3-6. The Category Model’s buildCategories() Method bqj_pekj^qeh`?]packneao$ _]packneao( l]najpE`% w  ?deh`?]packneao9]nn]u$%7  e`o9]nn]u$%7 bkna]_d$ _]packneao]o _]packnu%w eb$ _]packnuW#?]packnu#YW#l]najp[e`#Y99 l]najpE`%w  ?deh`?]packneaoWY9 _]packnuW#?]packnu#Y7 y  e`oW _]packnuW#?]packnu#YW#e`#YY9 _]packnuW#?]packnu#Y7 y  Dkh`L]najpE`9 l]najpE`7 sdeha$ Dkh`L]najpE`9,%w  l]najp9]nn]u$ e`oW Dkh`L]najpE`Y%7  _qnnajpE`9 l]najpW,YW#e`#Y7  Dkh`L]najpE`9 e`oW Dkh`L]najpE`YW#l]najp[e`#Y7 bkna]_d$ _]packneao]o _]packnu%w eb$ _]packnuW#?]packnu#YW#l]najp[e`#Y99 Dkh`L]najpE`""£ ej[]nn]u$ _]packnuW#?]packnu#Y( l]najp%%w  l]najpWY9 _]packnuW#?]packnu#Y7 y y ]nn]u[iqhpeoknp$ l]najp%7  j9_kqjp$ l]najp%7  ?deh`?]packneao.9]nn]u$%7 bkn$ e9,7 e8 j7 e''%w  ?deh`?]packneao.WY9 l]najpW eY7 eb$ l]najpW eYW#e`#Y99 _qnnajpE`%w  ?deh`?]packneao.9]nn]u[ianca$ ?deh`?]packneao.(  ?deh`?]packneao%7 y y  ?deh`?]packneao9 ?deh`?]packneao.7 y napqnj ?deh`?]packneao7 y This method takes two arguments: an array of the entire category records from the _]packneao table ( _]packneao) and a category’s parent ID ( l]najpE`). The cap?]packneao method in Listing 3-5 supplies the _]packneao array data used as the first argument in the ^qeh`?]packneao method in Listing 3-6.These two ?]packnu model methods, together with the pdeo):l]ooa`=ncoW#_#Y obtained from the user request, are used in the ?]packneao?kjpnkhhan class method called iajq to generate the application category navigation presented in the left column of the web pages. The ?]packneao?kjpnkhhan is discussed in the next section. In Listing 3-6, first we declare two array variables: ?deh`?]packneao and e`o. Using a bkn loop over _]packneao, if the current category’s parent ID equals that passed as an argument ( l]najpE`), we add the current category to the ?deh`?]packneao array variable. We also add


CHAPTER 3 N E-COMMERCE

the current category to the e`o array, making sure that the e`o array key is the category ID of the current category. This is followed by a sdeha loop to create a parent category and append children categories appropriately. Finally, the function formats and returns the current category list, which includes only the currently selected category and its children. This function is made so it can also handle deep category levels (more than two levels). Next, we create the cap?deh`?]packneao method, as shown in Listing 3-7. This method returns a list of the entire category IDs that belong to the children of a specified category. Listing 3-7. The Category Model’s getChildCategories() Method bqj_pekjcap?deh`?]packneao$ _]packneao( e`( na_qnoera9pnqa% w eb$ _]packneao99JQHH%w  _]packneao9pdeo):cap?]packneao$%7 y  j9_kqjp$ _]packneao%7  _deh`9]nn]u$%7 bkn$ e9,7 e8 j7 e''%w  _]pE`9 _]packneaoW eYW#e`#Y7  l]najpE`9 _]packneaoW eYW#l]najp[e`#Y7 eb$ l]najpE`99 e`%w  _deh`WY9 _]pE`7 eb$ na_qnoera%w  _deh`9]nn]u[ianca$ _deh`( pdeo):cap?deh`?]packneao$ _]packneao( _]pE`%%7 y y y napqnj _deh`7 y The arguments supplied to the cap?deh`?]packneao method contain the following information, in the order presented here: Ê

UÊ _]packneao: All the category lists stored in the _]packneao table.

Ê

UÊ e`: A category ID that requires its children category IDs.

Ê

UÊ na_qnoera: Whether it should include all levels deep of children categories in the operation. Its default value is the Boolean pnqa.

Next in this method we use an eb statement to check for a valid category list, if the cap?deh`?]packneao method is not supplied with a valid category argument. This means that if there is no category information from the _]packneao table stored in the _]packneao array, we use the cap?]packneao method to generate the entire category list and assign the result to the _]packneao variable. Next, we count the number of elements in the _]packneao array and assign the result to the j variable. We then declare an array variable called _deh`, which will contain a list of the children category IDs.

55


56

CH APT ER 3 N E-C OMMER C E

We then loop over the _]packneao array variable with a bkn loop and assign a category ID and its parent ID to _]pE` and l]najpE`, respectively. Next, using an Eb statement, we check that the current parent ID ( l]najpE`) we’ve extracted is the one for which we want to obtain children category IDs. If the l]najpE` is the same as the one passed to the cap?deh`?]packneao method as an argument ( e`), we add the current category ID to the _deh` array variable. By default, this method will use itself to perform the same tasks based on the current category ID, unless the na_qnoera argument is set to Boolean b]hoa. Lastly, this method will return the _deh` array variable containing all children category IDs of a specified category parent ID. The cap?deh`?]packneao method in Listing 3-7 is used within the Lnk`q_po?kjpnkhhan class method called heopo to provide this function with a list of category IDs. This function uses the list of category IDs, formatted as w-(.(/y, to fetch a list of all products that belong to these category IDs, presented in the middle column of the web page. The Lnk`q_po?kjpnkhhan is discussed a little later in this chapter.

The Categories Controller Now that we’ve created the ?]packnu model, let’s delve into the ?]packneao?kjpnkhhan class, as shown in Listing 3-8. Listing 3-8. The CategoriesController Class (app/controllers/categories_controller.php) 8;ldl _h]oo?]packneao?kjpnkhhanatpaj`o=ll?kjpnkhhanw r]n j]ia9#?]packneao#7 bqj_pekjcap=hh$%w napqnjpdeo):?]packnu):cap?]packneao$%7 y bqj_pekjiajq$%w  _]packneao9pdeo):cap=hh$%7 napqnjpdeo):?]packnu):^qeh`?]packneao$ _]packneao( pdeo):l]ooa`=ncoW#_#Y%7 y y ;: In the ?]packneao?kjpnkhhan, we make use of the services provided by the methods defined in the ?]packnu model, discussed in the previous section. Additionally, one of the properties inherited from the =ll?kjpnkhhan is the qoao array. This array includes an element that provides a reference to the ?]packnu model. Next, we declare the cap=hh method, which simply provides the list of all the categories information from the _]packneao table. This method returns the result of the pdeo):?]packnu): cap?]packneao$% statement when called by another object. The last method provided by the ?]packneao?kjpnkhhan is iajq. As the name implies, it helps with the creation of the categories navigation (menu) shown in the left column of the web site. The first statement of this method stores the categories information in the _]packneao array using the cap=hh method previously defined in this class. This array variable, as well as the current category ID (supplied by pdeo):l]ooa`=ncoW#_’]), is then passed to the ^qeh`_]packneao$% method to create an array formatted for the menu view. The array returned by the ^qeh`_]packneao method on the home page of the web site is structured as follows:


CHAPTER 3 N E-COMMERCE

=nn]u $ W,Y9:=nn]u $ We`Y9:-. Wl]najp[e`Y9:, Wj]iaY9:?h]ooe_]h W`ao_nelpekjY9:BnkiIa`ear]hpk?kjpailkn]nu Wei]caY9: % W-Y9:=nn]u $ We`Y9:-3 Wl]najp[e`Y9:, Wj]iaY9:F]vv W`ao_nelpekjY9:Aranupdejcbnki-45,o Wei]caY9: % % This array structure contains two first-level category records; that is, categories with their parent IDs equal to an integer value of , (zero). Next, we call the iajq method of the ?]packneao?kjpnkhhan within the ]ll+reaso+ahaiajpo+ iajq*_pl file to supply this view script with the categories information required to display the category navigation menu. The view takes the category list (stored in _]packneao) and displays its content in Cascading Style Sheets (CSS) 8qh: and 8he: tags in the left column of the layout. Since the category navigation is central to this application—that is, it must always be displayed—we’ve placed the following code snippet in the `ab]qhp*_pl layout file to include this element of the web site at all times: 8`ere`9habpj]r:8;ldla_dkpdeo):ahaiajp$iajq#%7;:8+`er: The content of the iajq*_pl view file is shown in Listing 3-9. Listing 3-9. The Category Navigation View for the Left Column (app/views/elements/menu.ctp) 8qh: 8he:8;9 dpih):hejg$#=hh?]packnu#(#+#%7;:8+he: 8;ldl _]packneao9pdeo):namqaop=_pekj$+_]packneao+iajq+_6 _]pE`+l6 l`E`+%7 bkna]_d$ _]packneao]o _]packnu%w atpn]_p$ _]packnu%7  harah9$ l]najp[e`99,%;-6.7  qnh9#+_]npo+ej`at+_]p[e`6#* e`7 eb$ harah99.%w  j]ia9zzz* j]ia7 y  heopE`9##7

57


58

CH APT ER 3 N E-C OMMER C E

eb$ e`99 _]pE`%w  heopE`9#e`9_qnnajp#7 y ;: 8he8;ldla_dk heopE`7;::8;9 dpih):hejg$ j]ia( qnh%7;:8+he: 8;ldl y ;: 8+qh: In Listing 3-9, the first line begins with the 8qh: opening tag. Next, using the dpih helper object, we created a link to display the message #=hh?]packnu#. The first line of the 8;ldl opening tag uses Cakeâ&#x20AC;&#x2122;s namqaop=_pekj function. It requests the iajq method of the ?]packneao?kjpnkhhan object to provide a list of categories information (stored in the _]packneao array variable) that match the category and the product IDs passed to this method using the _6 _]pE` and l6 l`E` parameters, respectively. Finally, using a bkna]_d loop, the _]packneao array content is extracted to generate the category navigation that appears in the left column throughout the application. Figure 3-2 shows the application response when the Classical menu item is selected by a user, with the submenu item Mozart displayed.

Figure 3-2. The screen showing levels of categories


CHAPTER 3 N E-COMMERCE

The Product Model Our next task is to implement the Lnk`q_p model class, which as the name suggests, provides product information from the lnk`q_po table. We will begin with the class properties, as shown in Listing 3-10. Listing 3-10. The Beginning of the Product Model (app/models/product.php) 8;ldl _h]ooLnk`q_patpaj`o=llIk`ah w r]n j]ia9#Lnk`q_p#7 r]n ^ahkjcoPk9]nn]u$#?]packnu#%7 In the j]ia property, the ^ahkjcoPk array variable tells the application that a product record belongs to a category. (The j]ia property works as described in the earlier discussion of the ?]packnu model.) Next is the heopo method, shown in Listing 3-11. This method provides all the product records based on one or more category IDs in the ascending order of product category ID. Listing 3-11. The Product Modelâ&#x20AC;&#x2122;s lists() Method bqj_pekjheopo$ _]pE`o9JQHH%w eb$eo[]nn]u$ _]pE`o%%w  naoqhpo9pdeo):bej`$#]hh#(]nn]u$ #_kj`epekjo#9:]nn]u$#Lnk`q_p*_]packnu[e`#9: _]pE`o%( #kn`an#9:#Lnk`q_p*_]packnu[e`=O?#%%7 napqnj naoqhpo7 y y

The Products Controller Now that weâ&#x20AC;&#x2122;ve created the Lnk`q_p model class, we need an object to provide some data and services to other objects in our shop application. The Lnk`q_po?kjpnkhhan class, shown in Listing 3-12, defines the heopo and reas methods to provide these services when called by other objects or scripts within the application. Listing 3-12. The ProductsController Class (app/controllers/products_controller.php) 8;ldl _h]ooLnk`q_po?kjpnkhhanatpaj`o=ll?kjpnkhhanw r]n j]ia9#Lnk`q_po#7 bqj_pekjheopo$%w  _]packneao9pdeo):?]packnu):bej`$#]hh#( ]nn]u$#kn`an#9:#?]packnu*e`=O?#%%7  _]packneao9pdeo):?]packnu):^qeh`?]packneao$ _]packneao( pdeo):l]ooa`=ncoW#_#Y%7  _deh`naj[e`o9pdeo):?]packnu):cap?deh`?]packneao$ _]packneao( pdeo):l]ooa`=ncoW#_#Y(pnqa%7

59


60

CH APT ER 3 N E-C OMMER C E

 ]hh?]pE`o9]nn]u[ianca$]nn]u$ pdeo):l]ooa`=ncoW#_#Y%( _deh`naj[e`o%7 napqnjpdeo):Lnk`q_p):heopo$ ]hh?]pE`o%7 y bqj_pekjreas$%w  naoqhp9pdeo):Lnk`q_p):bej`$#]hh#( ]nn]u$#_kj`epekjo#9:]nn]u$#Lnk`q_p*e`#9: pdeo):l]ooa`=ncoW#l`[e`#Y%%%7 eb$ailpu$ naoqhp%%w pdeo):na`ena_p$]nn]u$#_kjpnkhhan#9:#+a_kiian_a#(#]_pekj#9:#ej`at#%%7 y pdeo):oap$#lnk`q_p#( naoqhp%7 y y ;: The heopo method in Listing 3-12 returns a list of products based on one or more category IDs. The first statement in this method retrieves all the categories information and stores the result in the _]packneao array. This array is then used as the first argument of the ^qeh`?]packneao method of the ?]packnu model to provide a filtered set of category information, stored in the _]packneao array variable. The second argument, pdeo):l]ooa`=ncoW#_#], of this method determines the family of category information that is required. Next is the cap?deh`?]packneao method, which accepts the newly created _]packneao array as the first argument, the current category ID (stored in pdeo):l]ooa`=ncoW#_â&#x20AC;&#x2122;]), and a Boolean pnqa. We talked about this method earlier in the discussion of the ?]packnu model class (Listing 3-7). Here, this method returns the list of all children category IDs that belong to the category ID supplied as second argument of the method. Next, using the PHP ]nn]u[ianca function, the current category ID and that of the children are merged together and stored in the ]hh?]pE`o array variable. Finally, the ]hh?]pE`o variable is passed to the heopo method of the Lnk`q_p model, which returns a list of all products that belong to the category IDs available in the ]hh?]pE`o variable. The heopo method of the Lnk`q_po?kjpnkhhan is called or triggered when a user clicks a category. This method is called in the ]ll+reaso+ahaiajpo+lnk`q_po*_pl view file, which is shown in Listing 3-13. Listing 3-13. The Product List View for the Center Column (app/views/elements/products.ctp) 8;ldl lnk`q_po9pdeo):namqaop=_pekj$+lnk`q_po+heopo+_6 _]pE`+%7 bkna]_d$ lnk`q_po]o lnk`q_p%6;: 8`er_h]oo9lnk`q_p[_kjp]ejan: 8;ldl eb$ lnk`q_pW#Lnk`q_p#YW#pdqi^j]eh#Y%w  pdqi^j]eh9#+eic+lnk`q_po+#* lnk`q_pW#Lnk`q_p#YW#pdqi^j]eh#Y7 yahoaw  pdqi^j]eh9#jk)ei]ca)oi]hh*ljc#7 y


CHAPTER 3 N E-COMMERCE

a$dpih):hejg$ dpih):ei]ca$ pdqi^j]eh(]nn]u$#^kn`an#9:#,#%%( ]nn]u$#_kjpnkhhan#9:#lnk`q_po#( #]_pekj#9:reas+_]p[e`6 _]pE`+l`[e`6* lnk`q_pW#Lnk`q_p#YW#e`#Y %( ]nn]u$#ao_]la#9:b]hoa%%%7;: 8^n: 8;a_dkdpih):hejg$ lnk`q_pW#Lnk`q_p#YW#j]ia#Y(ÂŁ +lnk`q_po+reas+_]p[e`6 _]pE`+l`[e`6* lnk`q_pW#Lnk`q_p#YW#e`#Y%7;: 8^n:Lne_a6 8;9 lnk`q_pW#Lnk`q_p#YW#lne_a#Y7 ;: 8+`er: 8;aj`bkna]_d7;: In Listing 3-13, the first line uses Cakeâ&#x20AC;&#x2122;s namqaop=_pekj function to request the heopo method of the Lnk`q_po?kjpnkhhan object to provide a list of product information that matches the category ID passed to this method via the _6 _]pE` parameter. The resulting list of products is stored in the lnk`q_po array variable. Finally, using a bkna]_d loop, the content of the lnk`q_po array is displayed in the center of the web page. The resulting view is shown in Figure 3-3.

Figure 3-3. The view rendered when a category ID is selected

61


62

CH APT ER 3 N E-C OMMER C E

The last method in Listing 3-12, reas, uses Cakeâ&#x20AC;&#x2122;s oap method to automagically pass a full product description to the ]ll+reaso+lnk`q_po+reas*_pl file. Using the default bej` method against the Lnk`q_p object, our reas method retrieves a record of a product from the lnk`q_po table based on a specified product ID (retrieved from pdeo):l]ooa`=ncoW#l`[e`â&#x20AC;&#x2122;]). This product information is stored in the naoqhp array variable. If naoqhp is empty, then the application redirects the user to the home page; otherwise, the current product information is displayed on the page. If the product ID is set, then the content of the product details view stored in the ]ll+ reaso+ahaiajpo+lnk`q_p[`ap]eho*_pl file will be displayed in the center column. This view file is shown in Listing 3-14. Listing 3-14. The Product Details View for the Center Column (app/views/elements/product_ details.ctp) 8;ldl eb$ lnk`q_pW,YW#Lnk`q_p#YW#ei]ca#Y%w  l`[pdqi^j]eh9#+eic+lnk`q_po+#* lnk`q_pW,YW#Lnk`q_p#YW#ei]ca#Y7 yahoaw  l`[pdqi^j]eh9#jk)ei]ca)oi]hh*ljc#7 y a$ dpih):ei]ca$ l`[pdqi^j]eh( ]nn]u$#^kn`an#9:#,#(#se`pd#9:#-1,#(#daecdp#9:#-1,#%%%7 ;: 8^n+: 8opnkjc:8;ldla_dk lnk`q_pW,YW#Lnk`q_p#YW#j]ia#Y7;:8+opnkjc: 8^n+: Lne_a68;ldla_dk?kjbecqna66na]`$#Odkl*_qnnaj_u#%7;: 8;ldla_dk lnk`q_pW,YW#Lnk`q_p#YW#lne_a#Y7;:8^n: 8;ldl eb$ lnk`q_pW,YW#Lnk`q_p#YW#mpu#Y:,%w a$ dpih):hejg$#=``pkOdkllejc>]ogap#( #+_]npo+]``+_]p[e`6#* _]pE`*#+l`[e`6#* lnk`q_pW,YW#Lnk`q_p#YW#e`#Y%%7 yahoaw a$#KqpKbOpk_g#%7 y ;: 8^n+: 8;ldl a$jh.^n$ lnk`q_pW,YW#Lnk`q_p#YW#`ao_nelpekj#Y%%7 ;: In Listing 3-14, we use the lnk`q_p array variable passed in using pdeo):oap$#lnk`q_p#( naoqhp% from the reas method of the Lnk`q_po?kjpnkhhan. It displays the product details in the center of the web page, as shown in the example in Figure 3-4.


CHAPTER 3 N E-COMMERCE

The Lnk`q_po?kjpnkhhan and other controllers employ the services of the Lnk`q_p and ?]packnu models. Reference to these models is available in the =ll?kjpnkhhan class, as discussed a little later in the chapter.

Figure 3-4. The index view rendered when a product is selected

The Cart Model Next, weâ&#x20AC;&#x2122;ll implement the ?]np model class. Along with supplying the content of the shopping cart to the application, the ?]np model provides functionalities to manipulate the cart, as well as the checkout section of the application. We will begin with the class properties, shown in Listing 3-15. Listing 3-15. The Beginning of the Cart Model (app/models/cart.php) 8;ldl _h]oo?]npatpaj`o=llIk`ah w r]n j]ia9#?]np#7 r]n d]oI]ju9]nn]u$#Lnk`q_p#%7 The ?]np class starts with the class definition, as usual, and then establishes its relationship with the Lnk`q_p model object using r]n d]oI]ju9]nn]u$#Lnk`q_p#%7. This simply states that a cart can contain one or more products.

63


64

CH APT ER 3 N E-C OMMER C E

We’ll create the following methods in the ?]np model: Ê

UÊ cap?]np

Ê

UÊ eo?]npAilpu

Ê

UÊ ]``?]np

Ê

UÊ ql`]pa?]np

Ê

UÊ _ha]jQl

Ê

UÊ ailpu>]ogap

Ê

UÊ `kQl`]pa

Ê

UÊ cap?]np?kjpajp

The cap?]np method supplies all the information stored in the _]npo table. This method is shown in Listing 3-16. Listing 3-16. The Cart Model’s getCart() Method bqj_pekjcap?]np$ le`( oe`%w napqnjpdeo):bej`$#]hh#(]nn]u$ #_kj`epekjo#9:]nn]u$#?]np*lnk`q_p[e`#9: le`( #?]np*_p[oaooekj[e`#9: oe`%( #kn`an#9:#?]np*e`=O?#%%7 y The cap?]np method takes two arguments: le` (product ID) and oe` (session ID). These are used in Cake’s bej` method to filter the provided _]npo table records. The product ID is extracted from a user’s URL request. The session ID is obtained from Cake’s Oaooekj object. These variables are extracted in the ^abknaBehpan method of the =ll?kjpnkhhan object, as you will see later in this chapter. Next is the eo?]npAilpu method, which checks whether there is at least one record in the _]npo table. This method is shown in Listing 3-17. Listing 3-17. The Cart Model’s isCartEmpty() Method bqj_pekjeo?]npAilpu$ oe`9JQHH%w  naoqhp9pdeo):bej`$#benop#( ]nn]u$#_kj`epekjo#9:]nn]u$#?]np*_p[oaooekj[e`#9: oe`%( #na_qnoera#9:,%%7 eb$ailpu$ naoqhp%%w napqnjpnqa7 y napqnjb]hoa7 y The eo?]npAilpu method accepts oe` (session ID) as its argument and uses the bej` method to check whether the session ID exists in the _]npo table. If this session ID exists in the _]npo table, pnqa is returned; otherwise, b]hoa is returned, and the message “Shopping Basket is empty” is displayed. The status of the basket section, on the right side of the web site, depends on the value returned by this method.


CHAPTER 3 N E-COMMERCE

Next, we need the function to add a product to the _]npo table, ]``?]np, as shown in Listing 3-18. Listing 3-18. The Cart Model’s addCart() Method bqj_pekj]``?]np$ lnk`q_p[e`( oe`%w pdeo):`]p]W#?]np#YW#lnk`q_p[e`#Y9 lnk`q_p[e`7 pdeo):`]p]W#?]np#YW#mpu#Y9-7 pdeo):`]p]W#?]np#YW#_p[oaooekj[e`#Y9 oe`7  pdeo):o]ra$%7 y The ]``?]np method takes a product ID and the session ID as its arguments. Here, we use Cake’s model method o]ra to add the product ID, quantity, and session ID. We do not need to fill in the cart table’s _na]pa` field (see Listing 3-3), as this is one of Cake’s magic fields and will be filled in automatically by the model when the o]ra method is called. Now we need a function to update the quantity of a product in the _]npo table. This is the ql`]pa?]np, as shown in Listing 3-19. Listing 3-19. The Cart Model’s updateCart() Method bqj_pekjql`]pa?]np$ lnk`q_p[e`( oe`%w  omh9QL@=PA_]npo OAPmpu9mpu'SDANA_p[oaooekj[e`9# oe`#=J@lnk`q_p[e`9 lnk`q_p[e`7 pdeo):mqanu$ omh%7 y This is triggered when a user clicks the Add to Shopping Basket link on the product description page. If the displayed product ID and session ID match that of the argument, the record quantity is incremented by one. Next, we include a function to remove old cart records, _ha]jQl. Sometimes customers add products to the shopping basket, but don’t bother to either complete the transaction or empty the basket. The method shown in Listing 3-20 will handle cleaning up abandoned carts' records. Listing 3-20. The Cart Model’s cleanUp() Method bqj_pekj_ha]jQl$%w  pdnaa@]uo=ck9`]pa$#U)i)`D6e6o#( igpeia$,(,(,(`]pa$#i#%( `]pa$#`#%)/( `]pa$#U#%%%7   `ahapa[_kj`epekj9?]np*_na]pa`8# pdnaa@]uo=ck#7 pdeo):`ahapa=hh$ `ahapa[_kj`epekj(b]hoa%7 y The _ha]jQl method deletes records that were added to the basket three days ago from the _]npo table.

65


66

CH APT ER 3 N E-C OMMER C E

Next is the ailpu>]ogap method, shown in Listing 3-21. This method is used as the delete function that is triggered when a user clicks the Delete button on the checkout page. Listing 3-21. The Cart Model’s emptyBasket() Method bqj_pekjailpu>]ogap$ _]npE`9JQHH%w eb$ _]npE`%w pdeo):`ahapa$ _]npE`%7 y y The ailpu>]ogap method deletes a record from the _]npo table based on the cart ID. We also need to be able to update the quantity of products a customer wants to buy. This functionality is provided by the `kQl`]pa method, as shown in Listing 3-22. Listing 3-22. The Cart Model’s doUpdate() Method bqj_pekj`kQl`]pa$ jasMpu( _]pE`%w ++Ql`]palnk`q_pmq]jpepu pdeo):`]p]W#?]np#YW#mpu#Y9 jasMpu7 pdeo):e`9 _]pE`7  pdeo):o]ra$%7 y The `kQl`]pa method accepts two arguments: jasMpu supplies the new quantity of products the customer wants to purchase, and _]pE` specifies the ID of the _]npo table record to be updated. Finally, we add the cap?]np?kjpajp method to find out what’s in the cart, as shown in Listing 3-23. Listing 3-23. The Cart Model’s getCartContent() Method bqj_pekjcap?]np?kjpajp$ oe`%w  _]np?kjpajp9]nn]u$%7  omh9OAHA?P_p*e`(_p*lnk`q_p[e`(_p*mpu(l`*j]ia(l`*`ao_nelpekj( l`*lne_a(l`*pdqi^j]eh(l`*_]packnu[e` BNKI_]npo_p(lnk`q_pol`(_]packneao_]p SDANA _p[oaooekj[e`9# oe`#=J@ _p*lnk`q_p[e`9l`*e`=J@ _]p*e`9l`*_]packnu[e`7  naoqhpo9pdeo):mqanu$ omh%7 bkna]_d$ naoqhpo]o naoqhp%w  _]np?kjpajpWY9 naoqhp7 y napqnj _]np?kjpajp7 y y ;:


CHAPTER 3 N E-COMMERCE

The cap?]np?kjpajp method returns the contents of the _]npo table where the session ID field value matches the argument oe`. The result, stored in the _]np?kjpajp array, contains additional product and category information relating to the retrieved cart’s contents. If there is no match, an empty array variable is returned.

Handling User Requests Now that we have created all the functionality needed to interact with our database, we can begin the process of building our application’s controllers to handle user requests. We will need to decipher which action should be invoked and employ Cake’s MVC tricks to tie these actions to views that render the appropriate application display. We will start by creating the master controller, called the =ll?kjpnkhhan class. Our online shop controllers will borrow some properties and methods from this master controller to save the time of creating them in each individual controller.

The AppController Class By default, a Cake controller class extends the =ll?kjpnkhhan class. You’ve already been introduced to the ]ll+]ll[_kjpnkhhan*ldl class file in Chapter 1. Our shop =ll?kjpnkhhan class will contain all the common functionality required to centralize request handling and extract session IDs. The global properties and methods defined here are automatically available to the objects of requests or other classes that extend =ll?kjpnkhhan. Listing 3-24 shows the =ll?kjpnkhhan class properties. Listing 3-24. The Beginning of the AppController Class (app/app_controller.php) 8;ldl _h]oo=ll?kjpnkhhanatpaj`o?kjpnkhhanw r]n l]caPepha9#?d]lpan/)A_kiian_a#7 r]n oe`7 r]n _]pE`7 r]n l`E`7 r]n qoao9]nn]u$#Lnk`q_p#(#?]packnu#(#?]np#%7 r]n dahlano9]nn]u$#Bkni#(#Dpih#(#Oaooekj#(#F]r]o_nelp#%7 r]n _kilkjajpo9]nn]u$#Oaooekj#(#NamqaopD]j`han#(#Odkl#%7 The l]caPepha property sets an initial page title for this application, which can change according to a user’s page request. The oe` property will contain a session ID to identify our application user. As we mentioned earlier, to avoid repetition of code within this book, we’ve decided not to address authentication in this application. Hence, we’ve used the oe` variable to represent and track a user from page to page. The _]pE` and l`e` properties will be assigned the user-requested category and product values, respectively, when available. If these values are not available, we set the properties to an integer value of ,. Next in Listing 3-24, we include some of Cake’s built-in properties, such as the qoao array to require the Lnk`q_p, ?]packnu, and ?]np model objects. Then we include some helpers and components, which were introduced in Chapter 1.

67


68

CH APT ER 3 N E-C OMMER C E

Next, we override the ^abknaBehpan method, which is triggered first by default, before any other action in our =ll?kjpnkhhan, as shown in Listing 3-25. Listing 3-25. The AppControllerâ&#x20AC;&#x2122;s beforeFilter() Method bqj_pekj^abknaBehpan$%w eb$eooap$pdeo):l]ooa`=ncoW#_]p[e`#Y%"" $ejp% pdeo):l]ooa`=ncoW#_]p[e`#Y9-%w pdeo):_]pE`9$ejp% pdeo):l]ooa`=ncoW#_]p[e`#Y7 yahoaw pdeo):_]pE`9,7 y  eb$eooap$pdeo):l]ooa`=ncoW#l`[e`#Y%"" pdeo):l]ooa`=ncoW#l`[e`#Y9##%w pdeo):l`E`9$ejp% pdeo):l]ooa`=ncoW#l`[e`#Y7 yahoaw pdeo):l`E`9,7 y   `]p]9pdeo):Oaooekj):na]`$%7 pdeo):oe`9 `]p]W#?kjbec#YW#qoan=cajp#Y7 pdeo):oap$#_]pE`#(pdeo):_]pE`%7 pdeo):oap$#l`E`#(pdeo):l`E`%7 pdeo):oap$#oe`#(pdeo):oe`%7 pdeo):oapL]caPepha$%7 y In Listing 3-25, the overridden method checks the URL of a user request to extract and then determine the category ID and product ID values. The ^abknaBehpan method ensures that during the course of the application, the _]pE` and l`E` variables contain some integer values. For example, with this URL: dppl6++hk_]hdkop+_]ga+[[_d]lpano[[+a_kiian_a+ the values of these two properties will default to ,. If the URL is as follows the value of the current category ID will be -. and the product ID will be ,. dppl6++hk_]hdkop+_]ga+[[_d]lpano[[+a_kiian_a+a_kiian_a+ej`at+_]p[e`6-. In this case, the pdeo):l]ooa`=ncoW#_]p[e`#Y array stores the requested value of _]p[e`6-. of the URL. The last statement of the ^abknaBehpan method, pdeo):oapL]caPepha(), ensures that as a user moves from page to page, the current page title is reflected. The oapL]caPepha method, which sets the current page title, is shown in Listing 3-26.


CHAPTER 3 N E-COMMERCE

Listing 3-26. The AppController’s setPageTitle() Method bqj_pekjoapL]caPepha$%w eb$pdeo):l`E`:,%w  naoqhp9pdeo):Lnk`q_p):bej`$#]hh#( ]nn]u$#_kj`epekjo#9:]nn]u$#Lnk`q_p*e`#9:pdeo):l`E`%%%7 pdeo):l]caPepha9 naoqhpW,YW#Lnk`q_p#YW#j]ia#Y7 yahoaeb$pdeo):_]pE`:,%w  naoqhp9pdeo):?]packnu):bej`$#]hh#( ]nn]u$#_kj`epekjo#9:]nn]u$#?]packnu*e`#9:pdeo):_]pE`%%%7 pdeo):l]caPepha9 naoqhpW,YW#?]packnu#YW#j]ia#Y7 y y If the current product ID value $ pdeo):l`E`) is greater than zero, the value of  pdeo):l`E` is used to query the lnk`q_po table in order to extract the corresponding product name. The l]caPepha property is then assigned the appropriate product name. If the current category ID value is greater than zero, then the category ID $ pdeo):_]pE` ) is used to pull the corresponding category name from the _]packneao table, and finally, this category name is used as the page title. If the function fails to set a page title, the l]caPepha remains ?d]lpan/ÌA_kiian_a, as defined in the property section of the =ll?kjpnkhhan. Now that we have defined the properties and functionalities that we require in our =ll?kjpnkhhan class, let’s tie things together to enable users to navigate our shop.

The Home Page The starting point is the definition of our preferred home page. The ]ll+_kjbec+nkqpao*ldl file contains information about handling user requests for our application. We use the following line in our nkqpao file: Nkqpan66_kjja_p$#+#(]nn]u$#_kjpnkhhan#9:#_]npo#(#]_pekj#9:#ej`at#%%7 This defines a controller (_]npo) and an action (ej`at) within the ?]npo?kjpnkhhan class that serve as our shop’s home page. When a user types the URL dppl6++hk_]hdkop+_]ga+ [[_d]lpano[[+a_kiian_a+ in a web browser address bar or clicks the Home link on the web site, the request is handled by the ej`at action of the ?]npo?kjpnkhhan object. We’ll create the ?]npo?kjpnkhhan in the following section.

The Carts Controller Listing 3-27 shows the carts controller for our shop application. Listing 3-27. The CartsController Class (app/controllers/carts_controller.php) 8;ldl _h]oo?]npo?kjpnkhhanatpaj`o=ll?kjpnkhhanw r]n j]ia9#?]npo#7 bqj_pekjej`at$%w y y ;:

69


70

CH APT ER 3 N E-C OMMER C E

The ?]npo?kjpnkhhan class begins by extending the =ll?kjpnkhhan class. It then sets its j]ia property to ?]npo to ensure backward compatibility with PHP 4. By default, the ej`at action is mapped to the ]ll+reaso+_]npo+ej`at*_pl view file. Remember that the layout of our shop contains a middle section, or center column. Our ej`at*_pl view handles what is rendered in this area of the web site layout. The content of this view file is shown is shown in Listing 3-28. Listing 3-28. The View for the Center Column Content (app/views/carts/index.ctp) 8;ldl a$#Sah_kiapkpdah]j`kbiqoe_ 8^n+: Lha]oaoaha_pukqnksjiqoe_lnk`q_p 8^n+: Pd]jgobkn`nkllejc^u8^n+:#%7 eb$ l`E`%w a$pdeo):ahaiajp$#lnk`q_p[`ap]eho#%%7 yahoaeb$ _]pE`%w a$pdeo):ahaiajp$#lnk`q_po#%%7 yahoaw a$pdeo):ahaiajp$#_]packneao#%%7 y ;: In Listing 3-28, we first render our welcome message using the a$% function, which is a Cake convenience method for PHPâ&#x20AC;&#x2122;s a_dk statement. You can change this message to suit your needs. Next, we use the current values of the product ID ( l`E`) and category ID ( _]pE`), as defined in the ^abknaBehpan method of the =ll?kjpnkhhan class (Listing 3-25), to logically control the view that is finally displayed to web surfers. When a user visits our shop for the first time, the values of the product ID and category ID will be set to zero, as defined in the ^abknaBehpan method of the =ll?kjpnkhhan, since the user has not yet selected a category or a product from the home page. For this scenario, the view logic will render the content stored at ]ll+reaso+ahaiajpo+_]packneao*_pl. We will also have this scenario when a user clicks the Home link of the web site. The content of this view is shown in Listing 3-29. Listing 3-29. The Category List View for the Center Column (app/views/elements/categories.ctp) 8;ldl _]packneao9pdeo):namqaop=_pekj$+_]packneao+cap=hh%7 bkna]_d$ _]packneao]o _]packnu%6;: 8`er_h]oo9lnk`q_p[_kjp]ejan: 8; eb$ _]packnuW#?]packnu#YW#ei]ca#Y%w  _]p[pdqi^j]eh9#+eic+lnk`q_po+#* _]packnuW#?]packnu#YW#ei]ca#Y7 yahoaw  _]p[pdqi^j]eh9#jk)ei]ca)oi]hh*ljc#7 y


CHAPTER 3 N E-COMMERCE

a$dpih):hejg$ dpih):ei]ca$ _]p[pdqi^j]eh(]nn]u$#^kn`an#9:#,#%%( ]nn]u$#]_pekj#9:#+ej`at+_]p[e`6#* _]packnuW#?]packnu#YW#e`#Y%( ]nn]u$#ao_]la#9:b]hoa%%%7;: 8^n: 8;a$dpih):hejg$ _]packnuW#?]packnu#YW#j]ia#Y(£ +_]npo+ej`at+_]p[e`6* _]packnuW#?]packnu#YW#e`#Y%%7;: 8+`er: 8;aj`bkna]_d7;: In Listing 3-29, we also use Cake’s namqaop=_pekj method to trigger the cap=hh method of the ?]packneao?kjpnkhhan. The result of this method is a list of all the category information, which is stored in the _]packneao array variable. This variable is then looped over to display the list of categories, as shown in Figure 3-5.

Figure 3-5. The view showing the list of categories Now, we’re finished with the left column content—the category navigation—and the center column content. Let’s move to the right column, which displays the current shopping basket (cart) content (see Figure 3-5). If there is no information in the _]npo table, we’ll display the message “Shopping Basket is empty” in this area of the page. The view code to generate the basket content is stored at ]ll+reaso+ahaiajpo+^]ogap*_pl. This code is shown in Listing 3-30.

71


72

CH APT ER 3 N E-C OMMER C E

Listing 3-30. The Basket View for the Right Column (app/views/elements/basket.ctp) 8p]^hae`9ieje_]np: 8;ldl _]np?kjpajpo9pdeo):namqaop=_pekj$+_]npo+capIeje?]np+o6 oe`%7 eb$ailpu$ _]np?kjpajpo%""eo[]nn]u$ _]np?kjpajpo%%w Pkp]h9,7 ;: 8pn: 8p`_khol]j9.:?]np?kjpajp8+p`: 8+pn: 8;ldl bkna]_d$ _]np?kjpajpo]o _]np?kjpajp%w  Pkp]h'9 _]np?kjpajpW#l`#YW#lne_a#Y& _]np?kjpajpW#_p#YW#mpu#Y7 ;: 8pn: 8p`: 8;9 _]np?kjpajpW#_p#YW#mpu#Y7;:T 8;9 dpih):hejg$ _]np?kjpajpW#l`#YW#j]ia#Y( #+lnk`q_po+reas+l`[e`6#* _]np?kjpajpW#_p#YW#lnk`q_p[e`#Y*£ #_]p[e`6#* _]np?kjpajpW#l`#YW#_]packnu[e`#Y%7;:8+p`: 8p`se`pd9/,!]hecj9necdp:8;9?kjbecqna66na]`$#Odkl*_qnnaj_u#%7;: 8;9 _]np?kjpajpW#l`#YW#lne_a#Y& _]np?kjpajpW#_p#YW#mpu#Y7;:8+p`: 8+pn: 8;ldl y;: 8pn: 8p`]hecj9necdp:Pkp]h8+p`: 8p`se`pd9/,!]hecj9necdp: 8;9?kjbecqna66na]`$#Odkl*_qnnaj_u#%7;: 8;9 Pkp]h7;: 8+p`: 8+pn: 8pn: 8p`_khol]j9.:"j^ol78+p`:8+pn: 8pn: 8p`_khol]j9.]hecj9_ajpan:8;9 dpih):£ hejg$#CkPkOdkllejc?]np#(#+_]npo+reas#%7;:8+p`: 8+pn: 8;ldl yahoaw a_dk#8pn:8p`se`pd9-1,:Odkllejc>]ogapeoailpu8+p`:8+pn:#7 y ;: 8+p]^ha:


CHAPTER 3 N E-COMMERCE

Before we delve into the code in Listing 3-30, let’s add the product titled Mozart for Lovers to our basket by clicking the Add to Shopping Basket link on the product description page. Adding a product to the basket triggers the ?]npo?kjpnkhhan’s ]`` method, shown in Listing 3-31. Listing 3-31. The CartsController’s add() Method bqj_pekj]``$%w  `]p]9pdeo):Lnk`q_p):bej`>uE`$pdeo):l`E`%7 eb$ailpu$ `]p]%%w pdeo):na`ena_p$#+#%7 yahoaw eb$ `]p]W#Lnk`q_p#YW#mpu#Y89,%w pdeo):Oaooekj):oapBh]od$#Pdalnk`q_pukqnamqaopa`eo£ jkhkjcanejopk_g#%7 pdeo):na`ena_p$#+#%7 y y  oaooekj@]p]9pdeo):?]np):cap?]np$ pdeo):l`E`(pdeo):oe`%7 eb$ailpu$ oaooekj@]p]%%w pdeo):?]np):]``?]np$ pdeo):l`E`(pdeo):oe`%7 yahoaw pdeo):?]np):ql`]pa?]np$ pdeo):l`E`(pdeo):oe`%7 y pdeo):?]np):_ha]jQl$%7 pdeo):na`ena_p$]nn]u$#_kjpnkhhan#9:#Lnk`q_po#( #]_pekj#9:reas+_]p[e`6 pdeo):_]pE`+l`[e`6 pdeo):l`E`%%7 y In Listing 3-31, the first statement uses Cake’s bej`>uE` model method, which accepts a product ID $ pdeo):l`Id) to retrieve a product’s information from the lnk`q_po table. This product information is stored in the `]p] array variable. If `]p] is empty, the application redirects to the home page. Next, the script checks if the product quantity is less than or equal to zero. If so, the application uses the Cake Oaooekj object’s oapBh]od method to hold the message #Pdalnk`q_pukq namqaopa`eojkhkjcanejopk_g# in the Oaooekj object, and then redirects to the home page. Then the application calls the cap?]np method of the ?]npo model object in order to check the existence of this product in the shopping basket. The result of this method is stored in the oaooekj@]p] array variable. If the product does not exist in the shopping basket against the current session ID, the ]``?]np$% method of the ?]npo model object is called to insert a new product into the _]npo table. If the product does exist in the shopping basket, the ql`]pa?]np method is called to increment the quantity of the product in the _]npo table by one. Next, the script seizes the opportunity to do some housecleaning by calling the _ha]jQl method to remove records that are few days old from the _]npo table. Finally, the application redirects the user to the current product’s description page.

73


74

CH APT ER 3 N E-C OMMER C E

Now that we’ve added a product to the _]npo table, let’s jump back into the basket view code in Listing 3-30. First, we use the namqaop=_pekj method to get all the content of the cart from the _]npo table. This Cake method accepts the string that triggers the ?]npo?kjpnkhhan’s capIeje?]np method, which accepts the session ID (via o6 oe`) as an argument and assigns the result to the _]np?kjpajpo variable. Next, if the _]np?kjpajpo variable is an array and is not empty, the Pkp]h variable is assigned a value of zero. Finally, using the bkna]_d loop over _]np?kjpajpo, the current content of the basket now includes the newly added product Mozart for Lovers, costing $15, as shown in Figure 3-6.

Figure 3-6. The view showing Mozart for Lovers in the shopping basket in the right column Checking our user journey, our next action is to proceed to the shopping basket, to check that we are happy with our current product selections. If not, we will amend the selections or completely remove unwanted products from our shopping basket. This interface allows for cart-manipulation processes, such as updating the product quantity, deleting the product, and so on. Let’s suppose the user has clicked the Go to Shopping Cart link in Figure 3-6, and modified the cart content by removing the Mozart for Lovers and Dizzy 1990s items from her shopping basket. The new content of the shopping basket is shown in Figure 3-7.


CHAPTER 3 N E-COMMERCE

Figure 3-7. The view showing a sample cart content

The Order Model Next, we’re going to deal with the orders. We’ll start by creating the Kn`an model class, shown in Listing 3-32. Note that this class does not interact with any database table. Listing 3-32. The Order Model Class (app/models/order.php) 8;ldl _h]ooKn`anatpaj`o=llIk`ah w r]n j]ia9#Kn`an#7 r]n qoaP]^ha9b]hoa7 r]n r]he`]pa9]nn]u$ #j]ia#9:]nn]u$#nqha#9:]nn]u$#^apsaaj#(.(.11%( #namqena`#9:pnqa( #iaoo]ca#9:#Lha]oaajpan]j]ia*#%( #]``naoo#9:]nn]u$#nqha#9:]nn]u$#^apsaaj#(0(.11%( #namqena`#9:pnqa( #iaoo]ca#9:#Lha]oaajpan]j]``naoo*#%( #_kiiajp#9:]nn]u$#nqha#9:]nn]u$#^apsaaj#(1(.11%( #namqena`#9:pnqa( #iaoo]ca#9:#Lha]oaajpan]_kiiajp*#%%7 y ;:

75


76

CH APT ER 3 N E-C OMMER C E

In Listing 3-32, we define the r]he`]pa array to ensure input data integrity for the j]ia, ]``naoo, and _kiiajp form elements. Next, we’re going to click the Proceed to Checkout button. Our action will trigger the _da_gkqp method of the Kn`ano?kjpnkhhan object, which is defined in Listing 3-33. Listing 3-33. The OrdersController Class (app/controllers/orders_contoller.php) 8;ldl _h]ooKn`ano?kjpnkhhanatpaj`o=ll?kjpnkhhanw r]n j]ia9#Kn`ano#7 r]n qoao9]nn]u$#Kn`an#%7 bqj_pekj_da_gkqp$%w  `]p]9pdeo):l]ooa`=ncoW#_po#Y7 pdeo):oap$#`]p]#( `]p]%7 pdeo):h]ukqp9#_da_g^]oa#7 y bqj_pekj_kjbeni$%w pdeo):h]ukqp9#_da_g^]oa#7 eb$ailpu$ pdeo):`]p]%%w  kn`ano9pdeo):`]p]7  _]npo9pdeo):?]np):bej`$#]hh#(]nn]u$ #_kj`epekjo#9:]nn]u$#?]np*e`#9: pdeo):`]p]W#Kn`an#YW#_po#Y%( #na_qnoera#9:-%%7 pdeo):oap$_kil]_p$#_]npo#(#kn`ano#%%7 y y y ;: As usual, the Kn`ano?kjpnkhhan class references the Kn`ano model object using the qoao9 ]nn]u$Kn`an%7 statement. Next, we define the _da_gkqp method, which first extracts the current cart’s content IDs from pdeo):l]ooa`=ncoW#_po#Y array, and then stores the result in the `]p] array. The `]p] array is passed to the ]ll+reaso+kn`ano+_da_gkqp*_pl view file, shown in Listing 3-34, for display. The last statement of this method changes the default layout to _da_g^]oa. Listing 3-34. The Checkout View (app/views/orders/checkout.ctp) 8beah`oap: 8hacaj`: 8;ldla_dkpdeo):l]caPepha9[[$#8opnkjc:?da_gkqp8+opnkjc:#(pnqa%7;: 8+hacaj`: 8;ldl a_dkbkni):_na]pa$#Kn`an#(]nn]u$#qnh#9:#+kn`ano+_kjbeni+#%%7 a_dkbkni):annkn$#Kn`an*j]ia#%7


CHAPTER 3 N E-COMMERCE

a_dkbkni):ejlqp$#Kn`an*j]ia#(]nn]u$#e`#9:#kn`anj]ia#( #h]^ah#9:#J]ia6#(#oeva#9:#/,#( #i]thajcpd#9:#.11#(#annkn#9:b]hoa%%7 a_dkbkni):annkn$#Kn`an*]``naoo#%7 a_dkbkni):ejlqp$#Kn`an*]``naoo#(]nn]u$#e`#9:#kn`an]``naoo#( #pula#9:#patp]na]#(#h]^ah#9:#=``naoo6#( #nkso#9:#/#(#annkn#9:b]hoa%%7 a_dkbkni):annkn$#Kn`an*_kiiajp#%7 a_dkbkni):ejlqp$#Kn`an*_kiiajp#(]nn]u$#e`#9:#kn`an_kiiajp#( #pula#9:#patp]na]#(#h]^ah#9:#?kiiajp6#( #nkso#9:#1#(#annkn#9:b]hoa%%7 a_dkbkni):annkn$#Kn`an*l]uiajp#%7 a_dkbkni):ejlqp$#Kn`an*l]uiajp#(]nn]u$#pula#9:#n]`ek#( #klpekjo#9:]nn]u$-9:#Ckkcha#(.9:#L]ul]h#%%%7 a_dkbkni):ejlqp$#_po#(]nn]u$#pula#9:#de``aj#(#r]hqa#9: `]p]%%7 a_dkbkni):aj`$]nn]u$#h]^ah#9:#?kjbeniKn`an#%%7 ;: 8+beah`oap: 8^n+: 8;ldla_dkpdeo):ahaiajp$#_da_gkqp#%7;: In Listing 3-34, the code is divided into two main parts. The first part uses Cakeâ&#x20AC;&#x2122;s bkni object to render the checkout form. The second part renders the current content of the shopping basket, similar to the basket view code (Listing 3-30). Listing 3-34 produces the checkout form shown in Figure 3-8.

Figure 3-8. The checkout page

77


78

CH APT ER 3 N E-C OMMER C E

When the user clicks the Confirm Order button on the checkout page, the _kjbeni method of the Kn`ano?kjpnkhhan is triggered. If the submitted form data (stored in pdeo):`]ta) is not empty, then the form data is stored in the kn`ano array. Next, we retrieve the current cart content based on the cart ID (extracted from pdeo):`]p]W#Kn`an#YW#_po’]), and the result is stored in the _]npo array variable.

NNote It is important to include the statement r]n ^ahkjcoPk9]nn]u$#Lnk`q_p#%7 in the ?]np model class, because we’ll need to submit some vital product information (such as product name, price, and description) to our chosen payment gateway. This statement will ensure that the application includes related product information whenever _]npo table records are retrieved.

Finally, using Cake’s oap and _kil]_p functions, the two array variables are passed on to the ]ll+reaso+kn`ano+_kjbeni*_pl file. The structure of the array variables is shown in Listing 3-35. Listing 3-35. The Structure of $order and $cart Array Variables =nn]u $ WKn`anY9:=nn]u $ Wj]iaY9:Ie_da]hOq__ao W]``naooY9:-Oq__aoo=rajqa Oq__aoo Oq__aooOp]pa QO= W_kiiajpY9:Pdeokn`anodkqh`^a`aherana`sepd]^kpphakbNa`Seja* I]jupd]jgobknukqn]jpe_el]pa`nalkjoa* Wl]uiajpY9:W_poY9:1/ % % =nn]u $ W,Y9:=nn]u $ W?]npY9:=nn]u $ We`Y9:1/ Wlnk`q_p[e`Y9:.. WmpuY9:. W_p[oaooekj[e`Y9:/._]^^5`2b^/-0,0]1^3/24/,a]_2]]/ W_na]pa`Y9:.,,4),5).1./6/,6-4 %


CHAPTER 3 N E-COMMERCE

WLnk`q_pY9:=nn]u $ We`Y9:.. W_]packnu[e`Y9:-/ Wj]iaY9:@evvu]j`Op]j W`ao_nelpekjY9:Herasepd@evvuCehhaolea]j`Op]jCapv* Wlne_aY9:-/*,, WmpuY9:-, Wei]caY9:-*flc Wpdqi^j]ehY9:-*flc W_na]pa`Y9:,,,,),,),,,,6,,6,, Wik`ebea`Y9:,,,,),,),,,,6,,6,, % % % The array structures in Listing 3-35 are passed on to the _kjbeni*_pl view file, as shown in Listing 3-36. Listing 3-36. The OrdersControllerâ&#x20AC;&#x2122;s confirm() Method View 8;ldl eb$ kn`anW#Kn`an#YW#l]uiajp#Y99-%w a_dkpdeo):ahaiajp$#ckkcha[_da_gkqp#%7 yahoaw a_dkpdeo):ahaiajp$#l]ul]h[_da_gkqp#%7 y ;: If the order payment method selected equals -, then the Google Checkout payment form is displayed. If not, the PayPal form is presented.

The Google Checkout Button Google needs no introduction when it comes to the world of Internet. However, you should be aware that to use Google services, you need to have a Google account, which you probably already do if you use Google Mail, Google Docs, Google Adwords, or any of the numerous other Google offerings. Shoppers are often frustrated by needing to fill out lengthy online forms before making payments. It is easy to encourage users to check out via the Google Checkout button, which is secure and convenient. When this button is selected, the _]npo and kn`an array variables are passed to the ]ll+reaso+ahaiajpo+ckkcha[_da_gkqp*_pl file, shown in Listing 3-37.

79


80

CH APT ER 3 N E-C OMMER C E

Listing 3-37. Google Checkout View (app/views/elements/google_checkout.ctp) 8;ldl a_dkbkni):_na]pa$#Kn`an#( ]nn]u$#qnh#9:#dpplo6++_da_gkqp*ckkcha*_ki+]le+_da_gkqp+r.+£ _da_gkqpBkni+Ian_d]jp+ttttttttttttttt#( #]__alp)_d]noap#9:#qpb)4#%%7   e9,7  bkna]_d$ _]npo]o _]np%w   t9 e'-7  a_dkbkni):de``aj$epai[j]ia[ t( ]nn]u$#r]hqa#9: _]npW#Lnk`q_p#YW#j]ia#Y%%7 a_dkbkni):de``aj$epai[`ao_nelpekj[ t( ]nn]u$#r]hqa#9: _]npW#Lnk`q_p#YW#`ao_nelpekj#Y%%7 a_dkbkni):de``aj$epai[mq]jpepu[ t( ]nn]u$#r]hqa#9: _]npW#?]np#YW#mpu#Y%%7 a_dkbkni):de``aj$epai[lne_a[ t( ]nn]u$#r]hqa#9: _]npW#Lnk`q_p#YW#lne_a#Y%%7 a_dkbkni):de``aj$epai[_qnnaj_u[ t( ]nn]u$#r]hqa#9:?kjbecqna66na]`$#Epai*_qnnaj_u#%%%7 a_dkbkni):de``aj$odel[iapdk`[j]ia[ t( ]nn]u$#r]hqa#9:?kjbecqna66na]`$#Kn`an*odeliapdk`#%%%7 a_dkbkni):de``aj$odel[iapdk`[lne_a[ t( ]nn]u$#r]hqa#9:?kjbecqna66na]`$#Kn`an*odellne_a#%%%7 a_dkbkni):de``aj$p]t[n]pa( ]nn]u$#r]hqa#9:?kjbecqna66na]`$#Kn`an*p]tn]pa#%%%7 a_dkbkni):de``aj$p]t[qo[op]pa( ]nn]u$#r]hqa#9:?kjbecqna66na]`$#Kn`an*p]top]pa#%%%7 y  a_dkbkni):de``aj$#[_d]noap[#%7  a_dkdpih):ei]ca$#dppl6++_da_gkqp*ckkcha*_ki+^qppkjo+_da_gkqp*ceb;£ ian_d]jp[e`9ttttttttttttttt"s9-4,"d902"opuha9sdepa"r]ne]jp9patp"hk_9aj[QO#( ]nn]u$#j]ia#9:#Ckkcha?da_gkqp#( #]hp#9:#B]op_da_gkqppdnkqcdCkkcha#( #daecdp#9:#02#( #se`pd#9:#-4,#%%7  a_dkbkni):aj`$]nn]u$#h]^ah#9:#?kjbeniKn`an#%%7 ;: The view file shown in Listing 3-37 generates a page similar to the one shown in Figure 3-9.


CHAPTER 3 N E-COMMERCE

Figure 3-9. The Google checkout page Clicking the Google Checkout button will redirect the user to the Google sandbox environment, as shown in Figure 3-10.

Figure 3-10. The Google test sandbox

81


82

CH APT ER 3 N E-C OMMER C E

For more information about processing online sales using Google’s payment system, Google Checkout buttons, and the Google sandbox, visit the following sites: Ê

UÊ dpplo6++_da_gkqp*ckkcha*_ki+oahh+

Ê

UÊ dppl6++_k`a*ckkcha*_ki+]leo+_da_gkqp+`arahklan+Ckkcha[?da_gkqp[>]oe_[DPIH[ Ckkcha[?da_gkqp[>qppkjo*dpih

Ê

UÊ dppl6++_k`a*ckkcha*_ki+]leo+_da_gkqp+`arahklan+Ckkcha[?da_gkqp[TIH[=LE[?na`ep[ ?]n`[Paop[?]oao*dpih.

The PayPal Submit Button PayPal can be regarded as the father of online payment gateways. It’s ubiquitous when it comes to online payment choices. Here, we are going to create the payment form, in the ]ll+reaso+ahaiajpo+l]ul]h[_da_gkqp*_pl file, as shown in Listing 3-38. You can use the Buy-it-Now button form generator on PayPal to create a similar payment form. Listing 3-38. The PayPal View (app/views/elements/paypal_checkout.ctp) 8;ldl a_dkbkni):_na]pa$#Kn`an#( ]nn]u$#qnh#9:#dpplo6++sss*l]ul]h*_ki+_ce)^ej+sa^o_n#( #e`#9:#l]uL]hBkni#%%7 a_dkbkni):de``aj$epai[jqi^an(]nn]u$#r]hqa#9:PdaIqoe_?hq^%%7 a_dkbkni):de``aj$_i`(]nn]u$#r]hqa#9:[t_he_g%%7 a_dkbkni):de``aj$jk[jkpa(]nn]u$#r]hqa#9:-%%7 a_dkbkni):de``aj$^qoejaoo(]nn]u$#r]hqa#9:o]hao<ln]_pe_]h_]galdl*_ki%%7 a_dkbkni):de``aj$_qnnaj_u[_k`a(]nn]u$#r]hqa#9:QO@%%7 a_dkbkni):de``aj$napqnj(]nn]u$#r]hqa#9:dppl6++ln]_pe_]h_]galdl*_ki%%7  e9,7 bkna]_d$ _]npo=O _]np%w  t9 e'-7 a_dkbkni):de``aj$epai[jqi^an(]nn]u$#r]hqa#9:PdaIqoe_?hq^%%7 a_dkbkni):de``aj$epai[`ao_nelpekj[ t( ]nn]u$#r]hqa#9: _]npW#Lnk`q_p#YW#`ao_nelpekj#Y%%7 a_dkbkni):de``aj$epai[mq]jpepu[ t(]nn]u$#r]hqa#9: _]npW#?]np#YW#mpu#Y%%7 a_dkbkni):de``aj$epai[lne_a[ t(]nn]u$#r]hqa#9: _]npW#Lnk`q_p#YW#lne_a#Y%%7 y a_dkbkni):aj`$]nn]u$#h]^ah#9:#Oq^iep#%%7 ;: The PayPal view is passed the _]npo and the kn`an array variables. For further information about the numerous services provided by PayPal, visit dppl6++ sss*l]ul]h*_ki.


CHAPTER 3 N E-COMMERCE

Summary In this chapter, we went through the process of building an online shop. For this demonstration, we’ve kept its features to a minimum. However, users can navigate the product category menu, add products to a shopping basket, review the basket contents, and proceed to the checkout form. We started this chapter by looking at a typical shop layout, the shop user journey, and the creation of the database and tables needed for the shop application. We then proceeded to build all the model classes that interact with the database tables, such as those for categories, products, carts, and so on. To handle user requests, we built the =ll?kjpnkhhan class with properties and methods that provide functionality common to other controller classes. This helps us to avoid “reinventing the wheel” and to extend other controller classes, such as the category controller of the application. We then built the other controller classes to handle the application requests. Finally, we created checkout forms to handle payment transactions. We used a Google sandbox as our payment test environment and also created a PayPal form as an alternative payment option. Building a comprehensive e-commerce web site obviously involves more than what we covered in this chapter. For example, you would want to add an administration area to the web site to facilitate management.

83


C HAPTER

4

A Message Forum Web Service I

n this chapter, we’ll build a Cake-based forum. While there are a lot of popular open source forums such as phpBB, we like the idea of rolling our own. It’s a fantastic learning process, and we get to deal with a lot of new subjects that don’t come up in our day jobs. So that our forum will stand out from the crowd, we need a unique selling point. That will be a web service API for our forum. Web services are quite a common feature in many modern web applications, but not that common in many of the forums.

Our Take on Web Services The term web services can have many meanings. For example, simply entering the URL dppl6++sss*_]galdl*knc+ into your browser can be called a web service request, since you’re using HTTP CAP. The World Wide Web Consortium (W3C) has an official definition for web services (dppl6++sss*s/*knc+.,,.+so+=_perepu): Web services provide a standard means of interoperating between different software applications, running on a variety of platforms and/or frameworks. This meaning is quite general, indicating that web services are a way for computers to talk to each other, which may or may not include the Web. Before we get to creating our forum, let’s clear up what we mean by web services.

Web Service Elements There are many elements relating to web services. We start with a short explanation of each element to provide a foundation for our particular angle on web services.

85


86

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

Ê

UÊ API: This acronym stands for application programming interface. In the world of computers, much like the definition of web services, this is quite a general term. For us, it means a set of published functions or methods that can be directly accessed via URLs on the server, such as dppl6++sss*at]ilha*_ki+capSe`capo*fokj or dppl6++sss* at]ilha*_ki+capSe`capo+fokj.

Ê

UÊ SOAP: This stands for Simple Object Access Protocol, and is one of the main protocols of a web service. It piggybacks onto the HTTP protocol, considered too complex and verbose by many developers. Taking the previous example, our SOAP request would look something like this:

LKOP+DPPL+-*Dkop6sss*at]ilha*_ki ?kjpajp)Pula6patp+tih7_d]noap9qpb)4 ?kjpajp)Hajcpd6jjjj OK=L=_pekj6Okia)QNE 8OK=L)AJR6Ajrahkla tihjo6OK=L)AJR9dppl6++o_dai]o*tihok]l*knc+ok]l+ajrahkla+ OK=L)AJR6aj_k`ejcOpuha9dppl6++o_dai]o*tihok]l*knc+ok]l+aj_k`ejc+: 8OK=L)AJR6>k`u: 8i6capSe`capotihjo6i9Okia)QNE: 8pula:omq]na8+pula: 8+i6capSe`capo: 8+OK=L)AJR6>k`u: 8+OK=L)AJR6Ajrahkla: Ê

UÊ HTTP: In a sense, HTTP (Hypertext Transfer Protocol) and SMTP (Simple Mail Transfer Protocol) are the two main protocols people use on the Internet. They surf the Web using the HTTP protocol and read e-mail messages using the SMTP protocol. Many developers have adopted HTTP as their protocol for developing their web services; specifically, just the CAP and LKOP methods within that protocol. This is how we will be developing our API in this chapter’s application.

Ê

UÊ XML-RPC: The Extensible Markup Language Remote Procedure Call was created by David Winer, one of the pioneers in modern web services and blogging. It’s similar to SOAP, but simpler. This protocol is not frequently used by developers. The major web applications that support XML-RPC include Flickr and Amazon S3.

Ê

UÊ REST: This stands for representational state transfer. The term was coined by Roy Fielding, one of the main authors of HTTP. It is not a protocol, but a set of statements about how distributed media should be organized, with the Web being a key example.

Figure 4-1 illustrates how many web developers see web services. On the left side, we have the clients. They can be applications on other servers; desktop applications, which include browsers; and other devices, like mobile cell phones. These clients will most often use HTTP (CAP, LKOP, and so on) to send and request data to and from the server, shown on the right. The way the clients talk to the server is the protocol: XML-RPC, SOAP, RSS, and so on. These protocols are quite specific, since there are standards attached. For example, in RSS, you must end all requests with the *noo extension. The format you will receive will be in a specific format, as defined by the official standards body.


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

Figure 4-1. Elements of web services However, you can develop your own proprietary protocol using the features of HTTP. Many web service providers have gone this route—Google Maps, Flickr, and Twitter, to name a few. Mashing different services together is never an easy task. For example, an image will have a different context depending on the application. The use of REST complicates the picture. In Figure 4-1, it sits within generic HTTP, as we regard it as a specific way of using that protocol.

REST and HTTP Many people have advocated the use of the REST principle with HTTP for web services. In particular, the use of the HTTP methods should conform to the W3C standard. For example, CAP methods should not alter any data. Something like dppl6++sss*at]ilha*_ki+ a`epQoan+;e`9-"j]ia9jas[j]ia should not be allowed. In REST, this would look like dppl6++ sss*at]ilha*_ki+Qoan+-. The new name would be supplied as a key/value pair— j]ia9jas[j]ia—in the request body, and instead of using CAP, we would be using LQP. In a sense, we see HTTP as being a diluted form of REST. It can get quite confusing, as some meanings can overlap. We see the confusion surrounding REST much as we see the complexity of SOAP. Many developers find REST difficult to use. To use REST in its full meaning, you must conform to the correct use of the HTTP methods such as CAP, LKOP, LQP, and @AHAPA. Most browsers support only CAP and LKOP. You can use the other methods via TIHDpplNamqaop in Ajax scripting, but that just won’t be enough to conform to the principles of REST. To end our discussion of REST, the web services that we’re going to write in this chapter will not conform to the principles of REST.

87


88

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

NNote The four most important HTTP requests are CAP, LKOP, LQP, and @AHAPA. CAP requests a resource, such as an HTML file. (Requesting the resource must not cause a side effect, such as deleting a record). LKOP sends data to the resource to be processed. It creates a new resource, updates the resource, or both. We’ll consider the LQP operation to be the same as the LKOP. Elliotte Rusty Harold gives a good explanation at dppl6++sss*ahd]nk*_ki+^hkc+okbps]na)`arahkliajp+sa^)`arahkliajp+.,,1+-.+,4+ lkop)ro)lqp+. Finally, @AHAPA just deletes a resource, such as a user account.

We’ve always liked the principle of KISS, which means we prefer to Keep It Short and Simple. Logical standards like SOAP sometimes are just too logical. As such, like many web APIs, we’re just opting for plain old HTTP CAP and LKOP as the two modes that developers can use to access the innards of our forum. Referring to our diagram in Figure 4-1, we’re using the generic HTTP method.

Result Return Formats When we make a web service request, the result can be returned in many formats depending on the client request, including HTML, JSON, XML, and RSS. You can even specify the result to be returned as a comma-separated list or as a JavaScript-ready document output. For our application, we’ll use JSON. Developers can easily use our web services via Ajax or on the server using _qnh or scap.

Application Requirements One of the main focal points of our forum application is the API. Therefore, we’ll start by thinking about the methods that we will be exposing to the public. The API requests will come from other applications, not individuals using the application via an interface, so we must consider that in our planning. In our forum application, we want to include some common features that are found in all forums: Ê

UÊ *œÃÌʓiÃÃ>}iÃ

Ê

UÊ ,i«ÞÊ̜ʓiÃÃ>}iÃ

Ê

UÊ 6ˆiÜʓiÃÃ>}iÃ

Ê

UÊ -i>ÀV…Ê“iÃÃ>}iÃ

Since our own interface is basically also a client, we need to look at our own front end as if it were a third-party client application that is calling the processing scripts from a distant server. We know there are several ways to make a URL request. The following are the ones we are interested in: Ê

UÊ ,iµÕiÃ̈˜}Ê>Ê1,Êۈ>Ê_qnh or scap; they may also want it returned in a particular format

Ê

UÊ ,iµÕiÃ̈˜}Ê>Ê1,Êۈ>Ê>ÊLÀœÜÃiÀÊÕȘ}Ê//*ÊCAP or LKOP

Ê

UÊ ,iµÕiÃ̈˜}Ê>Ê1,Êۈ>ʍ>ÝÊÃVÀˆ«Ìˆ˜}ÊÕȘ}Ê//*ÊCAP or LKOP; that is, the TIHDpplNamqaop (TDN) within the browser makes the HTTP call


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

Some of our actions may support only CAP and/or LKOP. This is similar to many of the other web APIs. We must have a standard way to respond to requests. For example, in HTTP, the response code 200 is OK, and the response code 404 is resource or page not found. Furthermore, some requests return data, while others carry out particular actions like saving data. We must be able to return data in a consistent manner given different requests.

Threads and Posts For our forum, we need to decide how discussions should be organized. We simply define a discussion (commonly called a thread) as the messages and the subsequent messages (replies) to those messages. Letâ&#x20AC;&#x2122;s look at some of the ways in which messages could be organized.

Organized by Date Using this method, each message is organized by date order, regardless of to which message it is replying. Users can then see the most up-to-date messages as they come in. Organizing by date is problematic because we wonâ&#x20AC;&#x2122;t know which message a message is replying to. We can overcome this by including the message, but do we include the whole message or just part of it? Perhaps we could allow the users to select the parts they are replying to? Listing 4-1 shows a code snippet that allows a user to quote part of a message so other users can refer to it. Listing 4-1. JavaScript Code to Get Selected Text -68ejlqppula9^qppkjkjikqoa`ksj9`eolh]uOaha_pa`$%7: .6 /68o_nelp: 06 16bqj_pekj`eolh]uOaha_pa`$%w 26 36r]noaha_pa`Patp9##7 46 56eb$sej`ks*capOaha_pekj%w -,6oaha_pa`Patp9sej`ks*capOaha_pekj$%7 --6y -.6ahoaeb$`k_qiajp*oaha_pekj%w -/6oaha_pa`Patp9`k_qiajp*oaha_pekj*_na]paN]jca$%*patp7 -06y -16 -26napqnjoaha_pa`Patp7 -36 -46y -56 .,68+o_nelp:

89


90

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

You might want to use the code in Listing 4-1 if you decide to extend the forum application. It simply retrieves the text a user has selected with the mouse. On line 9, we check whether the user has selected any text on Firefox/Gecko-based browsers. If so, we place the text in to the oaha_pa`Patp variable. Line 12 checks for text selection in Internet Explorer/ Trident-based browsers.

Organized by First Post Using the by-first-post organization, we show only new messages, essentially the first messages, as they come in. We won’t show the replies. If users want to read the replies, they need to drill down; that is, make another request to a different Cake action. If a user replies to an old message, it won’t be displayed. It will remain relative to that old message. Users will know of that reply only when they drill down to it. An obvious problem is that active discussions will be followed only by those who participated in it at the early stages, when the discussions were at the top of the page. When new messages arrive, the old messages get pushed down. This is not desirable, since we want many people contributing to a discussion as long as possible. After all, if people are just asking questions on the forum, very few people would bother to read the forum.

Organized by Replies You can also organize the threads by the number of replies, so the thread that has the greatest number of replies is shown first. If no one has contributed to the thread for a while, it will still stay at the top. The problem with this organization is that current and active threads are not given priority. So we end up putting too much emphasis on a topic that may no longer be of interest to most people.

Organized by Last Post Another organization possibility is a slightly different take on the by-first-post organization. Using this method, we order a discussion by its last post, but we show the first post. This approach has a number of advantages. If a new message comes in, it floats to the top. However, if a reply to an old message is posted, the first post of that discussion floats to the top. In this way, we encourage people to participate in ongoing discussions. If the discussion has been exhausted, it simply floats back down the page. Organizing the posts by the last post seems to be the most sensible method. In fact, most forums organize discussions this way, and so will our application.

Web Service Requests Our application will support the following five API requests: Ê

UÊ iÌV…Êœ˜iʓiÃÃ>}i

Ê

UÊ iÌV…Ê“>˜ÞʓiÃÃ>}iÃ

Ê

UÊ iÌV…Ê̅Ài>`Ã

Ê

UÊ *ÀœViÃÃÊ>ʓiÃÃ>}i

Ê

UÊ -i>ÀV…ÊvœÀʓiÃÃ>}iÃ


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

These requests will be the ones that we will be publishing in our API documentation. They will all support Ajax from a browser, ordinary HTTP requests from a browser, and _qnh or scap calls from a server.

Layout The API is an important component to the application. However, we’re not just publishing an API. The application will also be a working forum where users can post messages. In that sense, we’re building a client as well as the API services within the same application. Our application front end will have all the essential features that any forum user will expect. A user can post messages, reply to messages, view topics, and search for messages. The layout of the interface will be similar to that of the other projects in this book. We start with a header, followed by a navigation bar, and then the main content area. When a user goes straight to the site, they will be presented with a view of the current threads, as shown in Figure 4-2.

Figure 4-2. A rough sketch of the forum application layout

Application Structure In the previous section, we talked about how we’re going to organize our messages according to threads. This relationship is a one-to-many association, where one thread ties together many messages. The two main database tables in our application are iaoo]cao and pdna]`o. The fields in these tables are shown in Tables 4-1 and 4-2.

91


92

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

Table 4-1. The Fields in the messages Table

Field Name

Data Type

Description

e`

_d]n$/2%

Primary key (note it’s a UUID and not an auto-increment field; see the action class IbIaoo]caLnk_aoo for an explanation)

j]ia

r]n_d]n$.11%

Name of the user posting the message

ai]eh

r]n_d]n$.11%

E-mail address of the user

iaoo]ca

ia`eqipatp

The message body itself

nalhu[pk

_d]n$/2%

If the message is a reply to another message, this is the reply message ID

Oq^fa_p

r]n_d]n$.11%

The subject of the message (replies will have a NA6 prefix)

p[_na]pa`[]p

`]papeia

Automagic field (but we fill this in ourselves; see the action class IbIaoo]caLnk_aoo for an explanation)

pdna]`[e`

_d]n$/2%

The thread this message belongs to

Table 4-2. The Fields in the threads Table

Field Name

Data Type

Description

e`

_d]n$/2%

Primary key (again, UUID and not an auto-increment field)

benop[iaoo]ca[e`

_d]n$/2%

Used so we can easily pick out the first message when it needs to be displayed in the threads listing

h]op[iaoo]ca[`]pa

`]papeia

Used so we can order the threads correctly according to the last message date

iaoo]ca[jqi

ejp$--%

The number of messages within this thread

NNote As we haven’t used database transactions in our application, the number in the iaoo]ca[jqi field of the pdna]`o table may not always be completely accurate, but that’s not critical at this stage, as it’s used only for display purposes.

You’ll notice that the pdna]`o table includes a few metadata fields to contain data that describes the thread. This helps us to cut down on the number of SQL calls needed to list our threads. Each time a new message is added to a thread, the code updates the h]op[iaoo]ca[ `]pa field with the date of that message. This way, we don’t need to look in the iaoo]cao table for the last message that was posted within a thread.

JSON Web Services We have specified that we’ll be using the JSON format for all our API returns. To get this part of our application working, we need to do some setup.


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

The Nkqpan class must be aware of the JSON extension. We take care of this by adding the following line in the +]ll+_kjbec+nkqpao*ldl file: Nkqpan66l]noaAtpajoekjo$#fokj#%7 Following this, we need to include the NamqaopD]j`han component by adding it into our _kilkjajpo variable in our +]ll+]ll[_kjpnkhhan*ldl file, so that itâ&#x20AC;&#x2122;s available to all controllers. We also need the Oaooekj component. Our _kilkjajpo variable will look like this: r]n _kilkjajpo9]nn]u$#Oaooekj#(#NamqaopD]j`han#%7 Now the NamqaopD]j`han will automatically map JSON requests to the correct layout and view. When a JSON request comes in, it will pick the layout file within the folder +]ll+reaso+ h]ukqp+fokj instead of +]ll+reaso+h]ukqp. Our JSON layout file is shown in Listing 4-2. Listing 4-2. JSON Layout File (/app/views/layout/base.ctp) 8;ldl ++Pdeoeoqoa`sdajpda_]hhatpajoekjeo*fokj da]`an$Ln]ci]6jk)_]_da%7 da]`an$#?kjpajp)Pula6patp+t)fokj#%7 da]`an$T)FOKJ6* _kjpajp[bkn[h]ukqp%7    

_kjpnkhhan9pdeo):j]ia7 ]_pekj9pdeo):]_pekj7 `]papeia9`]pa$U[I[f[[C[e[o[P%7 beha[j]ia9 _kjpnkhhan*#[#* ]_pekj*#[#* `]papeia7

da]`an$#?kjpajp)@eolkoepekj6]pp]_diajp7behaj]ia9#* beha[j]ia*#*fokj#%7 a_dk _kjpajp[bkn[h]ukqp7 ;: Any script that requests a JSON return can use the HTTP headers ?kjpajp)Pula and T)FOKJ to identify whether or not it is a JSON return. However, the _kjpajp[bkn[h]ukqp isnâ&#x20AC;&#x2122;t guaranteed to be JSON. We must manually put that into a JSON format. Once the layout has been picked out, the NamqaopD]j`han will look in a fokj folder within the reaso folder that corresponds to the controller, similar to how the h]ukqp folder structure works. In our application, all the API methods have the same fokj view. For example, in the reas file ]ll+reaso+ib[bap_d[pdna]`o+fokj+ej`at*_pl for the IbBap_dPdna]`o controller, we just make use of JavaScript helper to format our result in a JSON format, as shown here: 8;ldl a_dkf]r]o_nelp):k^fa_p$ naoqhp%7 ;:

93


94

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

Our Application Controller Throughout the development of the forum application, we’ve placed a lot of attention on our web services API. We’re going to continue with that line of thought by using a version of the Command design pattern, adapted for the Web, in our controller. The Command pattern is an object-oriented class design, where we encapsulate each action in a class of its own. Class names are usually nouns, because they represent objects. However, in the Command pattern, the names are verbs, and each class must implement an execution method, traditionally called ata_qpa$%; in our case, it will be called ej`at$%. (See dppl6++aj*segela`e]*knc+sege+?kii]j`[l]ppanj for more information about the traditional implementation of the Command pattern.) Why implement the actions as a class? The advantages are not so obvious in a web environment or with small applications. The following are the advantages of this approach: Ê

UÊ >V…Ê>V̈œ˜ÊV>ÃÃʈÃÊÌÀi>Ìi`Ê>ÃÊ>˜Ê*ÊÀiµÕiÃÌÊ>V̈œ˜°ÊÌʅ>ÃÊ>ʅˆ}…iÀÊÃÌ>ÌÕÃÊ̅>˜Ê̅iÊÛiÀLÊ object.

Ê

UÊ /…iÊV>ÃÃiÃÊ>ÀiÊÓ>iÀÊ>˜`ʓœÀiʓ>˜>}i>Li°

Ê

UÊ -Õ««œÀ̈˜}Êv՘V̈œ˜ÃÊvœÀÊi>V…Ê>V̈œ˜Ê>ÀiÊi˜V>«ÃՏ>Ìi`Ê܈̅ˆ˜Ê̅iÊ>V̈œ˜½ÃʜܘÊV>ÃÃ°Ê For example, each class has its own validation method.

To use the Command pattern in our controller, we start with a base controller, which acts as the parent class of all the action classes. Code that is common to all the action classes can be placed here. This base class is shown Listing 4-3. Listing 4-3. Base Controller (mf_controller.php) -68;ldl .6 /6_h]ooIb?kjpnkhhanatpaj`o=ll?kjpnkhhanw 06 16r]n j]ia9#Ib#7 26 36r]n qoao9]nn]u$#Pdna]`#(#Iaoo]ca#(£ #IbOa]n_dLnk_aoo#(#IbBap_dIaoo]ca#( 46#IbBap_dIaoo]cao#(#IbBap_dPdna]`o#%7 56 -,6bqj_pekj[_da_g=f]t$%w --6 -.6eb$pdeo):NamqaopD]j`han):eo=f]t$%%w -/6 -06++Pdeoiqopateop6]ll+reaso+h]ukqpo+fokj+]f]t*_pl -16pdeo):NamqaopD]j`han):naj`an=o$ pdeo(#fokj#%7 -26y -36y -46 -56bqj_pekjej`at$%w .,6 .-6y ..6y ./6;:


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

The [_da_g=f]t method on line 10 is used by the action classes to check whether the API call is an Ajax request. If it is an Ajax request, we render the Ajax layout file in ]ll+reaso+ h]ukqpo+fokj+]f]t*_pl. Following this, each action class extends the Ib?kjpnkhhan class. An example is shown in Listing 4-4. There are quite often other supporting functions that help the main ej`at function. Listing 4-4. Example of an Action Class That Extends the Main MfController Class -68;ldl .6 /6ej_hq`a[kj_a$#ib[_kjpnkhhan*ldl#%7 06 16_h]ooIbAt]ilha?kjpnkhhanatpaj`oIb?kjpnkhhanw 26 36r]n j]ia9#IbAt]ilha#7 46 56r]n naoqhp9]nn]u$#naoqhp#9:##( -,6#iaoo]ca#9:##( --6#annkno#9:##( -.6#`]p]#9:## -/6%7 -06 -16bqj_pekj^abknaBehpan$%w -26 -36pdeo):[_da_g=f]t$%7 -46y -56 .,6bqj_pekj[r]he`]pekj$%w .-6 ..6 naoqhp9pnqa7 ./6 .06++@kr]he`]pekj .16 .26napqnj naoqhp7 .36y .46 .56bqj_pekjej`at$%w /,6 /-6eb$pdeo):[r]he`]pekj$%%w /.6 //6++@k^qoejaoohkce_ /06y /16y /26 /36bqj_pekj^abknaNaj`an$%w /46 /56pdeo):oap$#naoqhp#(pdeo):naoqhp%7 0,6y 0-6y 0.6 0/6;:

95


96

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

When the controller is called, it first checks whether it’s an Ajax call in the ^abknaBehpan on line 15. Next, we go in to the main ej`at action on line 29. If the API call validates, we do the business logic. When we’re ready to display the results, we package it in the ^abknaNaj`an action on line 37. Taking this hypothetical example, when we request a Cake URL, it will look like this: dppl6++sss*at]ilha+IbAt]ilha+ej`at+l]n]i6-+ Now that we’ve talked about how the controllers are set up, we can show you how we’ve actually implemented it. Table 4-3 shows all the controller actions we have written. Table 4-3. Our Application Controllers

Controller File

Description

ib[_kjpnkhhan*ldl

Parent controller to all action classes

ib[bap_d[lkop[_kjpnkhhan*ldl

Fetch a message

ib[bap_d[lkopo[_kjpnkhhan*ldl

Fetch several messages

ib[bap_d[pdna]`o[_kjpnkhhan*ldl

Fetch the threads

ib[lkop[bkni[_kjpnkhhan*ldl

Post messages

ib[lkop[lnk_aoo[_kjpnkhhan*ldl

Process a message

ib[oa]n_d[lnk_aoo[_kjpnkhhan*ldl

Process a search request

Now, if we were to do this in the traditional Cake way, there would be only two files: iaoo]ca[ _kjpnkhhan*ldl, to contain all actions relating to messages, and pdna]`[_kjpnkhhan*ldl, to contain all actions relating to threads. The Iaoo]ca?kjpnkhhan would contain actions that fetch one or more posts and handle message posting, and it would contain various supporting functions. In this case, by separating out the actions as classes, we gain better management. All the action classes have their own corresponding model, as shown in Table 4-4. Table 4-4. Action Controllers and the Corresponding Models

Controller

Model

File

Ib?kjpnkhhan

No associated model

IbBap_dIaoo]ca?kjpnkhhan

IbBap_dIaoo]ca

]ll+ik`aho+ib[bap_d[iaoo]ca*ldl

IbBap_dIaoo]cao?kjpnkhhan

IbBap_dIaoo]cao

]ll+ik`aho+ib[bap_d[iaoo]cao*ldl

IbBap_dPdna]`o?kjpnkhhan

IbBap_dPdna]`o

]ll+ik`aho+ib[bap_d[pdna]`o*ldl

IbIaoo]caBkni?kjpnkhhan

IbIaoo]caBkni

]ll+ik`aho+ib[iaoo]ca[bkni*ldl

IbIaoo]caLnk_aoo?kjpnkhhan

IbIaoo]caLnk_aoo

]ll+ik`aho+ib[iaoo]ca[lnk_aoo*ldl

IbOa]n_dLnk_aoo?kjpnkhhan

IbOa]n_dLnk_aoo

]ll+ik`aho+ib[oa]n_d[lnk_aoo*ldl

Next, we’ll dive right into the heart of each controller and its view, starting with the IbBap_dIaoo]ca?kjpnkhhan controller.


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

Fetch a Message The IbBap_dIaoo]ca?kjpnkhhan is used to find a particular message using its e`. The bej`>uE` method executes a simple SQL OAHA?P statement to the database and fetches the single message record. The code is shown in Listing 4-5. Listing 4-5. Fetch One Message Controller (mf_fetch_message_controller.php) -68;ldl .6 /6ej_hq`a[kj_a$#ib[_kjpnkhhan*ldl#%7 06 16_h]ooIbBap_dIaoo]ca?kjpnkhhanatpaj`oIb?kjpnkhhanw 26 36r]n j]ia9#IbBap_dIaoo]ca#7 46 56r]n naoqhp9]nn]u$#naoqhp#9:##( -,6#iaoo]ca#9:##( --6#annkno#9:##( -.6#`]p]#9:## -/6%7 -06 -16bqj_pekj^abknaBehpan$%w -26 -36pdeo):[_da_g=f]t$%7 -46y -56 .,6bqj_pekj[r]he`]pekj$%w .-6 ..6 naoqhp9pnqa7 ./6 .06pdeo):`]p]9]nn]u$#IbBap_dIaoo]ca#%7 .16pdeo):`]p]W#IbBap_dIaoo]ca#YW#iaoo]caE`#Y9##7 .26 .36eb$eooap$pdeo):l]ooa`=ncoW#iaoo]caE`#Y%%w .46pdeo):`]p]W#IbBap_dIaoo]ca#YW#iaoo]caE`#Y9£ pdeo):l]ooa`=ncoW#iaoo]caE`#Y7 .56y /,6 /-6pdeo):IbBap_dIaoo]ca):oap$pdeo):`]p]%7 /.6 //6eb$ pdeo):IbBap_dIaoo]ca):r]he`]pao$%%w /06 /16 naoqhp9b]hoa7 /26 /36pdeo):naoqhpW#naoqhp#Y9#,#7 /46pdeo):naoqhpW#iaoo]ca#Y9£ Pdana]naokialnk^haiosepdukqnnamqaop*7

97


98

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

/56pdeo):naoqhpW#annkno#Y9£ pdeo):IbBap_dIaoo]ca):r]he`]pekjAnnkno7 0,6y 0-6 0.6napqnj naoqhp7 0/6y 006 016bqj_pekjej`at$%w 026 036eb$pdeo):[r]he`]pekj$%%w 046 056 iaoo]ca9pdeo):Iaoo]ca):bej`>uE`$£ pdeo):`]p]W#IbBap_dIaoo]ca#YW#iaoo]caE`#Y%7 1,6 1-6eb$ iaoo]ca99##%w 1.6pdeo):naoqhpW#naoqhp#Y9#,#7 1/6pdeo):naoqhpW#iaoo]ca#Y9£ #Pdanas]o]lnk^haibap_dejcpdaiaoo]ca*Lha]oapnu]c]ejh]pan*#7 106y 116ahoaw 126 136pdeo):naoqhpW#naoqhp#Y9#-#7 146pdeo):naoqhpW#iaoo]ca#Y9£ #Iaoo]cabap_da`oq__aoobqhhu*#7 156pdeo):naoqhpW#`]p]#Y9 iaoo]ca7 2,6y 2-6y 2.6y 2/6 206bqj_pekj^abknaNaj`an$%w 216 226pdeo):oap$#naoqhp#(pdeo):naoqhp%7 236y 246y 256 3,6;: Each action class returns a set of key/value pairs to the caller. On lines 9 through 12, there are four standard ones that will always be returned: Ê

UÊ naoqhp: Whether the request was successful or not: - or ,

Ê

UÊ iaoo]ca: The human-readable message that goes with the result

Ê

UÊ annkno: A set of key/value pairs, where the key is the parameter and the value is the error message

Ê

UÊ `]p]: If the request is for data, where to look for it


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

Most of the action classes have three methods: ^abknaBehpan, ej`at, and ^abknaNaj`an. The ^abknaBehpan method checks whether it’s an Ajax call. The parent [_da_g=f]t$% method looks like this: bqj_pekj[_da_g=f]t$%w eb$pdeo):NamqaopD]j`han):eo=f]t$%%w ++Pdeoiqopateop6X]llXreasoXh]ukqpoXfokjX]f]t*_pl pdeo):NamqaopD]j`han):naj`an=o$ pdeo(#fokj#%7 y y We have manually mapped Ajax calls to JSON returns. If it is an Ajax call, the layout X]llX reasoXh]ukqpoXfokjX]f]t*_pl is used. We would like to return data to callers in a standard way, of course. However, this is not always possible, Ajax and server-side calls can handle formatted data like JSON, but then HTML messes up the format. The main ej`at$% method is where all the action happens. We have created a [r]he`]pekj$% method. Any parameter coming into the action class must be validated, and we make use of Cake’s validation as much as we can. To do this, we create a model specifically for our action class called IbBap_dIaoo]ca, as shown in Listing 4-6. Listing 4-6. MfFetchMessageController Model (app/models/mf_fetch_message.php) 8;ldl _h]ooIbBap_dIaoo]caatpaj`o=llIk`ah w ++I]ejhubknLDL0qoano r]n j]ia9#IbBap_dIaoo]ca#7 r]n qoaP]^ha9b]hoa7 r]n r]he`]pa9]nn]u$#iaoo]caE`#9:]nn]u$ #nqha#9:]nn]u$#^apsaaj#(/2(/2%( #namqena`#9:pnqa( #iaoo]ca#9:#Lha]oalnkre`a]iaoo]cae`£ kb/2_d]n]_panoejhajcpd*#% %7 y ;: Once the validation has passed, we go ahead and carry out the business logic within ej`at. When that’s done, the ^abknaNaj`an$% method is called. This method sets the naoqhp variable for the views. Of course, we could have just as easily set the result in ej`at$%, but following the idea of the Command pattern, we’re keeping code decoupled and standardized. Our view for the IbBap_dIaoo]ca?kjpnkhhan is quite simple. It takes naoqhpW#`]p]#Y and formats it in HTML, ready to be displayed. It’s worth highlighting that the JSON output

99


100

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

also makes use of the naoqhp variable, but in that case, it formats the output in JSON notation instead of HTML. Our HTML view is shown in Listing 4-7. Listing 4-7. Fetch One Message View (app/views/mf_fetch_message/index.ctp) 8;ldl eb$eooap$ naoqhpW#`]p]#YW#Iaoo]ca#Y%%w a_dk#8`er_h]oo9iaoo]ca:#7 a_dk#8`er_h]oo9iaoo]ca[da]`an:#7 a_dk#8d/:#* naoqhpW#`]p]#YW#Iaoo]ca#Y£ Woq^fa_pY*#8+]:8+d/:#7 a_dk#"j^ol78d2:>u#* naoqhpW#`]p]#YW#Iaoo]ca#Y£ Wai]ehY*#8+d2:#7 a_dk#8+`er:#7  iaoo]ca[e`9 naoqhpW#`]p]#YW#Iaoo]ca#YWe`Y7  pdna]`[e`9 naoqhpW#`]p]#YW#Iaoo]ca#YWpdna]`[e`Y7 a_dk#8`er_h]oo9iaoo]caodknp[iaoo]ca9£ bqhh[iaoo]ca9bap_da`9,e`9iaoo]ca[#* iaoo]ca[e`*#:#7 a_dk naoqhpW#`]p]#YW#Iaoo]ca#YWiaoo]caY7  nalhu[hejg9dpih):hejg$#Nalhu#(£ #+_]ga+[[_d]lpano[[+iaoo]ca[bknqi+IbIaoo]caBkni+ej`at+£ nalhu[pk6#* iaoo]ca[e`*#+pdna]`[e`6#* pdna]`[e`*#+#%7 a_dk#8`er:#* nalhu[hejg*#8+`er:#7 a_dk#8+`er:#7 a_dk#8+`er:#7 y ;:

Fetch Several Messages At present, our IbBap_dIaoo]cao?kjpnkhhan, shown in Listing 4-8, helps us to find queries based on the thread ID.

NNote We can quite easily see the fetch several messages action being deprecated, in favor of using the IbIaoo]caLnk_aoo?kjpnkhhan as a generic “find any messages” class. We’ll leave that as an exercise for

the reader.


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

Listing 4-8. Fetch Several Messages Controller (mf_fetch_messages_controller.php) -68;ldl .6 /6ej_hq`a[kj_a$#ib[_kjpnkhhan*ldl#%7 06 16_h]ooIbBap_dIaoo]cao?kjpnkhhanatpaj`oIb?kjpnkhhanw 26 36r]n j]ia9#IbBap_dIaoo]cao#7 46 56++Pdaiaoo]canaoqhpo -,6r]n iaoo]cao9]nn]u$%7 --6 -.6++Pdaiaoo]canaoqhpokn`ana`sepdej`ajpej`e_]pkn -/6r]n iaoo]caoKn`ana`9]nn]u$%7 -06 -16r]n naoqhp9]nn]u$#naoqhp#9:##( -26#iaoo]ca#9:##( -36#annkno#9:##( -46#`]p]#9:## -56%7 .,6 .-6bqj_pekj^abknaBehpan$%w ..6 ./6pdeo):[_da_g=f]t$%7 .06y .16 .26bqj_pekj[r]he`]pekj$%w .36 .46 naoqhp9pnqa7 .56 /,6pdeo):`]p]9]nn]u$#IbBap_dIaoo]cao#%7 /-6pdeo):`]p]W#IbBap_dIaoo]cao#YW#pdna]`E`#Y9##7 /.6 //6eb$eooap$pdeo):l]ooa`=ncoW#pdna]`E`#Y%%w /06pdeo):`]p]W#IbBap_dIaoo]cao#YW#pdna]`E`#Y9£ pdeo):l]ooa`=ncoW#pdna]`E`#Y7 /16y /26 /36pdeo):IbBap_dIaoo]cao):oap$pdeo):`]p]%7 /46 /56eb$ pdeo):IbBap_dIaoo]cao):r]he`]pao$%%w 0,6 0-6 naoqhp9b]hoa7 0.6 0/6pdeo):naoqhpW#naoqhp#Y9#,#7 006pdeo):naoqhpW#iaoo]ca#Y9£ Pdana]naokialnk^haiosepdukqnnamqaop*7

101


102

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

016pdeo):naoqhpW#annkno#Y9£ pdeo):IbBap_dIaoo]ca):r]he`]pekjAnnkno7 026y 036 046napqnj naoqhp7 056y 1,6 1-6bqj_pekjej`at$%w 1.6 1/6eb$pdeo):[r]he`]pekj$%%w 106 116 _kj`epekjo9]nn]u$%7 126 136eb$eooap$pdeo):`]p]W#IbBap_dIaoo]cao#Y£ W#pdna]`E`#Y%%w 146 156 pdna]`E`9£ pdeo):`]p]W#IbBap_dIaoo]cao#YW#pdna]`E`#Y7 2,6 _kj`epekjoWY9]nn]u$£ Iaoo]ca*pdna]`[e`99: pdna]`E`%7 2-6y 2.6 2/6 iaoo]cao9pdeo):Iaoo]ca):bej`$#]hh#( 206]nn]u$#_kj`epekjo#9: _kj`epekjo( 216jqhh( 226#kn`an#9:#Iaoo]ca*p[_na]pa`[]p=O?# 236%%7 246 256eb$ iaoo]cao99##%w 3,6 3-6pdeo):naoqhpW#naoqhp#Y9#,#7 3.6pdeo):naoqhpW#iaoo]ca#Y9£ #Pdanas]o]lnk^haibap_dejcpdapdna]`o*Lha]oapnu]c]ejh]pan*#7 3/6y 306ahoaw 316 326pdeo):iaoo]cao9 iaoo]cao7 336 346pdeo):[oknpIaoo]cao$%7 356 4,6pdeo):naoqhpW#naoqhp#Y9#-#7 4-6pdeo):naoqhpW#iaoo]ca#Y9£ #Iaoo]caobap_da`oq__aoobqhhu*#7 4.6pdeo):naoqhpW#`]p]#Y9pdeo):iaoo]caoKn`ana`7 4/6y 406y 416


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

426pdeo):oap$#naoqhp#(pdeo):naoqhp%7 436y 446 456bqj_pekj^abknaNaj`an$%w 5,6 5-6pdeo):oap$#naoqhp#(pdeo):naoqhp%7 5.6y 5/6 506bqj_pekj[oknpIaoo]cao$ op]np[e`9##( harah9##%w 516 526op]pe_ opklNqj9-7 536 546++Ukqjarangjks 556eb$ opklNqj'':-,,,%w -,,6napqnj7 -,-6y -,.6 -,/6bkn$ e`t9,7 e`t8oevakb$pdeo):iaoo]cao%7 e`t''%w -,06 -,16eb$eooap$pdeo):iaoo]caoW e`tYW#@kja#Y%%w -,26 -,36++Bkqj`]nkkpiaoo]ca -,46eb$pdeo):iaoo]caoW e`tYW#Iaoo]ca#Y£ W#nalhu[pk#Y99 op]np[e`%w -,56 --,6pdeo):iaoo]caoW e`tYW#Iaoo]ca#Y£ W#ej`ajp#Y9 harah7 ---6 --.6pdeo):iaoo]caoKn`ana`WY9£ pdeo):iaoo]caoW e`tY7 --/6 --06 iaoo]ca[e`9£ pdeo):iaoo]caoW e`tYW#Iaoo]ca#YW#e`#Y7 --16 --26++Pd]p#o`kja7hap#onaikraep --36pdeo):iaoo]caoW e`tYW#@kja#Y9#-#7 --46 --56pdeo):[oknpIaoo]cao$ iaoo]ca[e`( harah*#*#%7 -.,6y -.-6y -..6y -./6y -.06y -.16 -.26;:

103


104

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

As you can see, the structure of this class is similar to that of the IbBap_dIaoo]ca?kjpnkhhan. In this case, we have an extra private method [oknpIaoo]cao$% on line 94, which sorts our message recursively according to replies. We have used a simple full stop to signify the depth of the message within the thread. For peace of mind, we’ve placed a stopper on line 99 just in case the method goes into an infinite recursive loop. Again, our view for the IbBap_dIaoo]cao controller simply takes the naoqhpW#`]p]#Y, loops through the data, and formats the output for HTML display. We’ve used the indent indicator to indent our messages from the left side of the browser. As we are multiplying the number of full stops by pixel value, the greater the depth, the further away it will be displayed from the left margin (see lines 7 and 9 in Listing 4-9). You can just as easily use ai, as that probably makes it more accessible. But hey, we just wanted to make it obvious that you can use pixels instead. Our view is shown in Listing 4-9. Listing 4-9. Fetch Multiple Messages View (app/views/mf_fetch_messages/index.ctp) -68d.:Iaoo]cao8+d.: .6 /68;ldl 06 16bkna]_d$ naoqhpW#`]p]#Y]o _qnnajp[iaoo]ca%w 26 36 ej`ajp9opnhaj$ _qnnajp[iaoo]caW#Iaoo]ca#YWej`ajpY%&.,7 46 56a_dk#8`eropuha9i]ncej)habp6#* ej`ajp*#lt7:#7 -,6 --6a_dk#8`er_h]oo9iaoo]ca[da]`an:#7 -.6a_dk#8d/:#* _qnnajp[iaoo]caW#Iaoo]ca#YWoq^fa_pY*#8+]:8+d/:#7 -/6a_dk#"j^ol78d2:>u£ #* _qnnajp[iaoo]caW#Iaoo]ca#YWai]ehY*#8+d2:#7 -06 -16a_dk#8+`er:#7 -26 -36 iaoo]ca[e`9 _qnnajp[iaoo]caW#Iaoo]ca#YWe`Y7 -46 pdna]`[e`9 _qnnajp[iaoo]caW#Iaoo]ca#YWpdna]`[e`Y7 -56 .,6a_dk#8`er_h]oo9iaoo]ca[iaoo]ca£ odknp[iaoo]ca9bqhh[iaoo]ca9bap_da`9,e`9iaoo]ca[#* iaoo]ca[e`*#:#7 .-6a_dk _qnnajp[iaoo]caW#Iaoo]ca#YWiaoo]caY7 ..6a_dk#8`er:£ 8]dnab9+_]ga+[[_d]lpano[[+iaoo]ca[bknqi+IbIaoo]caBkni+ej`at+£ nalhu[pk6#* iaoo]ca[e`*#+pdna]`[e`6#* pdna]`[e`*#+:Nalhu8+]:8+`er:#7 ./6a_dk#8+`er:#7 .06 .16a_dk#8+`er:#7 .26y .36 .46;:


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

Fetch the Threads We have used the pagination feature within Cake to separate the threads into pages. Listing 4-10 shows the IbBap_dPdna]`o?kjpnkhhan. Listing 4-10. Fetch the Threads Controller (mf_fetch_threads_controller.php) -68;ldl .6 /6ej_hq`a[kj_a$#ib[_kjpnkhhan*ldl#%7 06 16_h]ooIbBap_dPdna]`o?kjpnkhhanatpaj`oIb?kjpnkhhanw 26 36r]n j]ia9#IbBap_dPdna]`o#7 46 56r]n l]cej]pa9]nn]u$#heiep#9:.,( -,6#kn`an#9:]nn]u$£ #Pdna]`*h]op[iaoo]ca[`]pa#9:#@AO?#%%7 --6 -.6r]n naoqhp9]nn]u$#naoqhp#9:##( -/6#iaoo]ca#9:##( -06#annkno#9:##( -16#`]p]#9:## -26%7 -36 -46bqj_pekj^abknaBehpan$%w -56 .,6pdeo):[_da_g=f]t$%7 .-6y ..6 ./6bqj_pekj[r]he`]pekj$%w .06 .16 naoqhp9pnqa7 .26 .36napqnj naoqhp7 .46y .56 /,6bqj_pekjej`at$%w /-6 /.6eb$pdeo):[r]he`]pekj$%%w //6 /06 pdna]`o9pdeo):l]cej]pa$#Pdna]`#%7 /16 /26eb$ pdna]`o99##%w /36pdeo):naoqhpW#naoqhp#Y9#,#7 /46pdeo):naoqhpW#iaoo]ca#Y9£ #Pdanas]o]lnk^haibap_dejcpdapdna]`o*Lha]oapnu]c]ejh]pan*#7 /56y

105


106

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

0,6ahoaw 0-6pdeo):naoqhpW#naoqhp#Y9#-#7 0.6pdeo):naoqhpW#iaoo]ca#Y9£ #Pdna]`obap_da`oq__aoobqhhu*#7 0/6pdeo):naoqhpW#`]p]#Y9 pdna]`o7 006y 016y 026y 036 046bqj_pekj^abknaNaj`an$%w 056 1,6pdeo):oap$#naoqhp#(pdeo):naoqhp%7 1-6y 1.6y 1/6 106;: Adding pagination is essentially a three-step process. Referring to our controller class, first you set up the options in the controller via the l]cej]pa variable on line 9. In our case, we limit the number of records returned to 20. We also order the threads according to the h]op[iaoo]ca[`]pa field in descending order. Next, instead of using the Cake bej`>uWBeah` J]iaY method, we use the l]cej]pa method. This takes the model name as its main parameter (see line 34). The third and final step in using pagination is at the bottom of the view, shown in Listing 4-11. Cake provides a paginate helper (see line 43), which is included by default once the l]cej]pa method is used. We simply call the lnar and jatp methods, which will generate the necessary HTML links. Listing 4-11. Fetch the Threads View (app/views/mf_fetch_threads.php) -68d.:Pdna]`o8+d.: .6 /68;ldl 06a_dkf]r]o_nelp):hejg$#ib[bap_d[pdna]`o+ej`at#%7 16;: 26 368;ldl 46 56bkna]_d$ naoqhpW#`]p]#Y]o _qnnajp[iaoo]ca%w -,6 --6 iaoo]ca[e`9 _qnnajp[iaoo]caW#Iaoo]ca#YWe`Y7 -.6 pdna]`[e`9 _qnnajp[iaoo]caW#Iaoo]ca#YWpdna]`[e`Y7 -/6 iaoo]ca[jqi9 _qnnajp[iaoo]caW#Pdna]`#YWiaoo]ca[jqiY7 -06 -16a_dk#8`er_h]oo9pdna]`[da]`an:#7 -26a_dk#8d/:#* _qnnajp[iaoo]caW#Iaoo]ca#Y£ Woq^fa_pY*#8+]:8+d/:#7


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

-36a_dk#"j^ol78d2:Op]npa`>u£ #* _qnnajp[iaoo]caW#Iaoo]ca#YWj]iaY*#8+d2:#7 -46 -56++Jqi^ankbiaoo]cao .,6a_dk#"j^ol7x"j^ol7#* iaoo]ca[jqi*#iaoo]cao#7 .-6 ..6++Klajhejg ./6a_dk#"j^ol7x"j^ol78ol]je`9klaj[hejg[#* iaoo]ca[e`*#:£ 8]dnab9f]r]o_nelp6rke`$,%7£ kj_he_g9capIaoo]ca$X##* iaoo]ca[e`*#X#(X##* pdna]`[e`*#X#%7:Klaj8+]:8+ol]j:#7 .06 .16++Reaspdna]` .26a_dk#"j^ol7x"j^ol78]£ dnab9+_]ga+[[_d]lpano[[+iaoo]ca[bknqi+IbBap_dIaoo]cao+ej`at+pdna]`E`6#*£ pdna]`[e`*#+:HeopIaoo]cao8+]:#7 .36 .46++Hk]`ejc .56a_dk#"j^ol7x"j^ol78`ere`9hk]`ejc[#* iaoo]ca[e`*#:8+`er:#7 /,6 /-6a_dk#8+`er:#7 /.6 //6++@eolh]ubenopiaoo]ca /06a_dk#8`er_h]oo9pdna]`[iaoo]caodknp[iaoo]ca9 /16bqhh[iaoo]ca9bap_da`9,e`9iaoo]ca[#* iaoo]ca[e`*#:8+`er:#7 /26y /36 /46;: /56 0,68dn_h]oo9l]cej]pkn[heja: 0-6 0.68;ldl 0/6eb$eooap$ l]cej]pkn%%w 006 016a_dkl]cej]pkn):lnar$#ÃLnarekqo#(jqhh( 026jqhh(]nn]u$#_h]oo#9:#`eo]^ha`#%%7 036a_dk#"j^ol7#7 046a_dkl]cej]pkn):jatp$#JatpÄ#(jqhh( 056jqhh(]nn]u$#_h]oo#9:#`eo]^ha`#%%7 1,6a_dk#"j^ol7#7 1-6a_dkl]cej]pkn):_kqjpan$%7 1.6y 1/6;: Line 4 in Listing 4-11 creates an HTML o_nelp tag, which will call the JavaScript file located at ]ll+sa^nkkp+fo+ib[bap_d[pdna]`o+ej`at*fo. This file is shown in Listing 4-12.

107


108

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

Listing 4-12. JavaScript File Used to Support the Fetching of Threads (app/webroot/js/mf_fetch_ threads/index.js) -6bqj_pekjcapIaoo]ca$iaoo]ca[e`(pdna]`[e`%w .6 /6r]nbqhh[iaoo]ca9£ $#iaoo]ca[#'iaoo]ca[e`%*cap=ppne^qpa$#bqhh[iaoo]ca#%7 06 16eb$bqhh[iaoo]ca9##%w 26 $#iaoo]ca[#'iaoo]ca[e`%*ejjanDPIH9bqhh[iaoo]ca7 36napqnjb]hoa7 46y 56 -,6jas=f]t*Namqaop$#+_]ga+[[_d]lpano[[+iaoo]ca[bknqi+IbBap_dIaoo]ca+£ ej`at+iaoo]caE`6#'iaoo]ca[e`'#+*fokj#( --6w]ouj_dnkjkqo6pnqa( -.6ar]hO_nelpo6pnqa( -/6kj?kilhapa6bqj_pekj$naolkjoa(fokj%w -06 -16eb$fokjW#naoqhp#Y99#-#%w -26 -36iaoo]ca[hejgo9£ fokjW#`]p]#YW#Iaoo]ca#YW#iaoo]ca#Y7 -46iaoo]ca[hejgo'9#8`er:#7 -56iaoo]ca[hejgo'9#8]dnab9f]r]o_nelp6£ rke`$,%7kj_he_g9_hkoaIaoo]ca$X##'iaoo]ca[e`'#X#%7:?hkoa8+]:x#7 .,6iaoo]ca[hejgo'9£ #8]dnab9+_]ga+[[_d]lpano[[+iaoo]ca[bknqi+IbBap_dIaoo]cao+ej`at+£ pdna]`E`6#'pdna]`[e`'#+:HeopIaoo]cao8+]:x#7 .-6iaoo]ca[hejgo'9£ #8]dnab9+_]ga+[[_d]lpano[[+iaoo]ca[bknqi+IbIaoo]caBkni+ej`at+£ nalhu[pk6#'iaoo]ca[e`'#+pdna]`[e`6#'pdna]`[e`'#+:Nalhu8+]:#7 ..6iaoo]ca[hejgo'9#8+`er:#7 ./6 .06 $#iaoo]ca[#'iaoo]ca[e`%*ejjanDPIH9iaoo]ca[hejgo7 .16 .26 $#iaoo]ca[#'iaoo]ca[e`%*oap=ppne^qpa$£ #bqhh[iaoo]ca#( $#iaoo]ca[#'iaoo]ca[e`%*ejjanDPIH%7 .36 $#hk]`ejc[#'iaoo]ca[e`%*ejjanDPIH9##7 .46y .56y( /,6kjHk]`ejc6bqj_pekj$%w /-6 /.6 $#iaoo]ca[#'iaoo]ca[e`%*oap=ppne^qpa$£ #odknp[iaoo]ca#( $#iaoo]ca[#'iaoo]ca[e`%*ejjanDPIH%7 //6 $#hk]`ejc[#'iaoo]ca[e`%*ejjanDPIH9£ #8eicon_9+_]ga+[[_d]lpano[[+iaoo]ca[bknqi+eic+]f]t)hk]`an*ceb]hp9+:£ hk]`ejc(lha]oas]ep*#7 /06y /16y%7 /26y


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

/36 /46bqj_pekj_hkoaIaoo]ca$iaoo]ca[e`%w /56 0,6r]nodknp[iaoo]ca9 $#iaoo]ca[#'iaoo]ca[e`%*ÂŁ cap=ppne^qpa$#odknp[iaoo]ca#%7 0-6 $#iaoo]ca[#'iaoo]ca[e`%*ejjanDPIH9odknp[iaoo]ca7 0.6y When a user clicks the Open link (see line 23 in Listing 4-11), the capIaoo]ca function on line 1 in Listing 4-12 is called. This function makes an Ajax call to the IbBap_dIaoo]ca method (see line 10). That method will return the message in JSON format. We start the parsing on line 13. We finish the process by displaying the message together with some links, on line 24. A sample of the parsed output is shown in Figure 4-3.

Figure 4-3. Displaying threads

109


110

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

Post Messages Our message posting form, shown in Listing 4-13, posts messages using Ajax by default. However, if the user has JavaScript turned off, it will degrade to standard HTML posting. Because it's not part of our API method calls, its structure doesn’t mirror the API action classes. However, in the future we may include this as an API method call where users can use our form instead of writing their own. They can conveniently include the form in the sidebar of their web site—in a blog, for example. Listing 4-13. Post a Message Controller (mf_message_form_controller.php) 8;ldl ej_hq`a[kj_a$#ib[_kjpnkhhan*ldl#%7 _h]ooIbIaoo]caBkni?kjpnkhhanatpaj`oIb?kjpnkhhanw r]n j]ia9#IbIaoo]caBkni#7 bqj_pekjej`at$%w eb$eooap$pdeo):l]ooa`=ncoW#nalhu[pk#Y%%w pdeo):`]p]W#Iaoo]ca#YW#nalhu[pk#Y9pdeo):l]ooa`=ncoW#nalhu[pk#Y7  nalhuIaoo]caE`9pdeo):`]p]W#Iaoo]ca#YW#nalhu[pk#Y7  nalhuIaoo]ca9pdeo):Iaoo]ca):bej`>uE`$ nalhuIaoo]caE`%7 eb$ailpu$ nalhuIaoo]ca%%w pdeo):`]p]W#Iaoo]ca#YW#oq^fa_p#Y9£ #NA6#* nalhuIaoo]caW#Iaoo]ca#YW#oq^fa_p#Y7 y y eb$eooap$pdeo):l]ooa`=ncoW#pdna]`[e`#Y%%w pdeo):`]p]W#Iaoo]ca#YW#pdna]`[e`#Y9pdeo):l]ooa`=ncoW#pdna]`[e`#Y7 y y y ;: The view for the form is pretty sparse, as shown here: 8;ldl a_dkpdeo):ahaiajp$#iaoo]ca[bkni#%7 ;:


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

As you can see, the view for the message form is separated off into an element, as shown in Listing 4-14. Listing 4-14. Message Posting Form as an Element (/app/views/elements/message_form.ctp) -68;ldl .6eb$oaooekj):_da_g$#Iaoo]ca*bh]od#%%w /6a_dk#8`er_h]oo9dehecdp:#7 06oaooekj):bh]od$%7 16a_dk#8+`er:#7 26y 36;: 46 568))PejuI?A)): -,68;ldl --6a_dk f]r]o_nelp£ ):hejg$#fo_nelpo+pejui_a+fo_nelpo+peju[i_a+peju[i_a#%7 -.6;: -/68o_nelppula9patp+f]r]o_nelp: -06pejuI?A*ejep$w -16ik`a6patp]na]o( -26pdaia6]`r]j_a`( -36pdaia[]`r]j_a`[^qppkjo-6£ ^kh`(ep]he_(qj`anheja(oal]n]pkn(opnegapdnkqcd(fqopebuhabp(£ fqopebu_ajpan(fqopebunecdp(fqopebubqhh(^qhheop(jqiheop(£ qj`k(na`k(hejg(qjhejg( -46pdaia[]`r]j_a`[^qppkjo.6( -56pdaia[]`r]j_a`[^qppkjo/6( .,6pdaia[]`r]j_a`[pkkh^]n[hk_]pekj6pkl( .-6pdaia[]`r]j_a`[pkkh^]n[]hecj6habp( ..6pdaia[]`r]j_a`[op]pqo^]n[hk_]pekj6^kppki( ./6atpaj`a`[r]he`[ahaiajpo6£ ]Wj]iaxdnabxp]ncapxpephaxkj_he_gY(eicW_h]ooxon_x^kn`an9,x]hpx£ pephaxdol]_axrol]_axse`pdxdaecdpx]hecjxkjikqoakranxkjikqoakqpxj]iaY(£ dnW_h]ooxse`pdxoevaxjkod]`aY(bkjpWb]_axoevax_khknxopuhaY(£ ol]jW_h]oox]hecjxopuhaY( .06_kjpajp[_oo6+_]ga+[[_d]lpano[[+iaoo]ca[bknqi+_oo+chk^]h*_oo .16 .26y%7 .368+o_nelp: .468))+PejuI?A)): .56 /,68;ldl /-6a_dkf]r]o_nelp):hejg$#ahaiajpo+iaoo]ca[bkni#%7 /.6;: //6 /068`ere`9l]ca[iaoo]ca:8+`er: /16

111


112

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

/268`ere`9iaoo]ca[bkni: /36 /468;ldl /56a_dk]f]t):bkni$jqhh( 0,6#lkop#( 0-6]nn]u$#qnh#9:#+IbIaoo]caLnk_aoo+ej`at#( 0.6#_kilhapa#9:#ql`]paBkni$namqaop(fokj%7#( 0/6#^abkna#9:#^abknaIaoo]ca$%7# 006% 016%7 026;: 036 0468beah`oapopuha9^kn`an6-ltokhe`^h]_g7^]_gcnkqj`)ei]ca6qnh$£ #+_]ga+[[_d]lpano[[+iaoo]ca[bknqi+]ll+sa^nkkp+eic+^]_gcnkqj`*ceb#%7: 0568hacaj`:8;ldl[[$#=``]Iaoo]ca#%7;:8+hacaj`: 1,6Lha]oabehhej]hhbeah`o*Naiai^an(ol]i]j`^a`]ija` 1-68;ldl 1.6a_dkbkni):annkn$#Iaoo]ca*j]ia#%7 1/6a_dkbkni):ejlqp$#Iaoo]ca*j]ia#(]nn]u$£ #e`#9:#iaoo]caj]ia#(#h]^ah#9:#J]ia6#(#oeva#9:#1,#(£ #i]thajcpd#9:#.11#(#annkn#9:b]hoa%%7 106 116a_dkbkni):annkn$#Iaoo]ca*ai]eh#%7 126a_dk#Ukqnai]ehsehhjkp^a`eolh]ua`*#7 136a_dkbkni):ejlqp$#Iaoo]ca*ai]eh#(]nn]u$£ #e`#9:#iaoo]caai]eh#(#h]^ah#9:#Ai]eh6#(#oeva#9:#1,#(£ #i]thajcpd#9:#.11#(#annkn#9:b]hoa%%7 146 156a_dkbkni):annkn$#Iaoo]ca*oq^fa_p#%7 2,6a_dkbkni):ejlqp$#Iaoo]ca*oq^fa_p#(]nn]u$£ #e`#9:#iaoo]caoq^fa_p#(#h]^ah#9:#Oq^fa_p6#(#oeva#9:#1,#(£ #i]thajcpd#9:#.11#(#annkn#9:b]hoa%%7 2-6 2.6a_dkbkni):annkn$#Iaoo]ca*iaoo]ca#%7 2/6a_dkbkni):ejlqp$#Iaoo]ca*iaoo]ca#(]nn]u$£ #e`#9:#iaoo]caiaoo]ca#(#pula#9:#patp]na]#(#h]^ah#9:#Iaoo]ca6#(£ #nkso#9:#.,#(#annkn#9:b]hoa%%7 206 216a_dkbkni):de``aj$#Iaoo]ca*nalhu[pk#%7 226a_dkbkni):de``aj$#Iaoo]ca*pdna]`[e`#%7 236;: 2468+beah`oap: 256 3,68;ldla_dkbkni):aj`$]nn]u$#h]^ah#9:#Oq^iepIaoo]ca#%%7;: 3-6 3.68+`er:


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

There are a number of interesting things happening in this element. Before we go any further, we have to admit that this simple form turned out to be quite complex because of the use of Ajax and how it can degrade in the absence of JavaScript. First, we have included the TinyMCE what you see is what you get (WYSIWYG) web editor. It was either that or the FCKeditor, which is just as good.

NNote TinyMCE (dppl6+pejui_a*iktea_k`a*_ki) and FCKeditor (dppl6+sss*b_ga`epkn*jap) are two of the most popular web-based open source text editors. You will generally use them to replace the HTML patp]na] tag. They provide editing capabilities much like any desktop word processing editor.

Installing TinyMCE is quite easy. First, download the package from the TinyMCE web site (dppl6++pejui_a*iktea_k`a*_ki). Then unzip the code into the folder +]ll+sa^nkkp+fo+ fo_nelpo+. Next, we need to initialize the editor. This is done from lines 10 to 27 in Listing 4-14. Later, when the form is saved, we also need to trigger TinyMCE to save the content. This is done in the JavaScript helper file (see Listing 4-15, line 47). In Listing 4-14, we include our JavaScript helper file in the line a_dkf]r]o_nelp):hejg$ #ahaiajpo+iaoo]ca[bkni#%7 on line 31. The helper file, shown in Listing 4-15, is stored in + ]ll+sa^nkkp+fo+ahaiajpo+iaoo]ca[bkni*fo. We have created an ahaiajpo folder within +]ll+ sa^nkkp+fo. This allows us to easily pick out which JavaScript file goes with which *_pl file, as we have named the JavaScript file to be the same as the *_pl file that included it. Listing 4-15. JavaScript Helper Functions for the Message Posting Form (/app/webroot/js/elements/message_form.js) -6 .6bqj_pekjql`]paBkni$namqaop(fokj%w /6 06r]nioc[naj`an9##7 16r]nnaoqhp9fokjW#naoqhp#Y7 26r]niaoo]ca9fokjW#iaoo]ca#Y7 36r]nannkno9fokjW#annkno#Y7 46 56 $#l]ca[iaoo]ca#%*ejjanDPIH9#8`er_h]oo9dehecdp:#'iaoo]ca'#8+`er:#7 -,6 --6 $#*oq^iepejlqp#%W,Y*`eo]^ha`9b]hoa7 -.6 -/6++Naikra]hhlnarekqoannkniaoo]cao -06r]n_qnnajp[annkno9 $#*annkn)iaoo]ca#%7 -16 -26bkn$r]ne9,7e8_qnnajp[annkno*hajcpd7e''%w -36r]nannkn[p]c9_qnnajp[annknoWeY7 -46annkn[p]c*l]najpJk`a*naikra?deh`$annkn[p]c%7 -56y .,6

113


114

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

.-6++Ebpdana]naannkniaoo]cao(ql`]papdaoa ..6eb$annkno9##%w ./6 .06bkn$r]nbeah`[e`ejannkno%w .16 .26++Pdaannkniaoo]caej]`er .36r]n`er[annkn9`k_qiajp*_na]paAhaiajp$`er%7 .46`er[annkn*_h]ooJ]ia9annkn)iaoo]ca7 .56`er[annkn*ejjanDPIH9annknoWbeah`[e`Y7 /,6 /-6bkni[aha9 $#iaoo]ca#'beah`[e`%7 /.6l]najp[bkni[aha9bkni[aha*l]najpJk`a7 //6 /06l]najp[bkni[aha*ejoanp>abkna$`er[annkn( /16bkni[aha*lnarekqoOe^hejc%7 /26y /36y /46 /56++Ebeps]ooq__aoobqh(pdajsa_ha]npdabkni 0,6eb$naoqhp99-%w 0-6 $#iaoo]ca[bkni#%*ejjanDPIH9##7 0.6y 0/6y 006 016bqj_pekj^abknaIaoo]ca$%w 026 036pejuI?A*pneccanO]ra$%7 046 056 $#l]ca[iaoo]ca#%*ejjanDPIH9£ #8`er_h]oo9dehecdp:Lkopejc(lha]oas]ep***£ 8eicon_9+_]ga+[[_d]lpano[[+iaoo]ca[bknqi+eic+]f]t)hk]`an*ceb]hp9+:£ 8+`er:#7 1,6 1-6 $#*oq^iepejlqp#%W,Y*`eo]^ha`9pnqa7 1.6y 1/6 In the ql`]paBkni method in Listing 4-15, we basically parse the form process return results, which is in the standard format we described earlier, where the results contain the keys, message, errors, and data. We first remove any errors that were previously there. We do this simply by using the naikra?deh` method on line 18.


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

We then display any errors by looping through the annkno key value and displaying it before the field. The Cake Ajax form can easily do this step for us, but it displays the error messages after the field, and we want the user to read the error first and then see the field to which it refers. We use the DOM method ejoanp>abkna to insert a @ER tag, which contains the error message before the field. The web page dppl6++`arahklan*ikvehh]*knc+aj+`k_o+ @KI6ahaiajp*ejoanp>abkna has some good information about DOM methods. If there are no errors, the form has been posted successfully, and we then clear the form to avoid any trigger-happy user. Additionally, we can display some other useful information there at a later date—maybe some advertisement relating to the posted message, for example. Before posting the Ajax request, we call the ^abknaIaoo]ca$% method on line 45. In that function, we need to manually get TinyMCE to save our message. This happens only because we are using Ajax. If you’re using ordinary HTML to post, you won’t need to carry out this step with TinyMCE. After that, we simply add some user interface sugar, starting with a spinning Ajax loader image. Then we disable the submit button. Returning to our message posting form in Listing 4-14, our next step simply uses the Ajax and form helpers to add some form elements (see line 38). An important point to note is the handling of the error messages relating to the fields. This point applies only when the user browser is not running JavaScript; that is, HTML is being used to post messages. We have turned off the automatic display of the error messages relating to Cake’s rendering of the input tags. This is because we want the error messages to be displayed before the input fields. To add the error messages before the field, we manually display the error messages, as in this example: a_dkbkni):annkn$#Iaoo]ca*j]ia#%7 A sample form for adding a message is shown in Figure 4-4.

NNote The Ajax helper is a wrapper for Prototype’s methods. In the Ajax helper, you can use the ql`]pa option to specify which `er container to update the return result. If you don’t use the ql`]pa option, Cake will use Prototype’s Namqaop method. If you do specify an ql`]pa option, it will use the Ql`]pan method.

115


116

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

Figure 4-4. Posting a message

Process a Message In the processing or saving of a message, we use a model that directly maps to a table. This is unlike some of the earlier controller actions, where the models were essentially wrapper classes for validation, as IbIaoo]caLnk_aoo is an API method that weâ&#x20AC;&#x2122;re exposing. As shown in Listing 4-16, it follows the same class structure as the other API methods.


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

Listing 4-16. Save a Message Controller (mf_message_process_controller.php) -68;ldl .6 /6ej_hq`a[kj_a$#ib[_kjpnkhhan*ldl#%7 06 16_h]ooIbIaoo]caLnk_aoo?kjpnkhhanatpaj`oIb?kjpnkhhanw 26 36r]n j]ia9#IbIaoo]caLnk_aoo#7 46 56r]n naoqhp9]nn]u$#naoqhp#9:##( -,6#iaoo]ca#9:##( --6#annkno#9:##( -.6#`]p]#9:## -/6%7 -06 -16bqj_pekj^abknaBehpan$%w -26 -36pdeo):[_da_g=f]t$%7 -46y -56 .,6bqj_pekj[r]he`]pekj$%w .-6 ..6 naoqhp9pnqa7 ./6 .06eb$ailpu$pdeo):`]p]%%w .16 .26pdeo):Iaoo]ca):oap$pdeo):`]p]%7 .36 .46eb$ pdeo):Iaoo]ca):r]he`]pao$%%w .56 /,6 naoqhp9b]hoa7 /-6 /.6eb$pdeo):NamqaopD]j`han):namqaopa`Sepd$%99#bkni#%w //6pdeo):Oaooekj):oapBh]od$[[$£ #Oknnu(pdanas]o]lnk^haisepdukqnbkni`ap]eho(oaa^ahks*#(pnqa%%7 /06y /16 /26pdeo):naoqhpW#naoqhp#Y9#,#7 /36pdeo):naoqhpW#iaoo]ca#Y9£ Pdana]naokialnk^haiosepdukqnnamqaop*7 /46pdeo):naoqhpW#annkno#Y9£ pdeo):Iaoo]ca):r]he`]pekjAnnkno7 /56y 0,6y 0-6 0.6napqnj naoqhp7 0/6y 006

117


118

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

016bqj_pekjej`at$%w 026 036eb$pdeo):[r]he`]pekj$%%w 046 056 iaoo]ca[`]pa9`]pa$#u)i)`D6e6o#(igpeia$%%7 1,6 iaoo]ca[e`9Opnejc66qqe`$%7 1-6 pdna]`[e`9Opnejc66qqe`$%7 1.6 knecPdna]`E`9pdeo):`]p]W#Iaoo]ca#YW#pdna]`[e`#Y7 1/6 106eb$pdeo):`]p]W#Iaoo]ca#YW#pdna]`[e`#Y%w 116 pdna]`[e`9pdeo):`]p]W#Iaoo]ca#YW#pdna]`[e`#Y7 126y 136 146pdeo):Iaoo]ca):_na]pa$%7 156 2,6pdeo):`]p]W#Iaoo]ca#YW#p[_na]pa`[]p#Y9 iaoo]ca[`]pa7 2-6pdeo):`]p]W#Iaoo]ca#YW#pdna]`[e`#Y9 pdna]`[e`7 2.6pdeo):`]p]W#Iaoo]ca#YW#e`#Y9 iaoo]ca[e`7 2/6 206eb$pdeo):Iaoo]ca):o]ra$pdeo):`]p]%%w 216 226eb$pdeo):NamqaopD]j`han):namqaopa`Sepd$%99#bkni#%w 236pdeo):Oaooekj):oapBh]od$£ [[$#Ukqniaoo]cad]o^aajlkopa`#(pnqa%%7 246y 256 3,6pdeo):naoqhpW#iaoo]ca#Y9£ #Ukqniaoo]cad]o^aajlkopa`#7 3-6pdeo):naoqhpW#naoqhp#Y9#-#7 3.6pdeo):naoqhpW#annkno#Y9##7 3/6 306++O]rapdapdna]` 316eb$ailpu$ knecPdna]`E`%%w 326 336 pdna]`@]p]9]nn]u$%7 346 pdna]`@]p]W#benop[iaoo]ca[e`#Y9 iaoo]ca[e`7 356 pdna]`@]p]W#h]op[iaoo]ca[`]pa#Y9 iaoo]ca[`]pa7 4,6 pdna]`@]p]W#e`#Y9 pdna]`[e`7 4-6 pdna]`@]p]W#iaoo]ca[jqi#Y9#-#7 4.6 4/6pdeo):Pdna]`):_na]pa$%7 406 pdna]`[o]ra9pdeo):Pdna]`):o]ra$ pdna]`@]p]%7 416 426eb$ pdna]`[o]ra%w 436 446pdeo):Iaoo]ca):`ahapa$pdeo):`]p]%7 456y 5,6y


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

5-6ahoaw 5.6pdeo):Pdna]`):pdna]`LhqoKja$ knecPdna]`E`%7 5/6y 506 516++AranupdejcoaaioKG*Hap#o`k]na`ena_p]bpaniaoo]ca* 526++Eoep_kiejcbnki]op]j`]n`DPIHiaoo]cabkni 536eb$pdeo):NamqaopD]j`han):namqaopa`Sepd$%99#bkni#%w 546pdeo):na`ena_p$]nn]u$£ #_kjpnkhhan#9:#IbIaoo]caBkni#( 556#]_pekj#9:#ej`at#%%7 -,,6atep$%7 -,-6y -,.6y -,/6ahoaw -,06 -,16eb$pdeo):NamqaopD]j`han):namqaopa`Sepd$%99#bkni#%w -,26pdeo):Oaooekj):oapBh]od$£ [[$#Oknnu(pdanas]o]lnk^haisepdukqnbkni`ap]eho(oaa^ahks*#(pnqa%%7 -,36y -,46 -,56pdeo):naoqhpW#iaoo]ca#Y9£ #Oknnu(pdanas]o]lnk^haisepdukqnbkni`ap]eho*#7 --,6pdeo):naoqhpW#naoqhp#Y9#,#7 ---6pdeo):naoqhpW#annkno#Y9£ pdeo):Iaoo]ca):r]he`]pekjAnnkno7 --.6y --/6y --06y --16 --26bqj_pekj^abknaNaj`an$%w --36 --46pdeo):oap$#naoqhp#(pdeo):naoqhp%7 --56y -.,6y -.-6 -..6;: There isn’t much in the process view for HTML requests. It simply displays the message form again, as follows: 8;ldl a_dkpdeo):naj`anAhaiajp$#iaoo]ca[bkni#%7 ;: In Listing 4-16, we start off with some Cake validation. Once validation is all good (on line 47), we do the business stuff of saving the message. If a user is posting a new message, we also need to create a thread record for it. However, if the message wasn’t saved for some reason, we need to remove it from the thread record that we have already saved.

119


120

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

We have used UUIDs to help us with two coding tasks (see lines 50 and 51): Ê

UÊ ÌÊ>œÜÃÊÕÃÊ̜Êi>ȏÞÊ`iiÌiÊ̅iÊ̅Ài>`ÊÀiVœÀ`ʈvÊ̅iʓiÃÃ>}iÊÀiVœÀ`Ê`ˆ`˜½ÌÊÃ>Ûi°Ê This isn’t strictly needed, as we can always get the ID quite easily once the thread has been saved.

Ê

UÊ -ˆ˜ViÊ>Ê̅Ài>`ʘii`ÃÊ̅iÊ ʜvÊ̅iʏ>ÃÌʓiÃÃ>}iÊ«œÃÌi`Ê­œÀÊ̅iÊvˆÀÃÌʜ˜iʈvʈ̽ÃÊ>ÊvÀiÃ…Ê post), and a message needs the ID of the thread, it makes sense for us to generate the IDs within the code, rather than rely on the database to give us IDs. We save on the number of queries we make and have fewer lines of code.

Another feature within the code in Listing 4-16 is the redirect after the post, which is quite a common practice nowadays in order to avoid repeated posts. However, this feature isn’t needed in an Ajax call, so we filter this out on lines 32, 66, and 105.

Process a Search Request Again, the IbOa]n_dLnk_aoo?kjpnkhhan follows the structure of the other API methods, as shown in Listing 4-17. Listing 4-17. Search for Messages Controller (mf_search_process_controller.php) -68;ldl .6 /6ej_hq`a[kj_a$#ib[_kjpnkhhan*ldl#%7 06 16_h]ooIbOa]n_dLnk_aoo?kjpnkhhanatpaj`oIb?kjpnkhhanw 26 36r]n j]ia9#IbOa]n_dLnk_aoo#7 46 56r]n l]cej]pa9]nn]u$#heiep#9:.,( -,6#kn`an#9:]nn]u$£ #Iaoo]ca*p[_na]pa`[]p#9:#]o_#%%7 --6 -.6r]n naoqhp9]nn]u$#naoqhp#9:##( -/6#iaoo]ca#9:##( -06#annkno#9:##( -16#`]p]#9:##( -26#oa]n_d[pani#9:## -36%7 -46 -56r]n oa]n_d[pani9##7 .,6 .-6bqj_pekj[r]he`]pekj$%w ..6 ./6 naoqhp9pnqa7 .06 .16eb$eooap$pdeo):`]p]W#IbOa]n_dLnk_aoo#YW#oa]n_d[pani#Y%%w .26


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

.36 oa]n_d[pani9£ pdeo):`]p]W#IbOa]n_dLnk_aoo#YW#oa]n_d[pani#Y7 .46y .56ahoaeb$pdeo):Oaooekj):na]`$oa]n_d[pani%%w /,6 /-6 oa]n_d[pani9pdeo):Oaooekj):na]`$oa]n_d[pani%7 /.6pdeo):`]p]W#IbOa]n_dLnk_aoo#YW#oa]n_d[pani#Y9£ oa]n_d[pani7 //6y /06ahoaeb$eooap$pdeo):l]ooa`=ncoW#oa]n_d[pani#Y%%w /16 /26 oa]n_d[pani9pdeo):l]ooa`=ncoW#oa]n_d[pani#Y7 /36pdeo):`]p]W#IbOa]n_dLnk_aoo#YW#oa]n_d[pani#Y9£ oa]n_d[pani7 /46y /56 0,6pdeo):IbOa]n_dLnk_aoo):oap$pdeo):`]p]%7 0-6 0.6++Jks_da_goa]n_dpani 0/6eb$ pdeo):IbOa]n_dLnk_aoo):r]he`]pao$%%w 006 016 naoqhp9b]hoa7 026 036pdeo):naoqhpW#naoqhp#Y9#,#7 046 056++Oej_apdana#okjhu-beah`(bknpdaiejqpa 1,6++sa#hh]ooqiaep#obnkipdaoa]n_dpani 1-6 r]he`]pekj[annkn9##7 1.6 1/6eb$eooap$pdeo):IbOa]n_dLnk_aoo£ ):r]he`]pekjAnnknoW#oa]n_d[pani#Y%%w 106 r]he`]pekj[annkn9 pdeo£ ):IbOa]n_dLnk_aoo):r]he`]pekjAnnknoW#oa]n_d[pani#Y7 116y 126 136 iaoo]ca9[[$£ #Oknnu(pdanas]o]lnk^haisepdukqnoa]n_dbkni*#* r]he`]pekj[annkn(pnqa%7 146 156pdeo):naoqhpW#iaoo]ca#Y9 iaoo]ca7 2,6pdeo):naoqhpW#annkno#Y9£ pdeo):IbOa]n_dLnk_aoo):r]he`]pekjAnnkno7 2-6y 2.6 2/6pdeo):naoqhpW#oa]n_d[pani#Y9£ pdeo):`]p]W#IbOa]n_dLnk_aoo#YW#oa]n_d[pani#Y7 206pdeo):oa]n_d[pani9£ pdeo):`]p]W#IbOa]n_dLnk_aoo#YW#oa]n_d[pani#Y7 216

121


122

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

226napqnj naoqhp7 236y 246 256bqj_pekjej`at$%w 3,6 3-6 iaoo]cao9]nn]u$%7 3.6 3/6eb$pdeo):[r]he`]pekj$%%w 306 316 _kj`epekjo9]nn]u$%7 326 336eb$pdeo):oa]n_d[pani%w 346 356pdeo):Oaooekj):snepa$oa]n_d[pani(£ pdeo):oa]n_d[pani%7 4,6 4-6 oa]n_d[pani9pdeo):oa]n_d[pani7 4.6 4/6 _kj`epekjoWY9£ ]nn]u$I=P?D$ai]eh(oq^fa_p(iaoo]ca%=C=EJOP$# oa]n_d[pani#%%7 406y 416 426 iaoo]cao9pdeo):l]cej]pa$£ #Iaoo]ca#(]nn]u$kn9: _kj`epekjo%%7 436 446eb$ iaoo]cao99##%w 456pdeo):naoqhpW#naoqhp#Y9#,#7 5,6pdeo):naoqhpW#iaoo]ca#Y9£ #Pdanas]o]lnk^haisepdpdaoa]n_d*Lha]oapnu]c]ejh]pan*#7 5-6y 5.6ahoaw 5/6 506pdeo):naoqhpW#naoqhp#Y9#-#7 516pdeo):naoqhpW#iaoo]ca#Y9£ #Oa]n_dnaoqhpobap_da`oq__aoobqhhu*#7 526pdeo):naoqhpW#`]p]#Y9 iaoo]cao7 536y 546y 556y -,,6 -,-6bqj_pekj^abknaNaj`an$%w -,.6 -,/6pdeo):oap$#naoqhp#(pdeo):naoqhp%7 -,06y -,16y -,26 -,36;:


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

We first validate to see whether we have a search term on line 73. Once that passes, we use Cake’s pagination feature to split the results into pages. We have used a dummy model IbOa]n_dLnk_aoo as a way to validate our search term using Cake’s validation function. We need to store the search term in session so it can be used during the pagination when a user selects a different page. On line 83, we have used MySQL’s I=P?D=C=EJOP operator in our queries. This gives a wider range of accurate matches. To use the MySQL I=P?D=C=EJOP operator in your code, you will need to create a full-text index on the database fields using this command: ?NA=PABQHHPATPEJ@ATbqhh[patp[-KJiaoo]cao$ai]eh(oq^fa_p(iaoo]ca%7

NNote Avoid using the HEGA operator. The HEGA operator is quite expensive, as it must scan all the fields where the operator is used. Also, it doesn’t match variations of the word. For example, if the search term is running, it won’t search for run or runner. MySQL has many other search methods besides the standard HEGA. See dppl6++`ar*iuomh*_ki+`k_+nabi]j+1*,+aj+bqhhpatp)oa]n_d*dpih for details.

The view for our search function is shown in Listing 4-18. Listing 4-18. View Template for the Search Action Class (/app/views/mf_search_process/index.ctp) 8d.:Oa]n_dNaoqhpo8+d.: 8;ldl eb$ naoqhpW#naoqhp#Y99#,#%w a_dk#8`er_h]oo9dehecdp:#7 a_dk naoqhpW#iaoo]ca#Y7 a_dk#8+`er:#7 y ;: 8;ldl eb$ naoqhpW#`]p]#Y%w bkna]_d$ naoqhpW#`]p]#Y]o _qnnajp[iaoo]ca%w a_dk#8`er_h]oo9iaoo]ca[da]`an:#7 a_dk#8d/:#* _qnnajp[iaoo]caW#Iaoo]ca#Y£ Woq^fa_pY*#8+]:8+d/:#7 a_dk#"j^ol78d2:>u#* _qnnajp[iaoo]caW#Iaoo]ca#Y£ Wai]ehY*#8+d2:#7 a_dk#8+`er:#7

123


124

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

 iaoo]ca[e`9 _qnnajp[iaoo]caW#Iaoo]ca#YWe`Y7  pdna]`[e`9 _qnnajp[iaoo]caW#Iaoo]ca#YWpdna]`[e`Y7 a_dk#8`er_h]oo9iaoo]ca[iaoo]caodknp[iaoo]ca9£ bqhh[iaoo]ca9bap_da`9,e`9iaoo]ca[#* iaoo]ca[e`*#:#7 a_dkpatp):decdhecdp$ _qnnajp[iaoo]caW#Iaoo]ca#Y£ Wiaoo]caY(  naoqhpW#oa]n_d[pani#Y( #8ol]j_h]oo9decdhecdp[oa]n_d:X-8+ol]j:# %7 a_dk#8`er:8ol]je`9klaj[hejg[#* iaoo]ca[e`*#:£ 8]dnab9+_]ga+[[_d]lpano[[+iaoo]ca[bknqi+IbBap_dIaoo]cao+ej`at+£ pdna]`E`6#* pdna]`[e`*#+:Reasejpdna]`8+]:8+`er:#7 a_dk#8+`er:#7 y y ahoaw a_dk#8`er_h]oo9dehecdp:#7 a_dk#JkNaoqhpo#7 a_dk#8+`er:#7 y ;: 8dn_h]oo9l]cej]pkn[heja: 8;ldl eb$eooap$ l]cej]pkn%%w l]cej]pkn):klpekjo$]nn]u$£ #ql`]pa#9:#i]ej[_kjpajp[_kjp]ejan#(#ej`e_]pkn#9:#hk]`ejc#%%7 a_dkl]cej]pkn):lnar$#ÃLnarekqo#(jqhh(jqhh(£ ]nn]u$#_h]oo#9:#`eo]^ha`#%%7 a_dk#"j^ol7#7 a_dkl]cej]pkn):jatp$#JatpÄ#(jqhh(jqhh(£ ]nn]u$#_h]oo#9:#`eo]^ha`#%%7 a_dk#"j^ol7#7 a_dkl]cej]pkn):_kqjpan$%7 y ;:


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

The view loops through the message results and formats the output. In the pagination helper methods at the bottom, we have used Ajax for the jatp and lnar links. In Cake, we simply add the following line to Ajaxify the links: l]cej]pkn):klpekjo$]nn]u$#ql`]pa#9:#i]ej[_kjpajp[_kjp]ejan#( #ej`e_]pkn#9:#hk]`ejc#%%7

NTip We have used the text helper to highlight our search term. But don’t forget there are also some other basic functions in the Cake API that may help you out in other situations. For example, in parts of this application, we have used the [[$% helper function instead of using a_dk or even the Cake shorthand a_dk function bqj_pekja$%. See dppl6++]le*_]galdl*knc+^]oe_o[4ldl*dpih for details.

Writing the API Documentation For many developers, writing documentation is never a pleasant experience. But for this chapter, you could say it’s the end point. Without the documentation, there’s no reason for writing the API. Why bother to structure our actions around the Command pattern? It would have been easier to just write each action within one or two controllers. The following shows the documentation for the Web Forum API as it would appear on our forum web site. Welcome to our message forum API. We provide five different methods for you to use. All our method returns use the JSON format. Each request will return four or more keys. The standard four keys returned on every request are as follows: Ê

UÊ naoqhp: If 1 is returned, this means the request was processed successfully. If 0 is returned, then see iaoo]ca and annkno key.

Ê

UÊ iaoo]ca: A human-friendly return message. This will complement the naoqhp key.

Ê

UÊ annkno: This will contain error messages relating to the result. It will be given in key/ value pairs, where the gau is the name of the parameter and r]hqa contains the error message.

Ê

UÊ `]p]: If the request returns data, it will be held in this key. You must end all URL requests in *fokj. An example request would look like this:

dppl6++sss*at]ilha*_ki+IbBap_dIaoo]ca+£ ej`at+E`6044^^,02).]a4)0/_.)]b0-),-10_^``12_^+*fokj

125


126

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

And the return response may look like this: wnaoqhp6-(iaoo]ca6Iaoo]cabap_da`oq__aoobqhhu*(annkno6(`]p]6£ wIaoo]ca6we`6044^^,02).]a4)0/_.)]b0-),-10_^``12_^(j]ia6FkdjPepkn(£ ai]eh6obo`(iaoo]ca68l:Peiapn]rahi]_deja*Ckk`skngejckn`an*Qoa`£ kjhukj_a*-,(,,,Jejceokjk*ebukq#naejpanaopa`(lha]oa_]hhia]p£ /-0-15.21/*8X+l:(nalhu[pk6(oq^fa_p6Dulan@eiajoekj]hNaokj]pkn£ bkno]ha(p[_na]pa`[]p6.,,4),3).3,,6-26..(£ pdna]`[e`6044^^,02)1,,0)00a.)5`^`),-10_^``12_^y(£ Pdna]`6we`6044^^,02)1,,0)00a.)5`^`),-10_^``12_^(£ benop[iaoo]ca[e`6044^^,02).]a4)0/_.)]b0-),-10_^``12_^(£ h]op[iaoo]ca[`]pa6.,,4),3).3,,6-26..(iaoo]ca[jqi6-yyy The API documentation follows.

MfFetchMessage Get one forum message.

Arguments iaoo]caE` (Required)—The message ID

HTTP Method LKOP

Syntax dppl6++W`ki]ejY+IbBap_dIaoo]ca+ej`at+iaoo]caE`6Wiaoo]ca[e`Y+*fokj

Return Standard return keys

MfFetchMessages Note the extra letter o. Get more than one message from the forum. At present, we filter only by the thread ID.

Arguments pdna]`E` (Required)—The thread ID


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

HTTP Method LKOP

Syntax dppl6++W`ki]ejY+IbBap_dIaoo]cao+ej`at+pdna]`E`6Wpdna]`[e`Y+*fokj

Return Standard return keys

MfFetchThreads Get the forum threads. This returns a set of paginated messages. The messages are sorted according to the date of the last message that was posted within a thread. Each page has 20 messages. At present, this amount is fixed.

Arguments l]ca (Optional)—The page number starting from 1. Numeric.

HTTP Method LKOP

Syntax dppl6++W`ki]ejY+IbBap_dIaoo]cao+ej`at+l]ca6Wl]ca[jqi^anY+*fokj

Return Standard return keys

MfMessageProcess Post a message onto the forum.

Arguments Ê

UÊ j]ia (Optional)—Sender’s name. Maximum 255 characters.

Ê

UÊ ai]eh (Required)—Sender’s e-mail address. Maximum 255 characters.

Ê

UÊ oq^fa_p (Required) —Message subject. Maximum 255 characters.

Ê

UÊ iaoo]ca (Optional) —Message body. Maximum 16,777,215 characters.

127


128

CH APT ER 4 N A MES S A G E FOR U M W EB S ER VIC E

HTTP Method LKOP

Syntax dppl6++W`ki]ejY+IbIaoo]caLnk_aoo+ej`at*fokj

Return Standard return keys

MfSearchProcess Search for messages. The results are paginated with 20 messages per page.

Arguments Ê

UÊ oa]n_dPani (Required)—Search term. Maximum 255 characters.

Ê

UÊ l]ca (Optional)—Page number. Numeric.

HTTP Method LKOP

Syntax dppl6++W`ki]ejY+IbOa]n_dLnk_aoo+ej`at*fokj

Return Standard return keys, plus extra oa]n_d[pani key, which contains the search term


C H A P T E R 4 N A M E S S A G E F O R U M W E B S E R V I C E

Summary In this application, we’ve covered several Cake topics, including the use of Ajax, JSON web service returns, Cake pagination, the use of validation in a model with no associated table, and how to include the TinyMCE browser editor. The highlight of the chapter, however, was the building of a web service API. The application still has a number of features we should add before it can be used in a commercial environment. Here are some suggestions that you can use to further develop the forum application: Ê

UÊ /…ˆÃʈÃÊ>˜ÊœLۈœÕÃʜ˜i°Ê-̜«Êë>““iÀÃtÊ/…iÀiÊ>Àiʓ>˜ÞÊÌiV…˜ˆµÕiÃÊ̜ʫÀiÛi˜ÌÊë>“]Ê or at least keep it down to a minimum. In the final chapter in this book, we implement a Captcha authentication test. You can easily integrate this into the forum application. However, this puts the responsibility on every user. If you don’t like interrupting the usability of the site, you can employ a filter, like a Bayesian text filter, instead. There are several PHP versions of this filter floating about. For other techniques, see dppl6++ aj*segela`e]*knc+sege+Bknqi[ol]i.

Ê

UÊ 1ÃiÀÃÊŜՏ`ÊLiÊ>LiÊ̜ÊÕ«œ>`ʈ“>}iÃÊ̜Ê̅iÊvœÀՓ°

Ê

UÊ 1ÃiÀÃÊŜՏ`ÊLiÊ>LiÊ̜ÊÊi‡“>ˆÊÕ«`>ÌiÃʜ˜Ê>Ê̅Ài>`°Ê/…ˆÃʈÃÊ«>À̈VՏ>ÀÞʈ“«œÀÌ>˜ÌÊvœÀÊ users who have posted questions.

Ê

UÊ ``ÊÕÃiÀÊ>VVœÕ˜ÌðÊ9œÕÊVœÕ`Ê̅i˜Ê>œÜʜ˜ÞÊÀi}ˆÃÌiÀi`ÊÕÃiÀÃÊ̜ʫœÃÌʓiÃÃ>}iðÊœÜever, this might be a barrier to the use of the forum, since it’s one more hurdle for users to jump over. Fewer users posting messages means fewer people will find anything interesting on the forum.

Ê

UÊ 7iʅ>ÛiÊ̜Ê>`“ˆÌÊ̅>ÌʜÕÀÊ>««ˆV>̈œ˜Ê…>Ãʜ˜iÊψ}…̏ÞÊ՘Vœ“vœÀÌ>LiÊ>Ài>°Ê"ÕÀÊVˆi˜ÌÊ action classes like ib[lkop[bkni[_kjpnkhhan*ldl and our API action classes like ib[ oa]n_d[lnk_aoo[_kjpnkhhan*ldl more or less live within the same domain. They share the same folders and same parent controllers. It’s as if they were part of the API, but, of course, they are not. You should separate them out, either into separate controllers or separate folders.

129


C HAPTER

5

Google Maps and the Traveling Salesman S

ome friends of ours are about to go on a big European vacation. They talked about how they’ve used Google Maps to help them find the location of hotels, restaurants, and local attractions. They wanted to keep friends and families updated of their progress, but didn’t want to use e-mail. Furthermore, they weren’t sure in which order to visit the places. Being far more enthusiastic than they were, we said we would write an application for them that they can use to enter their destinations, make comments, and plan their journey. In our application, we’re going to be covering many topics. Since we’re going to be using Google Maps, client-side JavaScript will be employed. We also want to store the locations and the comments they make. Naturally, we’ll be creating some Cake models to represent these data entities. We will also be building a straightforward controller to hold the functions that will manage the locations and comments. One of the main features of the application relates to a classic computing puzzle called the “traveling salesman problem” (or in our case, the traveling tourist problem). Namely, a salesman needs to visit a number of cities only once, but return back to the same place as where he started. Devise an algorithm to find the shortest route for the whole trip. This part of the application will be done client side using a simple algorithm, but the calculated route will be stored on the database. Now, to get started, we’ll first talk about Google Maps.

Hello Map! Google Maps is pretty easy to use, so we can dive straight in with the Google Map equivalent of the Hello World program, as shown in Listing 5-1. Listing 5-1. A Simple Google Maps Example -68@K?PULAdpih)++S/?++@P@TDPIH-*,Opne_p++AJ£ dppl6++sss*s/*knc+PN+tdpih-+@P@+tdpih-)opne_p*`p`: .68dpihtihjo9dppl6++sss*s/*knc+-555+tdpih: /68da]`: 068iap]dppl)amqer9_kjpajp)pula_kjpajp9patp+dpih7_d]noap9qpb)4+: 168pepha:CkkchaI]loF]r]O_nelp=LEAt]ilha8+pepha: 268o_nelpon_9dppl6++i]lo*ckkcha*_ki+i]lo;beha9]le"]il7r9."]il7£ gau9ejoanp[ukqn[gau[danapula9patp+f]r]o_nelp:8+o_nelp:

131


132

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

368o_nelppula9patp+f]r]o_nelp: 46bqj_pekjejepe]heva$%w 56eb$C>nksoanEo?kil]pe^ha$%%w -,6r]ni]l9jasCI]l.$`k_qiajp*capAhaiajp>uE`$i]l[_kjp]ejan%%7 --6i]l*oap?ajpan$jasCH]pHjc$1-*055/3(),*-00.-%(-/%7 -.6y -/6y -068+o_nelp: -168+da]`: -268^k`ukjhk]`9ejepe]heva$%kjqjhk]`9CQjhk]`$%: -368`ere`9i]l[_kjp]ejanopuha9se`pd62,,lt7daecdp60,,lt:8+`er: -468+^k`u: -568+dpih: The code in Listing 5-1 displays a 600  400 pixel Google Map on the page. The location of the map is set to the coordinates for London, specified by the oap?ajpan$% function on line 11. The output from the code in Listing 5-1 is shown in Figure 5-1.

Figure 5-1. Google Maps showing London


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

To get started, we need to include the JavaScript Google Maps API file. This is done using the 8o_nelp: tag on line 6. Within the tag, you must provide your own Google Maps API key. You can get a key (which is free) at dppl6++i]lo*ckkcha*_ki.

NTip If you are developing on a local machine, you can still get a key. For example, you can use dppl6++-.3*,*,*- or dppl6++hk_]hdkop, depending on which local URL you are using.

Once the page has been loaded via the kjhk]` event on line 16, the ejepe]heva$% function is called. The ejepe]heva$% method, as defined on line 8, first checks whether we have a compatible browser. If we do, we then go ahead and create an object that will represent a map on the web page. This is done using the CI]l. class. Additionally, we also need to provide an area where it can display the map; in our case, it’s a 8`er: tag with an ID called i]l[_kjp]ejan on line 17. We’re not quite finished yet though. In order for a map to be displayed, we need to tell the map object to display a location, and this is done using the oap?ajpan$% function on line 11, which sets the location and displays the map at the same time. And that’s it! Wasn’t that easy? When the browser is closed or when a different page is brought up, the kjqjhk]` event calls CQjhk]`$%. This Google Map function closes down unwanted connections and is used to avoid memory leaks.

Google Maps Explained Google Maps is almost exclusively a client-side JavaScript API. Although you can make some server-side calls, that is not encouraged. After all, Google collects better statistics if the calls are made from the browser rather than from the server.

NNote To effectively use Google Maps, you need to have some basic knowledge of JavaScript, particularly the object-oriented areas of the language. Two sites to get you started are dppl6++sss*s/o_dkkho*_ki+ fO+fo[k^f[ejpnk*]ol and dppl6++`arahklan*ikvehh]*knc+aj+`k_o+Ejpnk`q_pekj[pk[ K^fa_p)Kneajpa`[F]r]O_nelp.

Before we start, let’s go over the main features of the API that are relevant to our application.

Geocoding Geocoding is the process of converting textual locations such as street addresses or place names into geographic coordinates. This is important for a number of reasons. We can locate exact positions on a map, enabling us to place markers accurately. It eliminates confusion where two or more places have the same name. The Google Maps API includes a class that provides us with a geocoding service. This is the C?heajpCak_k`an class.

133


134

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

Google Map Events Within browsers, JavaScript can be programmed to execute code depending on certain events. In traditional terminology, this is called event-driven programming. These events come in many forms: they can be mouse-based, keyboard-based, or even based on other events, such as when a page is completely loaded. Event-based programming is particularly important in an Ajax environment. Since calls are mostly asynchronous, things donâ&#x20AC;&#x2122;t happen in a nice serial fashion.

NNote Before the use of Ajax, just about every activity on a browser was synchronous. Users had to wait for feedback whenever they generated an event, such as by clicking a link or submitting a form. Essentially, you could make only one call to the server at any one time. With the use of TIHDpplNamqaop in Ajax, we can now make many calls to the server within a single web page, which makes them all asynchronous. Events can happen independently of each other.

Google Maps defines its own specialized events, which are handled by the API itself. These are separate from the DOM events within a browser, which are more generic. For example, a _he_g event can be attached to any instance of a map, so when a user clicks a map, a call is made to a function, which opens a window with information regarding the location that the user has clicked and additionally stores the coordinates of the location with a call to the server using Ajax. Map events are handled by the CArajp object. We will register events using the ]``Heopajan$% static method.

Map Interface Elements In the Google Maps API, you can add interface control elements, which allow you to interact with the map. Examples include buttons that you can use to move the map around, instead of using the mouse, and a sliding control bar to zoom in and out of the map. In Google Maps terminology, these are known as controls. All the control elements subclass the C?kjpnkh class. You can define your own control by subclassing this class. For example, you can create a button that makes an Ajax call to your database server, fetching any journey near that location.

Overlays Objects that move with the map are called overlays. These can be pushpins marking the location of a point or graphical lines that show route directions. The API provides several built-in overlay classes, which are listed in Table 5-1. Markers are interactive in that they can be dragged across the map and placed in a new location. Each marker has an icon attached to it. You can define your own icon or use the default one. A large number of markers can slow down the display of the map. As a result, the API has a marker manager class called I]nganI]j]can.


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

Table 5-1. Map Overlay Objects

Overlay

Description

CI]ngan

This class is used to mark a point on the map.

CLkhuheja

This class is used to lay down lines on the map. There is also a CLkhuckj class, where the lines form a closed area.

CCnkqj`Kranh]u

With this class, as well as drawing lines on the map, you can add images on top of them.

CPehaH]uanKranh]u With this class, the map itself is an overlay. You can modify the map itself with your own version of the map. However, you probably wonâ&#x20AC;&#x2122;t be using this very often. The pop-up bubble speech window is a special overlay; only one can exist in any one map instance.

Driving Directions One useful feature in the Google Maps API is the ability to map out a travel route via several locations. These routes are then marked in blue on the map. This is done via the C@ena_pekjo class. A very useful feature is the ability of the class to take locations either as textual names or latitude/longitude coordinate points. As an example, Listing 5-2 shows plotting a route from New York to Anchorage. Figure 5-2 shows the route map itself. Listing 5-2. Using the Google Maps GDirections Class to Find a Route -68dpih: .6 /68da]`: 068pepha:CkkchaI]loC@ena_pekjo?h]oo8+pepha: 16 268o_nelpon_9dppl6++i]lo*ckkcha*_ki+i]lo;beha9]le"r9.*t"ÂŁ gau9ejoanp[ukqn[gau[danapula9patp+f]r]o_nelp:8+o_nelp: 36 468o_nelppula9patp+f]r]o_nelp: 56 -,6bqj_pekjejepe]heva$%w --6i]l9jasCI]l.$`k_qiajp*capAhaiajp>uE`$i]l[_]jr]o%%7 -.6`ena_pekjo9jasC@ena_pekjo$i]l%7 -/6`ena_pekjo*hk]`$bnki6JasUkng(QO=pk6=j_dkn]ca%7 -06y -16 -268+o_nelp: -36 -468+da]`: -56 .,68^k`ukjhk]`9ejepe]heva$%: .-68`ere`9i]l[_]jr]oopuha9se`pd60,,lt7daecdp604,lt7:8+`er: ..68+^k`u: ./6 .068+dpih:

135


136

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

Figure 5-2. Route from New York to Anchorage This C@ena_pekjo class will be an important component of the project. When a query is sent off to the Google servers, it returns a number of useful items of information. One of which is the distance between the locations. This is very important to us, because it will provide the distance via the roads on the map rather than the straight linear distance between locations. However, if the user were planning to fly, the straight line distance would be more appropriate. In that case, we could easily calculate the distance using the latitude/longitude information. OK, now that we have explained how Google Maps work, we can start our application by gathering the requirements.

Application Requirements Our travel application will allow our friends and also the general public to plan their travel journeys and make comments on the places they visit. It will be a web site where they can keep friends and families up-to-date on their travels.


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

So that our application can be as successful as possible, we will employ a bit of usercentered design philosophy, a term originally coined by Donald Norman. We will think of the application in terms of users or personas, rather than application functions. Sometimes these needs also correlate directly with business objectives. Using our friends as our average persona, we map out their needs and the conclusions that we can draw from them. A user interface can then be created based on these conclusions. We run through the ways in which our friends will use the site. We start the process by asking them some broad questions. These are mapped out as follows: Ê

UÊ Scenarios/Needs: We’re going to Europe soon, and we want to keep a blog or journal of some kind to keep family and friends updated.

Ê

UÊ Conclusion: Users want to be able to enter destinations and make comments about those destinations. We need to save the destinations so they can make comments while they are on their journey. We can continue to draw conclusions from this simple need, but that is probably enough for us.

Ê

UÊ Scenarios/Needs: We’re not sure which places to visit first.

Ê

UÊ Conclusion: There are numerous conclusions we can draw from this statement. For example, we can map out a user journey based on different personas: art lovers, party people, or a combination of personas. Or we could map a user journey based on age groups, such as for students. But in this case, we will simply employ the traveling salesman algorithm to find the shortest route between each destination.

We will base our interface on what we know from this brief user-centered design exercise. So far, we have covered the broad issues of the application. Next, we will map out a functional specification that we can use for our Cake application. The functions will include the following: Ê

UÊ /…iÀiÊ܈ÊLiÊ>ÊVœ˜ÃˆÃÌi˜Ìʘ>ۈ}>̈œ˜ÊL>ÀÊ>ÌÊ̅iÊ̜«]ÊȘViÊ̅iÊvœVÕÃʈÃʜ˜Ê̅iÊ application.

Ê

UÊ 1ÃiÀÃÊ܈ÊLiÊ>LiÊ̜ʫ>˜Ê̅iˆÀʍœÕÀ˜iÞʜ˜Ê̅iÊvˆÀÃÌÊ«>}iʜvÊ̅iÊ>««ˆV>̈œ˜ÊLÞÊ entering their destination.

Ê

UÊ /…iÀiÊ܈ÊLiÊ>Ê«>}iÊ܅iÀiÊ̅iÞÊV>˜ÊÀiÌÀˆiÛiÊ>ÊÃ>Ûi`ʍœÕÀ˜iÞÊ>˜`ʓ>ŽiÊVœ““i˜Ìð

Ê

UÊ /…iÀiÊ܈ÊLiÊ>Ê«>}iÊ܅iÀiÊv>“ˆˆiÃÊ>˜`ÊvÀˆi˜`ÃÊV>˜ÊۈiÜÊ̅iˆÀÊVœ““i˜Ìð

In addition to these functions, we will add a further twist by allowing users to add tags to their journeys. This will be a comma-separated list of strings or tags, which you can associate with a journey. From the specification, we have sketched out the simple layout of the application in Figure 5-3.

137


138

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

Figure 5-3. Sketch of our home page

Application Structure We will set out to create our journeys controller, which will represent the journeys within the application. It will be responsible for the server-side needs of the application, saving and retrieving user journeys, for example. Along with the journeys controller, there will be three related models. Remember that the model class names follow the name of the controller. The model class names we will use are Fkqnjau, Hk_]pekj, and P]c. Table 5-2 shows the relationships among the different tables. This will give us an overall picture of how the different data elements are related to each other. Table 5-2. Main Database Table Relationships

Table

Relationship

fkqnjauo

Each journey is composed of different locations. Also, each journey can have more than one tag.

hk_]pekjo

One location belongs to only one journey.

p]co

One tag belongs to only one journey.

The information in Table 5-2 can also be shown graphically in an entity-relationship diagram, as in Figure 5-4.


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

Figure 5-4. Entity-relationship diagram of application tables

NTip Data schemas are quite valuable during development. They help you to visualize the relationships among elements, identify problems, and maybe even improve on the relationships. In our example, we see that a route has one tag line associated with it, but later on, we may also want tags associated with locations. But would this add too much complexity to the application? Always be aware of feature bloatâ&#x20AC;&#x201D;adding unnecessary features that may be used only by a small percentage of users.

From the data schema, we can create our database tables. Listing 5-3 shows the structure of the fkqnjauo table. Listing 5-3. The journeys Table Schema ?NA=PAP=>HA\fkqnjauo\$ \e`\ejp$--%JKPJQHH]qpk[ej_naiajp( \fkqnjau[j]ia\r]n_d]n$.11%JKPJQHH( \jkpao\patpJKPJQHH( \l]ooskn`\r]n_d]n$.11%JKPJQHH( LNEI=NUGAU$\e`\% %7 The fkqnjau[j]ia field stores the journey name that the user enters. The jkpao field is for comments about the journey itself. Editing a journey can be done only when a correct password is used, so we have created a l]ooskn` field. Listing 5-4 shows the structure of the hk_]pekjo table.

139


140

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

Listing 5-4. The locations Table Schema ?NA=PAP=>HA\hk_]pekjo\$ \e`\ejp$--%JKPJQHH]qpk[ej_naiajp( \hk_]pekj[j]ia\r]n_d]n$.11%JKPJQHH( \_kiiajpo\r]n_d]n$.11%`ab]qhpJQHH( \_kkn`\r]n_d]n$.11%JKPJQHH( \fkqnjau[e`\ejp$--%JKPJQHH( LNEI=NUGAU$\e`\% %7 The name of the location that the user enters is held in hk_]pekj[j]ia. The _kiiajpo field stores the comments for a particular location. The _kkn` field is longitude and latitude information taken from geocoding the location name. Finally, fkqnjau[e` is the foreign key to the fkqnjauo table. Listing 5-5 shows the p]co table structure. Listing 5-5. The tags Table Schema ?NA=PAP=>HA\p]co\$ \e`\ejp$-,%qjoecja`JKPJQHH]qpk[ej_naiajp( \p]c[j]ia\r]n_d]n$-,,%`ab]qhpJQHH( \fkqnjau[e`\r]n_d]n$.11%JKPJQHH( LNEI=NUGAU$\e`\% %7 The p]co table is pretty simple. The p]c[j]ia field holds a particular tag name for a journey. The fkqnjau[e` field is the foreign key to the fkqnjauo table.

Cake Models From the schema in Listings 5-3, 5-4, and 5-5, we created the Cake models, as shown in Listings 5-6, 5-7, and 5-8. Listing 5-6. The Journey Model (/app/models/journey.php) _h]ooFkqnjauatpaj`o=llIk`ahw r]n j]ia9#Fkqnjau#7 ++Pdafkqnjau`]p]r]he`]pekj r]n r]he`]pa9]nn]u$#fkqnjau[j]ia#9:]nn]u$ #nqha#9:]nn]u$#^apsaaj#(-(.11%( #namqena`#9:pnqa( #iaoo]ca#9:#Ukqnfkqnjauj]ia iqop^a^apsaaj-]j`.11 _d]n]_panohkjc*#%%7


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

++A]_dfkqnjaud]oi]juhk_]pekjo]j`]hoki]jup]co* r]n d]oI]ju9]nn]u$#Hk_]pekj#9:]nn]u$#_h]ooJ]ia#9:#Hk_]pekj#%( #P]c#9:]nn]u$#_h]ooJ]ia#9:#P]c#% %7 y

Listing 5-7. The Location Model (/app/models/location.php) _h]ooHk_]pekjatpaj`o=llIk`ahw r]n j]ia9#Hk_]pekj#7 r]n ^ahkjcoPk9]nn]u$#Fkqnjau#%7 y Listing 5-8. The Tag Model (/app/models/tag.php) _h]ooP]catpaj`o=llIk`ah w r]n j]ia9#P]c#7  r]n ^ahkjcoPk9]nn]u$#Fkqnjau#%7 y All three models are quite straightforward, except Fkqnjau, which contains a d]oI]ju association that reflects the schema. A simple validation code has also been added, requiring each journey entry into the database to have a fkqnjau[j]ia within it.

The Interface Like most modern web applications, a large part of our application is written in JavaScript that sits within the browser. Most of the action will initially occur in the browser itself. The server-side code comes into play when the user decides to save or retrieve the journey information.

The Global Layout We start off by creating the global layout file in +]ll+reaso+h]ukqpo+`ab]qhp*_pl, as shown in Listing 5-9.

141


142

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

Listing 5-9. The Global Layout File (/app/views/layouts/default.ctp) -68@K?PULAdpihLQ>HE?)++S/?++@P@TDPIH-*,Opne_p++AJ .6dppl6++sss*s/*knc+PN+tdpih-+@P@+tdpih-)opne_p*`p`: /6 068dpihtihjo9dppl6++sss*s/*knc+-555+tdpih: 168da]`: 26 368iap]dppl)amqer9_kjpajp)pula_kjpajp9patp+dpih7_d]noap9qpb)4+: 46 568))l]capepha)): -,68pepha:8;ldla_dk pepha[bkn[h]ukqp7;:8+pepha: --6 -.68))l]ca_oo)): -/68;ldla_dkdpih):_oo$#oepa#%7;: -06 -168o_nelpon_9dppl6++i]lo*ckkcha*_ki+i]lo;beha9]le"]il7r9."]il7£ gau9ejoanp[ukqn[gau[danapula9patp+f]r]o_nelp:8+o_nelp: -26 -368;ldl -46a_dkf]r]o_nelp):hejg$#o_nelp]_qhkqo)fo)-*4*-+he^+lnkpkpula#%7 -56a_dkf]r]o_nelp):hejg$#£ o_nelp]_qhkqo)fo)-*4*-+on_+o_nelp]_qhkqo*fo;hk]`9abba_po#%7 .,6 .-6++ej_hq`aoepa*fo ..6a_dkf]r]o_nelp):hejg$#oepa#%7 ./6;: .06 .168+da]`: .26 .368^k`ukjhk]`9ejepe]heva$%kjqjhk]`9CQjhk]`$%: .46 .568`ere`9_ajpan[_kjpajp: /,6 /-68`er_h]oo9da]`an[sn]llan: /.68d-:Pn]rahI]lln8+d-: //68d0:8e:>a_]qoahebaeo]fkqnjau6%8+e:8+d0: /068+`er: /16 /268`er_h]oo9j]r[-: /368;ldla_dkdpih):hejg$#Dkia#(#+^]oa#%7;: /46"j^ol7x"j^ol7 /56 0,68;ldla_dkdpih):hejg$#NapnearaFkqnjau#( 0-6#+fkqnjauo+napneara[bkni#%7;: 0.6"j^ol7x"j^ol7 0/6


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

0068;ldla_dkdpih):hejg$#@eolh]uFkqnjau#( 016#+fkqnjauo+`eolh]u[fkqnjau#%7;: 0268+`er: 036 0468`ere`9i]ej[_kjpajp[_kjp]ejan: 0568;ldla_dk _kjpajp[bkn[h]ukqp7;: 1,68+`er: 1-6 1.68+`er: 1/6 1068+^k`u: 1168+dpih:

NNote You can create many layouts in the h]ukqpo folder and change between them in the same view. Just set the h]ukqp variable in the controller action. For example, if you created a new layout file +h]ukqpo+ r]jehh]*_pl, you can change the layout from within your action with this statement: pdeo):h]ukqp9 #r]jehh]#7.

Let’s go through the important lines in Listing 5-9. We start by setting the title in line 10. Next, we include our CSS file for our application in line 13. On line 15, we bring in the Google Maps API. Remember to use your own key that correlates to your domain name. Following this, we use Cake’s JavaScript inclusion method on lines 18 and 19 to include the Prototype and script.aculo.us JavaScript libraries. We also include our site-wide JavaScript file oepa*fo, located in +]ll+sa^nkkp+fo+. Within the main ^k`u tag, the page starts off with a simple header followed by a navigation bar using Cake’s HTML helper to create the HTML links, as follows: Ê

UÊ Dkia: This simply takes a user back to the home page.

Ê

UÊ NapnearaFkqnjau: Allows a user to retrieve a saved trip from the database.

Ê

UÊ @eolh]uFkqnjau: A user can display any journey.

To finish, we echo the _kjpajp[bkn[h]ukqp variable on line 49. This takes the rendered controller action view content and inserts it into that position.

Home Page Now that the global layout has been set up, we can create our home page view. We’ll use Cake’s designated default home page dkia*_pl, in the folder +]ll+reaso+l]cao+*, shown in Listing 5-10. In our application, users must be able to plot out a journey quite easily. On the home page, we will create a form where users can create their journeys the moment they enter the site.

143


144

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

Listing 5-10. The Default View (/app/views/pages/home.ctp) -68le`9fkqnjau[dahlan[iaoo]ca: .6Ukq_qnnajphud]rajkfkqnjaulh]jja`( /6ajpan]op]npejchk_]pekjpk^acej* 068+l: 16 268`er: 36 468l: 56Hk_]pekjJ]ia6 -,6 --68;ldla_dkbkni):patp$#Hk_]pekjJ]ia#%7;: -.68;ldla_dkbkni):^qppkj$#Ajpan]Hk_]pekj#( -/6]nn]u$#e`#9:#hk_]pekj[j]ia[^qppkj#%%7 -06;: -168+l: -26 -368+`er: -46 -568`ere`9i]l[bqj_pekjo[sn]llan: .,6 .-68))bej`pda^aopnkqpa)): ..68;ldl ./6a_dkbkni):^qppkj$#?]h_qh]paFkqnjau#( .06]nn]u$#e`#9:#bej`[nkqpa[^qppkj#%%7 .16;: .26 .368))op]np]jasnkqpa)): .468;ldl .56a_dkbkni):^qppkj$#Op]np=c]ej#( /,6]nn]u$#e`#9:#op]np[]c]ej[^qppkj#%%7 /-6;: /.6 //68))o]rapdankqpa)): /068;ldl /16a_dkbkni):_na]pa$jqhh(]nn]u$#e`#9:#]``[bkni#( /26#qnh#9:#+fkqnjauo+]``[bkni#( /36#_h]oo#9:#bqj_pekj[bkni# /46%%7 /56 0,6++qoa`pkopknapdahk_]pekjejfokjbkni]p 0-6a_dkbkni):de``aj$#hk_]pekjo#%7 0.6 0/6a_dkbkni):oq^iep$#O]raFkqnjau#(]nn]u$#`er#9:b]hoa%%7 006 016a_dkbkni):aj`$%7


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

026;: 036 0468+`er: 056 1,68))PdeoeosdanakqnCkkchaI]lsehh^a`eolh]ua`)): 1-68`ere`9i]l[_]jr]o:8+`er: In Listing 5-10, we havenâ&#x20AC;&#x2122;t included any form-posting elements apart from the Save Journey button on line 43. All of the other buttons relate entirely to client-side code and will be used in conjunction with the Google Maps functionality. The first button, Enter a Location, on line 12, will save and display the location in Google Maps locally. The Calculate Journey button, on line 23, will use the Google Maps API and JavaScript to calculate the shortest journey. The Start Again button, on line 29, will clear the slate for a new journey to be entered. When this home page code is processed with the default layout, we get the output shown in Figure 5-5 (with Paris set as the starting location in this example). The code and functionality behind all these buttons will be explained in the next section.

Figure 5-5. The application home page

145


146

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

Travel Mappr Manager Now we’re going to talk about the Travel Mappr manager class in +]ll+sa^nkkp+fo+oepa*fo. The class will be called Pn]rahI]llnI]j]can, and it will handle all the client-side functionality relating to the application. oepa*fo is called from within the default layout `ab]qhp*_pl, as shown on line 21 in Listing 5-9. We use Prototype’s API to help us with the creation of the class itself.

NNote You may have noticed that Listing 5-10 doesn’t contain any kj_he_g events. If you are used to writing kj_he_g or kj_d]jca events within HTML code, consider using Prototype’s Arajp*k^oanra method instead. It allows you to separate any JavaScript code from the content.

Listing 5-11 shows the main skeleton structure of our Pn]rahI]llnI]j]can class in the oepa*fo file. We have purposely left out many other functions, as commented on line 75. These will be described individually. Listing 5-11. The Main JavaScript File Used in Our Application (/app/webroot/js/site.js) -6r]nPn]rahI]llnI]j]can9?h]oo*_na]pa$w .6 /6++e`kb_kjp]ejan 06i]l[_kjp]ejan6##( 16 26+&pda_qnnajpi]l&+ 36i]l6jqhh( 46 56+&cak_k`ejchk_]pekj&+ -,6cak_k`an6jqhh( --6 -.6+&qoanajpana`hk_]pekjo&+ -/6qoan[fkqnjau6jas=nn]u$%( -06 -16ejepe]heva6bqj_pekj$i]l[_kjp]ejan%w -26 -36pdeo*i]l[_kjp]ejan9i]l[_kjp]ejan7 -46 -56++op]nppdai]l .,6Arajp*k^oanra$sej`ks(#hk]`#(pdeo*`eolh]uI]l*^ej`$pdeo%%7 .-6 ..6++k^oanrapdai]l^qppkjo ./6Arajp*k^oanra$`k_qiajp(#`ki6hk]`a`#(£ pdeo*ejepK^oanrano*^ej`$pdeo%%7 .06 .16y( .26 .36`eolh]uI]l6bqj_pekj$%w .46


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

.56eb$C>nksoanEo?kil]pe^ha$%%w /,6 /-6eb$ $pdeo*i]l[_kjp]ejan%%w /.6 //6++_na]pa]i]lejop]j_a /06pdeo*i]l9jasCI]l.$ $pdeo*i]l[_kjp]ejan%%7 /16 /26++]``i]l_kjpnkho /36pdeo*i]l*]``?kjpnkh$jasCH]ncaI]l?kjpnkh$%%7 /46pdeo*i]l*]``?kjpnkh$jasCI]lPula?kjpnkh$%%7 /56 0,6++_ajpanpdai]l]p]_anp]ejhk_]pekj 0-6pdeo*i]l*oap?ajpan$jasCH]pHjc$04*41212(.*/1,53%(4%7 0.6 0/6++oapql]cak_k`ejcejop]j_a 006pdeo*cak_k`an9jasC?heajpCak_k`an$%7 016 026++qjhk]`i]l 036Arajp*k^oanra$sej`ks(#qjhk]`#(CQjhk]`%7 046y 056y 1,6y( 1-6 1.6ejepK^oanrano6bqj_pekj$%w 1/6 106eb$ $#hk_]pekj[j]ia[^qppkj#%%w 116 $#hk_]pekj[j]ia[^qppkj#%*k^oanra$ 126#_he_g#(pdeo*bej`Hk_]pekj*^ej`=oArajpHeopajan$pdeo%%7 136y 146 156eb$ $#bej`[nkqpa[^qppkj#%%w 2,6 $#bej`[nkqpa[^qppkj#%*k^oanra$ 2-6#_he_g#(pdeo*bej`>aopFkqnjau*^ej`=oArajpHeopajan$pdeo%%7 2.6y 2/6 206eb$ $#op]np[]c]ej[^qppkj#%%w 216 $#op]np[]c]ej[^qppkj#%*k^oanra$ 226#_he_g#(pdeo*op]np=c]ej*^ej`=oArajpHeopajan$pdeo%%7 236y 246 256eb$ $#]``[bkni#%%w 3,6 $#]``[bkni#%*k^oanra$#oq^iep#( 3-6pdeo*o]raFkqnjau*^ej`=oArajpHeopajan$pdeo%%7 3.6y 3/6y( 306 316++kpdanbqj_pekjo* 326%

147


148

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

At the beginning of Listing 5-11 are some variables to hold various journey-related values. When ?h]oo*_na]pa is called, the ejepe]heva method on line 15 is called. This loads and displays the map and also starts observing the map buttons we have created. Once the DOM has been fully loaded using the `ki6hk]`a` event on line 23, the buttons get the _he_g event attached to them. The bej`Hk_]pekj$% function will locate the place in Google Maps and display it in the map canvas and also save the details locally in a JavaScript variable. The bej`>aopFkqnjau$%function will carry out the algorithm for finding the shortest journey using the shortest neighbor algorithm. The op]np=c]ej$%function will clear reset variables and allow a user to enter a new journey. Finally, once a journey has been plotted, the o]raFkqnjau$% function will observe the submit event in the save journey form and post the journey details to the server for saving. In the following sections, weâ&#x20AC;&#x2122;ll describe each of the missing functions in Listing 5-11, starting with the function that helps us to find a Google map location.

Finding Locations When a user enters a location name and clicks the Enter a Location button, the bej`Hk_]pekj$% function, shown in Listing 5-12, is fired. Listing 5-12. JavaScript to Find a Google Map Location -6bej`Hk_]pekj6bqj_pekj$%w .6 /6hk_[j]ia9 $#Hk_]pekjJ]ia#%*r]hqa7 06 16eb$hk_[j]ia99##%w 26]hanp$Lha]oaajpan]hk_]pekjj]ia*%7 36napqnj7 46y 56 -,6++sakjhu]hhks]i]teiqijqi^ankbhk_]pekjo --6eb$pdeo*qoan[fkqnjau*hajcpd:9.,%w -.6]hanp$OknnuSad]rana]_da`pdai]teiqi -/6jqi^ankbhk_]pekjo*%7 -06napqnj7 -16y -26 -36++`kcak_k`ejc7bej`pdahkjcepq`a]j`h]pepq`akbpdahk_]pekj -46eb$pdeo*cak_k`an%w -56 .,6r]n_qnnajp[k9pdeo7 .-6 ..6pdeo*cak_k`an*capH]pHjc$ ./6hk_[j]ia( .06bqj_pekj$lkejp%w .16


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

.26eb$lkejp%w .36]hanp$hk_[j]ia'jkpbkqj`%7 .46yahoaw .56 /,6++opknapdahk_]pekj /-6_qnnajp[k*opknaHk_]pekj$hk_[j]ia(lkejp%7 /.6 //6++_ajpanpdahk_]pekjkjpdai]l]j` /06++]``lqodleji]ngan /16_qnnajp[k*i]l*oap?ajpan$lkejp(-/%7 /26r]ni]ngan9jasCI]ngan$lkejp%7 /36_qnnajp[k*i]l*]``Kranh]u$i]ngan%7 /46y /56y 0,6%7 0-6y 0.6y( 0/6 006opknaHk_]pekj6bqj_pekj$hk_[j]ia(lkejp%w 016 026r]njas[hk_9jas=nn]u$%7 036 046jas[hk_W#_kkn`#Y9lkejp*h]p$%'#(#'lkejp*hjc$%7 056jas[hk_W#hk_[j]ia#Y9hk_[j]ia7 1,6 1-6pdeo*qoan[fkqnjau*lqod$jas[hk_%7 1.6 1/6++ql`]papdafkqnjauiaoo]ca 106pdeo*ql`]paFkqnjauIaoo]ca$% 116y( This function starts with a couple of error-handling lines. Then we make the geocoding API call cak_k`an*capH]pHjc on line 22. If the Google API call finds the location, we store it using our opknaHk_]pekj$% function on line 44. We simply hold the location name and coordinate in an array and push it into a global array. Finally, we set the map to show the location and add a pushpin marker, starting from line 35. Figure 5-6 shows an example of what a user should see after entering a location. In the next section, we’ll look at the algorithm for our traveling salesman/tourist problem. It’s the shortest distance between locations. Even so, it’s pretty long, so you may want to jump to the next section and come back to the algorithm later.

149


150

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

Figure 5-6. User enters one location

The Traveling Salesman Algorithm When a user has entered a set number of locations and clicked the Calculate Journey button, we find the best journey with the â&#x20AC;&#x153;traveling salesmanâ&#x20AC;? algorithm. As the algorithm is quite large, we have split the code into three parts. We start the algorithm in Listing 5-13. Listing 5-13. The Traveling Salesman Algorithm Part 1 -6fkqnjau[_ki^ej]pekj6jas=nn]u$%( .6 /6bej`>aopFkqnjau6bqj_pekj$%w 06


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

16++saskj#p_]h_qh]pa]fkqnjauebpdanaeojkfkqnjaupk_]h_qh]pa 26eb$pdeo*qoan[fkqnjau*hajcpd8.%w 36]hanp$Lha]oaajpan]pha]op.hk_]pekjo*%7 46napqnj7 56y -,6 --6++saskj#p_]h_qh]papdafkqnjau]c]ejebepd]o]hna]`u^aaj`kja* -.6eb$pdeo*^aop[fkqnjau*hajcpd99pdeo*qoan[fkqnjau*hajcpd%w -/6napqnj7 -06y -16 -26++cap]hhpdafkqnjau_ki^ej]pekjo -36r]njqi[hk_o9pdeo*qoan[fkqnjau*hajcpd7 -46 -56bkn$r]nt9,7t8jqi[hk_o7t''%w .,6 .-6bnki[dana9pdeo*qoan[fkqnjauWtY7 ..6 ./6bkn$r]nu9t'-7u8jqi[hk_o7u''%w .06 .16pk[dana9pdeo*qoan[fkqnjauWuY7 .26 .36_qnnajp[fkqnjau9jas=nn]u$%7 .46 .56_qnnajp[fkqnjauWbnkiY9bnki[dana7 /,6_qnnajp[fkqnjauWpkY9pk[dana7 /-6_qnnajp[fkqnjauWfkqnjau[`eop]j_aY9##7 /.6 //6pdeo*fkqnjau[_ki^ej]pekj*lqod$_qnnajp[fkqnjau%7 /06y /16y /26 /36eb$pdeo*capFkqnjau@eop]j_a$%%w /46pdeo*_]h_POL$%7 /56y 0,6 0-6napqnjb]hoa7 0.6y( The variable at the top of Listing 5-13 holds all the journey combinations that the user has entered. The bej`>aopFkqnjau$% function starts on line 3 with a couple of lines of error checking. Next, we work out all the combinations between the locations on line 17 to line 35. After that, we call capFkqnjau@eop]j_a$% on line 37, which in turn makes the Google geocoding requests to fetch the distance for each pair of locations in fkqnjau[_ki^ej]pekj. Once that is done, we can start calculating the shortest distances between locations. We continue from the previous listing with Listing 5-14.

151


152

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

Listing 5-14. The Traveling Salesman Algorithm Part 2 -6capFkqnjau@eop]j_a6bqj_pekj$%w .6 /6++Op]npcappejcpdafkqnjau`eop]j_a*Kj_asad]rabkqj`]fkqnjau 06++sepdkqp]ju`eop]j_a(hap#ofqople_gpd]pkja]j`bap_dpda 16++fkqnjau`eop]j_abnkiCkkcha* 26r]n`k[fkqnjau9)-7 36 46bkn$r]nt9,7t8pdeo*fkqnjau[_ki^ej]pekj*hajcpd7t''%w 56 -,6eb$pdeo*fkqnjau[_ki^ej]pekjWtYW#fkqnjau[`eop]j_a#Y99##%w --6++jkfkqnjau`eop]j_adana(okhap#ocapep -.6r]n`k[fkqnjau9t7 -/6^na]g7 -06y -16y -26 -36eb$`k[fkqnjau:9,%w -46 -56++sabkqj`]fkqnjaupk`k .,6 .-6`ena_pekjo9jasC@ena_pekjo$%7 ..6 ./6CArajp*]``Heopajan$`ena_pekjo(hk]`(bqj_pekj$%w .06 .16++Cap]j`behhfkqnjau`eop]j_a*Sa]hs]uofqop .26++p]gapdabenopfkqnjau .36pdeo*fkqnjau[_ki^ej]pekjW`k[fkqnjauY£ W#fkqnjau[`eop]j_a#Y9`ena_pekjo*capFkqnjau$,%*cap@eop]j_a$%*iapano7 .46 .56++jkshap#obej`pdajatpkja /,6pdeo*capFkqnjau@eop]j_a$%7 /-6y%7 /.6 //6`ena_pekj[fkqnjau9#bnki6#7 /06`ena_pekj[fkqnjau'9£ pdeo*fkqnjau[_ki^ej]pekjW`k[fkqnjauYW#bnki#YW#_kkn`#Y7 /16`ena_pekj[fkqnjau'9#pk6#7 /26`ena_pekj[fkqnjau'9£ pdeo*fkqnjau[_ki^ej]pekjW`k[fkqnjauYW#pk#YW#_kkn`#Y7 /36 /46`ena_pekjo*hk]`$`ena_pekj[fkqnjau%7 /56y 0,6 0-6napqnjpnqa7 0.6y(


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

Notice that the capFkqnjau@eop]j_a$% function in Listing 5-14 is recursive. The Ajax geocoding call to the Google servers is asynchronous. We create a C@ena_pekjo object on line 21, make the call to fetch the geocoding data, and then quickly carry on with the next location. The CArajp*]``Heopajan statement will automatically get the distance for us when the reply comes back. OK, just to recap, we first work out all the combinations from one location to another and store this in the *fkqnjau[_ki^ej]pekj array. Next, we make geocoding requests to fetch the distance for all the location pairs in *fkqnjau[_ki^ej]pekj. Once all that is complete, we can start working out the shortest round-trip. Working out the shortest round-trip starts with the _]h_POL$% function in Listing 5-15. Before we start, there are two important variables to mention: reoepa` and ^aop[fkqnjau. From their names, you can probably guess what they hold: locations already visited and the final path that we have worked out. Listing 5-15. The Traveling Salesman Algorithm Part 3 -6++_epeao]hna]`ureoepa` .6reoepa`6jas=nn]u$%( /6 06++bkndkh`ejcpda^aopfkqnjau 16^aop[fkqnjau6jas=nn]u$%( 26 36_]h_POL6bqj_pekj$%w 46 56r]nopklEjbej9,7 -,6 --6++sdehapdanaeo]jatphk_]pekjpkreoep -.6sdeha$pdeo*[reoepJatp?epu$%%w -/6 -06++pailr]nbkndkh`ejcpda^aop$odknpaop% -16++ja]naopjaecd^knokb]n -26r]nja]naop[jaecd^kqn9)-7 -36 -46eb$opklEjbej:.,%wnapqnj7y -56opklEjbej''7 .,6 .-6op]np[dana9pdeo*[capJatpJaecd^kqn$%7 ..6 ./6++cap]hhjaecd^knopd]pd]rajkp^aajreoepa`bnkipda .06++op]np[danahk_]pekj .16r]njaecd^kqno9pdeo*[capJaecd^kqno$op]np[dana%7 .26 .36bkn$r]nt9,7t8jaecd^kqno*hajcpd7t''%w .46 .56eb$ja]naop[jaecd^kqn99)-%w /,6ja]naop[jaecd^kqn9jaecd^kqnoWtY7 /-6y /.6

153


154

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

//6++jksbej`pdaodknpaopfkqnjau /06eb$jaecd^kqnoWtYW#fkqnjau[`eop]j_a#Y8 /16ja]naop[jaecd^kqnW#fkqnjau[`eop]j_a#Y%w /26ja]naop[jaecd^kqn9jaecd^kqnoWtY7 /36y /46y /56 0,6++saodkqh`jksd]rapdajatpja]naopjaecd^kn 0-6pdeo*^aop[fkqnjau*lqod$ja]naop[jaecd^kqnW#pk#Y%7 0.6pdeo*[i]ngReoepa`$ja]naop[jaecd^kqnW#pk#Y%7 0/6y 006 016pdeo*[lhkp>aopFkqnjau$%7 026y( 036 046[reoepJatp?epu6bqj_pekj$%w 056 1,6eb$pdeo*reoepa`*hajcpd99pdeo*qoan[fkqnjau*hajcpd%w 1-6napqnjb]hoa7 1.6y 1/6 106napqnjpnqa7 116y( 126 136[capJatpJaecd^kqn6bqj_pekj$%w 146 156r]njatp[_epu9##7 2,6 2-6eb$pdeo*^aop[fkqnjau*hajcpd99,%w 2.6 2/6++ejep*Sap]gapdabenopfkqnjau]opdaop]npejclkejp 206op]np[dana9pdeo*fkqnjau[_ki^ej]pekjW,YW#bnki#Y7 216pdeo*^aop[fkqnjau*lqod$op]np[dana%7 226pdeo*[i]ngReoepa`$op]np[dana%7 236 246jatp[_epu9op]np[dana7 256y 3,6ahoaw 3-6 3.6++sale_gpdah]op_epu 3/6r]nh]op[hk_9pdeo*^aop[fkqnjau*hajcpd)-7 306jatp[_epu9pdeo*^aop[fkqnjauWh]op[hk_Y7 316y 326 336napqnjjatp[_epu7 346y( 356


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

4,6[i]ngReoepa`6bqj_pekj$hk_%w 4-6 4.6pdeo*reoepa`*lqod$hk_W#hk_[j]ia#Y%7 4/6y( 406 416[hk_Reoepa`6bqj_pekj$hk_[j]ia%w 426 436bkn$r]nt9,7t8pdeo*reoepa`*hajcpd7t''%w 446 456eb$hk_[j]ia99pdeo*reoepa`WtY%w 5,6napqnjpnqa7 5-6y 5.6y 5/6 506napqnjb]hoa7 516y( 526 536+& 546&Cap]hhjaecd^knojkpreoepa` 556&+ -,,6[capJaecd^kqno6bqj_pekj$bnki[hk_%w -,-6 -,.6r]nnaoqhp9jas=nn]u$%7 -,/6 -,06bkn$r]nt9,7t8pdeo*fkqnjau[_ki^ej]pekj*hajcpd7t''%w -,16 -,26r]njatp[hk_9jas=nn]u$%7 -,36jatp[hk_W#bnki#Y9bnki[hk_7 -,46jatp[hk_W#pk#Y9$£ pdeo*fkqnjau[_ki^ej]pekjWtYW#bnki#YW#hk_[j]ia#Y99£ bnki[hk_W#hk_[j]ia#Y%;pdeo*fkqnjau[_ki^ej]pekjWtYW#pk#Y6£ pdeo*fkqnjau[_ki^ej]pekjWtYW#bnki#Y7 -,56jatp[hk_W#fkqnjau[`eop]j_a#Y9£ pdeo*fkqnjau[_ki^ej]pekjWtYW#fkqnjau[`eop]j_a#Y7 --,6 ---6++_da_gsdapdanpdahk_]pekjd]o^aajreoepa`]hna]`u --.6eb$pdeo*[hk_Reoepa`$jatp[hk_W#pk#YW#hk_[j]ia#Y%%w --/6naoqhp*lqod$jatp[hk_%7 --06y --16y --26 --36napqnjnaoqhp7 --46y( Our _]h_POL function starts with an outer loop on line 12. If there is a next location to visit, we carry on with the algorithm. Within the loop, we first pick a starting location using [capJatpJaecd^kqn on line 21. Next, we work out the nearest neighbor to that point using the [capJaecd^kqno$% function on line 25. This gets all the neighbors that haven’t already been

155


156

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

visited. From this, we use a simple bubble sort to work out the shortest distance to the next location. When we come around the loop the next time, we pick the last city we came from as the next starting point and start over again. Once we have visited all the locations, we plot the journey path on the map via the [lhkp>aopFkqnjau$% function on line 45, which we will cover in the next section. There are many functions that support _]h_POL. These functions are described in Table 5-3. Table 5-3. Supporting Functions to calcTSP

Function

Description

[reoepJatp?epu

On line 48 in Listing 5-15. This function tells us whether there are any more locations to visit. Once there are no more locations to visit, we have found our shortest route.

[capJatpJaecd^kqn

On line 57 in Listing 5-15. This function provides us with the next location to visit, which is always the destination location of the last journey.

[i]ngReoepa`

On line 80 in Listing 5-15. Once a location has been visited, this function marks that location, so that we do not visit the same location.

[hk_Reoepa`

On line 85 in Listing 5-15. This tells us whether we have visited a location.

[capJaecd^kqno

On line 100 in Listing 5-15. This gets all the neighbors that we have not visited. Using the result returned, we can then find the neighbor with the shortest route to the location.

Plotting the Journey Using the Google Maps C@ena_pekjo class, we can plot the path between the locations. Using the hk]`BnkiS]ulkejpo method in the C@ena_pekjo class, a blue path is marked on the map itself. The code is shown in Listing 5-16. Listing 5-16. Plotting the Journey -6[lhkp>aopFkqnjau6bqj_pekj$%w .6 /6r]njas[fkqnjau9jas=nn]u$%7 06 16bkn$r]nt9,7t8pdeo*^aop[fkqnjau*hajcpd7t''%w 26 36`ena_pekj[fkqnjau9pdeo*^aop[fkqnjauWtYW#_kkn`#Y7 46jas[fkqnjauWtY9`ena_pekj[fkqnjau7 56y -,6 --6++]``pdaop]npejclkejp^]_g]oop]npejclkoepekj -.6jas[fkqnjau*lqod$pdeo*^aop[fkqnjauW,YW#_kkn`#Y%7 -/6 -06`ena_pekjo9jasC@ena_pekjo$pdeo*i]l%7 -16 -26r]n_qnnajp[k9pdeo7 -36


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

-46++naikrapda`ab]qhpna`i]ngano -56CArajp*]``Heopajan$`ena_pekjo(hk]`(bqj_pekj$%w .,6_qnnajp[k*i]l*_ha]nKranh]uo$%7 .-6y%7 ..6 ./6++naikrapdah]opi]ngan(okpdabenopkjaskqh`odksql .06CArajp*]``Heopajan$`ena_pekjo(]``kranh]u(bqj_pekj$%w .16r]njqi[i]ngano9`ena_pekjo*capJqiCak_k`ao$%7 .26_qnnajp[k*i]l*naikraKranh]u$ÂŁ `ena_pekjo*capI]ngan$jqi[i]ngano)-%%7 .36y%7 .46 .56`ena_pekjo*hk]`BnkiS]ulkejpo$jas[fkqnjau%7 /,6y( Most of this code is devoted to organizing the locations in a format that will be suitable for use for the hk]`BnkiS]ulkejpo$% function. We first get the shortest route from the ^aop[ fkqnjau variable by looping through it on line 5. Then, on line 12, we trace a route from the end point back to the start so we have a loop. On line 14, we create a C@ena_pekjo object for the plotting of the route. Next, starting from line 19, we need to carry out some housekeeping functions. Google automatically creates pushpin markers when we plot a location. We need to clear these, because the C@ena_pekjo object creates additional markers that show the numeric order of the locations. It is worth noting that for a lot of countries, the path and distance use the roads as the mode of travel, which is the route that we would prefer. However, in countries where Google doesn't have any road information, the straight path between the locations is used. And that is just about it. We finish +]ll+sa^nkkp+fo+oepa*fo with the class-creation code shown here: jasPn]rahI]llnI]j]can$#i]l[_]jr]o#%7 Weâ&#x20AC;&#x2122;re not quite finished yet on the client side, as there are two more buttons: Start Again and Save Journey. Start Again is pretty straightforward, as it just clears the variables and refreshes the map. Save Journey is a little more interesting. As shown in Listing 5-17, when o]raFkqnjau is called, we first check whether there is a journey to save. If there is, we basically create a JSON string format from the calculated route and insert it as a value in the hidden tag element with e`hk_]pekjo, after which the form is submitted to the server. Using the journey we plotted earlier, Listing 5-18 shows the data format of the locations as a JSON string.

NNote What is a JSON string format? JSON stands for JavaScript Object Notation. It is a data format much like XML or even CSV. The popularity of its use came as a result of Ajax, since the format is native to JavaScript. It is also less verbose than XML.

157


158

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

Listing 5-17. The saveJourney Function _da_gFkqnjauAteopo6bqj_pekj$%w eb$pdeo*^aop[fkqnjau*hajcpd99,%w ]hanp$#Jkfkqnjaupko]ra(_na]pa]fkqnjaubenop(XjknÂŁ i]u^apdafkqnjaud]ojkp^aaj_]h_qh]pa`uap*#%7 napqnjb]hoa7 y napqnjpnqa7 y( o]raFkqnjau6bqj_pekj$a%w eb$pdeo*_da_gFkqnjauAteopo$%%w ++_na]papdafokjjkp]pekj tih[hk_9#w#7 bkn$r]nt9,7t8pdeo*^aop[fkqnjau*hajcpd7t''%w tih[hk_'9##'t'#6#7 tih[hk_'9#w# tih[hk_'9#e`6#7 tih[hk_'9##7 tih[hk_'9#(#7 tih[hk_'9#_kiiajpo6#7 tih[hk_'9##7 tih[hk_'9#(#7 tih[hk_'9#_kkn`6#7 tih[hk_'9##'pdeo*^aop[fkqnjauWtYW#_kkn`#Y'##7 tih[hk_'9#(#7 tih[hk_'9#hk_[j]ia6#7 tih[hk_'9##'pdeo*^aop[fkqnjauWtYW#hk_[j]ia#Y'##7 tih[hk_'9#y# eb$t'-8pdeo*^aop[fkqnjau*hajcpd%wtih[hk_'9#(#7y y


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

tih[hk_'9#y#7  $#hk_]pekjo#%*r]hqa9tih[hk_7 napqnjpnqa7 y ahoaw Arajp*opkl$a%7 napqnjb]hoa7 y y

Listing 5-18. Our Journey Locations in a JSON String w ,6we`6( _kiiajpo6( _kkn`60/*.54/00(1*/4/..-( hk_]pekj[j]ia6I]noaehhay( -6we`6( _kiiajpo6( _kkn`604*412223(.*/1,543( hk_]pekj[j]ia6L]neoy( .6we`6( _kiiajpo6( _kkn`60,*0-230-()/*3,/.1( hk_]pekj[j]ia6I]`ne`y y We can now plot a journey and see how it looks on screen. Letâ&#x20AC;&#x2122;s assume our friends are going to visit three locations: Marseille in France, Madrid in Spain, and Paris in France again. After entering the three locations, our map application will look like the one shown in Figure 5-7. Now that we have completed the client side of the application, weâ&#x20AC;&#x2122;ll jump across to the server side and look at how a journey is saved into the database.

159


160

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

Figure 5-7. A journey with three locations

Journey Data For our application, we need to save the journey details and also the tags associated with a journey. We also need to give users the ability to retrieve journeys for viewing and editing. Without further ado, weâ&#x20AC;&#x2122;ll show you how these functions are done.

Saving a Journey All our actions are contained in the one and only Fkqnjauo?kjpnkhhan in the application. Within that controller, we save a journey using the ]``[bkni$% action, as shown in Listing 5-19. This is the target action for the Save Journey button on the client side. It parses the journey name, tags, and comments and also the journey details including the destination comments. The detail of the destinations arrives in the JSON format. We could have chosen XML or even some comma/semicolon type proprietary format. However, the JSON format seems to be the


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

de facto format nowadays for web client/server data exchange. We set two variables to be used by the view: hk_]pekjo and fkqnjau[e`. Listing 5-19. Saving Journeys bqj_pekj]``[bkni$%w ++cappdahk_]pekjobnkipdade``ajbkniahaiajp  hk_]pekjo9fokj[`a_k`a$pdeo):`]p]W#hk_]pekjo#Y(pnqa%7  fkqnjau[e`9jqhh7 pdeo):oap$_kil]_p$#hk_]pekjo#(#fkqnjau[e`#%%7

y Now let’s look at the view that goes with the ]``[bkni$% action. The fkqnjau[e` is used to decide whether we are saving a new journey or editing an existing one. The same form is used to add or edit a journey. The view for ]``[bkni$% action is shown in Listing 5-20. It is stored in +]ll+reaso+fkqnjauo+]``[bkni*_pl. The output of the view is shown in Figure 5-8.

NNote We have noticed that as applications get more complex, they often branch out into separate add or edit action/view pairs. Be careful, as the code in the controller and view can get out of hand. Use components in the controller and view helpers or elements in the view where you can spot common code. In fact, we were pretty close to having two views, as we weren’t sure whether to have the password field when editing a journey.

Listing 5-20. The View for the add_form Action -68;ldl .6eb$ailpu$ qoan[iaoo]ca%% /6a_dk qoan[iaoo]ca7 06;: 16 268l:Beah`oi]nga`sepd&]najaa`a`*8+l: 36 468`er: 56 -,68;ldl --6 -.6++@a_e`asdapdansa#na]``ejc]fkqnjaukna`epejc -/6eb$ fkqnjau[e`%w -06a_dkbkni):_na]pa$#Fkqnjau#( -16]nn]u$£ #qnh#9:#+fkqnjauo+a`ep+#* fkqnjau[e`%%7 -26y

161


162

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

-36ahoaw -46a_dkbkni):_na]pa$#Fkqnjau#( -56]nn]u$#qnh#9:#+fkqnjauo+]``#%%7 .,6y .-6 ..6a_dk#8`er_h]oo9bkni[beah`o:#7 ./6a_dk#8d1:FkqnjauJ]ia&68+d1:#7 .06a_dkbkni):ejlqp$#j]ia#(]nn]u$£ #`er#9:b]hoa(#h]^ah#9:b]hoa%%7 .16a_dk#8+`er:#7 .26 .36a_dk#8`er_h]oo9bkni[beah`o:#7 .46a_dk#8d1:L]ooskn`68+d1:#7 .56a_dkbkni):l]ooskn`$#l]ooskn`#(]nn]u$£ #`er#9:b]hoa(#h]^ah#9:b]hoa%%7 /,6a_dk#8l:Qoa`pknapnearaukqnfkqnjau*Ebukq`kjkpajpanukqnksj /-6l]ooskn`(kjasehh^acajan]pa`bknukq*8+l:8+`er:#7 /.6 //6a_dk#8`er_h]oo9bkni[beah`o:#7 /06a_dk#8d1:P]co68+d1:#7 /16a_dkbkni):ejlqp$#p]co#(]nn]u$£ #`er#9:b]hoa(#h]^ah#9:b]hoa%%7 /26a_dk#8l:Lha]oaoal]n]pap]cosepd_kii]o*8+l:8+`er:#7 /36 /46a_dk#8`er_h]oo9bkni[beah`o:#7 /56a_dk#8d1:Jkpao68+d1:#7 0,6a_dkbkni):patp]na]$#jkpao#( 0-6]nn]u$#`er#9:b]hoa(#h]^ah#9:b]hoa( 0.6#nkso#9:#3#(#_kho#9:#2,# 0/6%%7 006a_dk#8+`er:#7 016 026++hk_]pekjo 036a_dki]l):cajan]paBeah`o$ hk_]pekjo%7 046 056a_dk#8`er_h]oo9bkni[beah`o:#7 1,6a_dkbkni):oq^iep$#O]raFkqnjau#%7 1-6a_dk#8+`er:#7 1.6 1/6a_dkbkni):aj`$%7 106;: 116 1268+`er:


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

Figure 5-8. The add_form view In the ]``[bkni$% action, we decode the JSON locations details. These are then passed onto the view for display. In the view, we manage the layout of the elements ourselves by setting the `er and h]^ah parameters to b]hoa. Each journey needs to have a password so a user can come back and edit a journey. In practice, you would probably create a user account and attach journeys to a particular user. However, to keep the application simple, we have attached a password to each journey instead.

163


164

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

We have created a view helper named I]lDahlan, which is stored in +]ll+reaso+dahlano+ i]l*ldl. In the I]lDahlan class, shown in Listing 5-21, we have a cajan]paBeah`o$% method on line 5, which is used to help display the comment patp]na] tags that go with each location. Within the helper, we can use other helpers by including them in the dahlano array. Listing 5-21. The View Helper Class MapHelper (/app/views/helpers/map.php) -6_h]ooI]lDahlanatpaj`o=llDahlanw .6 /6r]n dahlano9]nn]u$#Bkni#%7 06 16bqj_pekjcajan]paBeah`o$ hk_]pekjo%w 26 36 naoqhp9##7 46 56bkn$ e`t9,7 e`t8oevakb$ hk_]pekjo%7 e`t''%w -,6 --6 e`9 hk_]pekjoW e`tYW#e`#Y7 -.6 _kkn`9 hk_]pekjoW e`tYW#_kkn`#Y7 -/6 hk_[j]ia9 hk_]pekjoW e`tYW#hk_[j]ia#Y7 -06 _kiiajpo9 hk_]pekjoW e`tYW#_kiiajpo#Y7 -16 -26 fokj9fokj[aj_k`a$ hk_]pekjoW e`tY%7 -36 -46 naoqhp*9#8`er_h]oo9bkni[beah`o:#7 -56 naoqhp*9#8d1:Hk_]pekj6#* hk_[j]ia*#8+d1:#7 .,6 naoqhp*9pdeo):Bkni):patp]na]$#jkpao#( .-6]nn]u$#r]hqa#9: _kiiajpo( ..6#j]ia#9:ÂŁ ./6`]p]WFkqnjauYWhk_]pekjoYW* e`t*YW_kiiajpoY( .06#`er#9:b]hoa(#h]^ah#9:b]hoa( .16#nkso#9:#1#(#_kho#9:#1,# .26%%7 .36 .46 naoqhp*9#8ejlqppula9de``aj .56j]ia9`]p]WFkqnjauYWhk_]pekjoYW#* e`t*#YW`]p]Y /,6r]hqa9X##* fokj*#X#+:#7 /-6 naoqhp*9#8+`er:#7 /.6y //6 /06napqnjpdeo):kqplqp$ naoqhp%7 /16y /26y In Listing 5-20, the form is posted to the ]``$% action on line 19. This is the action in the Fkqnjauo?kjpnkhhan that saves the journey when a user has entered the journey details. The ]``$% action is shown in Listing 5-22.


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

Listing 5-22. Saving the Journey Data -6bqj_pekj]``$%w .6 /6++Ebjk`]p]eooqllhea`(safqopnaj`anpdafkqnjaubkni 06eb$ailpu$pdeo):`]p]%%w 16pdeo):na`ena_p$#+#(jqhh(pnqa%7 26y 36ahoaw 46 56++Sdapdanpdao]ras]ooq__aoobqh -,6 o]ra[naoqhp9-7 --6 -.6eb$ o]ra[naoqhp%w -/6 -06++?da_gl]ooskn` -16 l]ooskn`9pdeo):`]p]W#Fkqnjau#YW#l]ooskn`#Y7 -26eb$ailpu$pdeo):`]p]W#Fkqnjau#YW#l]ooskn`#Y%%w -36 l]ooskn`9n]j`$-(-,,,%7 -46y -56 .,6++O]rafkqnjau .-6 fkqnjau9]nn]u$%7 ..6 fkqnjauW#j]ia#Y9pdeo):`]p]W#Fkqnjau#YW#j]ia#Y7 ./6 fkqnjauW#jkpao#Y9pdeo):`]p]W#Fkqnjau#YW#jkpao#Y7 .06 fkqnjauW#l]ooskn`#Y9i`1$ l]ooskn`%7 .16 o]ra[fkqnjau[naoqhp9pdeo):Fkqnjau):o]ra$ fkqnjau%7 .26 .36++Fkqnjau`e`j#po]ralnklanhu .46eb$ o]ra[fkqnjau[naoqhp%w .56 o]ra[naoqhp9,7 /,6y /-6y /.6 //6eb$ o]ra[naoqhp%w /06 /16++O]rahk_]pekjo /26 o]ra[hk_[naoqhp9pdeo):[o]ra[hk_]pekjo$ /36pdeo):`]p]W#Fkqnjau#YW#hk_]pekjo#Y( /46pdeo):Fkqnjau):e` /56%7 0,6 0-6++Hk_]pekjo`e`j#po]ralnklanhu 0.6eb$ o]ra[hk_[naoqhp%w 0/6 o]ra[naoqhp9,7 006y 016y 026

165


166

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

036eb$ o]ra[naoqhp%w 046 056++O]rap]co 1,6 o]ra[p]c[naoqhp9pdeo):[o]ra[p]co$ 1-6pdeo):`]p]W#Fkqnjau#YW#p]co#Y( 1.6pdeo):Fkqnjau):e` 1/6%7 106 116++P]co`e`j#po]ralnklanhu 126eb$ o]ra[p]c[naoqhp%w 136 o]ra[naoqhp9,7 146y 156y 2,6 2-6eb$ o]ra[naoqhp%w 2.6 2/6++Jksnaj`anpdaoq__aooiaoo]careas 206pdeo):oap$#fkqnjau[e`#(pdeo):Fkqnjau):e`%7 216 226pdeo):oap$#l]ooskn`#( l]ooskn`%7 236 246pdeo):naj`an$#]``[oq__aoo#%7 256y 3,6ahoaw 3-6 3.6pdeo):oap$#qoan[iaoo]ca#( 3/6#Lha]oa_knna_ppdabkniannkno]oodksj^ahks*#%7 306 316++Sad]rapknabknipdahk_]pekj`]p] 326 hk_]pekjo[bkn[bkni9pdeo):[nabkni]p[hk_]pekjo$ 336pdeo):`]p]W#Fkqnjau#YW#hk_]pekjo#Y 346%7 356pdeo):oap$#hk_]pekjo#( hk_]pekjo[bkn[bkni%7 4,6 4-6pdeo):oap$#fkqnjau[e`#(##%7 4.6 4/6pdeo):naj`an$#]``[bkni#%7 406y 416y 426y On line 5, if no data is supplied, we simply redirect the user back to the home page, as we regard that as an error. If data is supplied, we save the three data sets into the tables fkqnjauo, hk_]pekjo, and p]co. Note that in a production environment, these three units of code should be within a transaction block. If one fails, the previous save actions should be rolled back. If everything has been saved OK, we display the ]``[oq__aoo view on line 68. If not, we render the form again with error messages.


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

We have used two protected actions/functions to save the locations and tags: [o]ra[ hk_]pekjo and [o]ra[p]co. The underscore prefix tells Cake that they are protected actions and should not be executed via any URL request.

Saving Tags The tag data that goes with a journey is a set of comma-separated strings. These strings are split up and entered into the p]co table separately. The tag-saving protected action is shown in Listing 5-23.

NNote We could have placed the tags within a single database field in the fkqnjauo table and called it p]co. However, this would not conform to the first normal form in database normalization, where each field must contain single, not multiple, values. We would run into trouble when we wanted to query the tags within a route.

Listing 5-23. Saving the Journey Tags -6bqj_pekj[o]ra[p]co$ p]co( fkqnjau[e`%w .6 /6 p]co[]9atlhk`a$(( p]co%7 06 16bkn$ e`t9,7 e`t8oevakb$ p]co[]%7 e`t''%w 26 36 `^[p]c9]nn]u$%7 46 `^[p]cW#p]c#Y9pnei$ p]co[]W e`tY%7 56 `^[p]cW#fkqnjau[e`#Y9 fkqnjau[e`7 -,6 --6++Sajaa`pk_na]pa]jasp]c^abknao]rejc]jkpdan -.6pdeo):P]c):_na]pa$ `^[p]c%7 -/6 o]ra[naoqhp9pdeo):P]c):o]ra$ `^[p]c%7 -06 -16eb$ o]ra[naoqhp%w -26napqnjb]hoa7 -36y -46y -56 .,6napqnjpnqa7 .-6y In Listing 5-23, we simply use the PHP atlhk`a$% function to split the tags on line 3 and then loop through the strings and save the tags individually. When we are editing a journey, the saving or updating of the tags is done slightly differently, in that we first delete all the tags relating to the journey and then we save the updated tags as if they were new. We find this technique to be simpler to maintain and easier to read and reuse than the alternative method, where we update any tags that have been changed and delete any tags that have been removed.

167


168

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

Retrieving and Editing a Journey The code to retrieve a journey is pretty simple. The action is shown in Listing 5-24. Yes, it’s empty, because it’s just a simple form with no other dependencies. The main view elements are shown in Listing 5-25. We have cut some of the HTML markup to simplify the view. Listing 5-24. The Controller Action to Retrieve a Journey bqj_pekjnapneara[bkni$%w y

Listing 5-25. The View to Retrieve a Journey a_dkbkni):_na]pa$#Fkqnjau#(]nn]u$#qnh#9:#+fkqnjauo+napneara#%%7 a_dkbkni):ejlqp$#fkqnjau[e`#(]nn]u$#`er#9:b]hoa(#h]^ah#9:b]hoa%%7 a_dkbkni):ejlqp$#l]ooskn`#(]nn]u$#`er#9:b]hoa(#h]^ah#9:b]hoa%%7 a_dkbkni):oq^iep$#NapnearaFkqnjau#%7 The retrieve form simply renders a traditional HTML form with two input elements and a submit button. The target of the form is the napneara$% action. The outline of the code is shown in Listing 5-26. It’s very similar to the ]`` action. If no data is supplied, we simply redirect the user back to the retrieve form. If data is supplied, we use Cake’s bej`$% model method to find the journey based on the journey ID and encrypted MD5 password. If a journey is found, we’ll use the ]``[bkni action to display the results. If not, we will render the retrieve form with an error. Listing 5-26. Retrieving a Journey -6bqj_pekjnapneara$%w .6++Ebjk`]p]eooqllhea`(sana`ena_pqoan^]_gpkpdanapnearabkni /6eb$ailpu$pdeo):`]p]%%w 06pdeo):na`ena_p$#+fkqnjauo+napneara[bkni#(jqhh(pnqa%7 16 26y 36ahoa 46w 56 fkqnjau[e`9pdeo):`]p]W#Fkqnjau#YW#fkqnjau[e`#Y7 -,6 l]ooskn`9pdeo):`]p]W#Fkqnjau#YW#l]ooskn`#Y7 --6 fkqnjau9pdeo):Fkqnjau):bej`$ -.6]nn]u$#e`#9: fkqnjau[e`( -/6#l]ooskn`#9:i`1$ l]ooskn`%%%7 -06 -16eb$ fkqnjau%w -26 -36++J]iakbpdafkqnjau -46pdeo):`]p]W#Fkqnjau#YW#j]ia#Y9 fkqnjauW#Fkqnjau#YW#j]ia#Y7 -56


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

.,6++P]conah]pejcpkpdafkqnjau .-6pdeo):`]p]W#Fkqnjau#YW#p]co#Y9£ pdeo):[eilhk`a[p]c$ fkqnjauW#P]c#Y%7 ..6 ./6++Jkpaokbpdafkqnjau .06pdeo):`]p]W#Fkqnjau#YW#jkpao#Y9£ fkqnjauW#Fkqnjau#YW#jkpao#Y7 .16 .26++Hk_]pekjokbpdafkqnjau .36pdeo):oap$#hk_]pekjo#( fkqnjauW#Hk_]pekj#Y%7 .46 .56++FkqnjauE@ /,6pdeo):oap$#fkqnjau[e`#( fkqnjau[e`%7 /-6 /.6pdeo):naj`an$#]``[bkni#%7 //6y /06ahoa /16w /26pdeo):oap$#qoan[iaoo]ca#( /36#Oknnu(sa_kqh`jX#p /46bej`ukqnfkqnjau(knukqnl]ooskn`eo /56ej_knna_p#%7 0,6 0-6pdeo):naj`an$#napneara[bkni#%7 0.6y 0/6y 006y

Viewing a Journey Viewing a journey is similar to retrieving a journey, except we can only view the journey details (and not edit them). The action is shown in Listing 5-27. Listing 5-27. The Action to Display a Journey -6bqj_pekj`eolh]u[fkqnjau$ cap[fkqnjau[e`9##%w .6 /6 fkqnjau[e`9 cap[fkqnjau[e`7 06 16eb$pdeo):`]p]W#Fkqnjau#YW#fkqnjau[e`#Y%w 26 fkqnjau[e`9pdeo):`]p]W#Fkqnjau#YW#fkqnjau[e`#Y7 36y 46 56++Ebjk`]p]eooqllhea`(sana`ena_pqoan^]_gpkpdanapnearabkni -,6eb$ fkqnjau[e`%w --6 -.6 fkqnjau9pdeo):Fkqnjau):bej`>uE`$ fkqnjau[e`%7 -/6

169


170

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

-06eb$ fkqnjau%w -16pdeo):oap$#fkqnjau#( fkqnjau%7 -26y -36ahoaw -46pdeo):oap$#qoan[iaoo]ca#( -56#8`er_h]oo9annkn)iaoo]ca:Oknnu(sa .,6_kqh`jX#pbej`pdafkqnjau8+`er:#%7 .-6y ..6y ./6y The action handles both LKOP and CAP scenarios. In the CAP action, journeys can be displayed where the journey ID is within the URL request, as in +fkqnjauo+`eolh]u[fkqnjau+-. In a LKOP action, the journey ID is stored within the pdeo):`]p] variable. In this action, we have used Cakeâ&#x20AC;&#x2122;s bej`>u8beah`J]ia:$opnejc r]hqa% methods to retrieve the journey. The view is pretty straightforward and is shown in Listing 5-28. In this case, we have combined the display form with the view inserted below it. An example of the output is shown in Figure 5-9. Listing 5-28. The Journey View (/app/views/journeys/display_journey.ctp) 8;ldl eb$ailpu$ qoan[iaoo]ca%% a_dk qoan[iaoo]ca7 ;: 8l:Beah`oi]nga`sepd&]najaa`a`*8+l: 8`er: 8;ldl a_dkbkni):_na]pa$#Fkqnjau#( ]nn]u$#qnh#9:#+fkqnjauo+`eolh]u[fkqnjau#%%7 a_dk#8`er_h]oo9bkni[beah`o:#7 a_dk#8d1:FkqnjauE@6&8d1:#7 a_dkbkni):ejlqp$#fkqnjau[e`#(]nn]u$#`er#9:b]hoa(#h]^ah#9:b]hoa%%7 a_dk#8+`er:#7 a_dk#8`er_h]oo9bkni[beah`o:#7 a_dkbkni):oq^iep$#@eolh]uFkqnjau#%7 a_dk#8+`er:#7 a_dkbkni):aj`$%7 ;: 8+`er:


C HA P TER 5 N G O O G LE M A P S A N D T H E T R A V E LI N G S A LE S M A N

8))`eolh]ufkqnjaudana)): 8;ldl eb$eooap$ fkqnjau%%w a_dk#8`er_h]oo9`eolh]u[fkqnjau[_kjp]ejan:#7 a_dk#8d/:UkqnFkqnjau@ap]eho8+d/:#7 ++fkqnjauj]ia a_dk#8`er_h]oo9bkni[beah`o:#7 a_dk#8d0:FkqnjauJ]ia68+d0:#7 a_dk fkqnjauW#Fkqnjau#YW#j]ia#Y7 a_dk#8+`er:#7 ++fkqnjaujkpao a_dk#8`er_h]oo9bkni[beah`o:#7 a_dk#8d0:FkqnjauJkpao68+d0:#7 a_dkopn[nalh]_a$_dn$-,%(#8^n+:#( fkqnjauW#Fkqnjau#YW#jkpao#Y%7 a_dk#8+`er:#7 ++p]c  p]c9 fkqnjauW#P]c#Y7  p]c[opn9##7 bkn$ e`t9,7 e`t8oevakb$ p]c%7 e`t''%w  p]c[opn*9 p]cW e`tYW#p]c#Y7 eb$ e`t'-8oevakb$ p]c%%w p]c[opn*9#(#7y y a_dk#8`er_h]oo9bkni[beah`o:#7 a_dk#8d0:FkqnjauP]co68+d0:#7 a_dk p]c[opn7 a_dk#8+`er:#7 ++hk_]pekjo  hk_]pekjo9 fkqnjauW#Hk_]pekj#Y7 bkn$ e`t9,7 e`t8oevakb$ hk_]pekjo%7 e`t''%w a_dk#8`er_h]oo9bkni[beah`o:#7 a_dk#8d/:Hk_]pekj6#* hk_]pekjoW e`tYW#hk_[j]ia#Y*#8+d/:#7 a_dk hk_]pekjoW e`tYW#_kiiajpo#Y7 a_dk#8+`er:#7 y a_dk#8+`er:#7 y ;:

171


172

CH APT ER 5 N GOOG L E MA P S A ND THE TR A VEL ING S A LE S M A N

Figure 5-9. Viewing a journey

Summary In this chapter, we have put together a simple travel log application. On the front end, we have used Google Maps to plot and work out a journey plan using purely JavaScript. On the server, we’ve created a journeys controller to handle saving and retrieving data. In the Cake models, we’ve used d]oI]ju and ^ahkjcoPk associations, as well as some simple validation. It’s worth noting that some actions have more than one view. Friends and family members can easily see what the travelers are up to by retrieving a journey, either via a URL or by using the display journey form. As a result of the feedback we got from our traveling friends, we have more tweaks and changes to implement, which we’ll leave to you as an exercise. These are their comments: Ê

UÊ 7iÊܜՏ`ʏˆŽiÊ̜Ê>``Ê>ÊÌ>}ÊVœÕ`ÊÜÊÜiÊV>˜ÊÃiiÊ܅>ÌÊ«iœ«iÊ>ÀiÊ`œˆ˜}ʈ˜Ê}i˜iÀ>°

Ê

UÊ 7iÊÜ>˜ÌÊ̜ÊLiÊ>LiÊ̜ʍÕÃÌÊVˆVŽÊ̅iʓ>«Êˆ˜ÃÌi>`ʜvÊi˜ÌiÀˆ˜}Ê«>Viʘ>“ið

Ê

UÊ 7iÊÜ>˜ÌÊ̜ÊLiÊ>LiÊ̜Êi˜ÌiÀÊVœ““i˜ÌÃÊvœÀʜ˜iÊ`iÃ̈˜>̈œ˜Êœ˜Þ°

Ê

UÊ 7iÊÜ>˜ÌÊ̜Ê>œÜʜ̅iÀÊ«iœ«iÊ̜Êi˜ÌiÀÊVœ““i˜ÌðʏÜ]Êi>V…ÊVœ““i˜ÌÊŜՏ`ÊLiÊ a separate, new entry.

Ê

UÊ 7iÊÜ>˜ÌÊ̜ÊÃiiÊ܅>Ìʜ̅iÀÊ«iœ«iÊ>ÀiÊ`œˆ˜}ʈ˜Êȓˆ>ÀÊ`iÃ̈˜>̈œ˜Ãpܓi̅ˆ˜}ʏˆŽiÊ a public gallery.


C HAPTER

6

Mashing Twitter with the Google Translator F

or our fast-paced modern lifestyle, Twitter has filled a gap that fits between text messaging and blogging. You have a spare minute and want to let your pals know what you are doing or thinking, Twitter fits that need nicely. Twitter is a social networking and micro-blogging web application. You can post short messages to tell your friends and everyone else what you’re up to right now. These short messages are referred to as statuses, updates, or tweets. We can see Twitter being quite an addiction: Twitterdiction! In fact, we often view the Twitter public timeline, which is a listing of what people around the world are doing at that moment. However, quite a number of messages are in a foreign language. If a message has a cute picture, we cut and paste it into the Google Translate web site (dppl6++pn]joh]pa* ckkcha*_ki) to see what it says. Wouldn’t it be nice if we could do this translation automatically? Here’s a stroke of luck: Google now has a language translation web service within the Google Ajax Language API. And in true Web 2.0 and Cake fashion, we can easily mash them together and bake some Cake! In this chapter, we’re going to cover quite a number of Cake topics. Twitter comes with an API that we can call from the server. The Google Ajax Language API can be called from the browser via Ajax or the server, but in this chapter, we’ll be using only the server-side method. So, let’s get to creating our application, which we’ll call Twitter Twister.

The Twitter API The Twitter API comes with many methods. These methods are submitted via the principles of representational state transfer (REST). In most cases, this will be HTTP LKOP or CAP—what most people have been using since their early days of web development. Twitter will also return the appropriate HTTP status code. There are a few more items to be aware of when using the API: Ê

UÊ /܈ÌÌiÀʏˆ“ˆÌÃÊ̅iʘՓLiÀʜvÊrequests to 70 requests per 60 minutes. Essentially, if you make one request per minute, you’ll be OK.

Ê

UÊ ÃÊÕÃiÀÃÊV>˜Ê«œÃÌʈ˜Ê“>˜Þʏ>˜}Õ>}iÃ]Ê̅iÊÀiÌÕÀ˜i`Ê`>Ì>ÊvÀœ“Ê/܈ÌÌiÀʈÃÊi˜Vœ`i`ʈ˜Ê UTF-8. As such, we must develop our application with this in mind.

Ê

UÊ 7…i˜Ê/܈ÌÌiÀÊÀiÌÕÀ˜ÃÊ>˜ÊiÀÀœÀ]ʈÌÊ܈Ê`œÊÜʈ˜Ê̅iÊvœÀ“>ÌÊޜÕÊÀiµÕiÃÌi`° 173


174

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

Within the Twitter API, we’ll be using only one of the methods: the lq^he_[peiaheja. This returns the 20 most recent statuses from the server. This is the only method in the API that doesn’t require authentication. Calling the public timeline is easy. Using Cake’s DpplOk_gap, you can fetch the most recent 20 statuses as follows: =ll66eilknp$#DpplOk_gap#%7 dppl9jasDpplOk_gap$%7 namqaop9]nn]u$#qne#9:£ #dppl6++sss*pseppan*_ki+op]pqoao+lq^he_[peiaheja*tih#%7 ^k`u9dppl):namqaop$ namqaop%7 As you can see, requesting the public timeline is a simple case of supplying the namqaop method with the URL. The ^k`u variable will contain details of the 20 statuses in XML format, which we can easily handle in Cake or PHP. Listing 6-1 shows an example. Listing 6-1. Twitter XML Status Example -68op]pqo: .68_na]pa`[]p:PdqFqh-,.-6/-6-3',,,,.,,48+_na]pa`[]p: /68e`:-..,/5/018+e`: 068patp:Pdeoeoiubenoppseppan8+patp: 168okqn_a:8]dnab9dppl6++sss*pdeoeoiudkial]ca*_ki+:£ iudkial]ca8+]:8+okqn_a: 268pnqj_]pa`:b]hoa8+pnqj_]pa`: 368ej[nalhu[pk[op]pqo[e`:,-./,/0-5,8+ej[nalhu[pk[op]pqo[e`: 468ej[nalhu[pk[qoan[e`:-./0128+ej[nalhu[pk[qoan[e`: 568b]rknepa`+: -,68qoan: --68e`:543210/8+e`: -.68j]ia:IaIuoahb8+j]ia: -/68o_naaj[j]ia:FqopIa8+o_naaj[j]ia: -068hk_]pekj:Hkj`kj8+hk_]pekj: -168`ao_nelpekj:P]gapdaNa`Lehh8+`ao_nelpekj: -268lnkbeha[ei]ca[qnh:dppl6++o/*]i]vkj]so*_ki+pseppan[lnk`q_pekj+£ -36lnkbeha[ei]cao+543210/+iqcodkp*flc8+lnkbeha[ei]ca[qnh: -468qnh:dppl6++sss*pdeoeoiudkial]ca*_ki+8+qnh: -568lnkpa_pa`:b]hoa8+lnkpa_pa`: .,68bkhhksano[_kqjp:---8+bkhhksano[_kqjp: .-68+qoan: ..68+op]pqo: On line 4, note the patp tag, which is the tag that contains the Twitter status. Additionally, the tags patp, o_naaj[j]ia, and `ao_nelpekj (on lines 4, 13, and 15, respectively) are the three XML tags that may contain foreign/multibyte characters. However, in our application, to keep things simple, we’re just dealing with the patp tag.


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

NTip Some of the normal string manipulation functions do not always work on multibyte characters. For example, opnhaj may return different length sizes depending on whether the string is single or multibyte. Cake has a useful class called Iqhpe^upa, which contains some string-manipulation functions specifically written for multibyte characters, similar to PHP’s i^opnejc module.

Now that we have covered the basics of the Twitter API, we can show you how the Google Ajax Language API works.

The Google Ajax Language API The Google Ajax Language API is part of the Google Ajax API set of products. We’ll call it the Google Translator for short, as that’s its main feature. The API allows you to translate or detect language text. The API commands can be called via Ajax, through other non-JavaScript environments like Flash, or on the server. For further details on using the Ajax calls, visit the Google Language API web site at (dppl6++_k`a*ckkcha* _ki+]leo+]f]th]jcq]ca+).

NCaution It must be said that the quality of the Google Ajax Language API translation can be quite poor. However, the service will serve our purposes, since we just want to get an idea of what’s in the Twitter statuses.

To use the commands on the server side, again, we can employ Cake’s DpplOk_gap class. For example, to translate “hello world,” we use the code in Listing 6-2. Listing 6-2. Translating “Hello World” -6=ll66eilknp$#DpplOk_gap#%7 .6 /6 dppl9jasDpplOk_gap$%7 06 16 namqaop9]nn]u$ 26#qne#9:#dppl6++]f]t*ckkcha]leo*_ki+]f]t+oanre_ao+h]jcq]ca+pn]joh]pa;£ r9-*,"m9dahhk!.,sknh`"h]jcl]en9aj!3?f]#( 36#da]`an#9:]nn]u$ 46#Nabanan#9:#dppl6++#*ajr$#OANRAN[J=IA#% 56% -,6%7 --6 -.6 ^k`u9dppl):namqaop$ namqaop%7

175


176

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

In Listing 6-2, we use the pn]joh]pa command and pass three parameters to it: Ê

UÊ r, for version -*, of the API

Ê

UÊ m, for the dahhk!.,sknh` text we want to translate

Ê

UÊ h]jcl]en, for the source language English (aj) and target language Japanese (f]), separated by an entity-encoded vertical bar symbol: !3?

All the API commands respond in the JSON format, which we can easily decode using the PHP command fokj[`a_k`a. Google’s API documentation advises developers to make sure an HTTP referer header is always in place when making requests. This is shown in line 8 of Listing 6-2. Additionally, an API key should be sent. You can obtain a key from either of the following signup pages: Ê

UÊ œœ}iʍ>ÝÊ-i>ÀV…Ê­dppl6++_k`a*ckkcha*_ki+]leo+]f]toa]n_d+oecjql*dpih)

Ê

UÊ œœ}iÊ>«ÃÊ­dppl6++_k`a*ckkcha*_ki+]leo+i]lo+oecjql*dpih)

One useful feature is the language detection. If you do not know the original language that you want to translate, you can omit the source language in the h]jcl]en parameter. So, for example, we could simply write h]jcl]en9!3?f]. Now how cool is that!

NNote At the time of writing, the Google Ajax Language API is still quite new, and there don’t appear to be any request limits. However, we can all be quite certain this will change at some point in the future.

Application Requirements Even though we are essentially developing this application for fun, we still need to establish some requirements and consider usability. The broad requirement is to give users the ability to view the current public timeline in any language by using the Google Translator to translate the status text. This simple statement gives us a starting point for scoping the application. Scoping an application can be a lengthy task, involving many aspects, such as content, function, layout, wireframes, and site maps—just to mention a few. Since our application is quite small and should be fun, we will concentrate on the following simple functional requirements: Ê

UÊ /܈ÌÌiÀʅ>ÃÊ>ÊÕÃ>}iʏˆ“ˆÌ°Ê œ˜Ãˆ`iÀˆ˜}Ê̅iʘՓLiÀʜvÊ«iœ«iÊ܅œÊÕÃiÊ/܈ÌÌiÀ]ÊÜiÊ`ivˆnitely need to cache results. We will take advantage of Cake’s cache helper to assist us.

Ê

UÊ Ûi˜Ê̅œÕ}…Ê̅iÀiÊVÕÀÀi˜ÌÞÊ`œiؽÌÊÃii“Ê̜ÊLiÊ>ÊÕÃ>}iʏˆ“ˆÌʜ˜Ê̅iÊœœ}iÊ/À>˜Ã>̜À]Ê we still need to cache results and save on bandwidth and the time it takes for the translation round-trip.

Ê

UÊ -œ“iÊ«iœ«iʓ>ÞÊÜ>˜ÌÊ̜ÊۈiÜÊ̅iÊÌÀ>˜Ã>̈œ˜Êœ˜ÊœÌ…iÀÊ`iۈViðÊ-ˆ˜ViʈÌʈÃʵՈÌiÊi>ÃÞÊ for Cake to provide data in different formats, we will add an RSS web feed service as well. We will use Cake’s RSS helper.


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

Ê

UÊ ÃÊÜiÊ>ÀiÊÌÀ>˜Ã>̈˜}Ê̅iÊ/܈ÌÌiÀÊÃÌ>ÌÕÃiÃ]ʈÌʓ>ŽiÃÊÃi˜ÃiÊ̜ʅ>ÛiÊ̅iʜ̅iÀÊ«>ÀÌÃʜvÊ̅iÊ site available in other languages as well. Using Cake’s internationalization and localization classes, we can easily support this.

Ê

UÊ -ˆ˜ViÊÜiÊ܈ÊLiÊV>V…ˆ˜}Ê̅iÊÀiÃՏÌÃ]ÊÜiÊV>˜Ê>ÃœÊ«ÀœÛˆ`iÊ̅iÊ>LˆˆÌÞÊ̜ÊۈiÜÊ«>ÃÌÊÃÌ>ÌÕÃið Here are the details of these requirements:

Ê

UÊ >V…Ê/܈ÌÌiÀÊÀiµÕiÃÌÊÜiʓ>ŽiÊ܈Ê}i˜iÀ>ÌiÊÓäÊÃÌ>ÌÕÃið

Ê

UÊ ÊÕÃiÀÊVœ“iÃÊ̜Ê̅iÊÈÌiÊ܈̅œÕÌÊëiVˆvވ˜}Ê>˜Þʏ>˜}Õ>}i°Ê/…iʓœÃÌÊÀiVi˜ÌÊÓäÊÃÌ>ÌÕÃiÃÊ in their original language are displayed on the first page. Since this happens to every user, we must always cache the results. We will be making requests to Twitter every 60 seconds. As such, we will cache the results every 60 seconds.

Ê

UÊ 7iÊÜ>˜ÌÊ̅iÊ>LˆˆÌÞÊvœÀÊ>˜ÞÊÕÃiÀÊ̜ÊۈiÜÊ«>ÃÌÊÃÌ>ÌÕÃiÃÊ>ÃÊÜiÊ>ÃÊVÕÀÀi˜ÌÊÃÌ>ÌÕÃiðÊ/…iÀifore, we will have a background process that will make Twitter requests and cache the results every 60 seconds, regardless of whether anyone is making a request to view statuses. In this way, we have separated the viewing of the statuses and the process that requests Twitter statuses.

Ê

UÊ ÊÕÃiÀÊV>˜ÊÃiiVÌÊ>˜Þʏ>˜}Õ>}iÊ̜ÊۈiÜÊ̅iÊVÕÀÀi˜ÌʜÀÊ«>ÃÌÊÃÌ>ÌÕÃiðÊ/…ˆÃʏ>˜}Õ>}iÊÃiiVtion will also determine the language in which the rest of the site will be displayed.

In order to emphasize the raw nuts and bolts of the application, the interface layout will be kept as simple as possible. There will be two web pages: Ê

UÊ /…iÊvˆÀÃÌÊ>˜`ʓ>ˆ˜Ê«>}iÊ܈ÊˆÃÌÊÓäÊÃÌ>ÌÕÃiÃʈ˜Ê̅iÊÃiiVÌi`ʏ>˜}Õ>}i°Ê7iʅ>ÛiÊÎiÌV…i`Ê out a rough paper-and-pencil prototype in Figure 6-1. The top part consists of a header and tag line followed by a navigation area. We also allow the user to change the language at any point via a drop-down list on the right side of the page.

Figure 6-1. Sketch of the status listing page

177


178

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

Ê

UÊ /…iÊÃiVœ˜`Ê«>}iÊ܈ÊˆÃÌÊ̅iÊ/܈ÌÌiÀÊ>ÀV…ˆÛiÃ]Ê܅ˆV…ÊÜiʅ>ÛiÊÃ>Ûi`ʈ˜Ê̅iÊ`>Ì>L>Ãi°Ê As shown in Figure 6-2, it will just list the date and time of each Twitter request. Each item in the list will be a link to the first view statuses page. This page will also have the drop-down list to allow the user to change the language.

Figure 6-2. Sketch of the archive listing page

Application Structure Each Twitter request we make will need to be stored in a database table. Remember that a single Twitter request to the public timeline returns 20 statuses. This naturally maps into a one-to-many relationship. Listing 6-3 shows the ?NA=PAP=>HA statements for both the pseppan[namqaopo and pseppan[op]pqoao tables. Listing 6-3. The twitter_requests and twitter_statuses Table Schemas ?NA=PAP=>HA\pseppan[namqaopo\$ \e`\ejp$--%JKPJQHH]qpk[ej_naiajp( \namqaop[peia\peiaop]ilJKPJQHH( LNEI=NUGAU$\e`\% %7 ?NA=PAP=>HA\pseppan[op]pqoao\$ \e`\ejp$--%JKPJQHH]qpk[ej_naiajp( \pseppan[namqaop[e`\ejp$--%JKPJQHH( \p[_na]pa`[]p\peiaop]ilJKPJQHH( \p[e`\r]n_d]n$1,%_khh]pah]pej-[cajan]h[_eJKPJQHH( \p[patp\r]n_d]n$.11%_d]n]_panoapqpb4_khh]paqpb4[qje_k`a[_eJKPJQHH( \p[okqn_a\r]n_d]n$.11%_khh]pah]pej-[cajan]h[_eJKPJQHH( \p[pnqj_]pa`\r]n_d]n$.11%_khh]pah]pej-[cajan]h[_eJKPJQHH( \p[ej[nalhu[pk[op]pqo[e`\r]n_d]n$.11%_khh]pah]pej-[cajan]h[_eJKPJQHH( \p[ej[nalhu[pk[qoan[e`\r]n_d]n$.11%_khh]pah]pej-[cajan]h[_eJKPJQHH(


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

\p[b]rknepa`\r]n_d]n$.11%_khh]pah]pej-[cajan]h[_eJKPJQHH( \p[qoan[e`\r]n_d]n$1,%_khh]pah]pej-[cajan]h[_eJKPJQHH( \p[qoan[j]ia\r]n_d]n$.11%_khh]pah]pej-[cajan]h[_eJKPJQHH( \p[qoan[o_naaj[j]ia\r]n_d]n$.11%_d]n]_panoapqpb4_khh]pa£ qpb4[qje_k`a[_eJKPJQHH( \p[qoan[hk_]pekj\r]n_d]n$.11%_khh]pah]pej-[cajan]h[_eJKPJQHH( \p[qoan[`ao_nelpekj\r]n_d]n$.11%_d]n]_panoapqpb4_khh]pa£ qpb4[qje_k`a[_eJKPJQHH( \p[qoan[lnkbeha[ei]ca[qnh\r]n_d]n$.11%_khh]pah]pej-[cajan]h[_eJKPJQHH( \p[qoan[qnh\r]n_d]n$.11%_khh]pah]pej-[cajan]h[_eJKPJQHH( \p[qoan[lnkpa_pa`\r]n_d]n$.11%_khh]pah]pej-[cajan]h[_eJKPJQHH( \p[qoan[bkhhksano[_kqjp\r]n_d]n$1,%_khh]pah]pej-[cajan]h[_eJKPJQHH( LNEI=NUGAU$\e`\% %7 In the pseppan[namqaopo table, the namqaop[peia field simply holds the time of the request. The pseppan[op]pqoao table will mainly hold all the data that has been returned by the Twitter request. Most fields are stored in the h]pej-[cajan]h[_ebkni]p collation. However, the p[patp, p[`ao_nelpekj, and p[qoan[o_naaj[j]ia fields are stored in qpb4[qje_k`a[_e, since they will contain foreign characters. Notice that we’re not using qpb4[qje_k`a[^ej, as we may want to add search functionality to the fields later on; users expect searches to be case insensitive—_e. The structure of how the translation will work is slightly trickier. When a Twitter request is made, the statuses returned will contain different languages. Do we also want to automatically translate them into all the other available languages? Pondering this point, we come up with a half yes and half no answer. Yes, we do want to translate them into other languages, but no, not immediately after fetching them from Twitter. This job should be spread over a period of time instead. When a user does want to view the statuses in another language, whether they are current or past statuses, we will translate them on the fly and then cache the results. Thus, the first user who chooses to view a Twitter request in a specific language will need to endure the time delay that it takes to translate the 20 statuses. If we were running this application for real, we wouldn’t want this to happen, as users would start to talk about how slow the site is to use. When a status does get translated, the results are stored in the pseppan[pn]joh]pekjo table, shown in Listing 6-4. This gives us a one-to-many relationship between pseppan[ op]pqoao and pseppan[pn]joh]pekjo, with one status having many different translations. Listing 6-4. The twitter_translations Table Schema ?NA=PAP=>HA\pseppan[pn]joh]pekjo\$ \e`\ejp$--%JKPJQHH]qpk[ej_naiajp( \h]jc[bnki\r]n_d]n$-,%_khh]pah]pej-[cajan]h[_eJKPJQHH( \h]jc[pk\r]n_d]n$-,%_khh]pah]pej-[cajan]h[_eJKPJQHH( \p[patp[pn]joh]pekj\r]n_d]n$.11%_d]n]_panoapqpb4_khh]pa£ qpb4[qje_k`a[_eJKPJQHH( \pseppan[op]pqo[e`\ejp$--%JKPJQHH( LNEI=NUGAU$\e`\% %AJCEJA9IuEO=I

179


180

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

The h]jc[bnki and h]jc[pk fields will contain the language code to translate from and to, respectively. The h]jc[bnki field is, in a sense, redundant. When we are retrieving a translation of a status, we don’t really need to know the language it was in, as we have a foreign key link to the pseppan[op]pqoao table, but we may need it in the future. The p[patp[pn]joh]pekj field will contain the actual translation, so it needs to be in qpb4[qje_k`a[_e. Since localization will be involved somewhere, we see it as an advantage to have a language table that will help us bind different language areas together. Listing 6-5 shows the schema for this table, named h]jcq]cao. Listing 6-5. The languages Table Schema ?NA=PAP=>HA\h]jcq]cao\$ \e`\ejp$--%JKPJQHH]qpk[ej_naiajp( \h]jc[j]ia\r]n_d]n$.11%_khh]pah]pej-[cajan]h[_eJKPJQHH( \h]jc[_k`a\r]n_d]n$-,%_khh]pah]pej-[cajan]h[_eJKPJQHH( \ckkcha[h]jc[_k`a\r]n_d]n$-,%_khh]pah]pej-[cajan]h[_eJKPJQHH( LNEI=NUGAU$\e`\% %AJCEJA9IuEO=I7 The h]jcq]cao table is essentially a lookup table for language codes. The h]jc[j]ia field is for the name of the language, such as Japanese. The h]jc[_k`a field is the three-letter ISO 639-3 language code used by Cake. The ckkcha[h]jc[_k`a field is for the two-letter language code used by Google.

NNote After much digging, we’re still not sure why Google’s language code has mostly two letters. We think it’s a combination of codes, like the two-letter ISO 639-1 language code combined with locale names.

Figure 6-3 shows the relationships between the tables. The ckkcha[h]jc[_k`a field in the h]jcq]cao table is linked to the h]jc[bnki and h]jc[pk fields in the pseppan[pn]joh]pekjo table. So we have a translation from one language to another language based on the ckkcha[ h]jc[_k`a entry. In the pseppan[namqaopo table, each request gives us many statuses, which are recorded in the pseppan[op]pqoao table, and each status has many different translations, which are recorded in the pseppan[pn]joh]pekjo table.


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

Figure 6-3. Database schema for all the Twitter Twister tables

Cake Models We now have enough information to build our model classes. As shown in the database schema (Figure 6-3), one Twitter request generates many Twitter statuses. This relationship is shown in the PseppanNamqaop model using the d]oI]ju variable, as shown in Listing 6-6. Listing 6-6. The TwitterRequest Model (/app/models/twitter_request.php) 8;ldl _h]ooPseppanNamqaopatpaj`o=llIk`ahw ++I]ejhubknLDL0qoano r]n j]ia9#PseppanNamqaop#7 ++A]_dfkqnjaud]oi]juhk_]pekjo]j`]hoki]jup]co* r]n d]oI]ju9]nn]u$ #PseppanOp]pqo#9:]nn]u$ #_h]ooJ]ia#9:#PseppanOp]pqo#( #kn`an#9:#PseppanOp]pqo*p[_na]pa`[]p# % %7 y ;:

181


182

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

The pseppan[op]pqoao table sits between the pseppan[pn]joh]pekjo table and the pseppan[namqaopo table. One pseppan[op]pqoao record has many translations in the pseppan[ pn]joh]pekjo table. To complete the has-many relationship between the PseppanNamqaop and PseppanOp]pqo models, we need to add the ^ahkjcoPk relationship to the PseppanOp]pqo Cake model, shown in Listing 6-7. Listing 6-7. The TwitterStatus Model (/app/models/twitter_status.php) 8;ldl _h]ooPseppanOp]pqoatpaj`o=llIk`ah w ++I]ejhubknLDL0qoano r]n j]ia9#PseppanOp]pqo#7 ++Sde_d`^p]^hapkqoa r]n qoaP]^ha9#pseppan[op]pqoao#7 r]n d]oI]ju9]nn]u$ #PseppanPn]joh]pekj#9:]nn]u$ #_h]ooJ]ia#9:#PseppanPn]joh]pekj#( #bknaecjGau#9:#pseppan[op]pqo[e`#% %7 r]n ^ahkjcoPk9]nn]u$ #PseppanNamqaop#9:]nn]u$ #_h]ooJ]ia#9:#PseppanNamqaop#( #bknaecjGau#9:#pseppan[namqaop[e`#% %7 y ;: The PseppanPn]joh]pekj model, shown in Listing 6-8, is quite simple, in that one single translation belongs to one Twitter status. Listing 6-8. The TwitterTranslation Model (/app/models/twitter_translation.php) 8;ldl _h]ooPseppanPn]joh]pekjatpaj`o=llIk`ah w ++I]ejhubknLDL0qoano r]n j]ia9#PseppanPn]joh]pekj#7


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

++Sde_d`^p]^hapkqoa r]n qoaP]^ha9#pseppan[pn]joh]pekjo#7 r]n ^ahkjcoPk9]nn]u$ #PseppanOp]pqo#9:]nn]u$ #_h]ooJ]ia#9:#PseppanOp]pqo#( #bknaecjGau#9:#pseppan[op]pqo[e`#% %7 y ;: Note that weâ&#x20AC;&#x2122;ll be adding some methods to the PseppanOp]pqo and PseppanNamqaop models later in the chapter (see Listings 6-20 and 6-22). Oddly, the H]jcq]ca model is the most complex out of the lot, as shown in Listing 6-9. Some of the code will make more sense when we explain caching later on. Listing 6-9. The Language Model (/app/models/language.php) 8;ldl _h]ooH]jcq]caatpaj`o=llIk`ah w ++I]ejhubknLDL0qoano r]n j]ia9#H]jcq]ca#7 +& &Naikra_]_da]bpan`]p]^]oad]o^aaj_d]jca` &+ bqj_pekj]bpanO]ra$%w ?]_da66`ahapa$#capH]jc#%7 y +& &Cap]hhpdaPseppannamqaopo &+ bqj_pekjcapH]jc$%w  naoqhp9]nn]u$%7  ]hhH]jc9pdeo):bej`$#]hh#%7 bkna]_d$ ]hhH]jc]o h]jc%w  ckkcha[h]jc[_k`a9 h]jcWH]jcq]caYWckkcha[h]jc[_k`aY7  h]jc[j]ia9 h]jcWH]jcq]caYWh]jc[j]iaY7

183


184

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

 naoqhpW ckkcha[h]jc[_k`aY9 h]jc[j]ia7 y napqnj naoqhp7 y y ;: The H]jcq]ca model includes two methods: capH]jc and ]bpanO]ra. capH]jc simply fetches all the Twitter requests using the bej` method. There is nothing surprising about the method, but bear in mind that the data it generates will be cached. The ]bpanO]ra method is a Cake model callback. The code within the method is executed whenever some data is saved into the database. In our case, we want to delete the cache that holds the data for the language drop-down list, so we can have an up-to-date list of languages.

NCaution The ]bpanO]ra method is called only if you execute the o]ra model method. If you use the mqanu method to execute raw SQL statements, ]bpanO]ra won’t get executed.

Internationalization and Localization Internationalization (abbreviated as i18n) is the process of developing software so it is portable between different cultures without any change to its internal coding. Localization (abbreviated as l10n) is the process of adapting that software to any specific culture by using a predefined set of parameters called locales, normally stored in text files. In our case, a culture is defined by a number of parameters: its language, number format, date/time format, and currency. Adding or changing the locale in Cake is quite easy. Note that in our application, i18n and l10n will be handling only the static text of the site—such as tag lines, error messages, and so on—so they are quite separate from the job of the Google Translator. To get started, we first add the default language that we will use. In the +]ll+_kjbec+_kna* ldl file, we add the following line: ?kjbecqna66snepa$#?kjbec*h]jcq]ca#(ajc%

NTip In a real application, you would probably want to override ?kjbec*h]jcq]ca depending on where the user is connecting from. You can detect from a subdomain, the user agent header DPPL[=??ALP[H=JCQ=CA, or any of the IP geolocation web services. You can add this in the ^abknaBehpan so each action uses the correct language to display the view.


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

Next, we need to set up the locale files. For our application, we will have only two languages available: English and Japanese. We will create the two files as shown here: +]ll+hk_]ha+ajc+H?[IAOO=CAO+`ab]qhp*lk +]ll+hk_]ha+flj+H?[IAOO=CAO+`ab]qhp*lk The cultural locale parameters are divided into categories. The H?[IAOO=CAO category basically handles text messages. Other categories exist, like H?[PEIA to handle date and time formats, but we won’t be using those in this chapter. Cake’s i18n and l10n modules will use the content within the *lk files to map between languages. The folder name of the language uses the three-letter ISO 639-3 language code. The same three-letter code is also used in the ?kjbec*h]jcq]ca setting. If you want to expand the number of languages, either look in the Cake file +_]ga+he^o+h-,j*ldl or go to the official standards body web site dppl6++sss*oeh*knc+eok2/5) 3/. The *lk portable object files are human-readable and editable. There were originally developed as part of the GNU cappatp utilities for language translation. Listings 6-10 and 6-11 show our two *lk files. Listing 6-10. The English .po File ioce`]ll[p]c[heja iocopnBkqj`ejPn]joh]pekj

Listing 6-11. The Japanese. po File ioce`]ll[p]c[heja iocopnΊ஗⩳ズ➏࠷ It’s pretty obvious to see that ]ll[p]c[heja will be used as the handle for the translations. Now, to display the localized content, we use the global convenience function [[$%7 for example, 8;ldl[[$]ll[p]c[heja%;:. This will echo the iocopn text, which corresponds to the language that we have set in ?kjbec*h]jcq]ca. In the section “The Controllers” later in this chapter, we will go through how we have actually implemented i18n and l10n in our application.

NTip In a production environment where there will be a lot of *lk files, editing them should ideally be done with a *lk file editor, such as Poedit. Also, as *lk files may contain multibyte characters, remember to save them in UTF-8 format.

185


186

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

Web Services In order to provide instant gratification for our application when people are away from their PCs, we will give users the option to view our application as an RSS feed. They will be able to easily see translated statuses when they are using a handheld device. Adding different output formats for other devices to consume is a piece of cake! Or so we thought. . . . We wrote a few different methods to achieve what we wanted. Starting with our first method, we saw that in the Cake documentation and some forums, the standard way to output RSS or any other format is to attach the format name you want at the end of the action as a file extension, like this: +PseppanOp]pqo+ej`at*noo In our case, we’ll add the RSS feed to the ej`at action. To get this to work, we need to tell the Nkqpan class about our new extension. We do this by adding the following line in +]ll+ _kjbec+nkqpao*ldl: Nkqpan66l]noaAtpajoekjo$#noo#%7 Following this, we include the RSS helper in our ]ll[_kjpnkhhan*ldl file so we don’t need to manually deal with any of the nitty-gritty RSS XML tags or headers. Next, we need to have a specific layout for our RSS output. Under +]ll+reaso+h]ukqp+noo, we create a file called `ab]qhp*_pl. This is the layout that will surround the actual RSS data. As shown in Listing 6-12, we start off by adding the RSS header using the RSS helper. Next, we set up some basic channel data. And finally we echo the RSS document by passing noo):`k_qiajp the _kjpajp[bkn[h]ukqp, which contains the list of statuses. Listing 6-12. The RSS Layout File (/app/views/layout/rss/default.ctp) 8;ldl a_dknoo):da]`an$%7 eb$eooap$ _d]jjah%%w  _d]jjah9]nn]u$%7 y eb$eooap$ _d]jjahW#pepha#Y%%w  _d]jjahW#pepha#Y9 pepha[bkn[h]ukqp7 y a_dknoo):`k_qiajp$ noo):_d]jjah$]nn]u$%(  _d]jjah(  _kjpajp[bkn[h]ukqp%7 ;: Before we proceed further, let’s recap. We want to view the same data in different formats, while keeping the coding for the action unchanged. It will be the view that will change depending on the type of request. Now, having completed the layout part, we need to write the new RSS view. Under the controller view folder +]ll+reaso+pseppan[op]pqo+, we need


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

to create another folder called noo. In this folder, we create a file with the same name as the action, ej`at*_pl. Listing 6-13 shows this file. Listing 6-13. The RSS View (/app/views/twitter_status/rss/index.ctp) 8;ldl bqj_pekjnooPn]jobkni$ _qnnajp[op]pqo%w napqnj]nn]u$#pepha#9: _qnnajp[op]pqoW#r[p[qoan[j]ia#Y( #hejg#9:#dppl6++pseppan*_ki+#* _qnnajp[op]pqoW£ r[p[qoan[o_naaj[j]iaY( #cqe`#9:#dppl6++pseppan*_ki+#* _qnnajp[op]pqoW£ r[p[qoan[o_naaj[j]iaY( #`ao_nelpekj#9: _qnnajp[op]pqoW#r[p[patp#Y( #lq^@]pa#9: _qnnajp[op]pqoW#r[p[_na]pa`[]p#Y( %7 y a_dknoo):epaio$ op]pqoao(#nooPn]jobkni#%7 ;: In Listing 6-13, the method noo):epaio takes the op]pqoao array and loops through each status item through the function nooPn]jobkni, which sets up the RSS XML data tags—like pepha, hejg, and so on—in a form that the epaio method can use. Finally, we need to add the built-in NamqaopD]j`han component, so it can pick out the correct view: r]n _kilkjajpo9]nn]u$#NamqaopD]j`han#%7 And that is pretty much the standard way of adding an RSS feed to your data. When you specify the *noo extension, the class router parses the extension. If you don’t tell Cake about the extension and you make an ej`at*noo request, you will probably get an error like this: Pda]_pekjej`at*nooeojkp`abeja`ej_kjpnkhhanPseppanpseopan?kjpnkhhan* Once Cake knows about the extension through the Nkqpan class, the NamqaopD]j`han takes over and renders the view that corresponds to the extension. We haven’t quite finished with web services just yet. As we hinted early on, we ran into some trouble with our RSS feed. The problem starts when we add parameters to our URL action requests. For example, if want to view an archive Twitter request in another language, this is the URL we could use: +PseppanOp]pqo+ej`at+h]jc6f]+e`6-+ It’s fine as it is, but if we want to view it in XML format, the URL would need to look like this (note the *noo extension): +PseppanOp]pqo+ej`at+h]jc6f]+e`6-+*noo

187


188

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

or even like this: +PseppanOp]pqo+ej`at+h]jc6f]+e`6-*noo Basically, the Nkqpan class just parses out the extension at the end of the URL. We feel these are just too awkward looking. We want our URLs to look something like this instead: +PseppanOp]pqo+ej`at+h]jc6f]+e`6-+noo Basically, we just add +tih instead of *noo. To overcome this problem, we created two alternative methods. The first method is a bit hackish, while the second one works better. The first method is quite easy. Using the NamqaopD]j`han component, we just add the following code snippet in the ^abknaBehpan method in the ]ll[_kjpnkhhan*ldl: ++d]_geod eb$lnac[i]p_d$#+X+noo +#(Nkqpan66qnh$%%%w pdeo):NamqaopD]j`han):atp9#noo#7 y Nkqpan6qnh$%returns the requested URL, such as +PseppanOp]pqo+ej`at+h]jc6f]+e`6-+ noo. lnac[i]p_d then matches for the ending +noo. If a match is found, we artificially set the extension variable atp to noo. We feel quite uneasy with this method, as we shouldnâ&#x20AC;&#x2122;t really be setting class variables manually like this. But, hey, it works, and one alternative solution is better than none. The second method we used to handle the +noo extension is easier and more obvious than the first. We just write a ik`[nasnepa rule in our root *dp]__aoo file, as follows: 8EbIk`qhaik`[nasnepa*_: NasnepaAjcejakj NasnepaNqhaZ ]ll+sa^nkkp+WHY NasnepaNqha$*&%+noo ]ll+sa^nkkp+ -+*nooWHY NasnepaNqha$*&%]ll+sa^nkkp+ -WHY 8+EbIk`qha: The new rule is shown in bold. It matches anything ending with +noo and rewrites it in the *noo version. So if a user types +PseppanOp]pqo+ej`at+h]jc6f]+e`6-+noo it gets translated to +PseppanOp]pqo+ej`at+h]jc6f]+e`6-+*noo Using this ik`[nasnepa rule and the standard method to add web services, we feel this combination works well.

Caching Our seemingly simple application has gotten a lot more complicated with the need to cache results. To start caching, we need to turn on Cake caching. This is done in the controller +]ll+ _kjbec+_kna*ldl:


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

?kjbecqna66snepa$#?]_da*_da_g#(pnqa%7 We want to use the Cache helper. Weâ&#x20AC;&#x2122;ll just include it in ]ll[_kjpnkhhan*ldl, so all controllers in the future can have access to it. In our ]ll[_kjpnkhhan*ldl file, we simply add the following line: r]n dahlano9]nn]u$#?]_da#(#Bkni#(#Dpih#(#Noo#%7

Caching Views Caching is a broad term. In our application, weâ&#x20AC;&#x2122;re doing different types of caching, one of which is caching the views using Cake. This is where the output is saved, by default to +]ll+ pil+_]_da+reaso. To cache a view, the setting is made in the action that corresponds to the view. In the controller, there are two different ways you can do this. One way is to set the _]_da=_pekj member variable, as in this example: _]_da=_pekj9]nn]u$#PseppanNamqaop+reas(2,%7 This caches the reas=n_dera action for 60 seconds. We can also cache an action within the action function itself, like this: pdeo):_]_da=_pekj9]nn]u$#`qn]pekj#9:2,%7 This caches the current action for 60 seconds.

Caching Models Cake goes through a lot of processing to build the object-relational mapping part of the MVC structure. To save on the execution time, you can cache the model data by setting the lanoeopIk`ah controller variable to pnqa: r]n lanoeopIk`ah9pnqa7 The cached model data is stored in the +]ll+pil+_]_da+lanoeopajp folder.

NCaution If you change or add database fields, you must delete the cached data models. Be careful of cached data during your development. Sometimes you forget about your caching and then wonder why your changes are not showing up. Check your browser session cache and caching in Cake.

Caching Twitter and Google Translations Once we get data back from Twitter and Google, that data is fairly permanent. The data we get is saved to the database in the three tables we have created. This is unlike some web caching, where data can be occasionally purged or destroyed. In our application, the caching works in two levels. When a user requests the index page, Cake first checks to see whether the view is held in cache. If its not, the ej`at action is called.

189


190

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

This then fetches the most recent statuses from the database. This data is essentially saved or cached in the database by the background cron process, which fetches the actual status messages from Twitter.

Caching and the Application Layout Caching can bring up a lot of unforeseen problems within the application view. There are two main points to be aware of: Ê

UÊ 7iʘii`Ê̜ÊV>V…iʜ˜ÞÊܓiÊ«>ÀÌÃʜvÊ>ÊۈiÜ°Ê/œÊ>V…ˆiÛiÊ̅ˆÃ]ÊÜiÊÕÃiÊ̅iÊ >ŽiÊ 8_]ga6jk_]_da:Pdeoeojkp_]_da`8+_]ga6jk_]_da: tag to wrap content that we don’t want to cache.

Ê

UÊ ,i“i“LiÀÊ̅>ÌʘœÊ>V̈œ˜ÃÊ>ÀiÊV>i`ʈ˜Ê̅iÊVœ˜ÌÀœiÀ°Ê

When we specify in the controller that we want to cache an action view, Cake will also cache the application layout. As such, we can’t cache any dynamic content that changes within a session, whether in the action view or application layout. As shown in the application layout in Listing 6-14, we don’t cache our tag line, so we wrap it around the 8_]ga6jk_]_da: tag to say that it is not cached. Listing 6-14. Header HTML Code with the nocache Tag (in /app/views/layouts/base.ctp) 8`er_h]oo9da]`an[sn]llan: 8d-:PseppanPseopan8+d-: 8d.:8e:8_]ga6jk_]_da:8;[[$]ll[p]c[heja%;:8+_]ga6jk_]_da:8+e:8+d.: 8+`er:

Changing Languages Since the HTML language selection drop-down list is displayed on every page within the application layout, we have pushed it out as a Cake element, as shown in Listing 6-15. Listing 6-15. Language Selection Form (/app/views/elements/lang_drop.ctp) 8;ldl a_dkbkni):_na]pa$#Pseppanpseopan#( ]nn]u$#qnh#9:#+Pseppanpseopan+_d]jcaH]jcq]ca#( #_h]oo#9:#h]jc[_d]jca[bkni# %%7 ;: 8_]ga6jk_]_da: 8;ldl ?h]ooNaceopnu66]``K^fa_p$#reas#( pdeo%7


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

a_dkbkni):oaha_p$Pseppanpseopan*h]jc( oaooekj):na]`$capH]jc%( oaooekj):na]`$qoanH]jc%( jqhh( pnqa %7 ;: 8+_]ga6jk_]_da: 8;ldl a_dkbkni):oq^iep$#?d]jca#(]nn]u$#h]^ah#9:b]hoa( #`er#9:b]hoa %%7 a_dkbkni):aj`$%7 ;: The important part here is the 8_]ga6jk_]_da: tag. We don’t want to cache the HTML drop-down list, because if a user changes the language, the newly selected item in the language should be selected and not a cached selection. However, we do want to cache the language data that was generated by the SQL find operation from the h]jcq]cao table list. Some readers may notice this odd line of code: ?h]ooNaceopnu66]``K^fa_p$#reas#( pdeo%7 When a view is rendered from the cache, the current view object isn’t registered in Cake’s global object register. As a result, some helpers that depend on the view object, such as the form helper, fail. Because of this, we need to manually register the current view object. This highlights the complexity of caching. And in Cake, when an item is cached, no method in the controller is called. Therefore, we need to rely on session data as a conduit for any dynamic data that we need to pass to the view. As highlighted in the code, when we form the HTML oaha_p tag, we populate it with data that we saved into the Cake session. The capH]jc session variable holds the language data from the h]jcq]cao table, and qoanH]jc holds the current language that the user has selected.

Changing Locales As no methods are called in the controller when data is cached, we need to set the new locale in the top part of the base layout file +]ll+reaso+h]ukqpo+^]oa*_pl, as shown in Listing 6-16. When a user selects a new language, the cached page is presented while noncached content within the cached content is still being executed.

NCaution Adding caching to our application was complex and time-consuming, mainly because we were also using other Cake features such as locales. If you are going to add caching, try to add it early on in your development. This will make your life easier when your application grows.

191


192

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

Listing 6-16. Setting Locale in the Base View (/app/views/layouts/base.ctp) ++*** 8_]ga6jk_]_da: 8;ldl eb$oaooekj):na]`$qoanHk_]ha%%w ?kjbecqna66snepa$#?kjbec*h]jcq]ca#(oaooekj):na]`$qoanHk_]ha%%7 y ;: 8+_]ga6jk_]_da: ++***

The Controllers For our application, three controllers are used: Pseppanpseopan?kjpnkhhan, PseppanNamqaop?kjpnkhhan, and PseppanOp]pqo?kjpnkhhan. Letâ&#x20AC;&#x2122;s look at how each of these controllers works.

The Twittertwister Controller The Pseppanpseopan?kjpnkhhan class file is shown in Listing 6-17. This is a base controller for the application. At present, it holds one action called _d]jcaH]jcq]ca, which changes the viewing language of the application. Listing 6-17. The TwittertwisterController Class (app/controllers/twittertwister_controller.php) -68;ldl .6 /6_h]ooPseppanpseopan?kjpnkhhanatpaj`o=ll?kjpnkhhanw 06 16r]n j]ia9#Pseppanpseopan#7 26 36r]n qoao9]nn]u$%7 46 56+& -,6&Qoanola_ebe_]hhu_d]jca`h]jcq]ca --6&+ -.6bqj_pekj_d]jcaH]jcq]ca$%w -/6 -06eb$pdeo):`]p]WPseppanpseopanYWh]jcq]caY%w -16pdeo):Oaooekj):snepa$ -26qoanH]jc( -36pdeo):`]p]WPseppanpseopanYWh]jcq]caY%7 -46y -56


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

.,6++Saiqop]hok_d]jcapdahk_]hah]jcq]ca .-6pdeo):[[_d]jcaOaooekjHk_]ha$ ..6pdeo):`]p]WPseppanpseopanYWh]jcq]caY%7 ./6 .06 qnh9Nkqpan66l]noa$pdeo):nabanan$%%7 .16 .26 qnh[opn9#+#* qnhW#_kjpnkhhan#Y*#+#* qnhW#]_pekj#Y*#+#7 .36 .46eb$eooap$ qnhW#j]ia`#YW#e`#Y%%w .56 qnh[opn*9#e`6#* qnhW#j]ia`#YW#e`#Y*#+#7 /,6y /-6 /.6++Oaph]jcq]cal]n]iapanbkn]_pekjej_]hhejcl]ca //6 qnh[opn*9#h]jc6#* pdeo):`]p]W#Pseppanpseopan#YW#h]jcq]ca#Y*#+#7 /06 /16++Na`ena_p^]_gpk_]hhejcl]ca /26pdeo):na`ena_p$ qnh[opn%7 /36y /46 /56+& 0,6&?d]jcapdahk_]ha 0-6&+ 0.6bqj_pekj[[_d]jcaOaooekjHk_]ha$ ckkcha[h]jc[_k`a%w 0/6 006 h]jc9pdeo):H]jcq]ca):bej`>uCkkchaH]jc?k`a$ ckkcha[h]jc[_k`a%7 016 026eb$ h]jc%w 036pdeo):Oaooekj):snepa$qoanHk_]ha( 046 h]jcW#H]jcq]ca#YW#h]jc[_k`a#Y%7 056y 1,6y 1-6y 1.6 1/6;: This _d]jcaH]jcq]ca action is used by the language-selection form. Starting from line 12, this action takes the language code that the user has selected and changes the status viewing language on line 14 and the locale on line 21. From line 24 onwards, we redirect the users back to the page where they selected the language change, where they would view the same page they have selected in the new language. The private method [[_d]jcaOaooekjHk_]ha on line 42 is used to change the web site locale. The language code used by Google was incompatible with the ISO 639-3 three-letter language code used by Cake’s l10n. As a result, we needed to do some language code translation. We simply make a query to the h]jcq]cao table and get the three-letter code that corresponds with Google’s two-letter code, and then save this into the session. We do this using Cake’s model method bej`>uWbeah`[j]iaY$Wbeah`[r]hqaY%. Attach the field name in camel case as a suffix to the bej`>u keyword. In our case, the field name is ckkcha[h]jc[_k`a, so the method name will be bej`>uCkkchaH]jc?k`a. We then supply the method with the value of the field as an argument.

193


194

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

The TwitterRequest Controller The PseppanNamqaop?kjpnkhhan class is responsible for fetching Twitter statuses from the Twitter public timeline. The controller file ]ll+_kjpnkhhano+pseppan[namqaop[_kjpnkhhan*ldl is shown in Listing 6-18. Listing 6-18. The TwitterRequestController Class (app/controllers/twitter_request_controller.php) -68;ldl .6 /6_h]ooPseppanNamqaop?kjpnkhhanatpaj`o=ll?kjpnkhhanw 06 16r]n _]_da=_pekj9]nn]u$#PseppanNamqaop+reas#9:#2,#%7 26 36+& 46&Reasajpena]n_dera 56&+ -,6bqj_pekjreas$%w --6 -.6++Cap]hhPseppannamqaopo -/6 ]hhNamqaopo9pdeo):PseppanNamqaop):bej`$#]hh#( -06]nn]u$jqhh( -16jqhh( -26#na_qnoera#9:)-36%%7 -46 -56pdeo):oap$#pseppanNamqaopo#( ]hhNamqaopo%7 .,6y .-6 ..6+& ./6&Pdeoodkqh`^a_]hha`^u_nkjaranubasoa_kj`o .06&+ .16bqj_pekjcapPseppanNamqaopo$%w .26 .36pdeo):h]ukqp9#^h]jg#7 .46 .56pdeo):i]gaPseppanNamqaop$%7 /,6y /-6 /.6+& //6&Pdeo_]hhpdaPseppanlq^he_peiaheja /06&+ /16bqj_pekji]gaPseppanNamqaop$%w /26


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

/36++O]rapdanamqaopda]`an /46pdeo):PseppanNamqaop):o]raNamqaop$%7 /56 0,6++Oapql]j`ata_qpapdaok_gap_]hh 0-6 qnh9#dppl6++sss*pseppan*_ki+op]pqoao+lq^he_[peiaheja*tih#7 0.6 0/6=ll66eilknp$#DpplOk_gap#%7 006 dppl9jasDpplOk_gap$%7 016 namqaop9]nn]u$#qne#9: qnh%7 026 ^k`u9dppl):namqaop$ namqaop%7 036 046++Jkso]raejpk`^ 056pdeo):PseppanOp]pqo):o]raOp]pqoao$ ^k`u( 1,6pdeo):PseppanNamqaop):e`%7 1-6y 1.6 1/6y 106 116;: On line 5, we set _]_da=_pekj to cache the reas=n_dera action to 60 seconds. We will explain this at the end of this section. The controller contains two main actions: reas and capPseppanNamqaopo. The reas action on line 10 lists all the Twitter requests in the database. As we are just listing the Twitter requests, we don’t need the other tables that link to it, so we set na_qnoera to )-. Remember that we have cached this action at the start of the controller to 60 seconds, so we are not regenerating the same query for different users. One obvious shortcoming with this action is the number of calls that will be returned. As we are making Twitter requests every 60 seconds, it would quickly generate a lot of requests. In fact, it probably won’t take long before it would take more than 60 seconds to list all the status requests. Line 25 starts with the capPseppanNamqaopo action. This is essentially an action that we use during development to fetch statuses; however, it can still be used as the URL for a cron job entry. This action makes public timeline calls to Twitter requests every 60 seconds. The view in Listing 6-19 is even simpler. (If you use this in a cron entry, comment out the meta refresh, as that should be the job for cron.) Listing 6-19. The getTwitterRequests View (app/views/twitter_rquest/get_twitter_requests.ctp) 8iap]dppl)amqer9nabnaod_kjpajp92,: The i]gaPseppanNamqaop action shown on line 35 of Listing 6-18 carries out the task of requesting the public timeline from Twitter. We start on line 38 by calling the o]raNamqaop method in the PseppanNamqaop model, which is shown in Listing 6-20. On line 14 of this listing, the o]raNamqaop method simply saves a record into the pseppan[namqaopo table by using the model’s o]ra method on line 20.

195


196

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

Listing 6-20. The TwitterRequest Model with the saveRequest Method (app/models/twitter_ request.ctp) -68;ldl .6 /6_h]ooPseppanNamqaopatpaj`o=llIk`ah 06w 16++I]ejhubknLDL0qoano 26r]n j]ia9#PseppanNamqaop#7 36 46++A]_dfkqnjaud]oi]juhk_]pekjo]j`]hoki]jup]co* 56r]n d]oI]ju9]nn]u$ -,6#PseppanOp]pqo#9:]nn]u$ --6#_h]ooJ]ia#9:#PseppanOp]pqo#( -.6#kn`an#9:#PseppanOp]pqo*p[_na]pa`[]p#%%7 -/6 -06bqj_pekjo]raNamqaop$%w -16 -26++A]_dnamqaopiqop^ao]ra`ejpdapseppan[namqaopop]^ha -36 nam@]p]9]nn]u$%7 -46 nam@]p]W#namqaop[peia#Y9`]pa$#U)i)`D6e6o#(igpeia$%%7 -56pdeo):_na]pa$ nam@]p]%7 .,6pdeo):o]ra$%7 .-6y ..6y ./6 .06;: Let’s now go back to the i]gaPseppanNamqaop action in PseppanNamqaop?kjpnkhhan (Listing 6-18). Having now saved a request, we make a call to the Twitter public timeline using Cake’s DpplOk_gap class. We fetch the statuses and save the results into the ^k`u variable on line 46. The data returned will be in XML format. You can request the return format to be fokj, noo, or ]pki by appending those format strings as the extension instead of tih. Finally, on line 49 of the controller, we save the status return message into the pseppan[ op]pqoao table using the PseppanOp]pqo model method o]raOp]pqoao. We will talk more about this method in the next section.

The TwitterStatus Controller The PseppanOp]pqo?kjpnkhhan class is the largest of the three controllers. It’s responsible for displaying either statuses specified by the user or the most recent statuses that were fetched within the last minute. Listing 6-21 lists the controller with the actions omitted. As the controller is quite large, we will show each action in turn.


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

Listing 6-21. The TwitterStatusController Class (app/controllers/twitter_status_controller.php) -68;ldl .6 /6_h]ooPseppanOp]pqo?kjpnkhhanatpaj`o=ll?kjpnkhhanw 06 16++Reas]jul]npe_qh]nPseppannamqaop 26r]n _qnnajpPseppanNamE`9##7 36 46++]_pekjo*** 56 -,6y --6 -.6;: On line 6, the _qnnajpPseppanNamE` variable holds the current Twitter request, if any. If a user has requested the home page, this would be empty, and the most recent statuses will be returned. Before we talk about the controllerâ&#x20AC;&#x2122;s actions, let us first talk about the model. As shown in Listing 6-22, the model has only one method called o]raOp]pqoao. As we mentioned earlier, this method is used by the i]gaPseppanNamqaop action in the PseppanNamqaop?kjpnkhhan. It saves the statuses returned from a Twitter request. Listing 6-22. The TwitterStatus Model with the saveStatuses Method (app/models/twitter_status. ctp) -68;ldl .6 /6_h]ooPseppanOp]pqoatpaj`o=llIk`ah 06w 16++I]ejhubknLDL0qoano 26r]n j]ia9#PseppanOp]pqo#7 36 46++Sde_d`^p]^hapkqoa 56r]n qoaP]^ha9#pseppan[op]pqoao#7 -,6 --6r]n d]oI]ju9]nn]u$#PseppanPn]joh]pekj#9:]nn]u$ -.6#_h]ooJ]ia#9:#PseppanPn]joh]pekj#( -/6#bknaecjGau#9:#pseppan[op]pqo[e`#%%7 -06 -16r]n ^ahkjcoPk9]nn]u$#PseppanNamqaop#9:]nn]u$ -26#_h]ooJ]ia#9:#PseppanNamqaop#( -36#bknaecjGau#9:#pseppan[namqaop[e`#%%7 -46 -56+& .,6&O]raop]pqoaoejpk`]p]^]oa .-6&+ ..6bqj_pekjo]raOp]pqoao$ op]pqoao( pseppanNamE`%w ./6

197


198

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

.06++?da_gsad]ra]Pseppannamqaope` .16eb$eo[jqiane_$ pseppanNamE`%%w .26napqnj7 .36y .46 .56 tih9jasOeilhaTIHAhaiajp$ op]pqoao%7 /,6 /-6bkna]_d$ tih):op]pqo]o op]pqo%w /.6 //6 op]pqo@]p]9]nn]u$%7 /06 /16 op]pqo@]p]Wpseppan[namqaop[e`Y9 pseppanNamE`7 /26 /36 op]pqo@]p]Wp[_na]pa`[]pY9op]pqo):_na]pa`[]p7 /46 op]pqo@]p]Wp[e`Y9op]pqo):e`7 /56 op]pqo@]p]Wp[patpY9op]pqo):patp7 0,6 op]pqo@]p]Wp[okqn_aY9op]pqo):okqn_a7 0-6 op]pqo@]p]Wp[pnqj_]pa`Y9op]pqo):pnqj_]pa`7 0.6 op]pqo@]p]Wp[ej[nalhu[pk[op]pqo[e`Y9 0/6op]pqo):ej[nalhu[pk[op]pqo[e`7 006 op]pqo@]p]Wp[ej[nalhu[pk[qoan[e`Y9 016op]pqo):ej[nalhu[pk[qoan[e`7 026 op]pqo@]p]Wp[b]rknepa`Y9op]pqo):b]rknepa`7 036 046 op]pqo@]p]Wp[qoan[e`Y9op]pqo):qoan):e`7 056 op]pqo@]p]Wp[qoan[j]iaY9op]pqo):qoan):j]ia7 1,6 op]pqo@]p]Wp[qoan[o_naaj[j]iaY9 1-6op]pqo):qoan):o_naaj[j]ia7 1.6 op]pqo@]p]Wp[qoan[hk_]pekjY9op]pqo):qoan):hk_]pekj7 1/6 op]pqo@]p]Wp[qoan[`ao_nelpekjY9 106op]pqo):qoan):`ao_nelpekj7 116 op]pqo@]p]Wp[qoan[lnkbeha[ei]ca[qnhY9 126op]pqo):qoan):lnkbeha[ei]ca[qnh7 136 op]pqo@]p]Wp[qoan[qnhY9op]pqo):qoan):qnh7 146 op]pqo@]p]Wp[qoan[lnkpa_pa`Y9op]pqo):qoan):lnkpa_pa`7 156 op]pqo@]p]Wp[qoan[bkhhksano[_kqjpY9 2,6op]pqo):qoan):bkhhksano[_kqjp7 2-6 2.6pdeo):_na]pa$ op]pqo@]p]%7 2/6pdeo):o]ra$%7 206y 216y 226 236y 246 256;:


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

The o]raOp]pqoao method starts on line 22. We take the statuses and parse the XML using PHP’s OeilhaTIHAhaiajp class. You can, of course, accomplish the same thing using Cake. Listings 6-23 and 6-24 show how to get the _na]pa`[]p field using Cake’s XML classes. Listing 6-23. Using Cake’s XML Class, Longer Version =ll66eilknp$#Tih#%7 tih[-9jasTih$ op]pqoao%7 jk`a[-9tih[-):_deh`naj$#op]pqoao#%7 jk`a[.9jk`a[-W,Y):_deh`naj$#op]pqo#%7 jk`a[/9jk`a[.W,Y):_deh`naj$#_na]pa`[]p#%7 _na]pa`[]p9jk`a[/W,Y):_deh`najW,Y):r]hqa7

Listing 6-24. Using Cake’s XML Class, Shorter Version =ll66eilknp$#Tih#%7 tih[-9jasTih$ op]pqoao%7 jk`a[-9tih[-):_deh`$,%):_deh`$,%):_deh`naj$#_na]pa`[]p#%7 jk`a[.9jk`a[-W,Y):_deh`$,%):r]hqa7 Now we’ll look at each of the actions in the PseppanOp]pqo?kjpnkhhan:

The index() Action The ej`at action is shown in Listing 6-25. Listing 6-25. TwitterStatusController index Action -6bqj_pekjej`at$ pseppanNamE`9##( pn]joH]jc9##%w .6 /6++Kranne`a_qnnajpPseppannamqaop 06eb$ pseppanNamE`%w 16pdeo):_qnnajpPseppanNamE`9 pseppanNamE`7 26y 36 46eb$eooap$pdeo):l]ooa`=ncoW#e`#Y%%w 56pdeo):_qnnajpPseppanNamE`9pdeo):l]ooa`=ncoW#e`#Y7 -,6y --6 -.6++Ebpdanaeojke`bknpda_qnnajpnamqaop(pdajsa]ooqia -/6++ikopna_ajpop]pqoaooksakjhu_]_dabkn2,oa_o -06eb$pdeo):_qnnajpPseppanNamE`%w -16++?]_daepbkn]ua]n -26pdeo):_]_da=_pekj9]nn]u$#`qn]pekj#9:/-1/2,,,%7 -36y

199


200

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

-46ahoaw -56pdeo):_]_da=_pekj9]nn]u$#`qn]pekj#9:2,%7 .,6y .-6 ..6++Kranne`a_qnnajph]jcq]careas ./6eb$ pn]joH]jc%w .06pdeo):_qnnajpH]jc9 pn]joH]jc7 .16y .26 .36eb$eooap$pdeo):l]ooa`=ncoW#h]jc#Y%%w .46pdeo):_qnnajpH]jc9pdeo):l]ooa`=ncoW#h]jc#Y7 .56y /,6 /-6pdeo):[[`eolh]uPseppano$%7 /.6y On lines 4 and 8, we can override which Twitter request we want to view, via either the pretty URL method or the named parameter method. Both of the following examples would work: pseppanpseopan+ej`at+or pseppanpseopan+ej`at+e`6-+ Following this on line 14, if the user has requested to view a particular Twitter request, we will cache it for a whole year. We wanted to cache it indefinitely, but we couldn’t find an easy way except by hacking the Cake library files, which we definitely didn’t want to do. If a user hasn’t requested a particular ID, then by default, the most recent statuses would be displayed. In this case, we cache it for 60 seconds, as new statuses are fetched from the Twitter servers every 60 seconds as well. Next, we do the same check for the language selection. Once those two checks are complete, we display the Twitter statuses on line 31. On line 27, even if a user has selected to view statuses in a language via the language drop-down list, he can still override the viewing language by passing a different language code via the URL, which overrides the _qnnajpH]jc variable. For example, a Japanese user can still view a post in English by using a URL with a h]jc parameter in it set to aj*

The __displayTwitters() Action The private action [[`eolh]uPseppano, shown in Listing 6-26, is the core of the application.


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

Listing 6-26. TwitterStatusController __displayTwitters Action -6bqj_pekj[[`eolh]uPseppano$%w .6 /6++Sa_da_gsdapdan]l]npe_qh]nPseppannamqaops]onamqaopa`kn 06++safqopbap_dpdana_ajpkja 16 _kj`epekjo9]nn]u$%7 26 36eb$eo[jqiane_$pdeo):_qnnajpPseppanNamE`%%w 46 _kj`epekjoW#PseppanNamqaop*e`#Y9£ pdeo):_qnnajpPseppanNamE`7 56y -,6ahoaw --6 _kj`epekjo9]nn]u$%7 -.6 _kj`epekjoWY9]nn]u$ -/6PseppanOp]pqo*p[_na]pa`[]p89:`]pa$ -06#U)i)`D6e6,,#( -16opnpkpeia$)-iejqpa% -26%%7 -36 _kj`epekjoWY9]nn]u$ -46PseppanOp]pqo*p[_na]pa`[]p:9:`]pa$ -56#U)i)`D6e6,,#( .,6opnpkpeia$).iejqpa% .-6%%7 ..6y ./6 .06++?da_gpkoaaebqoand]ooaha_pa`pkreaspdaop]pqoaoej .16++]jul]npe_qh]nh]jcq]ca .26eb$pdeo):_qnnajpH]jc%w .36 .46 psepPn]joP]^ha9]nn]u$ .56#PseppanPn]joh]pekj#9:]nn]u$ /,6#_h]ooJ]ia#9:#PseppanPn]joh]pekj#( /-6#bknaecjGau#9:#pseppan[op]pqo[e`#( /.6#_kj`epekjo#9:£ PseppanPn]joh]pekj*h]jc[pk9#w pdeo):_qnnajpH]jcy#%%7 //6 /06pdeo):PseppanOp]pqo):^ej`Ik`ah$ /16]nn]u$#d]oI]ju#9: psepPn]joP]^ha%%7 /26y /36ahoaw /46++Jklkejpcappejcpn]joh]pekj(okhapoqj^ej`ep /56pdeo):PseppanOp]pqo):qj^ej`Ik`ah$ 0,6]nn]u$#d]oI]ju#9:]nn]u$#PseppanPn]joh]pekj#%%%7 0-6y 0.6

201


202

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

0/6 iej[op]pqoao9pdeo):PseppanOp]pqo):bej`$#]hh#( 006]nn]u$#_kj`epekjo#9: _kj`epekjo( 016jqhh( 026#kn`an#9:#PseppanOp]pqo*p[_na]pa`[]p@AO?# 036%%7 046 056++KG(jkssackppdaop]pqobknpdaiejqpaejmqaopekj* 1,6++Sa_da_gsdapdanpdah]jcq]capn]joh]pekjateopo 1-6++ejpdkoaop]pqoao 1.6 op]pqoaoPn]jo9pdeo):[[op]pqoPn]joh]pa$ iej[op]pqoao%7 1/6 106++Pdareasd]ojkgjksha`cakbsd]ph]jcq]ca 116++pk`eolh]uokiapdejc 126pdeo):oap$#op]pqoao#( op]pqoaoPn]jo%7 136y This method fetches Twitter statuses according to a number of query conditions, starting on line 5. We need to know what time period of statuses we want. Do we want archived statuses or the most recent statuses? When we are retrieving the most recent 20 statuses, we set it between 1 and 2 minutes behind the current time, so we will always get a full minute. To make the query more efficient, if no language was selected, there is no need to try to fetch any associated translations, which is by default what would happen—see line 26 onwards. Therefore, we unbind any associations using the qj^ej`Ik`ah method when no language was chosen. Once we have the statuses, on line 52, we make a call to [op]pqoPn]joh]pa, which will translate any statuses if there are any. Finally, we set the view variable op]pqoao so it’s available to be displayed in any view.

The __statusTranslate() Action The [[op]pqoPn]joh]pa private action, shown in Listing 6-27, is a supporting action to the [[`eolh]uPseppano action. It helps us to translate statuses transparently, independent of the language in which the status is originally. Listing 6-27. TwitterStatusController __statusTranslate Action -6bqj_pekj[[op]pqoPn]joh]pa$ op]pqoao%w .6 /6 naoqhp9]nn]u$%7 06 16bkn$ e`t9,7 e`t8oevakb$ op]pqoao%7 e`t''%w 26 36++Knecej]hh]jcq]capatp 46 p[qoan[j]ia9 op]pqoaoW e`tYWPseppanOp]pqoYWp[qoan[j]iaY7 56 p[patp9 op]pqoaoW e`tYWPseppanOp]pqoYWp[patpY7 -,6 p[qoan[qnh9 op]pqoaoW e`tYWPseppanOp]pqoYWp[qoan[qnhY7 --6 p[qoan[lnkbeha[ei]ca[qnh9£ op]pqoaoW e`tYWPseppanOp]pqoYWp[qoan[lnkbeha[ei]ca[qnhY7


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

-.6 p[qoan[hk_]pekj9 -/6 op]pqoaoW e`tYWPseppanOp]pqoYWp[qoan[hk_]pekjY7 -06 p[qoan[o_naaj[j]ia9 -16 op]pqoaoW e`tYWPseppanOp]pqoYWp[qoan[o_naaj[j]iaY7 -26 p[_na]pa`[]p9ÂŁ op]pqoaoW e`tYWPseppanOp]pqoYWp[_na]pa`[]pY7 -36 -46++Sakjhu_da_gebpdanaeo]`aopej]pekjh]jcq]caola_ebea` -56++?da_gebpdanaeo]pn]joh]pekjbnkipdaknecej]hpkpda .,6++`aopej]pekj7ebpdanaeo(sakranne`a(knecej]hpatp .-6eb$pdeo):_qnnajpH]jc%w ..6 ./6eb$eooap$ op]pqoaoW e`tYWPseppanPn]joh]pekjY%%w .06 .16++Jkpasakjhupn]joh]paop]pqo .26 .36 pn]jo[naoqhp9pdeo):[[capOp]pqoPn]joh]pekj$ .46 op]pqoaoW e`tY%7 .56 /,6eb$eooap$ pn]jo[naoqhpWp[patpY%%w /-6 p[patp9 pn]jo[naoqhpWp[patpY7 /.6y //6y /06y /16 /26 _qnnajp[naoqhp9]nn]u$%7 /36 /46 _qnnajp[naoqhpWr[p[qoan[j]iaY9 p[qoan[j]ia7 /56 _qnnajp[naoqhpWr[p[patpY9 p[patp7 0,6 _qnnajp[naoqhpWr[p[qoan[qnhY9 p[qoan[qnh7 0-6 _qnnajp[naoqhpWr[p[qoan[lnkbeha[ei]ca[qnhY9 0.6 p[qoan[lnkbeha[ei]ca[qnh7 0/6 _qnnajp[naoqhpWr[p[qoan[hk_]pekjY9 p[qoan[hk_]pekj7 006 _qnnajp[naoqhpWr[p[qoan[o_naaj[j]iaY9 p[qoan[o_naaj[j]ia7 016 _qnnajp[naoqhpWr[p[_na]pa`[]pY9 p[_na]pa`[]p7 026 036 naoqhpWY9 _qnnajp[naoqhp7 046y 056 1,6napqnj naoqhp7 1-6y Basically, if there is a translation found for the status, we replace the original status with that translation. This happens on line 21. If a translation is not found, we will just display the status in its original language. Additionally, we have formed a new result array to return on line 36. In that array, we prefix each key with r[ to make it clear that the array is to be used in the view.

203


204

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

Now that we have covered both [[`eolh]uPseppano and [[op]pqoPn]joh]pa, the following view (+]ll+reaso+pseppan[op]pqo+ej`at*_pl), which displays the statuses, should make sense. 8;ldl bkna]_d$ op]pqoao]o _qnnajp[op]pqo%w a_dk#8`er_h]oo9op]pqo[na_:#7 a_dk#8d/:8]dnab9dppl6++pseppan*_ki+#* _qnnajp[op]pqoW£ r[p[qoan[o_naaj[j]iaY*#p]ncap9[^h]jg:#* _qnnajp[op]pqoW£ r[p[qoan[j]iaY*#8+]:8+d/:#7 a_dk#8dn]hecj9habpjkod]`a9oeva9-se`pd9-,,!:#7 eb$ _qnnajp[op]pqoWr[p[qoan[qnhY%w a_dk#8]dnab9#* _qnnajp[op]pqoWr[p[qoan[qnhY*#:£ 8eic_h]oo9lnkbeha[eicon_9#* _qnnajp[op]pqoW£ r[p[qoan[lnkbeha[ei]ca[qnhY*#]hecj9habp:8+]:#7 y ahoaw a_dk#8eic_h]oo9lnkbeha[eicon_9#* _qnnajp[op]pqoW£ r[p[qoan[lnkbeha[ei]ca[qnhY*#]hecj9habp:#7 y a_dk _qnnajp[op]pqoWr[p[patpY*#8^n+:#7 eb$ _qnnajp[op]pqoWr[p[qoan[hk_]pekjY%w a_dk#8^:Bnki68+^:#* _qnnajp[op]pqoWr[p[qoan[hk_]pekjY7 y a_dk#8+`er:#7 y ;: Here, we basically loop through the statuses and display the fields. Figure 6-4 shows an example of the translated statuses page.


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

Figure 6-4. A translated statuses page

The __getStatusTranslation() Action The [[capOp]pqoPn]joh]pekj action, shown in Listing 6-28, complements the previous two actions.

205


206

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

Listing 6-28. TwitterStatusController __getStatusTranslation Action -6bqj_pekj[[capOp]pqoPn]joh]pekj$ op]pqoao%w .6 /6 naoqhp9]nn]u$%7 06 16 pn]joPk9pdeo):_qnnajpH]jc7 26 36++-*?da_gp[patppn]joh]pekj*Sa]hs]uoqoapdabenopkja 46eb£ $eooap$ op]pqoaoWPseppanPn]joh]pekjYW,YWp[patp[pn]joh]pekjY%%w 56 -,6++Uaopdanaeo]pn]joh]pekj*Hap#oqoapd]p --6 naoqhpWp[patpY9 -.6 op]pqoaoWPseppanPn]joh]pekjYW,YWp[patp[pn]joh]pekjY7 -/6y -06ahoaw -16 okqn_aH]jc9##7 -26 -36++Jkpdanaeojkpn]joh]pekj*Hap#ocapkja -46 -56++Op]npsepdp[patp .,6 p[patp9 op]pqoaoWPseppanOp]pqoYWp[patpY7 .-6 ckkcha[pn]jo[naoqhp9 ..6pdeo):[[pn]joh]paPatp$ p[patp( pn]joPk%7 ./6 .06 naoqhpWp[patpY9 ckkcha[pn]jo[naoqhpWpn]joh]pekjY7 .16 okqn_aH]jc9 ckkcha[pn]jo[naoqhpWokqn_a[h]jcY7 .26 .36pdeo):[[o]raPn]jo$ okqn_aH]jc( .46 pn]joPk( .56 naoqhp( /,6 op]pqoaoWPseppanOp]pqoYWe`Y%7 /-6y /.6 //6napqnj naoqhp7 /06y On line 8, if a translation already exists, we won’t translate it. If there isn’t a translation, we make the request to Google to translate the status, from line 14 onwards. If a translation is found, we always take the first translation, as we will explain shortly, in the description of the [o]raPn]jo action.

The __translateText() Action The private action in Listing 6-29 uses Cake’s DpplOk_gap class methods to make translation requests to Google. Sometimes, the call may fail. In that situation, we still return the status minus the translation. We throttle the translation requests with a sleep period, as that helps the reliability of any immediate future requests.


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

Listing 6-29. TwitterStatusController__translateText Action -6bqj_pekj[[pn]joh]paPatp$ pn]joPatp( `aopH]jc%w .6 /6 naoqhp9]nn]u$pn]joh]pekj9:( 06okqn_a[h]jc9:( 16naolkjoa[op]pqo9:%7 26 36eb$ailpu$ pn]joPatp%%wnapqnj7y 46 56 l]n]io9]nn]u$%7 -,6 l]n]ioWrY9-*,7 --6 l]n]ioWmY9 pn]joPatp7 -.6 l]n]ioWh]jcl]enY9x* `aopH]jc7 -/6 l]n]ioWgauY9EjoanpUkqnCkkcha=LEGauDana7 -06 -16 l]n]iOpn9pdeo):[[_kjopnq_pQNH$ l]n]io%7 -26 -36 qnh9£ dppl6++]f]t*ckkcha]leo*_ki+]f]t+oanre_ao+h]jcq]ca+pn]joh]pa;* l]n]iOpn7 -46 -56=ll66eilknp$#DpplOk_gap#%7 .,6 dppl9jasDpplOk_gap$%7 .-6 namqaop9]nn]u$ ..6#qne#9: qnh( ./6#da]`an#9:]nn]u$ .06#Nabanan#9:#dppl6++#*ajr$#OANRAN[J=IA#% .16% .26%7 .36 ^k`u9dppl):namqaop$ namqaop%7 .46 .56++Jks(lnk_aoopdaFOKJopnejc /,6 fokj9fokj[`a_k`a$ ^k`u%7 /-6 /.6eb$eooap$fokj):naolkjoaOp]pqo%%w //6 /06++Pn]joh]pekjs]ockk` /16eb$fokj):naolkjoaOp]pqo99.,,%w /26 naoqhpWpn]joh]pekjY9fokj):naolkjoa@]p]):pn]joh]pa`Patp7 /36 naoqhpWokqn_a[h]jcY9£ fokj):naolkjoa@]p]):`apa_pa`Okqn_aH]jcq]ca7 /46 naoqhpWnaolkjoa[op]pqoY9.,,7 /56y 0,6ahoaw 0-6++Safqopbehhsepdknecej]h 0.6 naoqhpWpn]joh]pekjY9 pn]joPatp7 0/6 naoqhpWokqn_a[h]jcY9QJGJKSJ7 006 naoqhpWnaolkjoa[op]pqoY9fokj):naolkjoaOp]pqo7

207


208

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

016y 026y 036 046++Sa]hs]uos]epbkn]^ep^abknajatp]_pekj(,*1oa_ 056qohaal$1,,,,,%7 1,6 1-6napqnj naoqhp7 1.6y As this action is used by [[capOp]pqoPn]jo]pekj, which in turn saves it into the database, we may occasionally see the value QJGJKSJ in the pseppan[pn]joh]pekjo table. In this chapter, we won’t be going into the reasons why some text doesn’t get translated. Our goal is to translate some piece of text using Google. If the translation fails for some reason, we still return the data in the same format, as if it were translated. This way, we have a log of the failure of the translation, and the user still gets to see the original text, which we think is better than seeing no status text or an empty translation display. We start the action off on line 7. If no text is given, we just return an empty string. If a string is given, we form the code to carry out the DpplOk_gap from line 9 to line 27. We then decode the returned result on line 30 onwards. On line 13, remember to use your own Google API key.

The __saveTrans() Action There isn’t much to the [[o]raPn]jo action, shown in Listing 6-30. Listing 6-30. TwitterStatusController__saveTrans Action -6bqj_pekj[[o]raPn]jo$ okqn_aH]jc( `aopH]jc( pn]joNaoqhp(£ pseppanOp]pqoE`%w .6 /6++Sabenop_da_gsdapdanpdapn]joh]pekjateopobknpda 06++pseppan[op]pqo[e`]j`h]jc[pk*Arajebep`kao(sai]u 16++opehhd]ra.kniknakbpdao]iaajpneaoejpda`]p]^]oa* 26 36 _kj`epekjo9]nn]u$ 46PseppanPn]joh]pekj*pseppan[op]pqo[e`9: pseppanOp]pqoE`( 56PseppanPn]joh]pekj*h]jc[pk9: `aopH]jc -,6%7 --6 -.6 pn]joAteop9pdeo):PseppanPn]joh]pekj):bej`$ -/6#benop#(]nn]u$#_kj`epekjo#9: _kj`epekjo%%7 -06 -16 -26eb$ailpu$ pn]joAteop%%w -36 -46 op]pqoPn]jo9]nn]u$%7 -56 op]pqoPn]joW#h]jc[bnki#Y9 okqn_aH]jc7 .,6 op]pqoPn]joW#h]jc[pk#Y9 `aopH]jc7


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

.-6 op]pqoPn]joW#p[patp[pn]joh]pekj#Y9 pn]joNaoqhpWp[patpY7 ..6 op]pqoPn]joW#pseppan[op]pqo[e`#Y9 pseppanOp]pqoE`7 ./6 .06pdeo):PseppanPn]joh]pekj):_na]pa$ op]pqoPn]jo%7 .16pdeo):PseppanPn]joh]pekj):o]ra$%7 .26y .36y On line 12, we check if there are two or more of the same translation. If not, we enter the translation into the pseppan[pn]joh]pekjo table on lines 24 and 25. Why would there be two or more of the same translation? Well, since we are not translating the statuses in a background process, any user who first brings up the statuses in a specific language would fire up the translation parts of the controller. As we are not using SQL transaction locks, there could easily be the situation where two or more users are requesting the same statuses at roughly the same time. Using transaction locks would hold up the rendering of the page. We donâ&#x20AC;&#x2122;t feel they are necessary, as we can always write some housekeeping function to clear any duplicate entries. This is better than delaying the translation of the page.

The AppController Along with our three controllers, the global =ll?kjpnkhhan also plays a part in our application. Listing 6-31 shows the contents of the =ll?kjpnkhhan file ]ll+]ll[_kjpnkhhan*ldl* Listing 6-31. The Application Base Controller (app/app_controller.php) -68;ldl .6 /6_h]oo=ll?kjpnkhhanatpaj`o?kjpnkhhanw 06 16++@ab]qhpl]capepha 26r]n l]caPepha9#?d]lpan2)ÂŁ I]odejcPseppansepdpdaCkkchaPn]joh]pkn#7 36 46++Pdareasdahlanopd]psa#hhqoachk^]hhu 56r]n dahlano9]nn]u$#?]_da#(#Bkni#(#Dpih#(#Noo#%7 -,6 --6++?kilkjajpopd]psa#hhkbpajqoa -.6r]n _kilkjajpo9]nn]u$#Oaooekj#(#NamqaopD]j`han#%7 -/6 -06++Pda`ab]qhph]jcq]capkreaspdaop]pqoao -16r]n _qnnajpH]jc9##7 -26 -36r]n qoao9]nn]u$#PseppanNamqaop#(#PseppanOp]pqo#( -46#PseppanPn]joh]pekj#(#H]jcq]ca#%7 -56 .,6++Sa_]_dapdaik`aho .-6r]n lanoeopIk`ah9pnqa7 ..6

209


210

CH APT ER 6 N MA S HING TW ITTER W ITH THE G OOG L E T R A N S LA T O R

./6bqj_pekj^abknaBehpan$%w .06 .16 _]_da[cap[h]jc9?]_da66na]`$#capH]jc#%7 .26 .36eb$ailpu$ _]_da[cap[h]jc%%w .46 .56++Pdeoeo]oepase`abqj_pekj /,6?]_da66snepa$#capH]jc#(pdeo):H]jcq]ca):capH]jc$%(,%7 /-6y /.6 //6 oaooekj[cap[h]jc9pdeo):Oaooekj):na]`$capH]jc%7 /06 /16eb$ailpu$ oaooekj[cap[h]jc%%w /26pdeo):Oaooekj):snepa$capH]jc(?]_da66na]`$#capH]jc#%%7 /36y /46 /56++D]_geod 0,6+& 0-6eb$lnac[i]p_d$#+X+noo +#(Nkqpan66qnh$%%%w 0.6pdeo):NamqaopD]j`han):atp9#noo#7 0/6y&+ 006 016pdeo):[[h]jc?dke_a$%7 026y 036 046bqj_pekj[[h]jc?dke_a$%w 056 1,6++Ebqoand]ooaha_pa``ab]qhpreasejch]jcq]ca 1-6eb$pdeo):Oaooekj):na]`$qoanH]jc%%w 1.6pdeo):_qnnajpH]jc9pdeo):Oaooekj):na]`$qoanH]jc%7 1/6y 106y 116 126y 136;: Starting on line 9, we employ a number of view helpers. The cache helper helps us to cache the output view. The form helper is needed for the language selection drop-down list. The HTML helper is used for various HTML tags. And last, the RSS helper deals with the output needed for RSS requests. We have also used a number of components. The Oaooekj component is used to store the language the user has selected and also the data generated from the language drop-down list. NamqaopD]j`han automatically handles user RSS web service requests by picking the correct layout and view. The NamqaopD]j`han will use the RSS layout under the h]ukqp folder. In the view, it will use the ej`at*_pl in the +]ll+reaso+pseppanpseopan+noo folder. Note, however, that beginning on line 40, we have used the alternative hack to get our +noo URL working. As we explained earlier, we want to have an RSS URL feed that ends with +noo. This method tricks the NamqaopD]j`han into thinking that the request has an noo extension.


C HA P TER 6 N M A S H I N G T W I T T E R W I T H T H E G O O G LE T R A N S LA T O R

Continuing our cache theme, on line 21, we are also caching the model using the lanoeopIk`ah variable. This will help to speed up the application. The code within the ^abknaBehpan just caches the data from the language drop-down list. We have commented some code at the end of the method. The ^abknaBehpan finishes with a call to the [[h]jc?dke_a private method. If a user has previously selected a language via the top navigation drop-down list, this method makes sure that all the other controllers are aware of the chosen language. We assign the session qoanH]jc value to the global _qnnajpH]jc value.

Summary In this chapter, we have successfully mashed two popular online applications. We have also covered a number of Cake topics, including caching. Its worth highlighting that caching is quite a loose term, with different meanings in different contexts, but the end result is always to save on some resource by not repeating the same action twice. Additionally, we added i18n and l10n. Note that we will come back to this topic in Chapter 9, where we will add different languages to data that is stored in a database. Since we have consumed two different web services, it seems only right that we also offer one as well. Adding the RSS web service feature was quite straightforward, except for our requirement that the URLs should end with +tih. There are quite a number of features you could add to this application. The following are some suggestions: Ê

UÊ /…iÊreas action could be split into years/months as one page, then days, then hours. Thus, you would only list up to 60 items in any one page. You could then have URLs like PseppanNamqaop+reas+.,,4+,4+,/+-0+,,.

Ê

UÊ 9œÕÊVœÕ`ÊvÕÀ̅iÀÊ̅iÊVÀœ˜ÊL>VŽ}ÀœÕ˜`Ê«ÀœViÃÃÊ>˜`ÊÌÀ>˜Ã>ÌiÊ>Ê>ÀV…ˆÛiÃʈ˜ÌœÊ>Ê>˜guages gradually over a period of time. This would make the archive available via links instead of a drop-down list, so it would be search engine optimization–friendly.

Ê

UÊ /…ˆÃʈÃÊ>ÊLˆ}ʜ˜i\Ê>``Ê̅iÊ>LˆˆÌÞÊvœÀÊÕÃiÀÃÊ̜ÊÜÀˆÌiʓiÃÃ>}iÃʈ˜Ê̅iˆÀʜܘʏ>˜}Õ>}iÊ>˜`Ê post it to Twitter in the recipient’s own language.

211


C HAPTER

7

Unit Testing and Web Testing A

s you may have inferred, unit testing is the practice of testing individual units of code, to check that the application code works as expected. To help developers with their testing, CakePHP 1.2 includes integrated unit testing features. In this chapter, we’ll show you how to use these features. We’ll start by looking at a methodology that can provide some insight into the goals of unit testing.

Getting Programming Done David Allen’s productivity book, Getting Things Done: The Art of Stress-Free Productivity (Penguin, 2002), has attracted a lot of interest in the past few years. The methodology, abbreviated GTD, has become especially popular among the tech crowd. It’s the primary subject of Merlin Mann’s 43folders.com web site and many other blogs. The GTD methodology might be summarized with these principles: Define what done looks like: Visualize what your end goal is. Envision what it will take to get there. Allow your mind to brainstorm how to get yourself there. Define what doing looks like: Decide what the next physical action is that will move you closer to your goal. What can you do to move closer to completion, based on your current priorities, resources, and context? Unit testing helps you define what done looks like for your code. Unit testing gives you a specific goal to aim for as you code. It requires mental exertion up-front, as you decide specifically what your code should do, and then it “signals” to you in clear terms when you’ve reached your goal. Over the life of your project, unit testing also provides one other GTD-like benefit: it helps you “get it all out of your head.” The GTD methodology encourages you to write down all of your “open loops”—things, large and small, that you want to do or change—to free your mind. As you free your mind of trying to remember everything that’s unfinished in your life, you’ll have more mental energy for creativity. Similarly, you may have noticed that when you refactor your code, especially in a dynamic, loosely typed language like PHP, you need to keep a lot in your head. You may wonder whether writing new code will break your existing code if you forget something. For example, have you ever had to rename a variable that was strewn throughout your code? Have you ever had to change all your 8d.: elements to 8d/: elements? If so, then you know the 213


214

CH APT ER 7 N UNIT TES TING A ND W EB TES TING

feeling. It’s worrisome to refactor your code and wonder if it will still work afterwards. Unit testing provides an alert system and a security net to inform you when you’ve broken something and to catch you if you make a mistake. By freeing your mind from worrying whether you’ll break something as you move forward, unit testing allows you to focus on the more creative aspects of your work. Now that you have an idea about the benefits of unit testing, let’s see how it works with a Cake application.

Our Case Study: An App Like In/Out In April 2008, Jason Fried announced that his company, 37signals, uses a simple internal application called In/Out for communicating among team members (see dppl6++sss* /3oecj]ho*_ki+orj+lkopo+532). In/Out shows what each team member is doing and what each has accomplished. Here, we’ll build a similar application as our case study. We’ll call it Accomplishments, and it will allow team members to create a log of tasks and projects they have accomplished. It won’t have a real authentication system or security. For this example, we’ll assume that it’s being deployed on an intranet or otherwise secured.

Creating the Application We’ll start with a fresh installation of CakePHP 1.2, which includes integrated unit testing features, though we still need to install the unit testing framework. Figure 7-1 shows the green messages that indicate Cake is ready to use. We’ve set up caching, a MySQL database, and a custom security salt, so the development environment is ready to use. For the application, we’ll create an ]__kilheodiajpo table as shown in Listing 7-1. Listing 7-1. The accomplishments Table Schema -6?NA=PAP=>HA\]__kilheodiajpo\$ .6\e`\ejp$--%JKPJQHH]qpk[ej_naiajp( /6\pa]i[iai^an\r]n_d]n$/,%JKPJQHH( 06\`ao_nelpekj\r]n_d]n$-0,%JKPJQHH( 16\_na]pa`\`]papeia`ab]qhpJQHH( 26\ik`ebea`\`]papeia`ab]qhpJQHH( 36LNEI=NUGAU$\e`\% 46%7 The table includes fields for a primary key, the team member’s name (this table isn’t normalized), a description of up to 140 characters (Twitter style), and created and modified dates.


C H A P T E R 7 N U N I T T E S T I N G A N D W E B T E S T I N G

Figure 7-1. A fresh installation of CakePHP 1.2 A simple model will connect the application to our database. The =__kilheodiajp model is shown in Listing 7-2. Listing 7-2. The Accomplishment Model (app/models/accomplishment.php) -68;ldl .6 /6_h]oo=__kilheodiajpatpaj`o=llIk`ahw 06r]n j]ia9#=__kilheodiajp#7 16 26y Next, we define an accomplishments controller, as shown in Listing 7-3.

215


216

CH APT ER 7 N UNIT TES TING A ND W EB TES TING

Listing 7-3. The AccomplishmentsController (app/controllers/accomplishment_controller.php) -68;ldl .6 /6=ll66eilknp$#?kna#(#O]jepeva#%7 06 16_h]oo=__kilheodiajpo?kjpnkhhanatpaj`o=ll?kjpnkhhanw 26r]n j]ia9#=__kilheodiajpo#7 36r]n dahlano9]nn]u$#Peia#%7 46 56bqj_pekjej`at$%w -,6eb$ailpu$ pdeo):l]n]ioW#qnh#YW#pa]i[iai^an#Y%%w --6pdeo):na`ena_p$]nn]u$#]_pekj#9:#hkcej#%(/,.%7 -.6y -/6 -06pdeo):oap$#iu[]__kilheodiajpo#(pdeo):=__kilheodiajp):bej`$#]hh#( -16]nn]u$#_kj`epekjo#9:]nn]u$=__kilheodiajp*pa]i[iai^an9:£ pdeo):=__kilheodiajp):`]p]W#=__kilheodiajp#YW#pa]i[iai^an#Y%( -26#kn`an#9:]nn]u$#=__kilheodiajp*_na]pa`@AO?#%%%%7 -36 -46pdeo):oap$#kpdan[]__kilheodiajpo#(pdeo):=__kilheodiajp):bej`$#]hh#( -56]nn]u$#_kj`epekjo#9:]nn]u$#jkp#9:]nn]u$£ =__kilheodiajp*pa]i[iai^an9:pdeo):£ =__kilheodiajp):`]p]W#=__kilheodiajp#YW#pa]i[iai^an#Y%%( .,6#kn`an#9:]nn]u$#=__kilheodiajp*_na]pa`@AO?#%%%%7 .-6y ..6 ./6bqj_pekjhkcej$%w .06y .16 .26bqj_pekj]``$%w .36eb$ailpu$ pdeo):`]p]%%w .46pdeo):=__kilheodiajp):o]ra$ pdeo):`]p]%7 .56y /,6pdeo):na`ena_p$+]__kilheodiajpo+;pa]i[iai^an9*£ pdeo):`]p]W#=__kilheodiajp#YW#pa]i[iai^an#Y(/,.%7 /-6y /.6y We load the Sanitize plugin in line 3 and the time helper in line 7, both of which will be used later. For simplicity, we’ll store the user’s name in the URL as a CAP variable. In lines 10 through 12, we check that the CAP variable pa]i[iai^an is not empty. If it is empty, the user is redirected to a login page. With pa]i[iai^an in hand, the controller calls the model to get a list of accomplishments by the user (lines 14 through 16). The model is also called for a list of the other team members’ accomplishments (lines 18 through 20). Line 23 defines a hkcej action. Line 26 defines an ]`` action that will allow us to insert new accomplishments into our database.


C H A P T E R 7 N U N I T T E S T I N G A N D W E B T E S T I N G

The login view, shown in Listing 7-4, prompts for a username and submits it as a URL parameter (a CAP variable). Both of our views use Cake’s default layout and styling. Listing 7-4. The Login View (app/views/accomplishments/login.ctp) -68;9bkni):_na]pa$#=__kilheodiajp#(]nn]u$#pula#9:#cap#(£ #]_pekj#9:#ej`at#%%;: .6 /68;9bkni):ejlqp$#pa]i[iai^an#(]nn]u$#h]^ah#9:#Lha]oaajpanukqnj]ia#%%;: 06 168;9bkni):oq^iep$#Hkcej#%;: 26 368+bkni: In Listing 7-5, we define a view for our index page. This is what the user will see after logging in. Listing 7-5. The Main View (app/views/accomplishments/index.ctp) -68d.:Pa]i=__kilheodiajpo8+d.: .68l:Sd]pd]raukq`kja;8+l: /68;9bkni):_na]pa$#=__kilheodiajp#%;: 068;9bkni):ejlqp$#`ao_nelpekj#%;: 168;9bkni):de``aj$#pa]i[iai^an#(]nn]u$#r]hqa#9:£ pdeo):l]n]ioW#qnh#YW#pa]i[iai^an#Y%%;: 268;9bkni):oq^iep$#Lkop=__kilheodiajp#%;: 368+bkni: 46 568d.:Iu=__kilheodiajpo8+d.: -,68;ldlbkna]_d$ iu[]__kilheodiajpo]o ]__kilheodiajp%6;: --68l:8opnkjc:8;9O]jepeva66dpih$ ]__kilheodiajpW#=__kilheodiajp#Y£ W#`ao_nelpekj#Y%;:8+opnkjc:8+l: -.68l:8oi]hh:8;9peia):je_aOdknp$ ]__kilheodiajpW#=__kilheodiajp#Y£ W#_na]pa`#Y%;:8+oi]hh:8+l: -/68^n+: -068;ldlaj`bkna]_d7;: -16 -268d.:Kpdano#=__kilheodiajpo8+d.: -368;ldlbkna]_d$ kpdan[]__kilheodiajpo]o ]__kilheodiajp%6;: -468l:8ai:8;9O]jepeva66dpih$ ]__kilheodiajpW#=__kilheodiajp#Y£ W#pa]i[iai^an#Y%;:8+ai:68opnkjc:8;9O]jepeva66dpih$£ ]__kilheodiajpW#=__kilheodiajp#YW#`ao_nelpekj#Y%£ ;:8+opnkjc:8+l: -568l:8oi]hh:8;9peia):je_aOdknp$ ]__kilheodiajpW#=__kilheodiajp#Y£ W#_na]pa`#Y%;:8+oi]hh:8+l: .,68^n+: .-68;ldlaj`bkna]_d7;:

217


218

CH APT ER 7 N UNIT TES TING A ND W EB TES TING

In lines 3 through 7, we provide a form for entering new accomplishments. We then display a list of accomplishments by the user, in lines 9 through 14, and by the user’s team members, in lines 16 through 21. You’ll notice we’re using the O]jepeva66dpih method (lines 11 and 18) to prevent cross-site scripting (XSS) attacks. This is a good practice whenever you’re echoing previously entered text back to the user. We now have a working, admittedly simplistic, application. We can log in (see Figure 7-2) and begin using our application (see Figure 7-3).

Figure 7-2. Logging in to our new Accomplishments application

Figure 7-3. Posting a completed accomplishment to our application


C H A P T E R 7 N U N I T T E S T I N G A N D W E B T E S T I N G

EDITING YOUR HOSTS FILE When working on a development machine, we find it convenient to create a dkopo entry, or â&#x20AC;&#x153;mock domain,â&#x20AC;? for each web site weâ&#x20AC;&#x2122;re developing. This allows us to access the web site at a convenient address like dppl6++_]galdl+. Youâ&#x20AC;&#x2122;ll see this mock address used throughout this chapter. You can create a similar mock domain by editing your dkopo file, as follows: s /N,INUXORA-AC FINDANDOPENTHEFILE+ap_+dkopo/N7INDOWS80 OPENTHEFILE?6XSEJ@KSOX ouopai/.X`neranoXap_Xdkopo. s !TTHEBOTTOMOFTHEFILE ADDANEWENTRY WITHTHE)0ADDRESS-.3*,*,*- on the left, and the hostname _]galdl (or whatever hostname you want) on the right, separated by space. !SSUMINGYOUALREADYHAVEYOURWEBSERVERINSTALLEDANDRUNNINGONYOURLOCALMACHINE YOUSHOULD now be able to access your web site in your browser at the address dppl6++_]galdl+. )FYOUHAVEMULTIPLEDEVELOPMENTWEBSITESHOSTEDONYOURLOCALMACHINE YOULLNEEDTOCREATEA Renpq]hDkopENTRYFOREACHONEINYOUR!PACHECONFIGURATIONFILE The rest of this chapter will assume youâ&#x20AC;&#x2122;ve created a host entry like our dppl6++_]galdl+ entry.

Adding Username Validation With our simple application now running, letâ&#x20AC;&#x2122;s suppose we want to add validation code to ensure that only alphabetic letters are acceptable for the username. We donâ&#x20AC;&#x2122;t want to allow any numbers, symbols, or spaces in usernames. Listing 7-6 shows the validation code added to our =__kilheodiajp model. Listing 7-6. Adding Username Validation to the Model (in app/models/accomplishment.php) -68;ldl .6 /6_h]oo=__kilheodiajpatpaj`o=llIk`ahw 06r]n j]ia9#=__kilheodiajp#7 16 26r]n r]he`]pa9]nn]u$ 36#pa]i[iai^an#9:]nn]u$ 46#nqha#9:]nn]u$#r]he`Qoanj]ia#%( 56#iaoo]ca#9:Ejr]he`Qoanj]ia -,6%( --6%7 -.6 -/6bqj_pekjr]he`Qoanj]ia$ `]p]%w -06napqnj$lnac[i]p_d$#+ZW=)V])vY' +#( `]p]W#pa]i[iai^an#Y%%7 -16y -26y We could use Cakeâ&#x20AC;&#x2122;s built-in validation rules, but for the sake of discussion, we define our own custom method for validating the pa]i[iai^an field, in lines 6 through 11. This custom method, r]he`Qoanj]ia$%, is defined in lines 13 through 15. It uses a regular expression to ensure

219


220

CH APT ER 7 N UNIT TES TING A ND W EB TES TING

that only uppercase and lowercase letters are allowed. In the real world, this method might connect to a centralized company directory web service to look up and validate the username. Next, we’ll modify our controller to do the validating, as shown in Listing 7-7 (additions shown in bold). Listing 7-7. The AccomplishmentsController Updated to Validate the team_member Name (app/controllers/accomplishment_controller.php) -68;ldl .6 /6=ll66eilknp$#?kna#(#O]jepeva#%7 06 16_h]oo=__kilheodiajpo?kjpnkhhanatpaj`o=ll?kjpnkhhanw 26r]n j]ia9#=__kilheodiajpo#7 36r]n dahlano9]nn]u$#Peia#%7 46 56bqj_pekjej`at$%w -,6eb$ailpu$ pdeo):l]n]ioW#qnh#YW#pa]i[iai^an#Y%%w --6pdeo):na`ena_p$]nn]u$#]_pekj#9:#hkcej#%(/,.%7 -.6y -/6 -06pdeo):=__kilheodiajp):oap$]nn]u$Ð=__kilheodiajpÑ9:£ ]nn]u$#pa]i[iai^an#9:pdeo):l]n]ioWÐqnhÑYWÐpa]i[iai^anÑY%%%7 -16 -26eb$ pdeo):=__kilheodiajp):r]he`]pao$%%w -36pdeo):Oaooekj):oapBh]od$ÐEjr]he`qoanj]ia6#*O]jepeva66dpih$£ pdeo):=__kilheodiajp):`]p]W#=__kilheodiajp#YW#pa]i[iai^an#Y%%7 -46pdeo):na`ena_p$]nn]u$Ð]_pekjÑ9:#hkcej#%(/,.%7 -56y .,6 .-6pdeo):oap$#iu[]__kilheodiajpo#(pdeo):=__kilheodiajp):bej`$#]hh#( ..6]nn]u$#_kj`epekjo#9:]nn]u$=__kilheodiajp*pa]i[iai^an9:£ pdeo):=__kilheodiajp):`]p]W#=__kilheodiajp#YW#pa]i[iai^an#Y%( ./6#kn`an#9:]nn]u$#=__kilheodiajp*_na]pa`@AO?#%%%%7 .06 .16pdeo):oap$#kpdan[]__kilheodiajpo#(pdeo):=__kilheodiajp):bej`$#]hh#( .26]nn]u$#_kj`epekjo#9:]nn]u$#jkp#9:]nn]u$£ =__kilheodiajp*pa]i[iai^an9:£ pdeo):=__kilheodiajp):`]p]W#=__kilheodiajp#YW#pa]i[iai^an#Y%%( .36#kn`an#9:]nn]u$#=__kilheodiajp*_na]pa`@AO?#%%%%7 .46y .56 /,6bqj_pekjhkcej$%w /-6y /.6 //6bqj_pekj]``$%w /06eb$ailpu$ pdeo):`]p]%%w /16pdeo):=__kilheodiajp):o]ra$ pdeo):`]p]%7 /26y


C H A P T E R 7 N U N I T T E S T I N G A N D W E B T E S T I N G

/36pdeo):na`ena_p$+]__kilheodiajpo+;pa]i[iai^an9*£ pdeo):`]p]W#=__kilheodiajp#YW#pa]i[iai^an#Y(/,.%7 /46y /56y In line 14, we load the pa]i[iai^an variable into the model. In line 16, we make sure the model validates. If the model does not validate, we know it must be an invalid username (because that’s the only thing we’ve changed), so we set an error message and redirect to the login page (lines 17 and 18). We are performing the validation explicitly in the controller, as opposed to implicitly when the model attempts to save to the database, because we need a valid username before we can display accomplishments. After adding username validation code, what if we discover that our code is too strict? What if we want to allow usernames with numeric digits? And, as a further complication, what if we don’t want numeric digits at the beginning of the username? Suppose we want to accept a username like f]na`----0, but not -0,/-^nepp]ju. This could quickly become complicated as we try to create an algorithm that will accept the usernames we want to accept and reject the usernames we want to reject. This is where unit testing comes in.

Using Cake’s Unit Testing Framework Begin by visiting dppl6++_]galdl+paop*ldl, the location of Cake’s testing interface. You should see the error message shown in Figure 7-4, indicating that SimpleTest is not yet installed.

Figure 7-4. You’ll see this message if Cake’s test interface, SimpleTest, is not yet installed.

221


222

CH APT ER 7 N UNIT TES TING A ND W EB TES TING

Installing SimpleTest SimpleTest is the third-party unit testing library (created by Marcus Baker, a developer in London) that powers Cakeâ&#x20AC;&#x2122;s unit testing module. SimpleTest can be obtained from dppl6++ sss*oeilhapaop*knc. As shown in Figure 7-5, the SimpleTest web site also offers a manual, a mailing list, and links to several articles and tutorials.

Figure 7-5. The SimpleTest web site (http://www.simpletest.org) After downloading and uncompressing SimpleTest, installation is simple. Just copy the oeilhapaop folder to either your raj`kno folder or your ]ll+raj`kno folder, depending on whether you want the SimpleTest library to be available to all your applications or to only this application. In our development environment, this decision will make little difference. Weâ&#x20AC;&#x2122;ll flip a coin and copy oeilhapaop to the raj`kno folder.


C H A P T E R 7 N U N I T T E S T I N G A N D W E B T E S T I N G

You’ll also need to make sure the `a^qc variable in ]ll+_kjbec+_kna*ldl is greater than 0. Now when you revisit dppl6++_]galdl+paop*ldl, you’ll see a list of test groups and test cases, as shown in Figure 7-6. This means that SimpleTest has been successfully installed.

Figure 7-6. SimpleTest is now successfully installed. You’ll notice a list of several test groups and a longer list of test cases. These are the tests that come with every installation of Cake. They are designed to ensure the correct operation of the core Cake code. If you click the ]_h group, you may get a screen like the one shown in Figure 7-7, showing that 146 tests passed and 0 tests failed. In general terms, this means that Cake’s ACL code is working correctly, according to the 146 criteria the Cake developers used to judge its correctness. This may not mean a lot to you now, but let’s give the Cake developers a virtual pat on the back for creating code that passes their own tests, and we’ll move along to create tests for our own code.

223


224

CH APT ER 7 N UNIT TES TING A ND W EB TES TING

Figure 7-7. Cake’s built-in Acl and Auth tests successfully passed.

Creating Your Own Unit Tests The problem at hand is that we want to ensure that certain usernames are allowed in our application and certain usernames are not allowed. For example, ]`]i, I=PP, Oa]j, and >D00 are allowed; 53`arej and Opqg`kc are not. We want to ensure, in a systematic way, that our code accepts the good usernames and rejects the bad ones. To ensure this, we’ll create unit tests.

Creating the Test File We’ll create a new test file at ]ll+paopo+_]oao+ik`aho+]__kilheodiajp*paop*ldl. Every test file should end with the double extension *paop*ldl, not just *ldl. The file name before the extension can be whatever you want. For convenience and as a matter of convention, we’ll use the same name as our model. Listing 7-8 shows the ]__kilheodiajp*paop*ldl file.


C H A P T E R 7 N U N I T T E S T I N G A N D W E B T E S T I N G

Listing 7-8. Our Test Module (app/tests/cases/models/accomplishment.test.php) -68;ldl .6 /6=ll66eilknp$#Ik`ah#(#=__kilheodiajp#%7 06 16_h]oo=__kilheodiajpPaopatpaj`o=__kilheodiajpw 26r]n j]ia9#=__kilheodiajpPaop#7 36r]n qoa@^?kjbec9#paop#7 46y 56 -,6_h]oo=__kilheodiajpPaop?]oaatpaj`o?]gaPaop?]oaw --6r]n betpqnao9]nn]u$#]ll*]__kilheodiajp[paop#%7 -.6 -/6bqj_pekjpaopR]he`Qoanj]ia$%w -06pdeo):=__kilheodiajpPaop9"jas=__kilheodiajpPaop$%7 -16 -26pdeo):]ooanpPnqa$ pdeo):=__kilheodiajpPaop):r]he`Qoanj]ia$£ ]nn]u$#pa]i[iai^an#9:#]`]i#%%%7 -36pdeo):]ooanpPnqa$ pdeo):=__kilheodiajpPaop):r]he`Qoanj]ia$£ ]nn]u$#pa]i[iai^an#9:#I=PP#%%%7 -46pdeo):]ooanpPnqa$ pdeo):=__kilheodiajpPaop):r]he`Qoanj]ia$£ ]nn]u$#pa]i[iai^an#9:#Oa]j#%%%7 -56pdeo):]ooanpPnqa$ pdeo):=__kilheodiajpPaop):r]he`Qoanj]ia$£ ]nn]u$#pa]i[iai^an#9:#>D00#%%%7 .,6pdeo):]ooanpB]hoa$ pdeo):=__kilheodiajpPaop):r]he`Qoanj]ia$£ ]nn]u$#pa]i[iai^an#9:#53`arej#%%%7 .-6pdeo):]ooanpB]hoa$ pdeo):=__kilheodiajpPaop):r]he`Qoanj]ia$£ ]nn]u$#pa]i[iai^an#9:#opqg`kc#%%%7 ..6y ./6y In ]__kilheodiajp*paop*ldl, we define a new class called =__kilheodiajpPaop, which extends the =__kilheodiajp model class (lines 5 through 8). Similarly, your test classes should follow the same naming convention of 8ik`ah_h]ooj]ia:Paop (although this is not required) and should extend your model’s class. Notice that we need to explicitly import our model (line 3). The Cake testing module doesn’t make the automagic assumptions that Cake does elsewhere, to avoid muddying the testing environment. The test class also defines a new database configuration (line 7). Next, we define a class called =__kilheodiajpPaop?]oa, which extends ?]gaPaop?]oa (line 10). Your test classes should follow the same naming pattern and extend ?]gaPaop?]oa. In the =__kilheodiajpPaop?]oa class, we define a method called paopR]he`Qoanj]ia. Each method in a test case class should begin with paop (as in line 13). The method paopR]he`Qoanj]ia begins by instantiating an object of the class =__kilheodiajpPaop (line 14). Then six assertions are performed against the =__kilheodiajpPaop object (lines 16 through 21). These assertions ensure that our r]he`Qoanj]ia method is behaving as expected. For example, if we pass in ]`]i, I=PP, Oa]j, or >D00, we expect r]he`Qoanj]ia to

225


226

CH APT ER 7 N UNIT TES TING A ND W EB TES TING

return pnqa, so we use the ]ooanpPnqa method to ensure it (lines 16 through 19). On the other hand, if we pass in 53`arej or Opqg`kc, we expect r]he`Qoanj]ia to return b]hoa, so we use the ]ooanpB]hoa method to ensure it (lines 20 and 21).

Creating a Test Fixture To test a data model, as we are doing here, we need to create a test fixture. A fixture is a set of data used for testing purposes. It’s called a fixture because it remains fixed across all tests, like the control group in a scientific experiment. Your fixture should use test data that approximates the breadth and variedness of your real data. Test fixtures are created using PHP code that looks like SQL code. You define a multidimensional array to represent the database fields, and another array to represent the database records. The advantage of defining test data in PHP code, as opposed to in your database, is that it is less likely to be changed arbitrarily from the outside. It can also be versioned in a code-versioning system such as Subversion. Listing 7-9 shows a hypothetical test fixture, which would go in ]ll+paopo+betpqnao+]__kilheodiajp[paop[betpqna*ldl, but we’re not going to use this one in our example. Listing 7-9. A Hypothetical Test Fixture -68;ldl .6 /6_h]oo=__kilheodiajpPaopBetpqnaatpaj`o?]gaPaopBetpqnaw 06r]n j]ia9#=__kilheodiajpPaop#7 16 26r]n beah`o9]nn]u$ 36#e`#9:]nn]u$#pula#9:#ejpacan#(#gau#9:#lnei]nu#%( 46#pa]i[iai^an#9:]nn]u$#pula#9:#opnejc#(#hajcpd#9:/,(#jqhh#£ 9:#b]hoa#%( 56#`ao_nelpekj#9:]nn]u$#pula#9:#opnejc#(#hajcpd#9:-0,(#jqhh#£ 9:#b]hoa#%( -,6#_na]pa`#9:#`]papeia#( --6#ik`ebea`#9:#`]papeia# -.6%7 -/6 -06r]n na_kn`o9]nn]u$ -16]nn]u$#e`#9:-(#pa]i[iai^an#9:#Ne_d]n`#(#`ao_nelpekj#9:£ #Snkpajasqjeppaopobkn]llhe_]pekj*#(#_na]pa`#9:£ #.,,4),5)-5-,6,,6,,#(#ik`ebea`#9:#.,,4),5)-5-,6,,6,,#%( -26]nn]u$#e`#9:.(#pa]i[iai^an#9:#Opara#(#`ao_nelpekj#9:£ #Lnkoa_qpa`_neiej]ho*#(#_na]pa`#9:#.,,4),5)-5--6,,6,,#(£ #ik`ebea`#9:#.,,4),5)-5--6,,6,,#%( -36]nn]u$#e`#9:/(#pa]i[iai^an#9:#@]re`#(#`ao_nelpekj#9:£ #O]ra`herao*#(#_na]pa`#9:#.,,4),5)-5-.6,,6,,#(#ik`ebea`#9:£ #.,,4),5)-5-.6,,6,,#% -46%7 -56y


C H A P T E R 7 N U N I T T E S T I N G A N D W E B T E S T I N G

Our particular unit tests don’t need any data. We’re simply testing the functionality of our validation method. So let’s just punt and use a simpler test fixture, as shown in Listing 7-10. Listing 7-10. The Simpler Fixture Definition for This Example (app/tests/fixtures/accomplishment_ test_fixture.php) -68;ldl .6 /6_h]oo=__kilheodiajpPaopBetpqnaatpaj`o?]gaPaopBetpqnaw 06r]n j]ia9#=__kilheodiajpPaop#7 16r]n eilknp9#=__kilheodiajp#7 26 36y Instead of defining data using PHP code, we’ll simply indicate that we want the test fixture to import data from our production database table, =__kilheodiajp (line 5), which we won’t use anyway. The test fixture uses the paop database connection defined in ]ll+_kjbec+`]p]^]oa*ldl if it is available. If not, it uses your production database connection, prepending the test tables with paop[ to avoid overwriting your existing tables.

Running the Tests Now that the tests are written and our fixture is set up, we can run our unit tests. Visit dppl6++ _]galdl+paop*ldl and then click Test Cases. You should see a test case entitled models / Accomplishment, as shown in Figure 7-8.

Figure 7-8. Our test case is now listed in the testing interface.

227


228

CH APT ER 7 N UNIT TES TING A ND W EB TES TING

Now, the moment of truth! Click the models / Accomplishment link to see how our tests do. Figure 7-9 shows the result.

Figure 7-9. Running our first test case You will see a lot of red! We failed our test, or more specifically, we failed one of the six tests, and it says the failure was in line 19 of ]__kilheodiajp*paop*ldl. Looking back at the code (Listing 7-8), weâ&#x20AC;&#x2122;re not surprised that the test for the username >D00 failed, because we havenâ&#x20AC;&#x2122;t yet coded r]he`Qoanj]ia to accept numeric digits. Go to ]ll+ik`aho+]__kilheodiajp*ldl and change the regular expression in line 14 from +ZW=)V])vY' + to +ZW=)V])v,)5Y' + to allow digits in the username. Listing 7-11 shows this change. Listing 7-11. Modified Regular Expression to Accept Numbers in the Username (in app/models/ accomplishment.php) -68;ldl .6 /6_h]oo=__kilheodiajpatpaj`o=llIk`ahw 06r]n j]ia9#=__kilheodiajp#7 16


C H A P T E R 7 N U N I T T E S T I N G A N D W E B T E S T I N G

26r]n r]he`]pa9]nn]u$ 36#pa]i[iai^an#9:]nn]u$ 46#nqha#9:]nn]u$#r]he`Qoanj]ia#%( 56#iaoo]ca#9:Ejr]he`Qoanj]ia -,6%( --6%7 -.6 -/6bqj_pekjr]he`Qoanj]ia$ `]p]%w -06napqnj$lnac[i]p_d$#+ZW=)V])v,)5Y' +#( `]p]W#pa]i[iai^an#Y%%7 -16y -26y With our new r]he`Qoanj]ia method, let’s rerun our tests and see what we get. Refresh your browser. As shown in Figure 7-10, once more, we see a lot of red, meaning our tests have failed again. But notice the failure is on a different line—line 20 instead of line 19. Our test for >D00 passed, but 53`arej did not. You may have expected this, since our new regular expression wasn’t sophisticated enough to reject usernames that begin with numeric digits, and our test case 53`arej slipped through.

Figure 7-10. Rerunning our test case to see if we’ve made progress

229


230

CH APT ER 7 N UNIT TES TING A ND W EB TES TING

Let’s tweak our r]he`Qoanj]ia$% method one more time and see if we can get it to behave as expected. We’ll change the regular expression from +ZW=)V])v,)5Y' + to +ZW=)V])vY W=)V])v,)5Y+$/, as shown in Listing 7-12. This requires the first character of the username to be a letter, while any subsequent character can be a letter or a number. This also implies that our username must be at least two characters long, which is fine. Listing 7-12. Modified Regular Expression to Reject Usernames That Begin with a Number (in apps/models/accomplishment.php) -68;ldl .6 /6_h]oo=__kilheodiajpatpaj`o=llIk`ahw 06r]n j]ia9#=__kilheodiajp#7 16 26r]n r]he`]pa9]nn]u$ 36#pa]i[iai^an#9:]nn]u$ 46#nqha#9:]nn]u$#r]he`Qoanj]ia#%( 56#iaoo]ca#9:Ejr]he`Qoanj]ia -,6%( --6%7 -.6 -/6bqj_pekjr]he`Qoanj]ia$ `]p]%w -06napqnj$lnac[i]p_d$#+ZW=)V])vYW=)V])v,)5Y' +#( `]p]W#pa]i[iai^an#Y%%7 -16y -26y Refresh your browser again. Good news! Now all of the tests pass. We’re rewarded with a green bar stating “6 passes, 0 fails and 0 exceptions,” as shown in Figure 7-11.

Figure 7-11. Our tests now pass.


C H A P T E R 7 N U N I T T E S T I N G A N D W E B T E S T I N G

231

Unit testing gives us confidence that our r]he`Qoanj]ia method now functions exactly as it should.

Using Assert Methods Our unit tests used only two of about a dozen available ]ooanp& methods. Table 7-1 lists the ]ooanp& methods that you can use in your unit testing. Table 7-1. SimpleTest Assert Methods

Method

Description

]ooanp?hkja$" t(" uW( iaoo]ca9#!o#Y( t( u%

Asserts that t and u should be clones of each other, meaning they are identical but not the same object

]ooanpAmq]h$ t( uW( iaoo]ca9#!o#Y%

Asserts that t should be equal to u

]ooanpB]hoa$ tW( iaoo]ca9#!o#Y%

Asserts that t should be false

]ooanpE`ajpe_]h$ t( uW( iaoo]ca9#!o#Y%

Asserts that t and u should be identical, meaning they have the same value and are of the same type

]ooanpEo=$ k^fa_p( _h]ooW( iaoo]ca9#!o#Y%

Asserts that k^fa_p should be of class _h]oo

]ooanpJkL]ppanj$ nacat( oq^fa_pW( iaoo]ca9#!o#Y%

Asserts that no portion of oq^fa_p should match the regular expression

]ooanpJkp=$ k^fa_p( _h]ooW( iaoo]ca9#!o#Y%

Asserts that k^fa_p should not be of the class _h]oo

]ooanpJkpAmq]h$ t( uW( iaoo]ca9#!o#Y%

Asserts that t should not be equal to u

]ooanpJkpE`ajpe_]h$ t( uW( iaoo]ca9#!o#Y%

Asserts that t should not be identical to u, meaning it should either have a different value and/or be of a different type

]ooanpJkpJqhh$ tW( iaoo]ca9#!o#Y%

Asserts that t should not be null

]ooanpJqhh$ tW( iaoo]ca9#!o#Y%

Asserts that t should be null

]ooanpKqpoe`aI]ncej$ t( u( i]ncejW( iaoo]ca9#!o#Y%

Asserts that t and u should differ by more than i]ncej

]ooanpL]ppanj$ nacat( oq^fa_pW( iaoo]ca9#!o#Y%

Asserts that oq^fa_p should match the regular expression nacat

]ooanpNabanaj_a$" t(" uW( iaoo]ca9#!o#Y( t( u%

Asserts that t and u should both refer to (be pointers to) the same object

]ooanpPnqa$ tW( iaoo]ca9b]hoaY%

Asserts that t should be true

]ooanpSepdejI]ncej$ t( u( i]ncejW( iaoo]ca9#!o#Y%

Asserts that t and u should be within i]ncej of each other

nacat


232

CH APT ER 7 N UNIT TES TING A ND W EB TES TING

Each ]ooanp method allows you to define an optional iaoo]ca to be displayed when the assertion fails. You can optionally use the placeholder !o in your message to display the default error details.

Testing the Entire MVC System The unit tests we wrote in the preceding example were for testing our model. But unit tests can also be written for testing controllers, views, plugins, and components. The process for testing controllers, plugins, and components is similar to the process of testing models. Testing views, on the other hand, is a different beast, and we’ll cover that in the next section.

Web Testing The SimpleTest library that powers Cake’s testing framework has a very cool web testing feature. It can simulate a user’s navigation through a web site, allowing you to test your views and make sure your web site is working properly “from the outside.” You might also call this a form of integration testing, since it can test the fitness and accuracy of the entire site, not just the individual units.

Creating Web Tests Let’s add a few web tests to our application, in ]ll+paopo+_]oao+ik`aho+]__kilheodiajp*paop* ldl, as shown in Listing 7-13. Listing 7-13. The Class AccomplishmentWebTestCase (in app/tests/cases/models/accomplishment. test.php) .06 .16_h]oo=__kilheodiajpSa^Paop?]oaatpaj`o?]gaSa^Paop?]oaw .26bqj_pekjpaopHkcejCkk`Qoanj]ia$%w .36pdeo):cap$#dppl6++_]galdl+]__kilheodiajpo+#%7 .46pdeo):oapBeah`$#pa]i[iai^an#(#Ne_d]n`#%7 .56pdeo):_he_g$#Hkcej#%7 /,6pdeo):]ooanpPatp$#Pa]i=__kilheodiajpo#%7 /-6pdeo):]ooanpPatp$#Iu=__kilheodiajpo#%7 /.6pdeo):]ooanpPatp$Kpdano#=__kilheodiajpo%7 //6y /06bqj_pekjpaopHkcej>]`Qoanj]ia$%w /16pdeo):cap$#dppl6++_]galdl+]__kilheodiajpo+#%7 /26pdeo):oapBeah`$#pa]i[iai^an#(#53`arej#%7 /36pdeo):_he_g$#Hkcej#%7 /46pdeo):]ooanpPatp$#Ejr]he`qoanj]ia#%7 /56y 0,6y


C H A P T E R 7 N U N I T T E S T I N G A N D W E B T E S T I N G

We define a class =__kilheodiajpSa^Paop?]oa, which extends ?]gaSa^Paop?]oa. The class contains two methods: paopHkcejCkk`Qoanj]ia will ensure that when we enter a valid username, we can log in, and paopHkcej>]`Qoanj]ia$% will ensure that when we enter an invalid username, we are denied access. You can probably guess what the code in Listing 7-13 does. In paopHkcejCkk`Qoanj]ia, we simulate a user going to the web site dppl6++_]galdl+]__kilheodiajpo+, entering Ne_d]n` into the pa]i[iai^an field, and clicking the Login button. We then assert that the resulting page contains three strings of text: Pa]i=__kilheodiajpo, Iu=__kilheodiajpo, and Kpdano# =__kilheodiajpo. The test could be more complex, but the presence of these three strings is likely to be a good indicator of whether the login was successful. In paopHkcej>]`Qoanj]ia, we repeat the same simulation, this time entering the username 53`arej, which we know to be unacceptable. We then test that the resulting page contains the text Ejr]he`qoanj]ia, which we expect when the user is unable to log in. Letâ&#x20AC;&#x2122;s run our tests again, by visiting the test page dppl6++_]galdl+paop*ldl, to see the results. As shown in Figure 7-12, we find that ten tests passed successfully, which include our six unit tests plus the four additional web tests weâ&#x20AC;&#x2122;ve just created.

Figure 7-12. Test results page after running our four web tests

233


234

CH APT ER 7 N UNIT TES TING A ND W EB TES TING

Web tests can be a powerful tool for ensuring that your web application is working correctly, in a holistic sense. With web tests, you can imitate the following user actions: Ê

UÊ ˆVŽˆ˜}ʏˆ˜ŽÃ]ÊVˆVŽˆ˜}ʈ“>}iÃ]Ê>˜`ÊÃÕL“ˆÌ̈˜}ÊvœÀ“Ã

Ê

UÊ ˆVŽˆ˜}Ê̅iÊL>VŽÊ>˜`ÊvœÀÜ>À`ÊLÕÌ̜˜Ã]Ê>˜`ÊÀivÀiň˜}Ê̅iÊ«>}i

Ê

UÊ -i˜`ˆ˜}Ê>˜`ÊV…iVŽˆ˜}ʅi>`iÀÃ

Ê

UÊ -i˜`ˆ˜}]ʈ}˜œÀˆ˜}]Ê>˜`ÊV…iVŽˆ˜}ÊVœœŽˆiÃ

Ê

UÊ œ}}ˆ˜}ʈ˜ÊÕȘ}Ê//*Ê>Õ̅i˜ÌˆV>̈œ˜

Ê

UÊ 1Ș}Ê>Ê«ÀœÝÞ

For a full list of available web testing methods, visit dppl6++sss*oeilhapaop*knc+]le+ OeilhaPaop+Sa^Paopan+Sa^Paop?]oa*dpih.

Web Testing Any Application One very cool aspect of the web testing framework, which may already be apparent to you, is that you can test any feature of any web site, not just Cake web sites or web sites you own. For example, imagine setting up tests to ensure that your legacy corporate web site is up and running, that the password protection is working, and that private areas of your site are not publicly accessible. You could set up a cron job to run the tests regularly and e-mail you when there are abnormalities. Listing 7-14 shows a hypothetical test for ensuring that the Wikipedia article on CakePHP mentions unit testing. As of this writing, unit testing is mentioned as a feature of CakePHP in the Wikipedia article. If this reference were ever removed, the following test would fail. Listing 7-14. A Hypothetical Test Case for Testing an External Web Site 0,6bqj_pekjpaopSegela`e]=npe_ha$%w 0-6pdeo):]``Da]`an$Qoan)=cajp6?]gaLDL+OeilhaPaop%7 0.6pdeo):cap$#dppl6++aj*segela`e]*knc+sege+?]galdl#%7 0/6pdeo):]ooanpPatp$#Qjeppaopejc#%7 006y

NCaution )FYOUUSE#AKESWEBTESTINGFEATURESTOTESTWEBSITESTHATYOUDONTOWN YOULLWANTTOMAKE sure you comply with their terms of usage.


C H A P T E R 7 N U N I T T E S T I N G A N D W E B T E S T I N G

Test-Driven Development Test-driven development is a form of agile development that requires unit tests to be written before writing application code. Writing the unit tests before the actual code requires developers to think carefully about what the application should do. It also requires thinking about development with an eye to modularity; each unit should do something distinct and uncoupled from other units. In fact, someone else on your team could be the one to write the unit tests, while you write the code, or vice versa. The ensuing communication and coordination would be healthy. Your lines of test code could easily outnumber your application code lines if you were to test every aspect of your application. This, of course, is not practical, nor is it smart business practice. You might consider writing tests only for the most important units of your code. What code might potentially cause the most damage if it were left to chance? Write unit tests for that code first. Also, as bugs are reported and fixed, write unit tests that ensure those bugs will not resurface in the future. This sort of testing is called regression testing, because it prevents your code from regressing to a prior, bug-laden state. Imagine if your home appliances were wired directly into the electrical system without using plugs and sockets. Moving a lamp to a new room would be a huge pain. You would need to cut the wire and resplice it. It’s much more convenient to use plugs and sockets. This also allows a separation of concerns; that is, if a lamp stops working, you can plug it into a different socket and see if it’s the lamp or the socket that failed. Likewise, when your code is modular and decoupled, you can easily move it, use it elsewhere, and test it. Unit testing encourages this sort of modularity.

Summary In this chapter, we have accomplished the following: Ê

UÊ Ài>Ìi`Ê>Êȓ«iÊÜiLÊ>««ˆV>̈œ˜ÊˆŽiÊ̅iÊÎÇÈ}˜>ÃʘÉ"ÕÌÊ>««ˆV>̈œ˜

Ê

UÊ ˜ÃÌ>i`Ê̅iÊ-ˆ“«i/iÃÌÊ՘ˆÌÊÌiÃ̈˜}ÊvÀ>“iܜÀŽ

Ê

UÊ i“œ˜ÃÌÀ>Ìi`ʅœÜÊ̜ÊÀ՘Ê̅iÊÊLՈÌ‡Êˆ˜Ê՘ˆÌÊÌiÃÌÃÊvœÀÊ >Ži

Ê

UÊ Ài>Ìi`ÊVÕÃ̜“Ê՘ˆÌÊÌiÃÌÃ

Ê

UÊ œ`ˆvˆi`Ê̅iÊ>««ˆV>̈œ˜ÊVœ`iÊ̜ʫ>ÃÃÊ՘ˆÌÊÌiÃÌÃ

Ê

UÊ Ài>Ìi`ÊÜiLÊÌiÃÌÃÊ>˜`ÊÀ՘Ê̅i“Ê>}>ˆ˜ÃÌÊ>ÊÜiLÊ>««ˆV>̈œ˜

Ê

UÊ i“œ˜ÃÌÀ>Ìi`ʅœÜÊÜiLÊÌiÃÌÃÊV>˜ÊLiÊÕÃi`Ê̜ÊÌiÃÌÊiÝÌiÀ˜>ÊÜiLÊÈÌiÃ

Ê

UÊ Ý«>ˆ˜i`Ê܅i˜Ê>˜`Ê܅ÞÊޜÕÊŜՏ`Ê`œÊ՘ˆÌÊÌiÃ̈˜}

Unit testing can be a powerful practice for ensuring that your application code works as you expect. It can catch errors before you release new code, and save you time and energy by freeing your mind of concern. Cheers to your newfound freedom!

235


C HAPTER

8

A Cake Control Panel L

et us first say that there is no such feature as a Cake Control Panel in CakePHP, which is why we are creating one in this chapter. Once you have developed several web sites, you will start to spot common functions that clients ask for time and again. Here are just some of the features clients typically request: Ê

UÊ LˆˆÌÞÊ̜ÊÕ«`>ÌiÊ̅iÊVœ˜Ìi˜ÌÊ̅i“ÃiÛiÃ

Ê

UÊ LˆˆÌÞÊ̜ʅ>ÛiÊ`ˆvviÀi˜ÌÊV>Ìi}œÀˆiÃʜvÊÕÃiÀÃ]Ê>˜`Ê>œÜʜ˜ÞÊViÀÌ>ˆ˜ÊÕÃiÀÃÊ̜ÊÕÃiÊ«>Àticular features of the site; for example, allow only registered users to access special promotions

Ê

UÊ LˆˆÌÞÊ̜ÊV…>˜}iÊ̅iÊÜiLÊÈÌiÊVœ˜vˆ}ÕÀ>̈œ˜Ê̅i“ÃiÛiÃ

Ê

UÊ LˆˆÌÞÊ̜ÊۈiÜÊ>««ˆV>̈œ˜ÊÃÌ>̈Ã̈VÃ]ÊÃÕV…Ê>ÃʘՓLiÀʜvÊÕÃiÀÃ]ʏ>ÃÌʏœ}ˆ˜]Ê>˜`ÊÜʜ˜

If your clients haven’t asked for these functions yet, you can always turn them off temporarily, or maybe increase your income by selling them these extra cool features! Developing a control panel for yourself makes a lot of sense. The same control panel can be used for different sites. You could say it's another form of the DRY principle. Security is a basic functionality to have in any web site and also one of the most complex. If you’re going to add a back-end administration area, or a control panel as we are calling it, this will be one of the functions that will be developed first. In this chapter, we’re just going to start the development of the control panel by writing a web-based front end that will allow a user to manage user security. Feel free to use the code in this chapter as a base for your own projects. We’ll use several different Cake features, including the authentication (=qpd) and access control list (=_h®ÊVœ“«œ˜i˜ÌÃ]Ê>˜`Ê̅iÊVÊ behavior, which also uses the Tree behavior.

Application Requirements The security management function we are building in the control panel will have the following functions: Ê

UÊ LˆˆÌÞÊ̜Ê>``]Êi`ˆÌ]Ê`iiÌi]Ê>˜`ÊۈiÜÊÕÃiÀ

Ê

UÊ LˆˆÌÞÊ̜Ê>``]Êi`ˆÌ]Ê`iiÌi]Ê>˜`ÊۈiÜÊ`ˆvviÀi˜ÌÊÕÃiÀÊ}ÀœÕ«Ã]ÊÃÕV…Ê>ÃÊ>`“ˆ˜ˆÃÌÀ>̜ÀÃÊ>˜`Ê ordinary users

Ê

UÊ LˆˆÌÞÊ̜Ê`i˜ÞʜÀÊ>œÜÊ>ÊÕÃiÀʜÀÊ}ÀœÕ«Ê>VViÃÃÊ̜ÊVœ˜ÌÀœiÀÊ>V̈œ˜Ã 237


238

CH APT ER 8 N A C A K E C ONTR OL P A NEL

The Authentication and ACL Components We’ll start by talking a little about both the =qpd and =_h components, and then we’ll show you how we have combined them. We will warn you that although Cake’s authentication component is easy to use, the access control list component is not that straightforward. However, using it is still much easier than writing the access-control code from scratch.

The Authentication Component The reason for the =qpd component is simple. It controls the login process and further controls access to controller actions. You can allow or deny access to certain actions using the component’s ]hhks and `aju methods, but not on a per-user basis. What the =qpd component doesn’t do is provide more granular access control between any one user and controller actions. This is where Cake’s =_h component comes in. To get started with the =qpd component, you will first need a qoano table. The one for this chapter’s application is shown in Listing 8-1. Listing 8-1. The users Table Schema ?NA=PAP=>HA\qoano\$ \e`\ejp$--%JKPJQHH]qpk[ej_naiajp( \qoanj]ia\r]n_d]n$.11%JKPJQHH( \l]ooskn`\r]n_d]n$.11%JKPJQHH( \cnkql[e`\ejp$--%JKPJQHH( LNEI=NUGAU$\e`\% % The first three fields—e`, qoanj]ia, and l]ooskn`—are mandatory for the =qpd component. The l]ooskn` field is a hashed field. We have included the cnkql[e` field because we’ll be adding user groups as well, so we can categorize users into groups.

The Access Control List Component Cake’s =_h component is a generic way to control the access rights between one entity and >˜œÌ…iÀÊi˜ÌˆÌްʘÊi˜ÌˆÌÞÊV>˜ÊÀi«ÀiÃi˜ÌÊ>“œÃÌÊ>˜Þ̅ˆ˜}ÊޜÕÊÜ>˜Ì]ÊLÕÌÊÕÃÕ>ÞʈÌÊ܈ÊLiÊÕÃiÀÃ]Ê user groups, and controller actions. For example, you can allow every developer access to a controller action, except for the new junior developer who just joined the team. The security permissions between entities can be stored either in a text file in ]ll+_kjbec+ ]_h*eje*ldl or in a database. Here, we’re just going to cover database storage, so we need to create the tables to store the permissions. One way to create the database tables required by the =_h component is to use the _]ga command to do this automatically. To take this approach, in your command-line environment, go to your ]ll folder and run the following command: _]ga]_hejep`^


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

This will create three database tables: Ê

UÊ ]_ko6 This table holds the access control objects, which are the entities to be controlled, such as actions.

Ê

UÊ ]nko: This table stores the access request objects, which are the entities that request access, such as users or groups.

Ê

UÊ ]nko[]_ko: This is the link table between the ]_ko and ]nkoÊÌ>LiðʘÊ]_ko object (for example, a controller action) can be accessed by many ]nko objects (such as users). Conversely, an ]nko object (such as a user) can have access to many ]_ko objects (such as controller actions).

If you want to create the tables manually, you can do that using the SQL statements in Listings 8-2, 8-3, and 8-4. Listing 8-2. The acos Acl Table Schema ?NA=PAP=>HA\]_ko\$ \e`\ejp$-,%JKPJQHH]qpk[ej_naiajp( \l]najp[e`\ejp$-,%`ab]qhpJQHH( \ik`ah\r]n_d]n$.11%`ab]qhpJQHH( \bknaecj[gau\ejp$-,%`ab]qhpJQHH( \]he]o\r]n_d]n$.11%`ab]qhpJQHH( \hbp\ejp$-,%`ab]qhpJQHH( \ncdp\ejp$-,%`ab]qhpJQHH( LNEI=NUGAU$\e`\% %

Listing 8-3. The aros Table Schema ?NA=PAP=>HA\]nko\$ \e`\ejp$-,%JKPJQHH]qpk[ej_naiajp( \l]najp[e`\ejp$-,%`ab]qhpJQHH( \ik`ah\r]n_d]n$.11%`ab]qhpJQHH( \bknaecj[gau\ejp$-,%`ab]qhpJQHH( \]he]o\r]n_d]n$.11%`ab]qhpJQHH( \hbp\ejp$-,%`ab]qhpJQHH( \ncdp\ejp$-,%`ab]qhpJQHH( LNEI=NUGAU$\e`\% %

239


240

CH APT ER 8 N A C A K E C ONTR OL P A NEL

Listing 8-4. The aros_acos Table Schema ?NA=PAP=>HA\]nko[]_ko\$ \e`\ejp$-,%JKPJQHH]qpk[ej_naiajp( \]nk[e`\ejp$-,%JKPJQHH( \]_k[e`\ejp$-,%JKPJQHH( \[_na]pa\r]n_d]n$.%JKPJQHH`ab]qhp#,#( \[na]`\r]n_d]n$.%JKPJQHH`ab]qhp#,#( \[ql`]pa\r]n_d]n$.%JKPJQHH`ab]qhp#,#( \[`ahapa\r]n_d]n$.%JKPJQHH`ab]qhp#,#( LNEI=NUGAU$\e`\% % The ]_ko and ]nko records are stored using Cakeâ&#x20AC;&#x2122;s own Tree behavior, which uses a binary tree data structure to store hierarchical data. One node (a record in our case) can have two children (records) below it, sometimes called the left branch and right branch. In turn, any one record can have a parent. Tables 8-1, 8-2, and 8-3 describe the important fields in each of these tables. Table 8-1. The acos Table Columns

Column

Description

l]najp[e`

ID of the parent ]_ko record

ik`ah

Model name of the entity

bknaecj[gau

Foreign key to the model record ID

]he]o

Unique name to identify the record

hbp

ID of the left branch of the record

ncdp

ID of the right branch of the record

Table 8-2. The aros Table Columns

Column

Description

l]najp[e`

ID of the parent ]nko record

ik`ah

Model name of the entity, which is normally Qoan or Cnkql

bknaecj[gau

Foreign key to the model record ID, which is normally the ID of the user or group record

]he]o

Unique name to identify the record

hbp

ID of the left branch of the record

ncdp

ID of the right branch of the record


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

Table 8-3. The aros_acos Table Columns

Column

Description

]nk[e`

Foreign key to the ]nko record ID

]_k[e`

Foreign key to the ]_ko record ID

[_na]pa

Controls access to the ]`` action—either 1 or 0

[na]`

Controls access to the ej`at or reas action—either 1 or 0

[ql`]pa

Controls access to the a`ep action—either 1 or 0

[`ahapa

Controls access to the naikra action—either 1 or 0

Component Setup To start using the =qpd and =_h components, we need to declare their use. This is done in the global =ll?kjpnkhhan file, ]ll+]ll[_kjpnkhhan*ldl, which is shown in Listing 8-5. Listing 8-5. Auth and Acl Components in the AppController Class (app/app_controller.php) -6_h]oo=ll?kjpnkhhanatpaj`o?kjpnkhhanw .6 /6r]n l]caPepha9#?d]lpan4)Pda?]ga?kjpnkhL]jah#7 06 16r]n _kilkjajpo9]nn]u$#=qpd#(#=_h#%7 26 36bqj_pekj^abknaBehpan$%w 46 56pdeo):=qpd):]qpdkneva9#]_pekjo#7 -,6 --6pdeo):=qpd):]qpdAnnkn9#Ukq`kjkpd]ralanieooekjpk]__aoo -.6pdal]caukqfqopoaha_pa`*#7 -/6 -06pdeo):=qpd):hkcejNa`ena_p9]nn]u$#_kjpnkhhan#9:£ #?kjpnkhL]jah#( -16#]_pekj#9:#ej`at#%7 -26y -36 -46y We include the two components on line 5. There is also a ^abknaBehpan, which is called before any other action. In it, we specify some =qpd settings. The ]qpdkneva parameter on line 9 is set to ]_pekjo. This parameter controls how a user is authorized. Setting it to ]_pekjo means we want the =_h component to authenticate the user for us automatically based on the entries in the qoano table. The ]qpdkneva parameter can also be set to _kjpnkhhan, _nq`, ]nn]u, or k^fa_p, as shown in Table 8-4.

241


242

CH APT ER 8 N A C A K E C ONTR OL P A NEL

Table 8-4. Settings for the authorize Parameter in the Auth Component

Values

Description

_kjpnkhhan

Defines an eo=qpdkneva` action in your controller; the user is authenticated depending on whether the function returns pnqa or b]hoa

]_pekjo

Uses the =_h’s _da_g method to authenticate users

_nq`

ÃœÊÕÃiÃÊ̅iÊ=_h’s _da_g method to authenticate users

]nn]u$#ik`ah#9:#j]ia#%

Defines an eo=qpdkneva (note no ` at the end) action in another model

k^fa_p

Uses the eo=qpdkneva` method in your own object to authenticate the user

The ]qpdAnnkn parameter on line 11 of Listing 8-5 is what gets displayed when a user does not have permission to view a controller action. The hkcejNa`ena_p parameter on line 14 specifies the URL to redirect the user to once a user has logged in.

Control Panel Application Controllers We will be using five different controllers in our application, as shown in Table 8-5. Table 8-5. The Controllers Used in Our Control Panel Application

Controller

Description

=_pekjo?kjpnkhhan

Manages which of our controller actions will be security-managed

Cnkqlo?kjpnkhhan

Manages user groups

Qoano?kjpnkhhan

Manages users

?kjpnkhL]jah?kjpnkhhan

Base controller for our application

Se`capo?kjpnkhhan

Sample controller to demonstrate the access control list security

The first three controllers are essential for the working of the application; the last two are mainly used to demonstrate our application. Now we’ll look at each controller, starting with the base control panel controller.

The Control Panel Controller The ?kjpnkhL]jah?kjpnkhhan, shown in Listing 8-6, is the base class for the application. It contains the first public page of the application.


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

Listing 8-6. Control Panel Controller ( app/controllers/control_panel_controller.php) -68;ldl .6 /6_h]oo?kjpnkhL]jah?kjpnkhhanatpaj`o=ll?kjpnkhhanw 06 16r]n j]ia9#?kjpnkhL]jah#7 26r]n dahlano9]nn]u$#Dpih#(#Bkni#%7 36 46r]n qoao9]nn]u$#Qoan#%7 56 -,6bqj_pekj^abknaBehpan$%w --6 -.6++Lq^he_]__aoo]_pekjo -/6pdeo):=qpd):]hhks$#sah_kia#%7 -06y -16 -26++Lq^he_sah_kial]cakb_kjpnkhl]jah -36bqj_pekjsah_kia$%w -46 -56++?da_gebpdapailkn]nuqoanateopo .,6 pilQoan9pdeo):Qoan):bej`>uQoanj]ia$#pail#%7 .-6 ..6eb$ailpu$ pilQoan%%w ./6 .06pdeo):Qoan):_na]pa$%7 .16pdeo):Qoan):o]ra$]nn]u$#qoanj]ia#9:#pail#( .26#l]ooskn`#9:£ Oa_qnepu66d]od$#pail#(jqhh(pnqa%%%7 .36y .46y .56 /,6++L]casdajhkcca`ej /-6bqj_pekjej`at$%w /.6 //6y /06 /16y /26;: On line 13, we explicitly allow access to the sah_kia action. If you use an asterisk symbol, all actions will be accessible. Within the sah_kia action itself, we set up a temporary user, since we’re starting off without any entries in the database tables. From line 20 onward, if we can’t find a user called pail, we create a user called pail with the password pail. The welcome screen of the control panel is shown in Figure 8-1.

243


244

CH APT ER 8 N A C A K E C ONTR OL P A NEL

Figure 8-1. The control panel welcome screen

The Actions Controller The actions controller is used to manage the access control objectsâ&#x20AC;&#x201D;essentially, the controller actions that need security management. We can add or delete which functions within the whole application a user can or cannot access. This controller is shown in Listing 8-7. Listing 8-7. Actions Controller (app/controllers/actions_controller.php) -68;ldl .6_h]oo=_pekjo?kjpnkhhanatpaj`o=ll?kjpnkhhanw /6 06r]n j]ia9#=_pekjo#7 16r]n dahlano9]nn]u$#Dpih#(#Bkni#%7 26 36bqj_pekj^abknaBehpan$%w 46 56++Sajaa`pkpailkn]nehu]hhks]__aoo`qnejcpdaoapql -,6pdeo):=qpd):]hhks$#ej`at#%7 --6y -.6 -/6++=``]j`naikra_kjpnkhhan]_pekjobkn=_k -06bqj_pekjej`at$%w -16 -26eb$ailpu$ pdeo):`]p]%%w -36 -46pdeo):[[lnk_aoo=_pekjo$%7 -56y .,6 .-6pdeo):[[heop=_pekjo$%7 ..6y ./6


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

.06++=``kn`ahapa]_pekjo .16bqj_pekj[[lnk_aoo=_pekjo$%w .26 .36 oa_qnepu=__aoo9pdeo):`]p]W#=_pekjo#YW#Oa_qnepu=__aoo#Y7 .46 .56 ejbha_p9jasEjbha_pkn$%7 /,6 /-6bkna]_d$ oa_qnepu=__aoo]o j]ia[l]en[gau9: ]__aoo[oaha_pekj%w /.6 //6 j]ia[l]en9atlhk`a$[[( j]ia[l]en[gau%7 /06 /16 _kjpnkhhan9ejbha_p):oejcqh]neva$ j]ia[l]enW,Y%7 /26 ]_pekj9 j]ia[l]enW-Y7 /36 /46eb$ ]__aoo[oaha_pekj99#`ahapa#%w /56 0,6 ]_k9jas=_k$%7 0-6 0.6 ]_k[na_kn`9]_k):bej`$]nn]u$ 0/6=_k*ik`ah9: _kjpnkhhan( 006=_k*]he]o9: ]_pekj%%7 016 026eb$ailpu$ ]_k[na_kn`%%w 036 046 `ahapa[e`9 ]_k[na_kn`W#=_k#YW#e`#Y7 056pdeo):=_pekj):=_k):@ahapa$ `ahapa[e`%7 1,6y 1-6y 1.6ahoaeb$ ]__aoo[oaha_pekj99#ej_hq`a#%w 1/6 106 l]najp[e`9#,#7 116 126++Bej`pdal]najp*Ebjkl]najp(sa_na]pakja 136 ]_k[l]najp9jas=_k$%7 146 ]_k[l]najp[na_kn`9]_k[l]najp):bej`$ 156]nn]u$=_k*ik`ah9: _kjpnkhhan( 2,6=_k*]he]o9: j]ia[l]enW,Y%%7 2-6 2.6eb$ailpu$ ]_k[l]najp[na_kn`%%w 2/6 206 ]_k[l]najp9jas=_k$%7 216 226]_k[l]najp):_na]pa$%7 236]_k[l]najp):o]ra$]nn]u$#ik`ah#9: _kjpnkhhan( 246#bknaecj[gau#9:##( 256#]he]o#9: j]ia[l]enW,Y( 3,6#l]najp[e`#9:## 3-6%%7 3.6

245


246

CH APT ER 8 N A C A K E C ONTR OL P A NEL

3/6 l]najp[e`9]_k[l]najp):e`7 306y 316ahoaw 326 336 l]najp[e`9 ]_k[l]najp[na_kn`W#=_k#YW#e`#Y7 346y 356 4,6++Jkshap#o_na]papda]_kna_kn`epoahb 4-6 ]_k9jas=_k$%7 4.6 4/6]_k):_na]pa$%7 406]_k):o]ra$]nn]u$#ik`ah#9: _kjpnkhhan( 416#bknaecj[gau#9:##( 426#]he]o#9: ]_pekj( 436#l]najp[e`#9: l]najp[e` 446%%7 456y 5,6y 5-6y 5.6 5/6bqj_pekj[[heop=_pekjo$%w 506 516++Cap]hhpda]_pekjoejpda_kjpnkhhano 526 536 ]_pekjo9]nn]u$%7 546 556=ll66eilknp$#Beha#(#Bkh`an#%7 -,,6 -,-6 bkh`an9jasBkh`an$=LL*#_kjpnkhhano+#%7 -,.6 bkh`ano9bkh`an):bej`$%7 -,/6 -,06bkna]_d$ bkh`ano]o beha%w -,16 -,26eb$eo[beha$=LL*#_kjpnkhhano+#* beha%%w -,36 -,46 beha9jasBeha$=LL*#_kjpnkhhano+#* beha%7 -,56 beha[_kjpajpo9beha):na]`$%7 --,6beha):_hkoa$%7 ---6 --.6++Cappda_kjpnkhhanj]ia --/6 _h]oo[l]ppanj9#+_h]ooW])v=)V,)5Y&?kjpnkhhanÂŁ atpaj`o=ll?kjpnkhhan+#7 --06lnac[i]p_d$ _h]oo[l]ppanj( beha[_kjpajpo( i]p_dao%7 --16 _h]oo[j]ia[-9opn[nalh]_a$#_h]oo#(##( i]p_daoW,Y%7 --26 _h]oo[j]ia9opn[nalh]_a$ --36#?kjpnkhhanatpaj`o=ll?kjpnkhhan#( --46##( _h]oo[j]ia[-%7 --56


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

-.,6++Cappda]_pekjj]iao -.-6 l]ppanj9#+bqj_pekjW])v=)V,)5Y&X$+#7 -..6lnac[i]p_d[]hh$ l]ppanj( beha[_kjpajpo( i]p_dao%7 -./6 -.06++Jksc]pdan]_pekj`ap]ehopkcapdan -.16 ]_pekj[cnkql9]nn]u$%7 -.26 -.36 ejbha_p9jasEjbha_pkn$%7 -.46 _h]oo[j]ia[oejc9ejbha_p):oejcqh]neva$ _h]oo[j]ia%7 -.56 -/,6 ]_pekj[cnkqlW#j]ia#Y9 _h]oo[j]ia7 -/-6 ]_pekj[cnkqlW#j]ia[oejcqh]n#Y9 _h]oo[j]ia[oejc7 -/.6 ]_pekj[cnkqlW#]_pekjo#Y9 i]p_daoW,Y7 -//6 -/06 ]_pekjoWY9 ]_pekj[cnkql7 -/16y -/26y -/36 -/46pdeo):oap$#]_pekjo#( ]_pekjo%7 -/56 -0,6++Cappdabqhhheopkb=_kna_kn`o -0-6 ]_k9jas=_k$%7 -0.6 -0/6 ]_k[heop9]_k):bej`$#]hh#%7 -006 -016 naoqhp9]nn]u$%7 -026 -036 ejbha_p9jasEjbha_pkn$%7 -046 -056bkna]_d$ ]_k[heop]o _qnnajp[]_k%w -1,6 -1-6 gau[,9 _qnnajp[]_kW#=_k#YW#ik`ah#Y7 -1.6 gau[-9 _qnnajp[]_kW#=_k#YW#]he]o#Y7 -1/6 -106 naoqhpW gau[,*#[[#* gau[-Y9 _qnnajp[]_k7 -116y -126 -136pdeo):oap$#]_k[heop#( naoqhp%7 -146y -156y -2,6;: The only action in this controller is the ej`at action. Figure 8-2 shows the page produced by this listing.

247


248

CH APT ER 8 N A C A K E C ONTR OL P A NEL

Figure 8-2. The index action in the actions controller


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

In the Cake =qpd component, if you set the ]qpdkneva parameter to _nq`, Cake assumes you have all the CRUD (create, read, update, and delete) actions in your controller: ej`at, ]``, a`ep, `ahapa, and reas. Cake will security-manage these actions for you using the fields [_na]pa, [na]`, [ql`]pa, and [`ahapa in the ]nko[]_ko table. However, when you set the parameter to ]_pekjo, as we have for this application, you can security-manage any actions in your controller. Essentially, the ]_pekjo value is more generic than the _nq` value in terms of the =qpd security. When the ]qpdkneva parameter is set to ]_pekjo, the ]_ko table needs to be in a specific format, structured as follows: ?kjpnkhhan= =_pekj=_pekj. =_pekj/ *** ?kjpnkhhan> =_pekj=_pekj. =_pekj/ *** There are only two levels. The top level is always occupied by the controllers, and the second levels form the controller actions that belong to the controller. ÃÊ>˜ÊiÝ>“«i]ÊÃÕ««œÃiÊÜiÊÃiiVÌʜ˜ÞÊ̅iʏ>ÃÌÊ>V̈œ˜Êˆ˜Ê̅iÊVœ˜ÌÀœÊ«>˜iÊ­Êˆ}ÕÀiÊn‡Ó®]ÊLÞÊ V…iVŽˆ˜}Ê̅iÊܓiV̈œ˜ÊV…iVŽÊLœÝÊ՘`iÀÊ7ˆ`}iÌÃÊ>˜`ÊVˆVŽˆ˜}Ê̅iÊ-ÕL“ˆÌÊLÕÌ̜˜°Ê/…ˆÃÊ܈Ê generate the entries in the ]_ko table shown in Figure 8-3.

Figure 8-3. The acos table entries after choosing the someAction action Now that you’ve seen how the actions controller works, the code in Listing 8-7 will be easier to understand. On line 10, we temporarily allow access to the ej`at action; otherwise, we wouldn’t be able to use it. The ej`at action is fairly simple. It has two private methods: [[heop=_pekjo and [[lnk_aoo=_pekjo. The [[heop=_pekjo action lists the actions available. The code for that starts on line 93. We use Cake’s Beha and Bkh`an convenience classes to get all the PHP files in the controller folder, and carry out a lnac[i]p_d operation on the content of the files, matching controller names and action names. The following is a sample of the HTML code for the check boxes in Figure 8-2: 8ejlqppula9_da_g^kt j]ia9`]p]W=_pekjoYWOa_qnepu=__aooYWSe`capo[[okia=_pekjY h]^ah9 `er9 r]hqa9ej_hq`a e`9=_pekjoOa_qnepu=__aooSe`capoOkia=_pekj+:

249


250

CH APT ER 8 N A C A K E C ONTR OL P A NEL

The j]ia attribute in this HTML code gives you an idea of the format of the data that will be returned to the action’s [[lnk_aoo=_pekjo method via the ej`at action. The [[lnk_aoo=_pekjo method is responsible for adding and deleting entries in the ]_ko Ì>Li°Ê}>ˆ˜]Ê>ÃÃՓˆ˜}ÊÜiÊÃiiVÌÊ̅iʏ>ÃÌÊi˜ÌÀÞʈ˜Êʈ}ÕÀiÊn‡ÓʭܓiV̈œ˜®]Ê̅iÊVœ˜ÌÀœiÀÊ`>Ì>Ê will contain the following entry: =nn]u $ W=_pekjoY9:=nn]u $ WOa_qnepu=__aooY9:=nn]u $ W=_pekjo[[^abknaBehpanY9:, W=_pekjo[[ej`atY9:, W?kjpnkhL]jah[[^abknaBehpanY9:, W?kjpnkhL]jah[[sah_kiaY9:, W?kjpnkhL]jah[[ej`atY9:, W?kjpnkhL]jah[[`]od>k]n`Y9:, WCnkqlo[[^abknaBehpanY9:, WCnkqlo[[]``Y9:, WCnkqlo[[a`epY9:, WCnkqlo[[oa_qnepuY9:, WCnkqlo[[ej`atY9:, WCnkqlo[[reasY9:, WCnkqlo[[`ahapaY9:, WQoano[[^abknaBehpanY9:, WQoano[[hkcejY9:, WQoano[[hkckqpY9:, WQoano[[a`epY9:, WQoano[[oa_qnepuY9:, WQoano[[ej`atY9:, WQoano[[reasY9:, WQoano[[]``Y9:, WQoano[[`ahapaY9:, WSe`capo[[okia=_pekjY9:ej_hq`a % % % Once the form has been submitted, the function [[lnk_aoo=_pekjo on line 25 kicks in. We start on line 31 by looping through the whole action list in the `]p] variable. Each entry is composed of a name/value pair in the following format: W_kjpnkhhanY[[W]_pekjY9:Woa_qnepu[r]hqaY In our example, the value is as follows: WSe`capo[[okia=_pekjY9:ej_hq`a


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

This tells us that the user wants to add the okia=_pekj action in the widgets controller into the ]_ko table, so the user can allow or deny access to certain users or groups. On line 38, if the user has selected to delete the ]_ko entry, we simply find the ]_ko entry and delete it using the model’s `ahapa method. If the user has decided to add the entry, we first check whether the controller parent record exists. If it doesn’t, we create one. If it does exist, we need the ID for the action entry. Both entries are shown in Figure 8-3. From line 141 onward, we fetch all the ]_koÊi˜ÌÀˆiÃÊvœÀÊ̅iÊۈiÜÊÜʈÌÊV>˜Ê`ˆÃ«>ÞÊ>˜Ê``Ê œÀÊ iiÌiÊV…iVŽÊLœÝ°ÊvÊ>˜Êi˜ÌÀÞÊ`œiؽÌÊi݈ÃÌ]ÊÜiÊ`ˆÃ«>ÞÊ>˜Ê``ÊV…iVŽÊLœÝ°ÊvÊ>˜Êi˜ÌÀÞÊ>Ài>`ÞÊ exists, we display a Delete check box, as shown in Figure 8-4.

Figure 8-4. The Delete check box option when the acos entry already exists To summarize, we now have one action called okia=_pekj in the widgets controller, which we can security-manage. If we didn’t add that entry in the ]_ko table, Cake’s =qpd component would always deny access to it, unless explicitly overridden by =qpd’s ]hhks method.

The Groups Controller The groups controller is an important element in our application. In Cake’s =_h component, we can control groups of users simply by changing the security on the group itself, rather than changing the security on every individual in that group. This is due to the fact that we can layer groups in a hierarchical fashion. For example, we can have a root administrator, and below that role, a department administrator, followed by department users. In the groups controller, we have the ability to list groups, add groups, edit groups, delete groups, and control the security access of groups. We start the development of the controller by using the ^]ga command to bake the code for the controller, model, and views. The code listing for the Cnkqlo?kjpnkhhan class is shown in Listing 8-8. Listing 8-8. Groups Controller (app/controllers/groups_controller.php) -68;ldl .6_h]ooCnkqlo?kjpnkhhanatpaj`o=ll?kjpnkhhanw /6 06r]n j]ia9#Cnkqlo#7 16r]n dahlano9]nn]u$#Dpih#(#Bkni#%7 26 36bqj_pekj^abknaBehpan$%w 46 56++Sajaa`pkpailkn]nehu]hhks]__aoo`qnejcpdaoapql -,6pdeo):=qpd):]hhks$#]``#(#ej`at#%7 --6y -.6

251


252

CH APT ER 8 N A C A K E C ONTR OL P A NEL

-/6bqj_pekj]``$%w -06 -16++Bkno]rejccnkql -26eb$ailpu$ pdeo):`]p]%%w -36pdeo):Cnkql):_na]pa$%7 -46eb$ pdeo):Cnkql):o]ra$ pdeo):`]p]%%w -56pdeo):Oaooekj):oapBh]od$£ [[$#PdaCnkqld]o^aajo]ra`#(pnqa%%7 .,6pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 .-6yahoaw ..6pdeo):Oaooekj):oapBh]od$[[$#PdaCnkql_kqh`jkp^a ./6o]ra`*Lha]oa(pnu]c]ej*#(pnqa%%7 .06y .16y .26 .36++Bknpdacnkqll]najpheopejc .46 cnkqlo9pdeo):Cnkql):bej`$#heop#%7 .56pdeo):oap$#l]najpo#( cnkqlo%7 /,6y /-6 /.6bqj_pekja`ep$ e`9jqhh%w //6 /06eb$ e`""ailpu$ pdeo):`]p]%%w /16pdeo):Oaooekj):oapBh]od$[[$#Ejr]he`Cnkql#(pnqa%%7 /26pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 /36y /46eb$ailpu$ pdeo):`]p]%%w /56eb$ pdeo):Cnkql):o]ra$ pdeo):`]p]%%w 0,6pdeo):Oaooekj):oapBh]od$£ [[$#PdaCnkqld]o^aajo]ra`#(pnqa%%7 0-6pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 0.6yahoaw 0/6pdeo):Oaooekj):oapBh]od$[[$#PdaCnkql_kqh`jkp^ao]ra`* 006Lha]oa(pnu]c]ej*#(pnqa%%7 016y 026y 036eb$ailpu$ pdeo):`]p]%%w 046pdeo):`]p]9pdeo):Cnkql):na]`$jqhh( e`%7 056y 1,6 1-6++Bknpdal]najpcnkql 1.6 cnkqlo9pdeo):Cnkql):bej`$#heop#%7 1/6pdeo):oap$#l]najpo#( cnkqlo%7 106y 116 126bqj_pekjoa_qnepu$ e`%w 136


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

146eb$ailpu$ pdeo):`]p]%%w 156 2,6++Hap#ocappda=nk(e*a*pdacnkql 2-6 ]nk[bknaecj[gau9pdeo):`]p]W#Cnkql#YW#e`#Y7 2.6 2/6 ]nk9jas=nk$%7 206 ]nk[na_kn`9]nk):bej`>u=he]o$#Cnkql6#* ]nk[bknaecj[gau%7 216 226 ]nk[]he]o9 ]nk[na_kn`W#=nk#YW#]he]o#Y7 236 ]_k[kb[]nk9 ]nk[na_kn`W#=_k#Y7 246 256++Hap#onqjpdnkqcdpdaoa_qnepuoaha_pekj 3,6 oa_[]__aoo9pdeo):`]p]W#Cnkql#YW#Oa_qnepu=__aoo#Y7 3-6 3.6 ]_k9jas=_k$%7 3/6 ejbha_p9jasEjbha_pkn$%7 306 316bkna]_d$ oa_[]__aoo]o ]_k[e`9: ]__aoo[pula%w 326 336 ]_k[na_kn`9]_k):bej`>uE`$ ]_k[e`%7 346 356 ik`ah[lhqn]h9ÂŁ ejbha_p):lhqn]heva$ ]_k[na_kn`W#=_k#YW#ik`ah#Y%7 4,6 4-6eb$ ]__aoo[pula99#]hhks#%w 4.6pdeo):=_h):]hhks$ ]nk[]he]o( 4/6 ik`ah[lhqn]h*#+#* ]_k[na_kn`W#=_k#YW#]he]o#Y(#&#%7 406y 416ahoaeb$ ]__aoo[pula99#`aju#%w 426pdeo):=_h):`aju$ ]nk[]he]o( 436 ik`ah[lhqn]h*#+#* ]_k[na_kn`W#=_k#YW#]he]o#Y(#&#%7 446y 456y 5,6y 5-6 5.6++Hap#oc]pdanpda]_koaha_pekjo]r]eh]^ha 5/6 ]_k9jas=_k$%7 506 516++Heoppdasdkhapnaa 526 ]_k[pnaa9]_k):cajan]paPnaaHeop$%7 536 546++Jkscappda`ap]ehokbpda=_kna_kn`o 556 ]_k[na_kn`o9]_k):bej`$#]hh#%7 -,,6 -,-6pdeo):oap$_kil]_p$#]_k[pnaa#(#]_k[na_kn`o#%%7 -,.6

253


254

CH APT ER 8 N A C A K E C ONTR OL P A NEL

-,/6pdeo):oap$#_qnnajp[]he]o#(£ pdeo):Cnkql):j]ia*#6#* pdeo):Cnkql):e`%7 -,06 -,16eb$ailpu$ pdeo):`]p]%%w -,26pdeo):`]p]9pdeo):Cnkql):na]`$jqhh( e`%7 -,36y -,46y -,56 --,6++Pdabkhhksejcs]o^]ga` ---6 --.6bqj_pekjej`at$%w --/6pdeo):Cnkql):na_qnoera9,7 --06pdeo):oap$#cnkqlo#(pdeo):l]cej]pa$%%7 --16y --26 --36bqj_pekjreas$ e`9jqhh%w --46eb$ e`%w --56pdeo):Oaooekj):oapBh]od$[[$#Ejr]he`Cnkql*#(pnqa%%7 -.,6pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 -.-6y -..6pdeo):oap$#cnkql#(pdeo):Cnkql):na]`$jqhh( e`%%7 -./6y -.06 -.16bqj_pekj`ahapa$ e`9jqhh%w -.26eb$ e`%w -.36pdeo):Oaooekj):oapBh]od$[[$#Ejr]he`e`bknCnkql#(pnqa%%7 -.46pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 -.56y -/,6eb$ pdeo):Cnkql):`ah$ e`%%w -/-6pdeo):Oaooekj):oapBh]od$[[$#Cnkql`ahapa`#(pnqa%%7 -/.6pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 -//6y -/06y -/16 -/26y -/36;: When we first ran the application, we found ourselves in a catch-22 scenario: we couldn’t log in because there were no users, but we had to log in to create a user. Of course, you can “>˜Õ>Þʈ˜ÃiÀÌÊi˜ÌÀˆiÃʈ˜ÌœÊ̅iÊ`>Ì>L>ÃiÊÕȘ}Ê>Ê̜œÊˆŽiÊ«…«Þ`“ˆ˜]ÊLÕÌÊÜiÊÜ>˜Ìi`ÊÌœÊ automate processes as much as possible. So initially, we allow access to actions without the user needing to log in. This is done on line 10 in Listing 8-8. The a`ep action beginning on line 32 is mostly based on baked code, with the exception of lines 52 and 53, which generate the parent drop-down list for the current group. This a`ep action follows the same pattern as the ]`` action beginning on line 13, except on line 48, where we need to read the record into the `]p] controller variable to be used in the edit form.


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

Adding a Group We need to add some more lines of code into the model in order to get Cakeâ&#x20AC;&#x2122;s =_h component to work. Listing 8-9 shows the Cnkql model. Listing 8-9. Group Model Class (app/models/group.php) -68;ldl .6_h]ooCnkqlatpaj`o=llIk`ahw /6 06r]n j]ia9#Cnkql#7 16 26r]n ]_po=o9]nn]u$#=_h#9:#namqaopan#%7 36 46r]n d]oI]ju9]nn]u$ 56#Qoan#9:]nn]u$#_h]ooJ]ia#9:#Qoan#( -,6#bknaecjGau#9:#cnkql[e`#( --6#`alaj`ajp#9:b]hoa( -.6#_kj`epekjo#9:##( -/6#beah`o#9:##( -06#kn`an#9:##( -16#heiep#9:##( -26#kbboap#9:##( -36#at_hqoera#9:##( -46#bej`anMqanu#9:##( -56#_kqjpanMqanu#9:## .,6% .-6%7 ..6 ./6r]n r]he`]pa9]nn]u$#pepha#9:R=HE@[JKP[AILPU%7 .06 .16bqj_pekj]bpanO]ra$ _na]pa`%w .26 .36eb$ _na]pa`%w .46 .56++Ep#o]_na]pekj /,6 /-6 e`9pdeo):capH]opEjoanpE@$%7 /.6 //6 ]nk9jas=nk$%7 /06 /16]nk):ql`]pa=hh$]nn]u$#]he]o#9:#X#Cnkql6#* e`*#X##%( /26]nn]u$#=nk*ik`ah#9:#Cnkql#( /36#=nk*bknaecj[gau#9: e`% /46%7 /56y 0,6ahoaw 0-6

255


256

CH APT ER 8 N A C A K E C ONTR OL P A NEL

0.6++Ep#o]ja`ep7sad]rapkql`]papdapnaa 0/6 `]p]9pdeo):na]`$%7 006 l]najp[e`9 `]p]W#Cnkql#YW#l]najp[e`#Y7 016 026 ]nk9jas=nk$%7 036 046 ]nk[na_kn`9]nk):bej`>uBknaecjGau$pdeo):e`%7 056 l]najp[na_kn`9]nk):bej`>uBknaecjGau$ l]najp[e`%7 1,6 1-6eb$ailpu$ ]nk[na_kn`%%w 1.6 1/6++Knld]ja`_deh` 106pdeo):=nk):o]ra$]nn]u$ 116#ik`ah#9:pdeo):j]ia( 126#bknaecj[gau#9:pdeo):e`( 136#]he]o#9:pdeo):j]ia*#6#* pdeo):e`( 146#l]najp[e`#9: l]najp[na_kn`W#=nk#YW#e`#Y 156%%7 2,6y 2-6ahoaw 2.6 2/6++Fqopikrejcjk`ao 206pdeo):=nk):o]ra$]nn]u$ 216#ik`ah#9:pdeo):j]ia( 226#bknaecj[gau#9:pdeo):e`( 236#]he]o#9:pdeo):j]ia*#6#* pdeo):e`( 246#l]najp[e`#9: l]najp[na_kn`W#=nk#YW#e`#Y( 256#e`#9: ]nk[na_kn`W#=nk#YW#e`#Y 3,6%%7 3-6y 3.6y 3/6 306napqnjpnqa7 316y 326 336bqj_pekjl]najpJk`a$%w 346 356++Pdeoodkqh`^apda]he]okbpdal]najp ik`ah66 e` 4,6 `]p]9pdeo):na]`$%7 4-6 4.6++Pdeojaa`opk^aqjemqa 4/6napqnj#Cnkql6#* `]p]W#Cnkql#YW#l]najp[e`#Y7 406y 416y 426;: "˜Êˆ˜iÊÈʈ˜ÊʈÃ̈˜}Ên‡™]ÊÜiÊ>``Ê̅iÊVÊLi…>ۈœÀ]Ê«ÀœÛˆ`ˆ˜}ʈÌÊ܈̅Ê̅iÊnamqaopan parameter value so it knows the Cnkql model is an =nk entity. This behavior automatically deals with the ]_ko and ]nko entries. However, it doesn’t quite do everything we need.


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

/…iÊVÊLi…>ۈœÀÊ>Õ̜“>̈V>ÞÊ>``ÃÊ>˜Êi˜ÌÀÞʈ˜ÌœÊ̅iÊ]nko table when we create a group by using the model’s o]ra method. Unfortunately, we need to update the entry with some additional details in order to get the =_h component to work properly, as follows: Ê

UÊ vÌiÀÊ>ʘiÜÊ]nko record has been created via the o]ra method, we need to update the ]he]o field because the =_h component sometimes uses this field as a unique field when fetching nodes. The format of the ]he]o field will be Cnkql6Wcnkql[e`Y, as shown in line 35 in Listing 8-9.

Ê

UÊ 7…i˜Ê>˜Êi݈Ã̈˜}ÊÀiVœÀ`ʈÃÊLiˆ˜}Êi`ˆÌi`Ê>˜`ÊÃ>Ûi`]ÊÜiʘii`Ê̜ʓ>˜Õ>ÞÊÕ«`>ÌiÊ̅iÊ l]najp[e` field in the ]nko table as well.

We also need to include the l]najpJk`aʓi̅œ`Ê܅i˜ÊÕȘ}Ê̅iÊVÊLi…>ۈœÀ°ÊÌʘii`ÃÊ to return the ]he]o value of the parent ]nko record. Each group can have only another group entity as a parent, so the parent ]he]o value will always be in the format Cnkql6Wcnkql[e`Y. Line 25 in Listing 8-9 starts the ]bpanO]ra operation. If it’s a new record, we update the ]he]o field with the unique string format Cnkql6Wqoan[e`Y. If it’s an edit, we face a special scenario unique to the groups controller: if the parent was previously deleted, the children may have pari˜ÌÊ ÃÊ«œˆ˜Ìˆ˜}Ê̜ʘœ˜i݈ÃÌi˜ÌÊÀiVœÀ`ÃÆÊ̅>ÌʈÃ]Ê̅iÞÊ>ÀiʜÀ«…>˜i`°Ê/…iÊVÊLi…>ۈœÀÊ`œiÃʘœÌÊ automatically reassign orphaned children, so we must do that ourselves. The code between lines 40 and 71 in Listing 8-9 takes care of that scenario. Within that section of code, we also deal with the case of simply changing the parent; see line 64. It’s worth noting that the Tree behavior will automatically adjust the other groups accordingly only when we are moving parents.

Group Security The other important action in the groups controller is the oa_qnepu action. To explain this action, it’s better to start from the group listing, as shown in the example in Figure 8-5.

Figure 8-5. The index action in the GroupController

257


258

CH APT ER 8 N A C A K E C ONTR OL P A NEL

In Figure 8-5, you can see a Security link next to a group record. We simply added the new link into the baked view of the ej`at action. When users click the Security link, they will be able to control the security settings relating to the group. Figure 8-6 shows the security page.

Figure 8-6. The security action in the GroupController When you first bring up the security page, it will list all the access control objects that you can security-manage. In our case, it will list only the okia=_pekj action. This is handled from line 92 onward in Listing 8-8. The =_k class has a method called cajan]paPnaaHeop, which generates the hierarchy of the tree. We also need the entire ]_ko entry in order to know which actions have been granted and which ones have been denied. "˜ViÊ>ÊÕÃiÀʅ>ÃÊÃiiVÌi`ʏœÜʜÀÊ i˜Þ]ÊÜiÊ«ÀœViÃÃÊ̅iÊi˜ÌÀÞÊvÀœ“ʏˆ˜iÊxnʜ˜Ü>À`ʜvÊ Listing 8-8. It’s similar to adding actions in the actions controller. We loop through the selec̈œ˜°ÊvÊ>ÊÕÃiÀʅ>ÃÊÃiiVÌi`ʏœÜ]ÊÜiÊÕÃiÊ̅ˆÃÊVœ““>˜`\ pdeo):=_h):]hhks$W]nk[]he]oY(#Wik`ah[lh]qn]hY+W]_k[]he]oY#(#&#%7 If a user has selected Deny, we use this command: pdeo):=_h):`aju$W]nk[]he]oY(#Wik`ah[lh]qn]hY+W]_k[]he]oY#(#&#%7 In both the ]hhks and `aju methods, we are specifying a security relationship between the ]nko record and the ]_ko record. The & is the standard value to use if the ]qpdkneva parameter is set to ]_pekjo. If it were set to _nq`, then you could specify which CRUD action to security-manage. But with the ]_pekjo setting (sometimes called actions mode), the CRUD database columns must be all 1 values, all 0 values, or –1 values. In Listing 8-8, the ej`at, reas, and `ahapa actions are shown for the sake of completeness. Note that when we use the `ahapaʓi̅œ`Ê̜Ê`iiÌiÊ>Ê}ÀœÕ«ÊÀiVœÀ`]Ê̅iÊVÊLi…>ۈœÀÊ>ÃœÊ deletes the ]nko record and rearranges the tree accordingly.


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

The Users Controller The users controller is essential for managing users. We will have the ability to list users, add users, edit users, delete users, and control the security access of users. ÃÊ܈̅Ê̅iÊ}ÀœÕ«ÃÊVœ˜ÌÀœiÀ]ÊÜiÊ}iÌÊ >ŽiÊ̜ʅi«ÊÕÃʜÕÌÊLÞÊÕȘ}Ê̅iÊ^]ga command to bake the code for the controller, model, and views. The code listing for the Qoano?kjpnkhhan is shown in Listing 8-10. Listing 8-10. Users Controller (app/controllers/users_controller.php) -68;ldl .6_h]ooQoano?kjpnkhhanatpaj`o=ll?kjpnkhhanw /6 06r]n j]ia9#Qoano#7 16r]n dahlano9]nn]u$#Dpih#(#Bkni#%7 26 36bqj_pekj^abknaBehpan$%w 46 56++Sajaa`pkpailkn]nehu]hhks]__aoo`qnejcpdaoapql -,6pdeo):=qpd):]hhks$#ej`at#(#oa_qnepu#( --6#]``#(#a`ep#(#`ahapa#%7 -.6y -/6 -06bqj_pekjhkcej$%w -16 -26y -36 -46bqj_pekjhkckqp$%w -56 .,6napqnjpdeo):na`ena_p$pdeo):=qpd):hkckqp$%%7 .-6y ..6 ./6bqj_pekja`ep$ e`9jqhh%w .06 .16eb$ e`""ailpu$ pdeo):`]p]%%w .26pdeo):Oaooekj):oapBh]od$[[$#Ejr]he`Qoan#(pnqa%%7 .36pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 .46y .56eb$ailpu$ pdeo):`]p]%%w /,6 /-6++Ebjkl]ooskn`eooqllhea`(sa`kj#p_d]jcaep /.6eb$pnei$pdeo):`]p]W#Qoan#YW#l]ooskn`#Y%99£ Oa_qnepu66d]od$##(jqhh(pnqa%%w //6qjoap$pdeo):`]p]W#Qoan#YW#l]ooskn`#Y%7 /06y /16

259


260

CH APT ER 8 N A C A K E C ONTR OL P A NEL

/26eb$ pdeo):Qoan):o]ra$ pdeo):`]p]%%w /36pdeo):Oaooekj):oapBh]od$ÂŁ [[$#PdaQoand]o^aajo]ra`#(pnqa%%7 /46pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 /56yahoaw 0,6pdeo):Oaooekj):oapBh]od$[[$#PdaQoan_kqh`jkp^ao]ra`* 0-6Lha]oa(pnu]c]ej*#(pnqa%%7 0.6y 0/6y 006eb$ailpu$ pdeo):`]p]%%w 016pdeo):`]p]9pdeo):Qoan):na]`$jqhh( e`%7 026 036++Saoappdal]ooskn`pkjkpdejc 046++L]ooskn`o]nakjhu_d]jca`ebukqajpanokiapdejc 056++oej_aep#okjas]ukjhu 1,6pdeo):`]p]W#Qoan#YW#l]ooskn`#Y9##7 1-6y 1.6 1/6++Bknpdal]najpcnkql 106 cnkqlo9pdeo):Qoan):Cnkql):bej`$#heop#%7 116pdeo):oap$#cnkqlo#( cnkqlo%7 126y 136 146bqj_pekjoa_qnepu$ e`%w 156 2,6eb$ailpu$ pdeo):`]p]%%w 2-6 2.6++Hap#ocappda=nk(e*a*(pdacnkql 2/6 ]nk[bknaecj[gau9pdeo):`]p]W#Qoan#YW#e`#Y7 206 216 ]nk9jas=nk$%7 226 ]nk[na_kn`9]nk):bej`>u=he]o$#Qoan6#* ]nk[bknaecj[gau%7 236 246 ]nk[]he]o9 ]nk[na_kn`W#=nk#YW#]he]o#Y7 256 ]_k[kb[]nk9 ]nk[na_kn`W#=_k#Y7 3,6 3-6++Hap#onqjpdnkqcdpdaoa_qnepuoaha_pekj 3.6 oa_[]__aoo9pdeo):`]p]W#Qoan#YW#Oa_qnepu=__aoo#Y7 3/6 306 ]_k9jas=_k$%7 316 ejbha_p9jasEjbha_pkn$%7 326 336bkna]_d$ oa_[]__aoo]o ]_k[e`9: ]__aoo[pula%w 346 356 ]_k[na_kn`9]_k):bej`>uE`$ ]_k[e`%7 4,6


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

4-6 ik`ah[lhqn]h9£ ejbha_p):lhqn]heva$ ]_k[na_kn`W#=_k#YW#ik`ah#Y%7 4.6 4/6eb$ ]__aoo[pula99#]hhks#%w 406pdeo):=_h):]hhks$ ]nk[]he]o(£ ik`ah[lhqn]h*#+#* ]_k[na_kn`W#=_k#YW#]he]o#Y(#&#%7 416y 426ahoaeb$ ]__aoo[pula99#`aju#%w 436pdeo):=_h):`aju$ ]nk[]he]o(£ ik`ah[lhqn]h*#+#* ]_k[na_kn`W#=_k#YW#]he]o#Y(#&#%7 446y 456y 5,6y 5-6 5.6++Hap#oc]pdanpda]_koaha_pekjo]r]eh]^ha 5/6 ]_k9jas=_k$%7 506 516++Heoppdasdkhapnaa 526 ]_k[pnaa9]_k):cajan]paPnaaHeop$%7 536 546++Jkscappda`ap]ehokbpda=_kna_kn`o 556 ]_k[na_kn`o9]_k):bej`$#]hh#%7 -,,6 -,-6pdeo):oap$_kil]_p$#]_k[pnaa#(#]_k[na_kn`o#%%7 -,.6 -,/6pdeo):oap$#_qnnajp[]he]o#(£ pdeo):Qoan):j]ia*#6#* pdeo):Qoan):e`%7 -,06 -,16eb$ailpu$ pdeo):`]p]%%w -,26pdeo):`]p]9pdeo):Qoan):na]`$jqhh( e`%7 -,36y -,46y -,56 --,6++Pdabkhhksejc]na^]ga` ---6 --.6bqj_pekjej`at$%w --/6pdeo):Qoan):na_qnoera9,7 --06pdeo):oap$#qoano#(pdeo):l]cej]pa$%%7 --16y --26 --36bqj_pekjreas$ e`9jqhh%w --46eb$ e`%w --56pdeo):Oaooekj):oapBh]od$[[$#Ejr]he`Qoan*#(pnqa%%7 -.,6pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 -.-6y -..6pdeo):oap$#qoan#(pdeo):Qoan):na]`$jqhh( e`%%7 -./6y -.06

261


262

CH APT ER 8 N A C A K E C ONTR OL P A NEL

-.16bqj_pekj]``$%w -.26eb$ailpu$ pdeo):`]p]%%w -.36pdeo):Qoan):_na]pa$%7 -.46eb$ pdeo):Qoan):o]ra$ pdeo):`]p]%%w -.56pdeo):Oaooekj):oapBh]od$£ [[$#PdaQoand]o^aajo]ra`#(pnqa%%7 -/,6pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 -/-6yahoaw -/.6pdeo):Oaooekj):oapBh]od$£ [[$#PdaQoan_kqh`jkp^ao]ra`*Lha]oa(pnu]c]ej*#(pnqa%%7 -//6y -/06y -/16 cnkqlo9pdeo):Qoan):Cnkql):bej`$#heop#%7 -/26pdeo):oap$_kil]_p$#cnkqlo#%%7 -/36y -/46 -/56bqj_pekj`ahapa$ e`9jqhh%w -0,6eb$ e`%w -0-6pdeo):Oaooekj):oapBh]od$[[$#Ejr]he`e`bknQoan#(pnqa%%7 -0.6++ pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 -0/6y -006eb$ pdeo):Qoan):`ah$ e`%%w -016pdeo):Oaooekj):oapBh]od$[[$#Qoan`ahapa`#(pnqa%%7 -026pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 -036y -046y -056 -1,6y -1-6;: Much of the code in Listing 8-10 follows the same pattern as the groups controller. On line 10, we temporarily allow access to some actions during the initial setup of the users. The hkcej and hkckqp actions, on lines 14 and 18, respectively, are just stub functions that are needed in order for the =qpd component to automatically log the user in and out. The a`ep action on line 23 is mostly based on baked code. There are two sections worth noting. When a user edits user details, the l]ooskn` field is set to blank on line 50. If no password has been supplied in the form, we don’t change the password; we simply check whether it is empty, on line 32. Passwords are hashed, so we never have the plain text of the original password. Therefore, we need to manually empty the l]ooskn` field; otherwise, Cake will fill it with the hashed password string. When we update the user details, and the user has provided a new password, the =qpd component will automatically hash the password provided.


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

User Security The oa_qnepu action is best explained by starting from the user listing (ej`at action), shown in Figure 8-7, and the security form, shown in Figure 8-8.

Figure 8-7. The index action in the UserController

Figure 8-8. The security action in the UserController

263


264

CH APT ER 8 N A C A K E C ONTR OL P A NEL

The oa_qnepu action in the users controller, on line 58 of Listing 8-10, is similar to the oa_qnepu action in the groups controller. We display all the ]_ko records, which we can security-manage. We allow the administrator to set whether the user should have access or ˜œÌÊLÞÊÃiiV̈˜}ʏœÜʜÀÊ i˜Þ°Ê7…i˜ÊÜiÊÃÕL“ˆÌÊ̅iÊvœÀ“]Ê̅iÊVœ`iÊLi}ˆ˜˜ˆ˜}ʜ˜Êˆ˜iÊÈäÊ in Listing 8-10 takes over. We loop over the selection, and depending on whether the user ÃiiVÌi`ʏœÜʜÀÊ i˜Þ]ÊÜiÊÕÃiÊ̅iÊ=_h component’s ]hhks or `aju method. In Listing 8-10, the ej`at, reas, ]``, and `ahapa methods are shown for the sake of com«iÌi˜iÃðÊÃÊ܈̅Ê̅iÊ}ÀœÕ«ÃÊVœ˜ÌÀœiÀ½ÃÊ`ahapa action, when we delete a user record, the action also deletes the ]nko record and rearranges the tree accordingly.

Adding a User The Qoan model code for adding a user is similar in structure to that in the Cnkql model. This code is shown in Listing 8-11. Listing 8-11. User Model (app/models/user.php) -68;ldl .6_h]ooQoanatpaj`o=llIk`ahw /6 06r]n j]ia9#Qoan#7 16 26r]n ]_po=o9]nn]u$#=_h#9:#namqaopan#%7 36 46r]n ^ahkjcoPk9]nn]u$ 56#Cnkql#9:]nn]u$#_h]ooJ]ia#9:#Cnkql#( -,6#bknaecjGau#9:#cnkql[e`#( --6#_kj`epekjo#9:##( -.6#beah`o#9:##( -/6#kn`an#9:## -06% -16%7 -26 -36bqj_pekj]bpanO]ra$ _na]pa`%w -46 -56eb$ _na]pa`%w .,6 .-6++Ep#o]_na]pekj ..6 ./6 e`9pdeo):capH]opEjoanpE@$%7 .06 .16 ]nk9jas=nk$%7 .26 .36]nk):ql`]pa=hh$]nn]u$#]he]o#9:#X#Qoan6#* e`*#X##%( .46]nn]u$#=nk*ik`ah#9:#Qoan#( .56#=nk*bknaecj[gau#9: e`% /,6%7 /-6y


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

/.6ahoaw //6 /06++Ep#o]ja`ep7sad]rapkql`]papdapnaa /16 `]p]9pdeo):na]`$%7 /26 l]najp[e`9 `]p]W#Qoan#YW#cnkql[e`#Y7 /36 /46 ]nk9jas=nk$%7 /56 0,6 ]nk[na_kn`9]nk):bej`>u=he]o$pdeo):j]ia*#6#* pdeo):e`%7 0-6 l]najp[na_kn`9]nk):bej`>u=he]o$#Cnkql6#* l]najp[e`%7 0.6 0/6eb$ailpu$ ]nk[na_kn`%%w 006 016 l]najp[e`9#,#7 026 036eb$ailpu$ l]najp[na_kn`%%w 046 l]najp[e`9 l]najp[na_kn`W#=nk#YW#e`#Y7 056y 1,6 1-6++Fqop_d]jcejcl]najpo 1.6pdeo):=nk):o]ra$]nn]u$ 1/6#l]najp[e`#9: l]najp[e`( 106#e`#9: ]nk[na_kn`W#=nk#YW#e`#Y 116%%7 126y 136y 146 156napqnjpnqa7 2,6y 2-6 2.6bqj_pekjl]najpJk`a$%w 2/6 206++Pdeoodkqh`^apda]he]okbpdal]najp ik`ah66 e` 216 `]p]9pdeo):na]`$%7 226 236++Pdeojaa`opk^aqjemqa 246napqnj#Cnkql6#* `]p]W#Qoan#YW#cnkql[e`#Y7 256y 3,6 3-6y 3.6;: vÌiÀÊ>Êo]ra operation, whether it is creating a new ]nko record or editing an existing one, we still need to update some of the ]nko record ourselves. Line 19 starts the ]bpanO]ra operation. If it’s a new record, we update the ]he]o field with the unique string format Qoan6Wqoan[e`Y.

265


266

CH APT ER 8 N A C A K E C ONTR OL P A NEL

Because of the hierarchical nature of ]nko records, we also need an action called l]najpJk`a. Ãʈ˜Ê̅iÊCnkql model, this must return the unique ]he]o value of the group, in the format Cnkql6Wcnkql[e`Y.

Testing the Control Panel Now that we have all the code and tables in place, we can run a little test to check whether our access control list is working properly. Starting from a blank database, follow these steps: 1. Make sure all the database tables are blank. See the Records column in Figure 8-9.

Figure 8-9. Blank database tables 2. Bring up the ?kjpnkhL]jah+sah_kia page (see Figure 8-1). This will automatically create the pail user entry in the qoano table and the ]nko table, as shown in Figures 8-10 and 8-11.

Figure 8-10. The temp user in the users table

Figure 8-11. The temp user in the aros table 3. Log in with the pail user name and pail password. Next, we start adding groups. Remember that we have temporarily allowed access to the ]`` and ej`at actions set in the ^abknaBehpan method of the groups controller (see Listing 8-8, line 10). Remove this when you have all the groups and users in place.


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

4. ``Ê>Ê}ÀœÕ«ÊV>i`Ê]`iej using the interface. Figure 8-12 shows the two entries in the ]nko table: one for pail and one for the ]`iej group that you just added.

Figure 8-12. The admin group entry in the aros table 5. ``Ê>˜œÌ…iÀÊ}ÀœÕ«ÊV>i`Êqoan. Figure 8-13 shows the ]nko table entries.

Figure 8-13. The user group entry in the aros table Remember that we have temporarily allowed access to the ]`` and ej`at actions set in the ^abknaBehpan method of the groups controller (see Listing 8-8, line 10). Remove this when you have all the groups and users in place. 6. ``Ê̅iʺÀi>»Ê]`iej user, using ]`iej for the username, password, and group, as shown in Figure 8-14. Figure 8-15 shows the ]nko table entry.

Figure 8-14. Adding an admin user

267


268

CH APT ER 8 N A C A K E C ONTR OL P A NEL

Figure 8-15. The admin user entry in the aros table 7. Log out, and then log back in using the ]`iej username and password. 8. Delete the pail user using the Delete link. 9. ˆVŽÊ̅iÊV̈œ˜Ãʏˆ˜ŽÊœ˜Ê̅iÊ̜«Ê“i˜Õ]ÊÃiiVÌÊ̅iÊܓiV̈œ˜Ê>V̈œ˜Êˆ˜Ê̅iÊvœÀ“]Ê>ÃÊ shown in Figure 8-16, and then submit it.

Figure 8-16. Selecting the someAction action 10. Click the Groups link, and select the Security link for the admin group. 11. …iVŽÊ̅iʏœÜÊÃiiV̈œ˜]Ê>ÃÊŜܘʈ˜Êʈ}ÕÀiÊn‡£Ç]Ê>˜`ÊÃÕL“ˆÌÊ̅iÊvœÀ“°Ê

Figure 8-17. Select the Allow check box.


C H A P T E R 8 N A C A K E C O N T R O L P A N E L

12. Click the Widgets link on the top menu. You should now have access to that page, as shown in Figure 8-18.

Figure 8-18. Access allowed 13. Return to the Security link for the ]`iej group, and this time select Deny. Then submit the form. 14. Click the Widgets link again. Now you should be denied access, as shown in Figure 8-19.

Figure 8-19. Access denied By controlling the group, you indirectly control the users who belong to that group. However, you can also control individual security if necessary.

269


270

CH APT ER 8 N A C A K E C ONTR OL P A NEL

Summary In this chapter, we used the idea of a control panel as a starting point for developing basic functions common to web applications. We began that process by using Cake’s =_h component to develop a web front end to manage user and group security. ÃÊÜiÊÃ>ˆ`]Ê >Ži½ÃÊ>VViÃÃÊVœ˜ÌÀœÊˆÃÌʈÃʜ˜iʜvʈÌÃʓœÃÌÊVœ“«iÝÊii“i˜ÌðÊÕV…ÊœvÊ̅iÊ complexity is due to its implicit link to other elements in Cake. Using the access control list functionality involves the =_h and =qpdÊVœ“«œ˜i˜ÌðÊ9œÕÊ>ÃœÊ˜ii`Ê̅iÊVÊLi…>ۈœÀ]Ê܅ˆV…Ê in turn uses the Tree behavior. On top of that, you still need to carry out some operations yourself. Furthermore, the =_h component behaves differently depending on the value of the ]qpdkneva parameter. But despite this complexity, it’s one of the most flexible security systems you can use. Once the basic system is up and running, it’s much easier to change and adapt your access control list for other scenarios. There are many other functions you can add to the access control list and to the control panel as a whole. Here are some ideas: Ê

UÊ ``Ê>Ê`>ÅLœ>À`Êvi>ÌÕÀiʈ˜Ê̅iÊ?kjpnkhL]jah?kjpnkhhan class to list useful statistics about the application. For example, if the control panel is used for an e-commerce application, the dashboard could list the number of products sold, number of new users, and so on.

Ê

UÊ “«ÀœÛiʜ˜Ê̅iÊ>VViÃÃÊVœ˜ÌÀœÊˆÃÌ°Ê9œÕʓ>ÞÊÜ>˜ÌÊ>Êvi>ÌÕÀiÊ܅iÀiÊޜÕÊV>˜Ê`ÀˆÊ`œÜ˜Ê from the actions listings in the top menu and find out which ]nk entry has access or no access to that particular action.

Ê

UÊ ÌÊ̅iʓœ“i˜Ì]ʈvÊޜÕÊ`iiÌiÊ>˜Ê>V̈œ˜ÊvÀœ“Ê̅iÊ]_ko list, security permissions on that list will no longer exist. It would be useful to have a feature that told the user which ]nko entities currently have permissions set on the action before deleting it.

Ê

UÊ "˜ViÊޜÕʅ>ÛiÊVÀi>Ìi`Ê̅iÊiÃÃi˜Ìˆ>Ê}ÀœÕ«ÃÊ>˜`ÊÕÃiÀÃÊ>˜`Ê>ÃœÊÀi“œÛi`Ê̅iÊÌi“«œÀ>ÀÞÊ ]hhks method in the controllers, these groups and users should remain permanent; no user should be able to delete them. You could modify the application so that the `ahapa method would not affect these special groups and users.


C HAPTER

9

Translating Stories I

n this chapter, we’ll be writing a news story application in which the news stories will be available in other languages. There will also be an admin area, which will give translators the ability to translate stories from a base language (in our case, English) to another language. To protect the admin area, we will build a simple authentication system. In Chapter 6, we covered Cake’s internationalization features and demonstrated using *lk files to display different languages. Using *lk files is adequate for static text. However, if the data is stored in the database, you need to employ Cake’s built-in Translate behavior. You’ll see how that works in this chapter.

Application Structure To start off, we need two database tables: opkneao and qoano. Naturally, opkneao will be used to store the stories, while qoano will be the admin users who will enter stories in different languages. There will also be two controllers to go with the two tables: Opkneao?kjpnkhhan in +]ll+ _kjpnkhhano+opkneao[_kjpnkhhan*ldl and Qoano?kjpnkhhan in +]ll+_kjpnkhhano+qoano[ _kjpnkhhan*ldl. The opkneao table schema is shown in Listing 9-1. We will discuss the qoano table later in the chapter, in the “Logging In” section. Listing 9-1. The stories Table Schema ?NA=PAP=>HA\opkneao\$ \e`\ejp$--%JKPJQHH]qpk[ej_naiajp( \pepha\r]n_d]n$.11%JKPJQHH( \^k`u\ia`eqipatpJKPJQHH( LNEI=NUGAU$\e`\% %7 The two fields we need to be concerned with are pepha, which holds the story title, and ^k`u, which holds the actual story itself. To use the Translate behavior, we need an extra table named e-4j, which will be used to store the translation. The schema is shown in Listing 9-2.

271


272

CH APT ER 9 N TRA NS L A TING S TOR IES

Listing 9-2. The i18n Table Schema ?NA=PAP=>HA\e-4j\$ \e`\ejp$--%JKPJQHH]qpk[ej_naiajp( \hk_]ha\r]n_d]n$2%JKPJQHH( \ik`ah\r]n_d]n$.11%JKPJQHH( \bknaecj[gau\ejp$-,%JKPJQHH( \beah`\r]n_d]n$.11%JKPJQHH( \_kjpajp\ia`eqipatp( LNEI=NUGAU$\e`\% %7 This table has the following fields: Ê

UÊ hk_]ha: This is the language locale code. We need to decide which language the translation refers to. At present, unlike for language codes, there are no ISO locale standard codes; different software uses slightly different codes. In Cake, you can see the locale codes in the file +_]ga+he^o+h-,j*ldl. For further reading, dppl6++sss*klaje-4j*knc is a good place to start.

Ê

UÊ ik`ah: Since there could be many different tables using the Translate behavior, we need this field to identify the correct table via the model. In our case, our model will be Opknu.

Ê

UÊ bknaecj[gau: We need the e` field to identify which record the translation relates to.

Ê

UÊ beah`: This is the name of the field in the database table that needs translation. In our case, it will be either pepha or opknu.

Ê

UÊ _kjpajp: This contains the translation text itself.

Using this e-4j table, we map one field in one record in our opkneao table to different translations. It’s a one-to-many association.

The Translate Behavior The Translate behavior provides the model class with a number of functions that assist with language translations in our own tables. It sits between the database and the controllers, transparently dealing with language translations between the two areas. To use the Translate behavior, we start with a simple statement we insert into our opknu* ldl model file: r]n ]_po=o9]nn]u$#Pn]joh]pa#9:]nn]u$#pepha#(#^k`u#%%7

NNote You can add other behaviors to the model by appending the behavior name to the ]_po=o array variable. In our example, if we were going to add the Containable behavior, the ]_po=o variable would look like this: ]nn]u$#Pn]joh]pa#9:]nn]u$#pepha#(#^k`u#%(#?kjp]ej]^ha#%7.


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

In this line, we bring in the Translate behavior, and tell it that we want the pepha and ^k`u fields in our opkneao table to be managed by the Translate behavior. When we say “managed,” we mean that any model database function relating to the fields we specified should be transparently handled when there is a translation available. For example, when we use a bej`$#]hh#% command, it will pick out the correct translation content relating to the language locale we specify.

Stories Our application centers around the news stories to be translated. We need to add stories and translate them. Users will be able to view the stories either in their original language or a translated version. We will also add functionality to allow administrators to manage the stories.

NNote To simplify our application, we have used Cake’s ^]ga command to generate most of the code relating to the controller and views. Additionally, we have created an admin section during the baking, so human translators can translate the stories from English into other languages.

Baking Cake The ^]ga command is a command-line tool that will generate the model, controller, and view files based on the database you created. For this chapter’s application, we will use Cake’s ^]ga command to generate the Cake files relating to the administration of the stories. We’re going to jump ahead a little by showing you the output of our ^]ga session, in Listing 9-3. Listing 9-3. Output of the bake Session -6?6X_d]lpan[5:_]gaX_kjokhaX_]ga^]ga .6 /6 06Sah_kiapk?]gaLDLr-*.*,*3.52N?.?kjokha 16))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) 26=ll6]ll 36L]pd6?6+_d]lpan[5+]ll 46))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) 56Ejpan]_pera>]gaOdahh -,6))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) --6W@Y]p]^]oa?kjbecqn]pekj -.6WIYk`ah -/6WRYeas -06W?Ykjpnkhhan -16WLYnkfa_p -26WMYqep -36Sd]pskqh`ukqhegapk>]ga;$@+I+R+?+L+M% -46:I

273


274

CH APT ER 9 N TRA NS L A TING S TOR IES

-56))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) .,6>]gaIk`ah .-6L]pd6?6+_d]lpan[5X]llXik`ahoX ..6))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) ./6Lkooe^haIk`aho^]oa`kjukqn_qnnajp`]p]^]oa6 .06-*E-4j .16.*Opknu .26/*Qoan .36Ajpan]jqi^anbnkipdaheop]^kra(pulaejpdaj]iakb]jkpdanik`ah(£ kn#m#pkatep .46WmY:. .56Skqh`ukqhegapkoqllhur]he`]pekj_nepane]bknpda£ beah`oejukqnik`ah;$u+j% /,6WuY:j /-6Skqh`ukqhegapk`abejaik`ah]ook_e]pekjo£ $d]oI]ju(d]oKja(^ahkjcoPk(ap_*%;$u+j% /.6WuY:j //6 /06))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) /16PdabkhhksejcIk`ahsehh^a_na]pa`6 /26))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) /36J]ia6Opknu /46=ook_e]pekjo6 /56))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) 0,6Hkkgkg]u;$u+j% 0-6WuY:u 0.6 0/6>]gejcik`ah_h]oobknOpknu*** 006 016?na]pejcbeha?6+_d]lpan[5X]llXik`ahoXopknu*ldl 026Snkpa?6+_d]lpan[5X]llXik`ahoXopknu*ldl 036?]gapaopoqepajkpejop]hha`*@kukqs]jppk^]ga£ qjeppaopbehao]jus]u;$u+j% 046WuY:j 056))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) 1,6Ejpan]_pera>]gaOdahh 1-6))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) 1.6W@Y]p]^]oa?kjbecqn]pekj 1/6WIYk`ah 106WRYeas 116W?Ykjpnkhhan 126WLYnkfa_p 136WMYqep 146Sd]pskqh`ukqhegapk>]ga;$@+I+R+?+L+M% 156:? 2,6))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) 2-6>]ga?kjpnkhhan 2.6L]pd6?6+_d]lpan[5X]llX_kjpnkhhanoX


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

2/6))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) 206Lkooe^ha?kjpnkhhano^]oa`kjukqn_qnnajp`]p]^]oa6 216-*E-4jo 226.*Opkneao 236/*Qoano 246Ajpan]jqi^anbnkipdaheop]^kra(pulaejpdaj]ia£ kb]jkpdan_kjpnkhhan(kn#m#pkatep 256WmY:. 3,6))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) 3-6>]gejcOpkneao?kjpnkhhan 3.6))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) 3/6Skqh`ukqhegapk^qeh`ukqn_kjpnkhhanejpan]_perahu;$u+j% 306WuY:u 316Skqh`ukqhegapkqoao_]bbkh`ejc;$u+j% 326WjY:j 336Skqh`ukqhegapkej_hq`aokia^]oe__h]ooiapdk`o£ $ej`at$%(]``$%(reas$%(a`ep$%%;$u+j% 346WjY:u 356Skqh`ukqhegapk_na]papdaiapdk`obkn]`iejnkqpejc;$u+j% 4,6WjY:u 4-6Skqh`ukqhegapdeo_kjpnkhhanpkqoakpdandahlano£ ^aoe`aoDpihDahlan]j`BkniDahlan;$u+j% 4.6WjY:j 4/6Skqh`ukqhegapdeo_kjpnkhhanpkqoa]ju_kilkjajpo;$u+j% 406WjY:j 416Skqh`ukqhegapkqoaOaooekjo;$u+j% 426WuY:j 436 446))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) 456Pdabkhhksejc_kjpnkhhansehh^a_na]pa`6 5,6))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) 5-6?kjpnkhhanJ]ia6Opkneao 5.6))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) 5/6Hkkgkg]u;$u+j% 506WuY:u 516 526?na]pejcbeha?6+_d]lpan[5X]llX_kjpnkhhanoXopkneao[_kjpnkhhan*ldl 536Snkpa?6+_d]lpan[5X]llX_kjpnkhhanoXopkneao[_kjpnkhhan*ldl 546?]gapaopoqepajkpejop]hha`*@kukqs]jppk^]ga£ qjeppaopbehao]jus]u;$u+j% 556WuY:j -,,6))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) -,-6Ejpan]_pera>]gaOdahh -,.6))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) -,/6W@Y]p]^]oa?kjbecqn]pekj -,06WIYk`ah -,16WRYeas -,26W?Ykjpnkhhan

275


276

CH APT ER 9 N TRA NS L A TING S TOR IES

-,36WLYnkfa_p -,46WMYqep -,56Sd]pskqh`ukqhegapk>]ga;$@+I+R+?+L+M% --,6:R ---6))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) --.6>]gaReas --/6L]pd6?6+_d]lpan[5X]llXreasoX --06))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) --16Lkooe^ha?kjpnkhhano^]oa`kjukqn_qnnajp`]p]^]oa6 --26-*E-4jo --36.*Opkneao --46/*Qoano --56Ajpan]jqi^anbnkipdaheop]^kra(pulaejpdaj]iakb£ ]jkpdan_kjpnkhhan(kn#m#pkatep -.,6WmY:. -.-6Skqh`ukqhegapk_na]paokiao_]bbkh`a`reaso£ $ej`at(]``(reas(a`ep%bknpdeo_kjpnkhhan; -..6JKPA6>abkna`kejcok(ukq#hhjaa`pk_na]paukqn£ _kjpnkhhan]j`ik`ah_h]ooao$ej_hq`ejc]ook_e]pa`ik`aho%*$u+j% -./6WjY:u -.06Skqh`ukqhegapk_na]papdareasobkn]`iejnkqpejc;$u+j% -.16WuY:u -.26 -.36?na]pejcbeha?6+_d]lpan[5X]llXreasoXopkneaoXej`at*_pl -.46Snkpa?6+_d]lpan[5X]llXreasoXopkneaoXej`at*_pl -.56 -/,6?na]pejcbeha?6+_d]lpan[5X]llXreasoXopkneaoXreas*_pl -/-6Snkpa?6+_d]lpan[5X]llXreasoXopkneaoXreas*_pl -/.6 -//6?na]pejcbeha?6+_d]lpan[5X]llXreasoXopkneaoX]``*_pl -/06Snkpa?6+_d]lpan[5X]llXreasoXopkneaoX]``*_pl -/16 -/26?na]pejcbeha?6+_d]lpan[5X]llXreasoXopkneaoXa`ep*_pl -/36Snkpa?6+_d]lpan[5X]llXreasoXopkneaoXa`ep*_pl -/46 -/56?na]pejcbeha?6+_d]lpan[5X]llXreasoXopkneaoX]`iej[ej`at*_pl -0,6Snkpa?6+_d]lpan[5X]llXreasoXopkneaoX]`iej[ej`at*_pl -0-6 -0.6?na]pejcbeha?6+_d]lpan[5X]llXreasoXopkneaoX]`iej[reas*_pl -0/6Snkpa?6+_d]lpan[5X]llXreasoXopkneaoX]`iej[reas*_pl -006 -016?na]pejcbeha?6+_d]lpan[5X]llXreasoXopkneaoX]`iej[]``*_pl -026Snkpa?6+_d]lpan[5X]llXreasoXopkneaoX]`iej[]``*_pl -036 -046?na]pejcbeha?6+_d]lpan[5X]llXreasoXopkneaoX]`iej[a`ep*_pl -056Snkpa?6+_d]lpan[5X]llXreasoXopkneaoX]`iej[a`ep*_pl -1,6))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) -1-6


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

-1.6ReasO_]bbkh`ejc?kilhapa* -1/6 -106))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) -116Ejpan]_pera>]gaOdahh -126))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) -136W@Y]p]^]oa?kjbecqn]pekj -146WIYk`ah -156WRYeas -2,6W?Ykjpnkhhan -2-6WLYnkfa_p -2.6WMYqep -2/6Sd]pskqh`ukqhegapk>]ga;$@+I+R+?+L+M% -206: As you can see, the ^]ga command first asks what we would like to bake. We actually need to bake the story model first, before the controller or view. Line 46 confirms that the model has been created. Next, we need to create the story controller, starting on line 69. The two most important questions are on lines 77 and 79: whether we want some basic class methods and admin routing. We say yes to both questions. The ^]ga command will create the code for those actions for us. We finish off by creating the views for the stories, beginning on line 109. On lines 121 and 124, we are asked about creating scaffolding views and the views for admin routing, and we say yes. The code we have baked is shown at the end of this chapter.

Adding Stories Our application will start with an empty e-4j table and an empty opkneao table. So letâ&#x20AC;&#x2122;s start at the beginning with adding a story. Listing 9-4 shows the ]`iej[]`` action in +]ll+ _kjpnkhhano+opkneao[_kjpnkhhan*ldl, which adds a story. Listing 9-4. Adding a Story (in /app/controllers/stories_controller.php) -6bqj_pekj]`iej[]``$%w .6 /6pdeo):[oapE-4j>uHk_]ha$#aj[qo#%7 06 16eb$ailpu$ pdeo):`]p]%%w 26pdeo):Opknu):_na]pa$%7 36eb$ pdeo):Opknu):o]ra$ pdeo):`]p]%%w 46pdeo):Oaooekj):oapBh]od$[[$#Opknuo]ra`*#(pnqa%%7 56pdeo):na`ena_p$]nn]u$#_kjpnkhhan#9:#Opkneao#(ÂŁ #]_pekj#9:#ej`at#%%7 -,6yahoaw --6y -.6y -/6y

277


278

CH APT ER 9 N TRA NS L A TING S TOR IES

In the ]`iej[]`` action, the important method is the oapE-,j>uHk_]ha call on line 3. It’s one of our own private methods, which is also housed within the Opkneao?kjpnkhhan. Listing 9-5 shows this method. Listing 9-5. The setI10nByLocale Method (in /app/controllers/stories_controller.php) -6bqj_pekj[oapE-,j>uHk_]ha$ _qnnajp[hk_]ha9jqhh%w .6 /6++@ab]qhphk_]haeoaj[qo 06 hk_]ha9aj[qo7 16 26++@a_e`akjoaooekj 36eb$ oaooekj[hk_]ha9pdeo):Oaooekj):na]`$#hk_]ha#%%w 46 hk_]ha9 oaooekj[hk_]ha7 56y -,6 --6++Qoan_]jkranne`ahk_]ha -.6eb$ _qnnajp[hk_]ha9##%w -/6 hk_]ha9 _qnnajp[hk_]ha7 -06y -16 -26pdeo):Opknu):hk_]ha9 hk_]ha7 -36y The [oapE-,j>uHk_]ha method decides which locale, and thus which language, we’ll be using in the Translate behavior. We start off with some default settings on line 4, and then we ask whether the locale has already been decided beforehand by checking the session on line 7. Line 16 sets the locale for the model. In the ]`iej[]`` action (Listing 9-4), we start off by setting the locale for the model so that the Translate behavior knows which locale we’ll dealing with. The section of code after that is simply baked using Cake’s ^]ga command, which saves a record in the Opknu model. (See the “Baked Code” section at the end of this chapter for the actual baked version of the ]`iej[]`` action.) Now we enter three sample stories into our application. When the o]ra command in the Opknu mode is called, we actually get a total of three different records for each story. We get the entry in the opkneao table, which we expect, but we also get two entries in the e-4j table. The records for the three stories are shown in Figures 9-1 and 9-2.

Figure 9-1. The stories table records


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

Figure 9-2. The i18n table records for the title and body As it stands, the records in the e-4j table just look like unnecessary duplication. However, the Translate behavior will show its usefulness when we start inserting other languages, as you’ll see a little later in the “Translating Stories” section.

Administering Stories Most CakePHP sites have a back-end administrative area. It would be convenient to have all actions come under one specific folder so administration can be more easily managed. There is a helpful feature in Cake that helps us with this. In the _kjbec+_kna*ldl file, we uncomment the following line of code: ?kjbecqna66snepa$#Nkqpejc*]`iej#(#]`iej#%7 With this line uncommented, Cake will map all actions in the format ]`iej[W]_pekj[j]iaY$% to the URL +]`iej+W_kjpnkhhan[j]iaY+W]_pekj[j]iaY. For example, the ]`iej[ej`at action in the Opkneao?kjpnkhhan would be accessed via +]`iej+Opkneao+ej`at. However, Cake doesn’t automatically password-protect those admin actions, so we will need to do that ourselves, as discussed in the “User Authentication” section.

Translating Stories The first task for translating stories is to list them. We will list only the stories that need translating. This makes it slightly easier for the human translator to pick out which stories need translating. This is handled by using the ]`iej[pkPn]jo method, as shown in Listing 9-6. Listing 9-6. Listing Stories to Translate (in /app/controllers/stories_controller.php) -6bqj_pekj]`iej[pkPn]jo$%w .6 /6pdeo):oap$#pn]jo[h]jc#(##%7 06 h]jcq]ca9##7 16 26++Kj_aqoand]ole_ga`pdah]jcq]ca(danasaheoppdaopkneao 36++pd]pjaa`pn]joh]pejc 46eb$ailpu$pdeo):l]n]ioW#qnh#YW#h]jcq]ca#Y%%w 56 h]jcq]ca9pdeo):l]n]ioW#qnh#YW#h]jcq]ca#Y7 -,6y

279


280

CH APT ER 9 N TRA NS L A TING S TOR IES

--6ahoaeb$eooap$pdeo):l]ooa`=ncoW#h]jcq]ca#Y%%w -.6 h]jcq]ca9pdeo):l]ooa`=ncoW#h]jcq]ca#Y7 -/6y -06 -16eb$ h]jcq]ca%w -26 -36++Pdah]jcq]casa#naqoejcpkpn]joh]papdaopkneaoej -46pdeo):Opknu):pn]joH]jcq]ca9 h]jcq]ca7 -56pdeo):oap$#pn]jo[h]jc#( h]jcq]ca%7 .,6 .-6++Cappdah]jcq]caj]ia(a*c*(Cani]j ..6 _]p9pdeo):capH]jc$ h]jcq]ca%7 ./6pdeo):oap$#h]jcq]ca#( _]pW#h]jcq]ca#Y%7 .06 .16++Sde_dl]cej]pekjiapdk`sa#naqoejc .26pdeo):Opknu):qoaL]cej]pa9#l]cej]paPn]joh]pekj#7 .36pdeo):oap$#opkneao#(pdeo):l]cej]pa$%%7 .46y .56y In Listing 9-6, we start by initializing the variables on lines 3 and 4. Then we decide how the language code is picked out from the URL in the eb statement on line 8. Once we know which language the user wants, we start retrieving the results using the controller l]cej]pa method on line 27. Cake’s l]cej]pa method turned out to be unsuitable for our needs. It lacks the functionality that returns only the stories that have not been translated in the language we chose—which is understandable, as that functionality is quite unique to our application. We had to override Cake’s l]cej]pa method and write our own. We will go into the pagination a bit later, in the “Translation Pagination” section. The story listing is shown in Figure 9-3. As you can see, each story has two links: View and Translate. Assuming we have a Japanese translator, she can view the story in English by clicking the View link. She can then click the Translate link to go to the story editing screen, as shown in Figure 9-4. A sample Translate URL link looks like this: dppl6++hk_]hdkop+_d]lpan[5+]`iej+opkneao+a`ep+.+pn]jo[h]jc6flj


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

Figure 9-3. Stories that need translating

Figure 9-4. Story editing in the translation phase

281


282

CH APT ER 9 N TRA NS L A TING S TOR IES

For this form, we have simply used the baked ]`iej[a`ep*_pl view. However, we have added a hidden tag named pn]jo[h]jc, which holds the language code in which we want the story to be saved. After the Japanese translator has translated the story and saved it, the Translate behavior creates two extra records: one for the title in Japanese and another for the body in Japanese. Figures 9-5 and 9-6 show how our e-4j table looks now. You can see how our translation functions are taking place. We have a main story stored in opkneao and the language versions of those stories held in e-4j. Notice that our story in the opkneao table is now in Japanese as well. This is a side effect of the Translate behavior; however, it will display the correct version when the specified locale is used.

Figure 9-5. The stories table after our first translation

Figure 9-6. The i18n table after our first translation

Viewing Stories When a user visits the home page, we list the stories in the language that is automatically selected by the Translate behavior. On the top navigation bar, we inserted three links that allow us to view the stories if the translated stories are available. The code for these links is shown in Listing 9-7. They belong in the `ab]qhp*_pl layout (+]ll+reaso+h]ukqpo+`ab]qhp*_pl). Listing 9-7. Links to Change the Locale (/app/views/layouts/default.ctp) -68;ldl .6a_dkdpih):hejg$#aj#(#+Opkneao+_d]jcaHk_]ha+hk_]ha6aj[qo#%7 /6a_dk#"j^ol7x"j^ol7#7 06a_dkdpih):hejg$#f]#(#+Opkneao+_d]jcaHk_]ha+hk_]ha6flj#%7 16a_dk#"j^ol7x"j^ol7#7 26a_dkdpih):hejg$#`a#(#+Opkneao+_d]jcaHk_]ha+hk_]ha6`aq#%7 36;:


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

As you can see in Listing 9-7, the Cake hejg methods all point to the _d]jcaHk_]ha action in the Opkneao?kjpnkhhan. The named variable hk_]ha is picked up via two methods in the controller: ^abknaBehpan and _d]jcaHk_]ha itself, both shown in Listing 9-8. Listing 9-8. StoriesController Methods to Change the Locale (in /app/controllers/stories_ controller.php) -6bqj_pekj^abknaBehpan$%w .6 /6++Pdahk_]ha_]j^aoap^u]ju]_pekj 06eb$eooap$pdeo):l]ooa`=ncoW#hk_]ha#Y%%w 16pdeo):Oaooekj):snepa$#hk_]ha#(pdeo):l]ooa`=ncoW#hk_]ha#Y%7 26y 36 46l]najp66^abknaBehpan$%7 56y -,6 --6bqj_pekj_d]jcaHk_]ha$%w -.6 -/6++Pdahk_]haoaooekjr]neo]_pq]hhu_d]jca`ejpda=ll^abknaBehpan -06 -16++Na`ena_p^]_gpk_]hhejcl]ca -26pdeo):na`ena_p$pdeo):nabanan$%%7 -36y In the ^abknaBehpan method in Listing 9-8, we set the locale in the session so it can be used by other methods. The _d]jcaHk_]ha method simply redirects users back to the page where they clicked the link. We have used the ^abknaBehpan method because we may want to change the locale later on via other links. Now when we click the ja link on the top navigation, we just get the Japanese translated stories, as shown in Figure 9-7.

Figure 9-7. Viewing Japanese stories

283


284

CH APT ER 9 N TRA NS L A TING S TOR IES

Deleting Stories Deleting stories is quite a simple affair. When the user clicks the Delete link relating to a story, the story record in the opkneao table and the associated records in the e-4j table are deleted. This includes all the translations as well. The `ahapa action code is shown in Listing 9-9. Listing 9-9. The delete Action (/app/controllers/stories_controllers.php) bqj_pekj]`iej[`ahapa$ e`9jqhh%w eb$ e`%w pdeo):Oaooekj):oapBh]od$[[$#Ejr]he`Opknu*#(pnqa%%7 y eb$ pdeo):Opknu):`ah$ e`%%w pdeo):Oaooekj):oapBh]od$[[$#Opknu`ahapa`*#(pnqa%%7 y pdeo):na`ena_p$]nn]u$#_kjpnkhhan#9:#Opkneao#(#]_pekj#9:#ej`at#%%7 y

Listing Stories Listing of the stories is a basic function. Users need to view stories that interest them. The people who manage and translate the stories also need to list the stories in the database. We have written two story listing versions. One version will list the stories in the specified locale for public viewing, and the other will list the stories in the admin section. The controller action for the public story listing is shown in Listing 9-10. Listing 9-10. Listing Stories for Public Viewing (/app/controllers/stories_controller.php) -6bqj_pekjreas=hhOpkneao$%w .6 /6pdeo):[oapE-,j>uHk_]ha$%7 06 16pdeo):Opknu):na_qnoera9,7 26pdeo):oap$#opkneao#(pdeo):l]cej]pa$%%7 36y Line 3 sets the locale. Since we want only the stories, we turn off any fetching of associative model data in line 5. Line 6 is the workhorse of the action; it fetches the stories using the standard l]cej]pa method. The corresponding view that goes with the reas=hhOpkneao action is shown in Listing 9-11. We start off with line 4, which returns pagination information. Lines 8 to 12 simply loop through the stories and display the title and the body in full. We complete the view by providing pagination previous and next links, starting on line 18.


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

Listing 9-11. Listing the Stories (in app/views/stories/view_all_stories.ctp) -68`er: .6 /68;ldl 06a_dkl]cej]pkn):_kqjpan$]nn]u$#bkni]p#9:[[$#L]ca!l]ca!kb£ !l]cao!(odksejc!_qnnajp!na_kn`okqpkb!_kqjp!pkp]h(op]npejckjna_kn`£ !op]np!(aj`ejckj!aj`!#(pnqa%%%7 16;: 26 368;ldl 46bkna]_d$ opkneao]o opknu%w 56 -,6a_dk#8d.:#* opknuW#Opknu#YW#pepha#Y*#8+d.:#7 --6a_dk#8l:#* opknuW#Opknu#YW#^k`u#Y*#8+l:#7 -.6y -/6;: -06 -168+`er: -26 -368`er_h]oo9l]cejc: -468;ldla_dkl]cej]pkn):lnar$#88#*[[$#lnarekqo#(pnqa%(]nn]u$%(£ jqhh(]nn]u$#_h]oo#9:#`eo]^ha`#%%7;: -56x8;ldla_dkl]cej]pkn):jqi^ano$%7;: .,68;ldla_dkl]cej]pkn):jatp$[[$#jatp#(pnqa%*#::#(]nn]u$%(£ jqhh(]nn]u$#_h]oo#9:#`eo]^ha`#%%7;: .-68+`er: A typical listing of the stories is shown in Figure 9-8. Just to illustrate Cake’s pagination function, we have specified two stories per page.

Figure 9-8. Listing stories in the default language

285


286

CH APT ER 9 N TRA NS L A TING S TOR IES

The listing of the stories in the admin section is very similar to the public listing. In the admin section, we list all the stories in the base language (English, in our case). Additionally, we adopt a traditional table format listing, with each record occupying a single record. There will also be an Actions column, which will contain View, Edit, and Delete links. The code for this controller action is shown in Listing 9-12. Listing 9-12. Admin Story Listing (in app/controllers/stories_controller.php) -6bqj_pekj]`iej[ej`at$%w .6 /6pdeo):[oapE-,j>uHk_]ha$#aj[qo#%7 06 16pdeo):Opknu):na_qnoera9,7 26pdeo):oap$#opkneao#(pdeo):l]cej]pa$%%7 36y The difference between this listing and the public listing (Listing 9-10) is in the setting of the locale on line 3. In the admin version, we specifically set the locale to the US English. The corresponding view is quite straightforward and is composed of two parts. The first part is the view file itself (+]ll+reaso+opkneao+]`iej[ej`at*_pl). This file just contains the following lines: 8;ldl a_dkpdeo):ahaiajp$#]`iej[heop[opkneao#%7 ;: The element that it points to is shown in Listing 9-13. Listing 9-13. The Admin Story Listing Element (/app/views/elements/admin_list_stories.ctp) -68`er: .6 /68d.:8;ldl[[$#Opkneao#%7;:8+d.: 068l: 168;ldl 26a_dkl]cej]pkn):_kqjpan$]nn]u$#bkni]p#9:£ [[$#L]ca!l]ca!kb!l]cao!(odksejc!_qnnajp!na_kn`o£ kqpkb!_kqjp!pkp]h(op]npejckjna_kn`!op]np!(aj`ejckj!aj`!#(£ pnqa%%%7 36;: 468+l: 56 -,68p]^ha_h]oo9heop[opkneao_ahhl]``ejc9,_ahhol]_ejc9,: --6 -.68pn: -/68pd:8;ldla_dkl]cej]pkn):oknp$#e`#%7;:8+pd: -068pd:8;ldla_dkl]cej]pkn):oknp$#pepha#%7;:8+pd: -168pd:8;ldla_dkl]cej]pkn):oknp$#^k`u#%7;:8+pd: -268pd_h]oo9]_pekjo:8;ldl[[$#=_pekjo#%7;:8+pd: -368+pn: -46


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

-568;ldl .,6 e9,7 .-6bkna]_d$ opkneao]o opknu%6 ..6 _h]oo9jqhh7 ./6eb$ e''!.99,%w .06 _h]oo9#_h]oo9]hpnks#7 .16y .26;: .368pn8;ldla_dk _h]oo7;:: .46 .568p`: /,68;ldla_dk opknuW#Opknu#YW#e`#Y7;: /-68+p`: /.6 //68p`: /068;ldla_dk opknuW#Opknu#YW#pepha#Y7;: /168+p`: /26 /368p`: /468;ldla_dk opknuW#Opknu#YW#^k`u#Y7;: /568+p`: 0,6 0-68p`_h]oo9]_pekjo: 0.68;ldla_dkdpih):hejg$£ [[$#Reas#(pnqa%(]nn]u$#]`iej#9:##(#]_pekj#9:#reas#(£ opknuW#Opknu#YW#e`#Y%(]nn]u$#p]ncap#9:#[^h]jg#%%7;: 0/68;ldla_dk#"j^ol7x"j^ol7#7;: 0068;ldla_dkdpih):hejg$[[$#A`ep#(pnqa%(£ ]nn]u$#]_pekj#9:#a`ep#( opknuW#Opknu#YW#e`#Y%%7;: 0168;ldla_dk#"j^ol7x"j^ol7#7;: 0268;ldla_dkdpih):hejg$£ [[$#@ahapa#(pnqa%(]nn]u$#]_pekj#9:#`ahapa#( opknuW#Opknu#YW#e`#Y%(£ jqhh(olnejpb$[[$#=naukqoqnaukqs]jppk`ahapa!o;#(pnqa%(£ opknuW#Opknu#YW#e`#Y%%7;: 0368+p`: 046 0568+pn: 1,6 1-68;ldlaj`bkna]_d7;: 1.68+p]^ha: 1/6 1068+`er: 116 1268`er_h]oo9l]cejc: 1368;ldla_dkl]cej]pkn):lnar$#88#*[[$#lnarekqo#(pnqa%(£ ]nn]u$%(jqhh(]nn]u$#_h]oo#9:#`eo]^ha`#%%7;: 146x8;ldla_dkl]cej]pkn):jqi^ano$%7;: 1568;ldla_dkl]cej]pkn):jatp$[[$#jatp#(pnqa%*#::#(£ ]nn]u$%(jqhh(]nn]u$#_h]oo#9:#`eo]^ha`#%%7;: 2,68+`er:

287


288

CH APT ER 9 N TRA NS L A TING S TOR IES

We start with some pagination information on line 6. This is followed by the listing of the stories in a tabular format on line 10. Cake’s paginator helper comes into play again, starting from line 13, with links to sort the data columns. We start the looping of the stories on line 21. The view finishes with previous and next links. An example of this view is shown in Figure 9-9.

Figure 9-9. The admin story listing

Translation Pagination Earlier, we mentioned that the pagination of the stories to be translated wasn’t that straightforward. We had to override Cake’s l]cej]pkn controller method and create our custom l]cej]pkn method. The entire opknu*ldl model, which is mainly composed of code relating to the pagination, is shown in Listing 9-14. Listing 9-14. The Story Model (/app/models/story.php) -68;ldl .6_h]ooOpknuatpaj`o=llIk`ahw /6 06r]n j]ia9#Opknu#7 16 26r]n ]_po=o9]nn]u$#Pn]joh]pa#9:]nn]u$#pepha#(#^k`u#%%7 36 46r]n qoaL]cej]pa9#l]cej]paOp]j`]n`#7 56 -,6r]n pn]joH]jcq]ca9##7 --6


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

-.6bqj_pekjl]cej]pa$ _kj`epekjo( beah`o( kn`an( heiep( -/6 l]ca9-( na_qnoera9jqhh%w -06 -16osep_d$pdeo):qoaL]cej]pa%w -26 -36_]oa#l]cej]paOp]j`]n`#6 -46napqnjpdeo):l]cej]paOp]j`]n`$ _kj`epekjo( -56 beah`o( .,6 kn`an( .-6 heiep( ..6 l]ca( ./6 na_qnoera%7 .06 .16_]oa#l]cej]paPn]joh]pekj#6 .26napqnjpdeo):l]cej]paPn]joh]pekj$ _kj`epekjo( .36 beah`o( .46 kn`an( .56 heiep( /,6 l]ca( /-6 na_qnoera%7 /.6y //6y /06 /16bqj_pekjl]cej]pa?kqjp$ _kj`epekjo9jqhh( na_qnoera9,%w /26 /36osep_d$pdeo):qoaL]cej]pa%w /46 /56_]oa#l]cej]paOp]j`]n`#6 0,6napqnjpdeo):l]cej]pa?kqjpOp]j`]n`$ _kj`epekjo( 0-6 na_qnoera%7 0.6 0/6_]oa#l]cej]paPn]joh]pekj#6 006napqnjpdeo):l]cej]pa?kqjpPn]joh]pekj$ _kj`epekjo( 016 na_qnoera%7 026y 036y 046 056+&Pdabkhhksejc]napda`ebbanajpl]cej]pekjbqj_pekjo&+ 1,6 1-6++Iapdk`1.6bqj_pekjl]cej]paOp]j`]n`$ _kj`epekjo( beah`o( kn`an( 1/6 heiep( l]ca9-( 106 na_qnoera9jqhh%w 116 126 na_qnoera9)-7 136 146napqnjpdeo):bej`$#]hh#(]nn]u$#_kj`epekjo#9: _kj`epekjo( 156#beah`o#9: beah`o(

289


290

CH APT ER 9 N TRA NS L A TING S TOR IES

2,6#kn`an#9: kn`an( 2-6#heiep#9: heiep( 2.6#l]ca#9: l]ca( 2/6#na_qnoera#9: na_qnoera 206%%7 216y 226 236bqj_pekjl]cej]pa?kqjpOp]j`]n`$ _kj`epekjo9jqhh( na_qnoera9,%w 246 256 na_qnoera9)-7 3,6 3-6napqnjpdeo):bej`$#_kqjp#(]nn]u$#_kj`epekjo#9: _kj`epekjo( 3.6#na_qnoera#9: na_qnoera 3/6%%7 306y 316 326++Iapdk`. 336bqj_pekjl]cej]paPn]joh]pekj$ _kj`epekjo( beah`o( kn`an( 346 heiep( l]ca9-( 356 na_qnoera9jqhh%w 4,6 4-6 hk_]ha9pdeo):capHk_]ha$pdeo):pn]joH]jcq]ca%7 4.6 kbboap9heiep&$ l]ca)-%7 4/6 406napqnjpdeo):mqanu$oaha_p&bnkiopkneao]oOpknu 416sdana 426Opknu*e`jkpej 436$ 446oaha_pbknaecj[gaubnkie-4j 456sdana 5,6hk_]ha9# hk_]ha# 5-6% 5.6heiep kbboap( heiep 5/6%7 506y 516 526bqj_pekjl]cej]pa?kqjpPn]joh]pekj$ _kj`epekjo9jqhh(  na_qnoera9,%w 536 546 hk_]ha9pdeo):capHk_]ha$pdeo):pn]joH]jcq]ca%7 556 -,,6 naoqhpo9pdeo):mqanu$oaha_pe`bnkiopkneao]oOpknu -,-6sdana -,.6Opknu*e`jkpej


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

-,/6$ -,06oaha_pbknaecj[gaubnkie-4j -,16sdana -,26hk_]ha9# hk_]ha# -,36% -,46%7 -,56 --,6napqnj_kqjp$ naoqhpo%7 ---6y --.6 --/6bqj_pekjcapHk_]ha$ h]jc%w --06 --16=ll66eilknp$#e-4j#%7 --26 E-4j9"E-4j66capEjop]j_a$%7 --36 h]jc?k`a9E-4j):h-,j):i]l$ h]jc%7 --46 _]p9E-4j):h-,j):_]p]hkc$ h]jc?k`a%7 --56 -.,6eb$eooap$ _]pW#hk_]ha#Y%%w -.-6napqnj _]pW#hk_]ha#Y7 -..6y -./6 -.06napqnj##7 -.16y -.26y -.36;: Table 9-1 lists the methods in the model. Table 9-1. Story Model Class Methods

Method

Purpose

l]cej]pa

Cake’s pagination method, which we override

l]cej]pa?kqjp

Another method we must override so Cake can get the correct page count

l]cej]paOp]j`]n`

Same as Cake’s l]cej]pa method

l]cej]pa?kqjpOp]j`]n`

Used by the standard pagination method

l]cej]paPn]joh]pekj

The pagination method used by the translation listing

l]cej]pa?kqjpPn]joh]pekj

Used by the translation listing to count the number of records

Although we override Cake’s l]cej]pa method, we still make use of Cake’s pagination helper. The qoaL]cej]pa variable on line 8 indicates which pagination method to use: the standard one or the translation pagination. If it’s ordinary pagination of results, such as from a bej` command, we basically paginate the results in the same way as how Cake would do it. This seems like duplication, but part of the problem is that once we override the l]cej]pa method, there’s no easy way of going back temporarily to use Cake’s built-in l]cej]pa method.

291


292

CH APT ER 9 N TRA NS L A TING S TOR IES

When qoaL]cej]pa is set to l]cej]paPn]joh]pekj, the l]cej]paPn]joh]pekj method is called. Here, we create a manual SQL command to fetch all the stories that we need to translate. The l]cej]pa?kqjpPn]joh]pekj method is used by Cake so it can provide us with the correct number of total records. One interesting method in the model is capHk_]ha. This gets the locale information from the e-4j object using the language. When developing any i18n/l10n application, you should have a good grasp of the language codes and locales. We had a hard time picking whether to use language codes or locales in the various actions. The following section will give you a better understanding of the Translate behavior in relation to locales and language codes.

Locale and Language Selection Setting the locale via the model is the main technique for telling the Translate behavior which locale to use. However, there are other techniques, all of which will give you an understanding of how the behavior works. If we do not set the locale anywhere, the Translate behavior uses aj[qo as the default locale, which is set in the class itself.

Setting Locale by Browser If you do not specify a locale, the behavior uses the browserâ&#x20AC;&#x2122;s DPPL[=??ALP[H=JCQ=CA header to work out which language to use. Cake automatically maps this out in the key value of the [[h-,j?]p]hkc variable (see +_]ga+he^o+h-,j*ldl). If DPPL[=??ALP[H=JCQ=CA is aj, for example, the aj value in the [[h-,j?]p]hkc variable is used. Listing 9-15 shows an example. Listing 9-15. A Sample Listing in the $__l10nCatalog Array r]n [[h-,j?]p]hkc9]nn]u$ #aj#9:]nn]u$#h]jcq]ca#9:#Ajcheod#( #hk_]ha#9:#ajc#( #hk_]haB]hh^]_g#9:#ajc#( #_d]noap#9: #qpb)4#%( #aj)c^#9:]nn]u$#h]jcq]ca#9:#Ajcheod$>nepeod%#( #hk_]ha#9:#aj[c^#( #hk_]haB]hh^]_g#9:#ajc#( #_d]noap#9:#qpb)4#%( #aj)qo#9:]nn]u$#h]jcq]ca#9:#Ajcheod$Qjepa`Op]pao%#( #hk_]ha#9:#aj[qo#( #hk_]haB]hh^]_g#9:#ajc#( #_d]noap#9:#qpb)4#%( #f]#9:]nn]u$#h]jcq]ca#9:#F]l]jaoa#( #hk_]ha#9:#flj#( #hk_]haB]hh^]_g#9:#flj#( #_d]noap#9:#qpb)4#% %7


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

In this method, we use the @AB=QHP[H=JCQ=CA constant to override the DPPL[=??ALP[ H=JCQ=CA header; however, this method works only in a specific situation. If [OANRANW#DPPL[ =??ALP[H=JCQ=CA#Y is set and Cake has found a match, the @AB=QHP[H=JCQ=CA value will have no effect. You cannot override the browser DPPL[=??ALP[H=JCQ=CA value. However, if Cake cannot find a match, the @AB=QHP[H=JCQ=CA language will be used. This constant uses the three-letter ISO 639-3 language code standard.

NNote If you are interested in the format of DPPL[=??ALP[H=JCQ=CA, see section 14.4 Accept-Language of the HTTP standard $dppl6++sss*s/*knc+Lnkpk_kho+nb_.2-2+nb_.2-2)oa_-0*dpih).

Setting Locale by Language Code You can set the locale manually via the two-letter language code. This is done as follows in the h-,j class, which is used by the Translate behavior. =ll66eilknp$#e-4j#%7 E-4j9"E-4j66capEjop]j_a$%7 E-4j):h-,j):cap$#f]#%7 Here, we set the locale to Japanese. To set the locale, we first import the e-4j class file in +_]ga+he^o+e-4j*ldl. Next, we get the instance of that class. Calling the cap method in +_]ga+ he^o+h-,j*ldl sets the locale.

Setting Locale by Hand To give you an idea of the additional ways for setting the locale, here’s an alternate, albeit not recommended, method: if you manually set the DPPL[=??ALP[H=JCQ=CA header, the cap method in +_]ga+he^o+h-,j*ldl will pick that as the language to use. Here is an example: [OANRANW#DPPL[=??ALP[H=JCQ=CA#Y9#aj)c^#7 =ll66eilknp$#?kna#(#E-4j#%7 E-4j9"E-4j66capEjop]j_a$%7 E-4j):h-,j):cap$%7

User Authentication In the baking of our application, we were asked whether we also wanted admin features as well. We answered yes, and the ^]ga command created the actions and the corresponding views for us. Four admin actions were created: ]`iej[reas, which lists stories with links to edit and delete in each record; and ]`iej[]``, ]`iej[a`ep, and ]`iej[`ahapa, which add, edit, and delete stories, respectively. However, the baking doesn’t add user functionality or authentication. We’re happy to say that adding user authentication is a straightforward process.

293


294

CH APT ER 9 N TRA NS L A TING S TOR IES

In Cake, you can easily use the =qpd component to add user authentication, as we have shown in the previous chapter. In this chapter, we’re going to show you how authentication can be added manually. For authentication, we create a user session variable, which tells us whether the user is logged in. Using the ^abknaBehpan command, we check whether the user is accessing any of the admin features by checking the URL for the ]`iej keyword. If that exists, we then check whether the user session variable has been set. If it has, we do nothing and just let execution continue on to the action. If the user session variable has not been set, we redirect the user to the login screen. This checking is placed in the /]ll+]ll[_kjpnkhhan*ldl file, as shown in Listing 9-16, so it is called automatically on every action. Listing 9-16. Admin Authentication (in /app/app_controller.php) bqj_pekj_da_g=`iejOaooekj$%w eb$ pdeo):Oaooekj):_da_g$#Qoan#%%w ++Oapbh]odiaoo]ca]j`na`ena_p pdeo):Oaooekj):oapBh]od$[[$#Lha]oahkcejbenop*#(pnqa%%7 pdeo):na`ena_p$#+qoano+hkcej+#%7 y y

bqj_pekj^abknaBehpan$%w eb$eooap$pdeo):l]n]ioW#]`iej#Y%%w pdeo):_da_g=`iejOaooekj$%7 y y

Logging In Before we talk about the hkcej action, we need to look at the qoano table. This table’s schema is shown in Listing 9-17. Listing 9-17. The users Table Schema ?NA=PAP=>HA\qoano\$ \e`\ejp$--%JKPJQHH]qpk[ej_naiajp( \j]ia\r]n_d]n$.11%JKPJQHH( \qoanj]ia\r]n_d]n$.11%JKPJQHH( \l]ooskn`\r]n_d]n$.11%JKPJQHH( LNEI=NUGAU$\e`\% %


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

As we are just creating a simple authentication system, the Qoan model is almost empty. 8;ldl _h]ooQoanatpaj`o=llIk`ahw r]n j]ia9#Qoan#7 y ;: Next, we create the login action in the Qoan?kjpnkhhan, as shown in Listing 9-18. Listing 9-18. The login Action (/app/controllers/user_controller.php) 8;ldl _h]ooQoano?kjpnkhhanatpaj`o=ll?kjpnkhhanw r]n j]ia9#Qoano#7  r]n dahlano9]nn]u$#Dpih#(#Bkni#%7  bqj_pekjhkcej$%w  eb$ailpu$pdeo):`]p]%%w   qoan9pdeo):Qoan):bej`>uQoanj]ia$pdeo):`]p]W#Qoan#YW#qoanj]ia#Y%7  eb$ qoan%w  eb$ qoanW#Qoan#YW#l]ooskn`#Y99i`1$ÂŁ pdeo):`]p]W#Qoan#YW#l]ooskn`#Y%%w  pdeo):Oaooekj):snepa$#Qoan#( qoan%7  pdeo):Oaooekj):oapBh]od$#Dahhk#* qoanW#Qoan#YW#j]ia#Y%7  pdeo):na`ena_p$#+#%7  y ahoaw pdeo):oap$#annkn#(#HkcejB]eha`#%7 y y y y y ;:

295


296

CH APT ER 9 N TRA NS L A TING S TOR IES

When a user logs in, the hkcej action in the Qoan?kjpnkhhan is called. This action is wholly used for the process of attempting to login the user. The corresponding login view simply holds the login form. In the hkcej action, we first check whether any data is being submitted. Then we try to locate the userâ&#x20AC;&#x2122;s name. If one is found, we check the passwordâ&#x20AC;&#x201D;using MD5 hashing, naturally. If the password is found, we assign the result to the user session variable, set a flash welcome message, and redirect the user back to the home page. The layout in +]ll+reaso+h]ukqp+`ab]qhp*_pl contains some user session-related code. These are the links that are displayed when a user logs in: 8;ldl eb$oaooekj):_da_g$#Qoan#%%w a_dkdpih):hejg$[[$#Hkckqp#(pnqa%(#+Qoano+hkckqp#%7 a_dk#"j^ol7x"j^ol7#7 a_dkdpih):hejg$[[$#HeopOpkneao#(pnqa%(#+]`iej+Opkneao+ej`at#%7 a_dk#"j^ol7x"j^ol7#7 a_dkdpih):hejg$[[$#JasOpknu#(pnqa%(#+]`iej+Opkneao+]``#%7 a_dk#"j^ol7x"j^ol7#7 a_dkdpih):hejg$[[$#Pn]joh]pa#(pnqa%(#+]`iej+Opkneao+pkPn]jo#%7 y ahoaw a_dkdpih):hejg$#Hkcej#(#+Qoano+hkcej#%7 y ;:

Logging Out Logging a user out of the system is probably the easiest action in the whole application. We simply delete the user session variable, set a flash message, and then redirect the user back to the home page. The logout action is created in the Qoano?kjpnkhhan. No view is needed, as we are redirecting the user. It looks like this: bqj_pekjhkckqp$%w pdeo):Oaooekj):`ahapa$#Qoan#%7 pdeo):Oaooekj):oapBh]od$#HkckqpKG*Lha]oa_kia^]_gokkj#%7 pdeo):na`ena_p$#+#%7 y


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

Baked Code Listings 9-19 through 9-28 show the code that was automatically generated using Cakeâ&#x20AC;&#x2122;s ^]ga command. Listing 9-19. The Story Model Class (/app/models/story.php) 8;ldl _h]ooOpknuatpaj`o=llIk`ahw r]n j]ia9#Opknu#7 y ;:

Listing 9-20. The StoriesController Class (/app/controllers/stories_controller.php) 8;ldl _h]ooOpkneao?kjpnkhhanatpaj`o=ll?kjpnkhhanw r]n j]ia9#Opkneao#7 r]n dahlano9]nn]u$#Dpih#(#Bkni#%7 bqj_pekjej`at$%w pdeo):Opknu):na_qnoera9,7 pdeo):oap$#opkneao#(pdeo):l]cej]pa$%%7 y bqj_pekjreas$ e`9jqhh%w eb$ e`%w pdeo):bh]od$[[$#Ejr]he`Opknu#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7 y pdeo):oap$#opknu#(pdeo):Opknu):na]`$jqhh( e`%%7 y bqj_pekj]``$%w eb$ailpu$ pdeo):`]p]%%w pdeo):Opknu):_na]pa$%7 eb$ pdeo):Opknu):o]ra$ pdeo):`]p]%%w pdeo):bh]od$[[$#Opknuo]ra`*#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7 yahoaw y y y

297


298

CH APT ER 9 N TRA NS L A TING S TOR IES

bqj_pekja`ep$ e`9jqhh%w eb$ e`""ailpu$ pdeo):`]p]%%w pdeo):bh]od$[[$#Ejr]he`Opknu#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7 y eb$ailpu$ pdeo):`]p]%%w eb$ pdeo):Opknu):o]ra$ pdeo):`]p]%%w pdeo):bh]od$[[$#PdaOpknud]o^aajo]ra`*#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7 yahoaw y y eb$ailpu$ pdeo):`]p]%%w pdeo):`]p]9pdeo):Opknu):na]`$jqhh( e`%7 y y bqj_pekj`ahapa$ e`9jqhh%w eb$ e`%w pdeo):bh]od$[[$#Ejr]he`Opknu#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7 y eb$ pdeo):Opknu):`ah$ e`%%w pdeo):bh]od$[[$#Opknu`ahapa`#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7 y y

bqj_pekj]`iej[ej`at$%w pdeo):Opknu):na_qnoera9,7 pdeo):oap$#opkneao#(pdeo):l]cej]pa$%%7 y bqj_pekj]`iej[reas$ e`9jqhh%w eb$ e`%w pdeo):bh]od$[[$#Ejr]he`Opknu#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7 y pdeo):oap$#opknu#(pdeo):Opknu):na]`$jqhh( e`%%7 y


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

bqj_pekj]`iej[]``$%w eb$ailpu$ pdeo):`]p]%%w pdeo):Opknu):_na]pa$%7 eb$ pdeo):Opknu):o]ra$ pdeo):`]p]%%w pdeo):bh]od$[[$#Opknuo]ra`*#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7 yahoaw y y y bqj_pekj]`iej[a`ep$ e`9jqhh%w eb$ e`""ailpu$ pdeo):`]p]%%w pdeo):bh]od$[[$#Ejr]he`Opknu#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7 y eb$ailpu$ pdeo):`]p]%%w eb$ pdeo):Opknu):o]ra$ pdeo):`]p]%%w pdeo):bh]od$[[$#PdaOpknud]o^aajo]ra`*#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7 yahoaw y y eb$ailpu$ pdeo):`]p]%%w pdeo):`]p]9pdeo):Opknu):na]`$jqhh( e`%7 y y bqj_pekj]`iej[`ahapa$ e`9jqhh%w eb$ e`%w pdeo):bh]od$[[$#Ejr]he`Opknu#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7 y eb$ pdeo):Opknu):`ah$ e`%%w pdeo):bh]od$[[$#Opknu`ahapa`#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7 y y y ;:

299


300

CH APT ER 9 N TRA NS L A TING S TOR IES

Listing 9-21. The add Action View File (/app/views/stories/add.ctp) 8`er_h]oo9opkneaobkni: 8;ldla_dkbkni):_na]pa$#Opknu#%7;: 8beah`oap: 8hacaj`:8;ldl[[$#=``Opknu#%7;:8+hacaj`: 8;ldl a_dkbkni):ejlqp$#pepha#%7 a_dkbkni):ejlqp$#^k`u#%7 ;: 8+beah`oap: 8;ldla_dkbkni):aj`$#Oq^iep#%7;: 8+`er: 8`er_h]oo9]_pekjo: 8qh: 8he:8;ldla_dkdpih):hejg$[[$#HeopOpkneao#(pnqa%(]nn]u£ $#]_pekj#9:#ej`at#%%7;:8+he: 8+qh: 8+`er:

Listing 9-22. The admin_add Action View File (/app/views/stories/admin_add.ctp) 8`er_h]oo9opkneaobkni: 8;ldla_dkbkni):_na]pa$#Opknu#%7;: 8beah`oap: 8hacaj`:8;ldl[[$#=``Opknu#%7;:8+hacaj`: 8;ldl a_dkbkni):ejlqp$#pepha#%7 a_dkbkni):ejlqp$#^k`u#%7 ;: 8+beah`oap: 8;ldla_dkbkni):aj`$#Oq^iep#%7;: 8+`er: 8`er_h]oo9]_pekjo: 8qh: 8he:8;ldla_dkdpih):hejg$[[$#HeopOpkneao#(pnqa%(]nn]u£ $#]_pekj#9:#ej`at#%%7;:8+he: 8+qh: 8+`er:


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

Listing 9-23. The admin_edit Action View File (/app/views/stories/admin_edit.ctp) 8`er_h]oo9opkneaobkni: 8;ldla_dkbkni):_na]pa$#Opknu#%7;: 8beah`oap: 8hacaj`:8;ldl[[$#A`epOpknu#%7;:8+hacaj`: 8;ldl a_dkbkni):ejlqp$#e`#%7 a_dkbkni):ejlqp$#pepha#%7 a_dkbkni):ejlqp$#^k`u#%7 ;: 8+beah`oap: 8;ldla_dkbkni):aj`$#Oq^iep#%7;: 8+`er: 8`er_h]oo9]_pekjo: 8qh: 8he:8;ldla_dkdpih):hejg$[[$#@ahapa#(pnqa%(]nn]u$#]_pekj#9:£ #`ahapa#(bkni):r]hqa$#Opknu*e`#%%(jqhh(olnejpb$[[$#=naukqoqnaukqs]jppk£ `ahapa!o;#(pnqa%(bkni):r]hqa$#Opknu*e`#%%%7;:8+he: 8he:8;ldla_dkdpih):hejg$[[$#HeopOpkneao#(pnqa%(]nn]u£ $#]_pekj#9:#ej`at#%%7;:8+he: 8+qh: 8+`er:

Listing 9-24. The admin_index Action View File (/app/views/stories/admin_index.ctp) 8`er_h]oo9opkneaoej`at: 8d.:8;ldl[[$#Opkneao#%7;:8+d.: 8l: 8;ldl a_dkl]cej]pkn):_kqjpan$]nn]u$ #bkni]p#9:[[$#L]ca!l]ca!kb!l]cao!(odksejc!_qnnajp!na_kn`okqpkb !_kqjp!pkp]h(op]npejckjna_kn`!op]np!(aj`ejckj!aj`!#(pnqa% %%7 ;:8+l: 8p]^ha_ahhl]``ejc9,_ahhol]_ejc9,: 8pn: 8pd:8;ldla_dkl]cej]pkn):oknp$#e`#%7;:8+pd: 8pd:8;ldla_dkl]cej]pkn):oknp$#pepha#%7;:8+pd: 8pd:8;ldla_dkl]cej]pkn):oknp$#^k`u#%7;:8+pd: 8pd_h]oo9]_pekjo:8;ldl[[$#=_pekjo#%7;:8+pd: 8+pn:

301


302

CH APT ER 9 N TRA NS L A TING S TOR IES

8;ldl e9,7 bkna]_d$ opkneao]o opknu%6  _h]oo9jqhh7 eb$ e''!.99,%w  _h]oo9#_h]oo9]hpnks#7 y ;: 8pn8;ldla_dk _h]oo7;:: 8p`: 8;ldla_dk opknuW#Opknu#YW#e`#Y7;: 8+p`: 8p`: 8;ldla_dk opknuW#Opknu#YW#pepha#Y7;: 8+p`: 8p`: 8;ldla_dk opknuW#Opknu#YW#^k`u#Y7;: 8+p`: 8p`_h]oo9]_pekjo: 8;ldla_dkdpih):hejg$[[$#Reas#(pnqa%( ]nn]u$#]_pekj#9:#reas#( opknuW#Opknu#YW#e`#Y%%7;: 8;ldla_dkdpih):hejg$[[$#A`ep#(pnqa%(]nn]u$#]_pekj#9:#a`ep#(  opknuW#Opknu#YW#e`#Y%%7;: 8;ldla_dkdpih):hejg$[[$#@ahapa#(pnqa%( ]nn]u$#]_pekj#9:#`ahapa#( opknuW#Opknu#YW#e`#Y%(jqhh( olnejpb$[[$#=naukqoqnaukqs]jppk`ahapa!o;#(pnqa%(  opknuW#Opknu#YW#e`#Y%%7;: 8+p`: 8+pn: 8;ldlaj`bkna]_d7;: 8+p]^ha: 8+`er: 8`er_h]oo9l]cejc: 8;ldla_dkl]cej]pkn):lnar$#88#*[[$#lnarekqo#(pnqa%(]nn]u$%( jqhh(]nn]u$#_h]oo#9:#`eo]^ha`#%%7;: x8;ldla_dkl]cej]pkn):jqi^ano$%7;: 8;ldla_dkl]cej]pkn):jatp$[[$#jatp#(pnqa%*#::#(]nn]u$%(jqhh( ]nn]u$#_h]oo#9:#`eo]^ha`#%%7;: 8+`er: 8`er_h]oo9]_pekjo: 8qh: 8he:8;ldla_dkdpih):hejg$[[$#JasOpknu#(pnqa%( ]nn]u$#]_pekj#9:#]``#%%7;:8+he: 8+qh: 8+`er:


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

Listing 9-25. The admin_view Action View File (/app/views/stories/admin_view.ctp) 8`er_h]oo9opkneaoreas: 8d.:8;ldl[[$#Opknu#%7;:8+d.: 8`h:8;ldl e9,7 _h]oo9#_h]oo9]hpnks#7;: 8`p8;ldleb$ e!.99,%a_dk _h]oo7;::8;ldl[[$#E`#%7;:8+`p: 8``8;ldleb$ e''!.99,%a_dk _h]oo7;:: 8;ldla_dk opknuW#Opknu#YW#e`#Y7;: "j^ol7 8+``: 8`p8;ldleb$ e!.99,%a_dk _h]oo7;::8;ldl[[$#Pepha#%7;:8+`p: 8``8;ldleb$ e''!.99,%a_dk _h]oo7;:: 8;ldla_dk opknuW#Opknu#YW#pepha#Y7;: "j^ol7 8+``: 8`p8;ldleb$ e!.99,%a_dk _h]oo7;::8;ldl[[$#>k`u#%7;:8+`p: 8``8;ldleb$ e''!.99,%a_dk _h]oo7;:: 8;ldla_dk opknuW#Opknu#YW#^k`u#Y7;: "j^ol7 8+``: 8+`h: 8+`er: 8`er_h]oo9]_pekjo: 8qh: 8he:8;ldla_dkdpih):hejg$[[$#A`epOpknu#(pnqa%( ]nn]u$#]_pekj#9:#a`ep#( opknuW#Opknu#YW#e`#Y%%7;:8+he: 8he:8;ldla_dkdpih):hejg$[[$#@ahapaOpknu#(pnqa%( ]nn]u$#]_pekj#9:#`ahapa#( opknuW#Opknu#YW#e`#Y%( jqhh(olnejpb$[[$#=naukqoqnaukqs]jppk`ahapa!o;#(pnqa%(  opknuW#Opknu#YW#e`#Y%%7;:8+he: 8he:8;ldla_dkdpih):hejg$[[$#HeopOpkneao#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7;:8+he: 8he:8;ldla_dkdpih):hejg$[[$#JasOpknu#(pnqa%( ]nn]u$#]_pekj#9:#]``#%%7;:8+he: 8+qh: 8+`er:

Listing 9-26. The edit Action View File (/app/views/stories/edit.ctp) 8`er_h]oo9opkneaobkni: 8;ldla_dkbkni):_na]pa$#Opknu#%7;: 8beah`oap: 8hacaj`:8;ldl[[$#A`epOpknu#%7;:8+hacaj`: 8;ldl a_dkbkni):ejlqp$#e`#%7 a_dkbkni):ejlqp$#pepha#%7 a_dkbkni):ejlqp$#^k`u#%7 ;: 8+beah`oap:

303


304

CH APT ER 9 N TRA NS L A TING S TOR IES

8;ldla_dkbkni):aj`$#Oq^iep#%7;: 8+`er: 8`er_h]oo9]_pekjo: 8qh: 8he:8;ldla_dkdpih):hejg$[[$#@ahapa#(pnqa%( ]nn]u$#]_pekj#9:#`ahapa#(bkni):r]hqa$#Opknu*e`#%%( jqhh(olnejpb$[[$#=naukqoqnaukqs]jppk`ahapa!o;#(pnqa%( bkni):r]hqa$#Opknu*e`#%%%7;:8+he: 8he:8;ldla_dkdpih):hejg$[[$#HeopOpkneao#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7;:8+he: 8+qh: 8+`er:

Listing 9-27. The index Action View File (/app/views/stories/index.ctp) 8`er_h]oo9opkneaoej`at: 8d.:8;ldl[[$#Opkneao#%7;:8+d.: 8l: 8;ldl a_dkl]cej]pkn):_kqjpan$]nn]u$ #bkni]p#9:[[$#L]ca!l]ca!kb!l]cao!(odksejc!_qnnajp!na_kn`okqpkb !_kqjp!pkp]h(op]npejckjna_kn`!op]np!(aj`ejckj!aj`!#(pnqa% %%7 ;:8+l: 8p]^ha_ahhl]``ejc9,_ahhol]_ejc9,: 8pn: 8pd:8;ldla_dkl]cej]pkn):oknp$#e`#%7;:8+pd: 8pd:8;ldla_dkl]cej]pkn):oknp$#pepha#%7;:8+pd: 8pd:8;ldla_dkl]cej]pkn):oknp$#^k`u#%7;:8+pd: 8pd_h]oo9]_pekjo:8;ldl[[$#=_pekjo#%7;:8+pd: 8+pn: 8;ldl e9,7 bkna]_d$ opkneao]o opknu%6  _h]oo9jqhh7 eb$ e''!.99,%w  _h]oo9#_h]oo9]hpnks#7 y ;: 8pn8;ldla_dk _h]oo7;:: 8p`: 8;ldla_dk opknuW#Opknu#YW#e`#Y7;: 8+p`: 8p`: 8;ldla_dk opknuW#Opknu#YW#pepha#Y7;: 8+p`:


C H A P T E R 9 N T R A N S LA T I N G S T O R I E S

8p`: 8;ldla_dk opknuW#Opknu#YW#^k`u#Y7;: 8+p`: 8p`_h]oo9]_pekjo: 8;ldla_dkdpih):hejg$[[$#Reas#(pnqa%( ]nn]u$#]_pekj#9:#reas#( opknuW#Opknu#YW#e`#Y%%7;: 8;ldla_dkdpih):hejg$[[$#A`ep#(pnqa%( ]nn]u$#]_pekj#9:#a`ep#( opknuW#Opknu#YW#e`#Y%%7;: 8;ldla_dkdpih):hejg$[[$#@ahapa#(pnqa%( ]nn]u$#]_pekj#9:#`ahapa#( opknuW#Opknu#YW#e`#Y%( jqhh(olnejpb$[[$#=naukqoqnaukqs]jppk`ahapa!o;#(pnqa%(  opknuW#Opknu#YW#e`#Y%%7;: 8+p`: 8+pn: 8;ldlaj`bkna]_d7;: 8+p]^ha: 8+`er: 8`er_h]oo9l]cejc: 8;ldla_dkl]cej]pkn):lnar$#88#*[[$#lnarekqo#(pnqa%(]nn]u$%(jqhh(]nn]u£ $#_h]oo#9:#`eo]^ha`#%%7;: x8;ldla_dkl]cej]pkn):jqi^ano$%7;: 8;ldla_dkl]cej]pkn):jatp$[[$#jatp#(pnqa%*#::#(]nn]u$%(jqhh(]nn]u£ $#_h]oo#9:#`eo]^ha`#%%7;: 8+`er: 8`er_h]oo9]_pekjo: 8qh: 8he:8;ldla_dkdpih):hejg$[[$#JasOpknu#(pnqa%(]nn]u£ $#]_pekj#9:#]``#%%7;:8+he: 8+qh: 8+`er:

Listing 9-28. The view Action View File (/app/views/stories/view.ctp) 8`er_h]oo9opkneaoreas: 8d.:8;ldl[[$#Opknu#%7;:8+d.: 8`h:8;ldl e9,7 _h]oo9#_h]oo9]hpnks#7;: 8`p8;ldleb$ e!.99,%a_dk _h]oo7;::8;ldl[[$#E`#%7;:8+`p: 8``8;ldleb$ e''!.99,%a_dk _h]oo7;:: 8;ldla_dk opknuW#Opknu#YW#e`#Y7;: "j^ol7 8+``: 8`p8;ldleb$ e!.99,%a_dk _h]oo7;::8;ldl[[$#Pepha#%7;:8+`p: 8``8;ldleb$ e''!.99,%a_dk _h]oo7;:: 8;ldla_dk opknuW#Opknu#YW#pepha#Y7;: "j^ol7 8+``:

305


306

CH APT ER 9 N TRA NS L A TING S TOR IES

8`p8;ldleb$ e!.99,%a_dk _h]oo7;::8;ldl[[$#>k`u#%7;:8+`p: 8``8;ldleb$ e''!.99,%a_dk _h]oo7;:: 8;ldla_dk opknuW#Opknu#YW#^k`u#Y7;: "j^ol7 8+``: 8+`h: 8+`er: 8`er_h]oo9]_pekjo: 8qh: 8he:8;ldla_dkdpih):hejg$[[$#A`epOpknu#(pnqa%( ]nn]u$#]_pekj#9:#a`ep#( opknuW#Opknu#YW#e`#Y%%7;:8+he: 8he:8;ldla_dkdpih):hejg$[[$#@ahapaOpknu#(pnqa%( ]nn]u$#]_pekj#9:#`ahapa#( opknuW#Opknu#YW#e`#Y%( jqhh(olnejpb$[[$#=naukqoqnaukqs]jppk`ahapa!o;#(pnqa%(  opknuW#Opknu#YW#e`#Y%%7;:8+he: 8he:8;ldla_dkdpih):hejg$[[$#HeopOpkneao#(pnqa%( ]nn]u$#]_pekj#9:#ej`at#%%7;:8+he: 8he:8;ldla_dkdpih):hejg$[[$#JasOpknu#(pnqa%( ]nn]u$#]_pekj#9:#]``#%%7;:8+he: 8+qh: 8+`er:

Summary In this chapter, we introduced Cake’s Translate behavior. Using Cake’s e-4j table, we were able to store the translations of stories held in a database, rather than in a static HTML file. Next, we created some admin actions using Cake’s ^]ga command, which generated actions with the ]`iej[ prefix. Using those actions, a real human translator will have the ability to translate stories from one language to another. Within the Opknu model, we wrote our own pagination code so the appropriate stories will be paginated depending on the selected language. Finally, to secure the admin actions, we rolled our own authentication code.


C HAPTER

10

Adding Automagic Fields I

n many other MVC frameworks, certain database fields have special significance when a user accesses the model data. These fields are often called magic fields, because the underlying controller automatically works out which value it should contain. Cake also has such magic fields. In addition to using the built-in magic fields, you can create custom magic fields to suit your needs. In this chapter, we’ll create three new magic fields. But before we begin, let’s look at the built-in magic fields.

Cake’s Built-in Magic Fields When you use Cake’s built-in magic fields, you don’t need to write any code in order for Cake to automatically update them. Once the field is present in the database, Cake will detect its presence and update the value automatically. Table 10-1 lists the magic database fields in Cake. Table 10-1. Cake’s Magic Fields

Field

Type

Description

e`

ejp, ^ecejp, or r]n_d]n

This is the default field name for the primary key of the table. If it is defined as an ejp field with ]qpk[ej_naiajp, it will automatically generate a numeric primary key. However, if the field is something like a r]n_d]n$/2%, Cake will generate and manage a UUID for this field.

j]ia

r]n_d]n or other text type

Cake will use this field in various circumstances, mainly for the Scaffolding, List, and Tree behaviors. For example, when you create an HTML drop-down list using the oaha_p method in the form helper, it will automatically use the j]ia field as the display string in the drop-down list.

pepha

This is an alias for the j]ia field.

_na]pa`

`]papeia

When a new record is added, this field contains a timestamp of when the record was created.

ik`ebea`

`]papeia

Similar to the _na]pa` field, when a record is changed, this field contains a timestamp of when it was modified.

ql`]pa`

This is an alias for the ik`ebea` field.

Woejcqh]nik`ah Matches type in associated j]iaY[e`

This is the foreign key reference used in model associations. If you do not manually specify the foreign key field name, this is what it would use.

table

307


308

CH APT ER 10 N AD DING A U TOMA G IC FIEL DS

There are other special fields that relate only to particular behaviors. For example, in the Tree behavior, the following three fields are used: Ê

UÊ l]najp stores the ID of the parent field.

Ê

UÊ hbp stores the ID of the left-branch record of the tree structure.

Ê

UÊ ncdp stores the ID of the right-branch record of the tree structure.

Writing a Custom Behavior Magic fields are managed by the model layer through resources called behaviors. Behaviors make it possible to perform automagic methods on database fields as the model runs its various data-handling methods, such as ]bpanBej` or ^abknaO]ra. For instance, upon saving a new record to the table, the model passes all of its data through to any attached behavior classes. This gives the attached behaviors the opportunity to intercept the save process and perform any business logic based on or relating to the intercepted data. This may involve cross-table or cross-database updates based on what is being saved. In other words, an automagic update occurs in fields that are not necessarily part of the record being saved. So, before we get to creating custom magic fields, we need to talk about how to create your own custom behavior. First, you create a PHP file to be stored in the folder +]ll+ik`aho+^ad]rekno. This file contains the code that will drive the behavior. The file name must be in lowercase, and multiple words are separated with underscores. The behavior class name must also be in camel case, with the word >ad]rekn appended, and it must extend the class Ik`ah>ad]rekn. Here’s how to start a custom behavior class: 8;ldl _h]oo?qopki>ad]reknatpaj`oIk`ah>ad]reknw y ;: The next step is to include the behavior in the model itself. This is done by including the ]_po=o variable in the model, as follows: r]n ]_po=o9]nn]u$#?qopki#9:]nn]u$#l]n]iapan#(£ #]jkpdan[l]n]iapan#%%7 A Cake behavior helps you by transparently performing some operation in the background. When the model methods `ahapa, o]ra, and bej` are used, it will trigger other functions (commonly called callback functions) in your behavior class. Here are the other functions of the model’s `ahapa method in a behavior and the sequence in which they are called: 1. Model behaviors’ ^abkna@ahapa$% method 2. Model’s `ahapa$% method 3. Model behaviors’ ]bpan@ahapa$% method


C H A P T E R 1 0 N A D D I N G A U T O M A G I C F I E LD S

So, when a model’s `ahapa method is called, starting from step 1, the ^abkna@ahapa method in all the behaviors that are attached to the model is called before the record is deleted. In step 2, the record is deleted. And finally, in step 3, the ]bpan@ahapa method in all the behaviors that are attached to the model is called. Here are the other functions of the model’s o]ra method in a behavior and their order: 1. Model behaviors’ ^abknaR]he`]pekj$% method 2. Model behaviors’ ^abknaO]ra$% method 3. Model’s o]ra$% method 4. Model behaviors’ ]bpanO]ra$% method And the following are the other functions of the model’s bej` method in a behavior and their order: 1. Model behaviors’ ^abknaBej`$% method 2. Model’s bej`$% method 3. Model behaviors’ ]bpanBej`$% method Within your behavior class, there is also a method called oapql. This method is called when the parent model is instantiated. Its syntax is as follows: bqj_pekjoapql$" ik`ah( _kjbec9]nn]u$%%w y The model is passed by reference, which means you can directly manipulate the values in the model. The _kjbec variable contains the values you passed to the behavior in the model.

NTip Sometimes, you may need to carry out your own SQL queries within a model rather than using the model’s standard CRUD methods. The callbacks would not work as intended, since they would not know the kind of query you have made. However, you can still make use of the behavior by using the oapql method as an entry point into the behavior, since that is called whenever the model is invoked in any way. This is not an ideal solution, since you would need to manually call the methods within the model behavior yourself; however, it does work.

Building Custom Magic Fields Now that you know how to create a custom behavior, we can start building some magic fields. First, we need to create our behavior, starting with the behavior file itself, which we’ll call I]ce_Beah`oLhqo. The behavior file is created as ]ll+ik`aho+^ad]rekno+i]ce_[beah`o[lhqo* ldl. The skeleton of the file is shown in Listing 10-1. We’ll be adding callback methods to the class. Note that in our case, the oapql method is empty. You can easily add parameters that you can use to alter the way the behavior works.

309


310

CH APT ER 10 N AD DING A U TOMA G IC FIEL DS

Listing 10-1. The MagicFieldsPlus Cake Behavior (app/models/behaviors/magic_fields_plus.php) 8;ldl _h]ooI]ce_Beah`oLhqo>ad]reknatpaj`oIk`ah>ad]reknw bqj_pekjoapql$" ik`ah( _kjbec9]nn]u$%%w y ++?]hh^]_giapdk`odana*** y ;: To avoid potential field name clashes, we’ll append the prefix i[ to the names of all our magic fields.

Access Data Field We’re going to start with something simple. This magic field will increment by one whenever it is accessed. We will consider only the use of the model’s bej` method as an “access.” Using the o]ra method will not be counted. (Of course, you can easily change this behavior.) To get this field working, we need to have a field called i[]__aooa`, which will be updated during the ]bpanBej` callback. Since the ]bpanBej` command is a generic method, we’re not going to put the code that will actually do the incrementing in that method. Instead, we’ll create a separate method and call it from the ^abknaBej` method. This two-step process is shown in Listing 10-2. Listing 10-2. Methods for the Access Data Field -6bqj_pekj]bpanBej`$" ik`ah( naoqhpo( lnei]nu%w .6pdeo):i[]__aooa`[i]ce_$ ik`ah( naoqhpo( lnei]nu%7 /6napqnj naoqhpo7 06y 16 26bqj_pekji[]__aooa`[i]ce_$" ik`ah( naoqhpo( lnei]nu%w 36eb$ik`ah):d]oBeah`$#i[]__aooa`#%%w 46bkna]_d$ naoqhpo]o na_kn`%w 56 na_kn`Wik`ah):j]iaYW#i[]__aooa`#Y''7 -,6ik`ah):o]ra$ na_kn`%7 --6y -.6y -/6y Starting from the ]bpanBej` method, this simply calls the i[]__aooa`[i]ce_ method on line 2. Within the i[]__aooa`[i]ce_ method, we first check whether the field name i[]__aooa` exists. If it does, we loop through the results, incrementing the i[]__aooa` field by one in each case.


C H A P T E R 1 0 N A D D I N G A U T O M A G I C F I E LD S

NNote This access data field can be quite useful for data-intelligence gathering. However, it’s obviously not that efficient, as it needs to save each record in turn. As an exercise, you can change the code to save the access data out to an external flat file and update the i[]__aooa` field at a later date.

Record Order Data Field Sometimes, you may just want to order the fields numerically by default. For example, in a shop’s products listing, the shop owner may want to place the best-selling items at the top. Our next magic field applies to find operations. We want the results returned to be ordered numerically. We will add a new field called i[na_kn`[kn`an. We will specify the ordering in the ^abknaBej` callback. Similar to how we constructed the access data field, the record order data field will be composed of two parts within the behavior, as shown in Listing 10-3. Listing 10-3. Methods for the Record Order Data Field -6bqj_pekj^abknaBej`$" ik`ah( mqanu%w .6napqnjpdeo):i[na_kn`[kn`an[i]ce_$ ik`ah( mqanu%7 /6y 06 16bqj_pekji[na_kn`[kn`an[i]ce_$" ik`ah( mqanu%w 26eb$ik`ah):d]oBeah`$#i[na_kn`[kn`an#%%w 36 mqanuW#kn`an#Y9#i[na_kn`[kn`an@AO?#7 46y 56napqnj mqanu7 -,6y The method i[na_kn`[kn`an[i]ce_ is called from the ^abknaBej` callback. On line 6, we check whether the field exists. If it does, we specify a particular ordering in the mqanu array on line 7. The format of the kn`an key is the same as the kn`an attribute in the model’s bej` method, so you can order it according to your own needs. For example, if you have another field called lnk`q_p[cnkql[e`, you can order it according to lnk`q_p[cnkql[e` and then by i[na_kn`[ kn`an. So, you can use any of the following statements for the kn`an value: Ê

UÊ lnk`q_p[cnkql[e`(i[na_kn`[kn`an@AO?

Ê

UÊ lnk`q_p[cnkql[e`@AO?(i[na_kn`[kn`an=O?

Ê

UÊ ]nn]u$#lnk`q_p[cnkql[e`#(#i[na_kn`[kn`an@AO?#%

Ê

UÊ ]nn]u$#lnk`q_p[cnkql[e`@AO?#(#i[na_kn`[kn`an=O?#%

If you do not want to hard-code the ordering direction, you can specify it in the ]_po=o behavior variable. There are any number of array formats that you can use to pass the `ena_pekj parameter from the ]_p=o variable into the behavior. In the example in Listing 10-4, we’re using the magic field name as the key, with the value containing an associative array of key/ value pairs that the magic field can use.

311


312

CH APT ER 10 N AD DING A U TOMA G IC FIEL DS

Listing 10-4. Passing Configuration Parameters to the Behavior r]n ]_po=o9]nn]u$#I]ce_Beah`oLhqo#9:£ ]nn]u$i[na_kn`[kn`an9:]nn]u$`ena_pekj9:=O?%%%7 Once we have set up the configuration in the model file, we need to catch the configuration values in the oapql method in the behavior itself. This is shown in Listing 10-5. Listing 10-5. Setting the Default Values in the Behavior (/app/models/ behaviors/magic_fields_ plus.php) -6r]n i]ce_Beah`L]n]io9]nn]u$%7 .6 /6bqj_pekjoapql$" ik`ah( _kjbec9]nn]u$%%w 06pdeo):i]ce_Beah`L]n]io9]i$pdeo):i]ce_Beah`L]n]io( _kjbec%7 16y The _kjbec variable on line 3 will now contain the configuration values as passed to it in the model’s ]_p=o variable. We’ve also added a i]ce_Beah`L]n]io variable, which we’ll use to store the configuration values. The contents of the _kjbec variable are as follows: =nn]u $ Wi[na_kn`[kn`anY9:=nn]u $ W`ena_pekjY9:=O? % % Using Cake’s convenience method ]i for merging arrays, we merge the class member variable i]ce_Beah`L]n]io with the _kjbec variable. Now using our configuration parameters for the sorting direction, we have a new i[na_kn`[kn`an[i]ce_ method, which is shown in Listing 10-6. It is similar to the one in Listing 10-3, except that instead of hard-coding our sorting direction, we’re picking it up from the value that was passed to us from the model’s ]_p=o variable. Listing 10-6. Magic Method Using Configuration Values bqj_pekji[na_kn`[kn`an[i]ce_$" ik`ah( mqanu%w eb$ik`ah):d]oBeah`$#i[na_kn`[kn`an#%%w  `ena_pekj9#@AO?#7 eb$eooap$pdeo):i]ce_Beah`L]n]ioW#i[na_kn`[kn`an#Y£ W#`ena_pekj#Y%%w  `ena_pekj9pdeo):i]ce_Beah`L]n]ioW#i[na_kn`[kn`an#Y£ W#`ena_pekj#Y7 y  mqanuW#kn`an#Y9#i[na_kn`[kn`an#* `ena_pekj7 y napqnj mqanu7 y


C H A P T E R 1 0 N A D D I N G A U T O M A G I C F I E LD S

Locking Data Field Our third magic field is related to optimistic locking. It is more complicated than the previous two. First, let’s consider how optimistic locking works. When two or more processes or users are accessing the same record, who should update first? This question arises quite frequently. In a relational database, the problem falls under the heading of concurrency control. For example, in ticket-booking systems, you sometimes have a time limit for your booking. If you fail to purchase the ticket within the time frame, you probably must start again, and by then, another user may have gotten there first. The time limit demonstrates the use of optimistic locking. When you read the record, you mark it with a value. You take this value with you within the web session. Now when you come to updating the record again, you check whether the value that you are still holding matches the marked record in the database. If it’s different, another user may be trying to update the same record at the same time. You can develop your own ways to mark a record. For example, you might have an application where registered users can override nonregistered users when booking a ticket. Here are some standard methods: Ê

UÊ Use a modified date as the handle. You can still list and view the record, but during updates, you will use the modified date as the comparison.

Ê

UÊ Use a unique ID field as the handle. You write a unique ID to a field when you access the record. If, during an update, it is different from the one you already have in the session, you don’t perform the update.

Ê

UÊ Use an access time field as the handle. Each process will check the access time. If it’s more than a certain set limit, you can access the record and attempt to write new changes.

You can also use another concurrency control called pessimistic locking. This is where you completely lock the record for certain actions like oaha_p or ql`]pa, until the process that owns the lock releases it. But in a stateless web environment, this is obviously not practical. Just imagine the scenario where a user is looking at the prices for football game tickets. Using pessimistic locking, we will prevent all other users from looking at those prices, until the user who has the lock releases the lock. But what indicates that the user is releasing the lock? When he closes the browser window? When he navigates to another page? What happens if he just minimizes that particular page and decides to get a drink before making a purchase? As you can see, pessimistic locking is just not workable here. Now let’s go over how we have implemented optimistic locking in our behavior. We simply use a unique ID to mark our records using a field called i[hk_g. Our magic field will be used only when a user edits a single record and then attempts to update it. The process is split into two stages: Ê

UÊ vÌiÀÊ>Êvˆ˜`ʜ«iÀ>̈œ˜]ÊÜiÊÕ«`>ÌiÊ̅iÊÀiVœÀ`Ê܈̅Ê̅iÊ՘ˆµÕiÊ °

Ê

UÊ 7…i˜Ê>ÊÕÃiÀÊ>ÌÌi“«ÌÃÊ̜ÊÃ>ÛiÊ̅iÊÀiVœÀ`]ÊÜiÊV…iVŽÊ̅iÊ Ê>}>ˆ˜ÃÌÊ̅iʜ˜iÊÃ̜Ài`ʈ˜Ê̅iÊ database; if it’s different, we reject the change. Listing 10-7 shows how we have carried out the first stage in the process.

313


314

CH APT ER 10 N AD DING A U TOMA G IC FIEL DS

Listing 10-7. Optimistic Locking with a Model Behavior -6bqj_pekj]bpanBej`$" ik`ah( naoqhpo( lnei]nu%w .6pdeo):i[hk_g[i]ce_$ ik`ah( naoqhpo( lnei]nu%7 /6napqnj naoqhpo7 06y 16 26bqj_pekji[hk_g[i]ce_$" ik`ah(" naoqhpo( lnei]nu%w 36eb$ik`ah):d]oBeah`$#i[hk_g#%%w 46eb$oevakb$ naoqhpo%99-%w 56 qqe`9Opnejc66qqe`$%7 -,6++Naoqhpopd]psasehhlnaoajppkpdaqoan --6 naoqhpoW,YWik`ah):j]iaYW#i[hk_g#Y9 qqe`7 -.6y -/6 p]^haJ]ia9ik`ah):p]^ha7 -06 e`9ik`ah):e`7 -16ik`ah):mqanu$ql`]pa p]^haJ]iaoapi[hk_g9£ #* qqe`*#sdanae`9#* e`*#%7 -26++Pda_qnnajpik`ah`]p](i]u^aqoa`ej]bkni -36ik`ah):`]p]W ik`ah):j]iaYW#i[hk_g#Y9 qqe`7 -46y -56y On line 6, we call our i[hk_g[i]ce_ method, which will do the work for the first stage. First, we check whether the field i[hk_g exists, on line 7. Next, we proceed only if there’s just one record. Basically, we assume it’s an edit for now. If it is, we create a unique ID using Cake’s qqe`$% method. Next, we update the i[hk_g field by running a SQL QL@=PA statement. We are using a manual update because using the o]ra command would cause a loop by calling our magic field behavior. Alternatively, you can use the behavior’s `eo]^ha$% and aj]^ha$% methods to temporarily disconnect the behavior from the model, but we just wanted to point out that query commands have no effect on behaviors. The naoqhpo array now contains the unique ID, which it can use as a hidden field in a form. In the second stage of the optimistic locking, we carry out the validation. This is where we compare the ID that’s being used on a form and the ID that’s in the database. This code is shown in Listing 10-8. Listing 10-8. Validating an Optimistic Locking Data Field -6bqj_pekj^abknaR]he`]pa$" ik`ah%w .6++Benopbej`pdana_kn` /6eb$eooap$ik`ah):`]p]W ik`ah):j]iaYW#e`#Y%%w 06 e`9ik`ah):`]p]W ik`ah):j]iaYW#e`#Y7 16 p]^ha9ik`ah):p]^ha7 26 _qnnajpNa_kn`9ik`ah):bej`$#]hh#(£ ]nn]u$#_kj`epekjo#9:]nn]u$#e`#9: e`%%%7


C H A P T E R 1 0 N A D D I N G A U T O M A G I C F I E LD S

36eb$ailpu$ _qnnajpNa_kn`%%w 46eb$eooap$ik`ah):`]p]W ik`ah):j]iaYW#i[hk_g#Y%%w 56eb$ik`ah):`]p]W ik`ah):j]iaYW#i[hk_g#Y9£ _qnnajpNa_kn`W,YW p]^haYW#i[hk_g#Y%w -,6ik`ah):r]he`]pekjAnnknoW#i[hk_g#Y9#£ Ql`]pa_kjbhe_p(]jkpdanqoand]o]hna]`uql`]pa`pdana_kn`*Lha]oa£ heop]j`a`eppdana_kn`]c]ej*#7 --6napqnjb]hoa7 -.6y -/6y -06y -16y -26napqnjpnqa7 -36y On line 3, we first check whether we are editing an existing record. If so, we fetch the record from the database using the model’s bej` method. Once a record is found, we check that record against the one in the model data array. If it is different, we manually set the r]he`]pekjAnnkno error array with an error message and then return b]hoa, which in turn will prevent the o]ra command from going forward.

Summary Magic fields are database fields that have special meanings within a Cake model. In this chapter, we added new, custom magic data fields, which involved building custom Cake behaviors. This chapter also highlights a particular point. There’s a school of thought in MVC that recommends that developers write fat models and skinny controllers. Any data manipulation, such as finding or saving records, should be done in the model. Controller actions should be skinny managers with surrounding support from components, models, and behaviors. As you’ve seen in this chapter, by using behaviors, you can really cut down on the amount of logic that is performed by the controller. Some of our magic fields are essentially metadata fields. You might want to move all of them out to a separate metatable. Additionally, you could quickly make the following improvements: Ê

UÊ ``Ê>˜Êi[oa_qnepu magic field. This can store a qoan[cnkql[e` type field. If a user is not within this group, access will be denied to that user.

Ê

UÊ ``Ê>˜Êi[`eolh]u magic field. Use this field to turn the display of the record on or off in the view. For example, you may have an article that you want to display only occasionally, such as once every few weeks.

Ê

UÊ œÃÌÊ`iÛiœ«iÀÃÊ«ÀœL>LÞÊ܈Ê˜œÌÊÕÃiÊ>Ê̅iʓ>}ˆVÊvˆi`ÃÊ>ÌÊ̅iÊÃ>“iÊ̈“i]ÊÜʈÌÊÃii“ÃÊ logical to separate them into separate behaviors.

Ê

UÊ ``ʓ>}ˆVÊvˆi`ÃÊ̅>ÌÊ>ÀiÊëiVˆvˆVÊ̜ÊViÀÌ>ˆ˜Ê>««ˆV>̈œ˜Ã°ÊœÀÊiÝ>“«i]ʈ˜Ê>˜Ê e-commerce application, you might have a jqi^an[kb[o]hao field in a product table. This would allow you to place orders based on the best-selling products.

315


C HAPTER

11

Cake Tags I

n this chapter, we’re going to develop our own HTML-based tags to display two Yahoo! maps. The idea for our application stems from our strong opinion on an important aspect in web development: avoiding mixing presentation markup and logic. We’ll start off this chapter by addressing that point. Our discussion isn’t limited to Cake but covers many other languages and frameworks, including Ruby on Rails, Extensible Stylesheet Language Transformations (XSLT), and the Smarty template engine.

Content and Data Separation The basic premise is that no programming logic should appear in any presentation files, namely templates. To see what we mean, take a look at the semi-pseudo PHP code in Listing 11-1. Listing 11-1. Web Programming in the 1990s -68^k`u: .6 /68;ldl 06 _kjj9iuomh[_kjja_p$hk_]hdkop(iuomh[qoan(iuomh[l]ooskn`%7 16 26 omh9OAHA?Pl]peajp[j]ia(`]pa[kb[^enpd(]``naoo 36BNKIl]peajpo 46SDANAcaj`an9#i]ha#7 56 -,6 naoqhp9iuomh[mqanu$ omh%7 --6 -.6a_dk#8p]^ha:#7 -/6 -06sdeha$ nks9iuomh[bap_d[]ook_$ naoqhp%%w -16a_dk#8pn:#7 -26a_dk#8p`:#* nksWl]peajp[j]iaY*#8+p`:#7 -36a_dk#8p`:#* nksW`]pa[kb[^enpdY*#8+p`:#7 -46a_dk#8p`:#* nksW]``naooY*#8+p`:#7 -56a_dk#8+pn:#7 .,6y .-6

317


318

CH APT ER 11 N CA K E TA G S

..6a_dk#8+p]^ha:#7 ./6;: .06 .168+^k`u: Here, we create a MySQL connection on line 4. Then we execute a query on line 10. Next, we loop through the results, mixing HTML markup with the database data to create a particular view. This code suffers from a number of problems. Suppose that you wanted to change the output formatâ&#x20AC;&#x201D;for example, instead of displaying the data in a p]^ha tag, you wanted it to appear in an RSS format. In this case, you would need to add another layer of logic between the data and the display. You could do that within the code itself with an eb statement, as in this example: eb$ [CAPW#bkni]p#Y99#NOO#%w ++KqplqpejNOObkni]p y ahoaw ++Fqopkqplqpejp]^hap]c y Using an eb statement is OK, but you will run into other problems. For example, when more logic is added, where do you put it? The code will start to get more and more proprietary. No one will understand your structure unless you write good documentation to go with it, and even when you do, other developers may not agree with you or your structure. You also may find that you have not taken other scenarios into account. You could also create another separate file, as in Listing 11-1, that specifically deals with RSS output. So instead of outputting HTML, you output XML in the RSS format. The code in Listing 11-1 can be improved by encapsulating some of the code in functions, as shown in Listing 11-2. Listing 11-2. Using PHP Includes -68^k`u: .6 /68;ldl 06 16i]ga@]p]^]oa?kjja_pekj$%7 26 36 omh9OAHA?Pl]peajp[j]ia(`]pa[kb[^enpd(]``naoo 46BNKIl]peajpo 56SDANAcaj`an9#i]ha#7 -,6 --6 naoqhp9iuomh[mqanu$ omh%7 -.6 -/6eb$ [CAPWbkni]pY99TIH%w -06`eolh]uTIH$ naoqhp%7 -16y


C H A P T E R 1 1 N C A K E T A G S

-26ahoaw -36`eolh]uDPIH$ naoqhp%7 -46y -56;: .,6 .-68+^k`u: This is better, and using an MVC pattern helps, but developers can still develop proprietary designs within the controller. And with such proprietary designs, documentation should be written, but sadly, often it is not.

NNote As a brief diversion, there’s an entertaining take on the separation of data and content on dppl6++ sss*ukqpq^a*_ki+s]p_d;r92ciL0jg,AKA.

We jump ahead now to the use of MVC in the web development process. In basic terms, the controller delegates incoming requests and funnels them to the appropriate end point, which is normally an action in a class. The model handles the data, and the view is responsible for the return format to the recipient. However, the solution still has a problem: in too many cases, we see developers putting more and more logic into the view. Plus, it’s often difficult to distinguish whether a piece of code relates to the application or to the view—for example, when there is some specific data or code that’s just used for a particular format. And with time pressures, it’s often easier to place it in the view. Our Cake tags approach is one small step toward addressing the problem. Following from the previous examples, Listing 11-3 shows how Cake tags would do it. Listing 11-3. Using Cake Tags 8^k`u: 8_plhqcej9@]p]^]oa=__aoo_kjpnkhhan9@^Na_kn`o£ ]_pekj9heopNa_kn`op]^ha9l]peajpocaj`an9i]ha+: 8+^k`u: Our idea in using tags isn’t new, of course. ColdFusion has used it since the 1990s, and Java has JSP tags. For example, in ColdFusion, you can send an e-mail message using the following tag: 8_bi]ehpk9]jkpdan<at]ilha*_kibnki9]jkpdan.<at]ilha*_ki£ oq^fa_p9DahhkBneaj`:Dks]napdejco;8+_bi]eh:

View Template The best place to start explaining how we wrote our Cake tags is from the view. In this application, our Cake tags will be available to use in any view. We’re going to create a sample page in +]ll+reaso+l]cao+dkia*_pl, Cake’s default home page.

319


320

CH APT ER 11 N CA K E TA G S

A Cake tag is essentially an XML wrapper for Cake plugins, where the output from the plugin replaces the Cake tag. We could have used any number of ways of interfacing the tag with Cake, but plugins seem generic enough. Additionally, we envisage some point in the future where the Cake tags can be used as a clean interface between third-party code (Cake plugins) and Cake itself. We can even go one step further and imagine a framework where we can add Cake plugins in a visual development environment and specify the attribute values using a form-based user interface. Now back to our application. In it, we will have a Yahoo! Maps plugin. This plugin will display a geographical map location, which we specify, much the same as with Google Maps. How the Yahoo! Maps plugin is written will be explained a little later, in the “Cake Plugins” section. From our view in Listing 11-4, using our tag method, we will make two requests to display the Yahoo! maps via our Cake tags on lines 3 and 7. Listing 11-4. The Home Page (/app/views/pages/home.ctp) -68d/:IuR]_]pekj@aopej]pekjo8+d/: .6 /68_plhqcej9U]dkki]lo_kjpnkhhan9I]lo]_pekj9`eolh]u£ h]pepq`a904*4125.1hkjcepq`a9.*/0-.-,+: 06 168^n+: 26 368_plhqcej9U]dkki]lo_kjpnkhhan9I]lo]_pekj9`eolh]u£ hk_]pekj9O]jBn]j_eo_k+: 46 568^n+: From this listing, you can see that our Cake tags are named _p (for Cake tag, of course). We’ll be using standard XML syntax format for the tags. A Cake tag is formed with a single XML tag, with no tag end. The attributes are used to pass key value parameters to the Cake plugin. Table 11-1 describes these attributes. Table 11-1. Cake Tag Attributes

Attribute

Description

lhqcej

The name of the plugin that we are calling

_kjpnkhhan The controller within the plugin that we are calling ]_pekj Others

The action within the controller that we are calling Passed into the plugin as named parameters, which can be accessed via Cake’s

l]ooa`=nco controller variable If you ran the code in Listing 11-4 as it is, without overriding Cake’s view, it will just display “My Vacation Destinations” in the d/ tag format, which is not very useful. Our goal is to display two Yahoo! maps, one after the other. In order for that to happen, we must override Cake’s view class so we can parse our Cake tags, as described next.


C H A P T E R 1 1 N C A K E T A G S

Cake View Class Extension Using your own view is quite simple, as shown in Listing 11-5. Listing 11-5. Overriding Cake’s View -68;ldl .6 /6=ll66eilknp$#Reas#(#?]gaP]co#(]nn]u$#beha#9:#_]ga[p]co*ldl#%%7 06 16_h]oo=ll?kjpnkhhanatpaj`o?kjpnkhhanw 26 36r]n l]caPepha9#?d]lpan--)?]gap]co#7 46 56r]n reas9#?]gaP]co#7 -,6y --6;: First, in the global controller +]ll+]ll[_kjpnkhhan*ldl, we import the view using Cake’s =ll66eilknp command (line 3 in Listing 11-5). Next, we set the name of our view class in the controller to our own on line 9.

NNote If you set the Controller’s ]qpkNaj`an variable to b]hoa, no view is rendered, regardless of whether the view was overridden or not.

Next, we create our new view class, as shown in Listing 11-6. Listing 11-6. Our New View Class (/app/views/cake_tags.php) -68;ldl .6 /6_h]oo?]gaP]coReasatpaj`oReasw 06 16bqj_pekjnaj`an$ ]_pekj( h]ukqp( beha%w 26 36 naoqhp9l]najp66naj`an$ ]_pekj( h]ukqp( beha%7 46 56 naoqhp9pdeo):[naj`an?p$ naoqhp%7 -,6 --6napqnj naoqhp7 -.6y -/6 -06bqj_pekj[naj`an?p$ kqplqp%w -16

321


322

CH APT ER 11 N CA K E TA G S

-26 naoqhp9 kqplqp7 -36 i]p_d9-7 -46 kbboap9,7 -56 .,6sdeha$ i]p_d%w .-6 ..6lnac[i]p_d$+8_p$WXsY'%WZ:Y&X+:+( naoqhp(£ i]p_d(LNAC[KBBOAP[?=LPQNA( kbboap%7 ./6 .06eb$ i]p_d%w .16 .26 lhqcej9 _kjpnkhhan9 ]_pekj9 l]n]io9##7 .36 .46 p]c9 i]p_dW,YW,Y7 .56 kbboap9 i]p_dW,YW-Y7 /,6 /-6 tih9jasOeilhaTIHAhaiajp$ p]c%7 /.6 //6bkna]_d$tih):]ppne^qpao$%]o ]ppn9: r]hqa%w /06 /16osep_d$ ]ppn%w /26 /36_]oa#lhqcej#6 /46 lhqcej9 r]hqa7 /56^na]g7 0,6 0-6_]oa#_kjpnkhhan#6 0.6 _kjpnkhhan9 r]hqa7 0/6^na]g7 006 016_]oa#]_pekj#6 026 ]_pekj9 r]hqa7 036^na]g7 046 056`ab]qhp6 1,6 l]n]io*9 ]ppn*#6#* r]hqa*#+#7 1-6^na]g7 1.6y 1/6y 106 116eb$ _kjpnkhhan"" ]_pekj%w 126 136 p]cNaoqhp9pdeo):namqaop=_pekj$£ #+#* lhqcej*#+#* _kjpnkhhan*#+#* ]_pekj*#+#* l]n]io(]nn]u$#napqnj#%%7 146 156 naoqhp9opn[nalh]_a$ p]c( p]cNaoqhp( naoqhp%7 2,6y 2-6y


C H A P T E R 1 1 N C A K E T A G S

2.6ahoaw 2/6^na]g7 206y 216y 226 236napqnj naoqhp7 246y 256y 3,6 3-6;: Our view class name must be in the format WUkqnReasJ]iaYReas and it must extend Cake’s Reas class. The next step is to override the naj`an method. In line 7, we first render the real view using Cake’s naj`an command. On line 9, we intercept the output and parse the _p tags. This is done using our [naj`an?p method, starting from line 14. (If you were to comment out line 9, it would be as if you had not changed any of Cake’s original view output.) In the [naj`an?p method, we take the output of the view after Cake has rendered it, parse any _p tags we find, and call the relevant plugin as specified in the _p tag attributes. We continuously loop through the output and parse and replace the _p tags until there are no more _p tags to process. The _p tags are simply matched with the regular expression in the following line of code: +8_p$WXsY'%WZ:Y&X+:+ Once a match is found, we attempt to fill the four main variables: lhqcej, _kjpnkhhan, ]_pekj, and l]n]io. PHP’s OeilhaTIHAhaiajp class is used to extract all the attributes. Once the _kjpnkhhan and ]_pekj values are in place, we call the actions by using the pdeo):namqaop=_pekj call. In line 59, we simply replace the whole _p tag with the output of the pdeo):namqaop=_pekj call. In line 57 of Listing 11-6, we make a request to a particular action in a Cake plugin. If you were to build your own Cake tag, it would need to be a Cake plugin, so line 57 could access that action in the URL format +lhqcej+_kjpnkhhan+]_pekj+l]n]io.

Cake Plugins Next, to create our Yahoo! Maps plugin, we first create a folder called u]dkki]lo in the ]ll+ lhqcejo folder. Within that folder, we create several files and folders, which will resemble a Cake application folder structure, as follows: U]dkki]lo u]dkki]lo[]ll[_kjpnkhhan*ldl u]dkki]lo[]ll[ik`ah*ldl _kjpnkhhano i]lo[_kjpnkhhan*ldl ik`aho reaso i]lo `eolh]u*_pl

323


324

CH APT ER 11 N CA K E TA G S

The two main files we are concerned with are i]lo[_kjpnkhhan*ldl and `eolh]u*_pl. The i]lo[_kjpnkhhan*ldl file is shown in Listing 11-7. Listing 11-7. Map Controller (maps_controller.php) 8;ldl _h]ooI]lo?kjpnkhhanatpaj`oCkkchaI]lo=ll?kjpnkhhanw r]n qoao9jqhh7 bqj_pekj`eolh]u$%w ++`khkjcepq`a  hkjcepq`a9#),*-.3-00#7 eb$eooap$pdeo):l]ooa`=ncoW#hkjcepq`a#Y%%w  hkjcepq`a9pdeo):l]ooa`=ncoW#hkjcepq`a#Y7 y pdeo):oap$#hkjcepq`a#( hkjcepq`a%7 ++`kh]pepq`a  h]pepq`a9#1-*1,2/.1#7 eb$eooap$pdeo):l]ooa`=ncoW#h]pepq`a#Y%%w  h]pepq`a9pdeo):l]ooa`=ncoW#h]pepq`a#Y7 y pdeo):oap$#h]pepq`a#( h]pepq`a%7 ++Hk_]pekj_]j]hok^aola_ebea` ++sde_dkranne`aopdahkjc]j`h]pr]hqao pdeo):oap$#hk_]pekj#(##%7 eb$eooap$pdeo):l]ooa`=ncoW#hk_]pekj#Y%%w pdeo):oap$#hk_]pekj#(pdeo):l]ooa`=ncoW#hk_]pekj#Y%7 y y y ;: To be honest, this example isn’t terribly exciting. The `eolh]u method simply acts as a proxy for passing values from the _p tag to the view. If no hkjcepq`a or h]pepq`a values are passed, we use some default values, which at present are set to London. However, don’t underestimate what you can actually do. Since you can essentially invoke any plugin, controller, or action, you can wrap any functionality behind a Cake tag.


C H A P T E R 1 1 N C A K E T A G S

The other two files, u]dkki]lo[]ll[_kjpnkhhan*ldl and u]dkki]lo[]ll[ik`ah*ldl, are shown in Listings 11-8 and 11-9, respectively. These are the global controller and model files, similar to the ]ll[_kjpnkhhan*ldl and ]ll[ik`ah*ldl files. In Listing 11-8, we need the JavaScript helper to display the Yahoo! Maps API JavaScript files. Listing 11-8. Yahoo! Maps Controller (yahoomaps_app_controller.php) 8;ldl _h]ooU]dkkI]lo=ll?kjpnkhhanatpaj`o=ll?kjpnkhhanw r]n dahlano9]nn]u$#F]r]o_nelp#%7 y ;:

Listing 11-9. Yahoo! Maps Model (yahoomaps_app_model.php) 8;ldl _h]ooU]dkkI]lo=llIk`ahatpaj`o=llIk`ahw y ;: You can achieve more complex operations in other scenarios. Here are some examples: Ê

UÊ ˆÃ«>ÞÊ̅iÊVÕÀÀi˜ÌÊshopping basket, with the total number of products and a total cost, as follows: 8_blhqcej9A_kiian_a_kjpnkhhan9>]ogap]_pekj9`eolh]uogej9iejei]heop+:

Ê

UÊ ˆÃ«>ÞÊ̅iÊproducts available as a tree menu: 8_blhqcej9A_kiian_a_kjpnkhhan9Lnk`q_po]_pekj9heopLnk`q_poPnaa+:

Ê

UÊ ˆÃ«>ÞÊ̅iÊTwitter public timeline messages in 3D using a Flash 3D display engine called Papervision3D: 8_blhqcej9Pseppan_kjpnkhhan9Op]pqoIapdk`o]_pekj9lq^he_[peiaheja£ bkni]p9l]lanReoekj/@+:

Yahoo! Maps Adding Yahoo! Maps is similar to adding Google Maps. We start by including Yahoo!’s JavaScript Map API. Listing 11-10 shows the view.

325


326

CH APT ER 11 N CA K E TA G S

Listing 11-10. Yahoo! Maps View (/app/plugins/yahoomaps/views/maps/display.ctp) -68;9f]r]o_nelp):hejg$#dppl6++]le*i]lo*u]dkk*_ki+]f]tui]l£ ;r9/*4"]lle`9Wukqksj]legauY#%;: .6 /68opuhapula9patp+_oo: 06i]lw 16daecdp631!7 26se`pd6-,,!7 36y 468+opuha: 56 -,68;ldl --6 qqe`9Opnejc66qqe`$%7 -.6a_dk#8`ere`9#* qqe`*#:8+`er:#7 -/6;: -06 -168o_nelppula9patp+f]r]o_nelp: -26 -36++?na]pa]i]lk^fa_p -46r]ni]l9jasUI]l$`k_qiajp*capAhaiajp>uE`$#8;ldla_dk qqe`7;:#%%7 -56 .,6++Vkki?kjpnkh .-6i]l*]``VkkiHkjc$%7 ..6 ./6++=``i]lpula_kjpnkh .06i]l*]``Pula?kjpnkh$%7 .16 .26++Oapi]lpulapkaepdankb6U=DKK[I=L[O=P(£ U=DKK[I=L[DU>(U=DKK[I=L[NAC .36i]l*oapI]lPula$U=DKK[I=L[NAC%7 .46 .56++@eolh]updai]l_ajpana`kj]cak_k`a`hk_]pekj /,68;ldl /-6eb$ hk_]pekj%w /.6a_dki]l*`n]sVkki=j`?ajpan$#* hk_]pekj*#(/%77 //6y /06ahoaw /16a_dki]l*`n]sVkki=j`?ajpan$£ jasUCakLkejp$* h]pepq`a*(* hkjcepq`a*%(/%77 /26++a_dki]l*`n]sVkki=j`?ajpan$£ jasUCakLkejp$-2*33/04,()53*303-31%(/%77 /36y /46;: /56 0,68+o_nelp:


C H A P T E R 1 1 N C A K E T A G S

When including the API, you need to provide your application ID, which you can get from dppl6++sss*`arahklan*u]dkk*_ki+i]lo+. Next, we create the `er container, which will hold the map, on lines 10 through 13. Since this plugin may be included in the same view more than once, we create a unique ID for the 8`er: element using Cakeâ&#x20AC;&#x2122;s qqe`$% string method. Just to recap, the output from Listing 11-10 will replace the _p tag that called for it. A sample output of the two Yahoo! maps is shown in Figure 11-1.

Figure 11-1. Using Cake tags to display Yahoo! maps Our Yahoo! Maps example is quite simple. We can easily specify other parameters to pass to Yahoo! Maps. For example, to add a zoom level, our Cake tag would look like this: 8_plhqcej9U]dkki]lo_kjpnkhhan9I]lo]_pekj9`eolh]uÂŁ hk_]pekj9O]jBn]j_eo_kvkki9.+:

327


328

CH APT ER 11 N CA K E TA G S

On line 32 in Listing 11-10, the `n]sVkki=j`?ajpan command would now look like this: a_dki]l*`n]sVkki=j`?ajpan$#* hk_]pekj*#(#* vkki*#%77 And in the `eolh]u action in Listing 11-10, we would need to capture the zoom value and pass it to the view with the following lines of code: ++@kvkki vkki9#/#7 eb$eooap$pdeo):l]ooa`=ncoW#vkki#Y%%w  vkki9pdeo):l]ooa`=ncoW#vkki#Y7 y pdeo):oap$#vkki#( vkki%7

Summary In this chapter, we have shown how you can override Cakeâ&#x20AC;&#x2122;s output. Additionally, we created a Cake plugin that displays Yahoo! maps. We mentioned early on that the whole Cake tags idea is a small step toward solving the problem of content and data separation. In our view, this is a big problem, because so many modern applications need to talk to other applications. Good separation of these two layers is vital in web development. However, at some stage, you will inevitably need to mix them. The questions will be how much and where. One thing is certain: you should never put any presentational markup in the controller. With Cake, use Cake elements and helpers to reduce the size of your views.


C HAPTER

12

Dynamic Data Fields I

n this chapter, weâ&#x20AC;&#x2122;ll present a snippet of an e-commerce feature. We will supply enough code and explanation to allow you to use this feature in a real-life project. Our feature centers on product searching. We take a nontraditional approach to this feature, basing it on dynamic data fields. Weâ&#x20AC;&#x2122;ll start off by reviewing how product searches are usually conducted.

Traditional Product Searching While shopping online, many e-commerce sites allow you to narrow down the product range by selecting specific attributes of interest. For example, you can narrow down the search to just a particular brand or a particular price range. Figures 12-1 and 12-2 show typical product filtering on Amazon and Kelkoo, respectively.

Figure 12-1. Amazon product filtering 329


330

CH APT ER 12 N D YNA MIC DA TA FIEL DS

Figure 12-2. Kelkoo product filtering Traditionally, to provide such a feature, you would put the products and their attributes in a single table, as shown in Listing 12-1. Listing 12-1. A Typical Products Table ?NA=PAP=>HA\lnk`q_po\$ \e`\ejp$--%JKPJQHH]qpk[ej_naiajp( \pepha\r]n_d]n$.11%JKPJQHH( \lne_a\bhk]pJKPJQHH( \opk_g[mpu\ejp$--%JKPJQHH( \_khkn\r]n_d]n$.11%JKPJQHH( \oeva\r]n_d]n$.11%JKPJQHH( LNEI=NUGAU$\e`\% %7 You would then create a form that contained hard-coded fields that users could select. These fields would be passed to a standard SQL OAHA?P statement via a LKOP action, and the filtered results would be returned. The traditional method works well if the products are mostly the same or you have only a few hundred products. However, if you want to build a more flexible system and be able to handle a much larger product base with attributes that vary widely, you need a different approach.

The Dynamic Data Approach Our method turns the traditional products table on its side. For example, in the traditional table, the price field occupies one column on its own, with the prices running down the table, as shown in Figure 12-3.

Figure 12-3. A table with a traditional price field


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

In our approach, we have the price field as a data type in itself, and create a separate record for each price based on that price field data type, as shown in Figure 12-4. Our price field now is essentially dynamic data. We can add and delete it as if it were ordinary data. Taking this concept further, we can dynamically create table data fields.

Figure 12-4. The price field as a database record From an e-commerce standpoint, we can now create thousands or millions of products with varying properties. Each property or attribute would be a record in itself.

Considerations for Using the Dynamic Data Approach Since we’re moving away from the standard way of creating relational tables, we need to consider the implications of taking this approach. There are both advantages and disadvantages. Our approach has the following disadvantages: Ê

UÊ ˆÌiÀˆ˜}Ê`>Ì>ÊÕȘ}Ê̅iÊÃÌ>˜`>À`ÊSDANA clause conditions will not work in some circumstances. For example, the simple SQL statement oaha_p&bnkilnk`q_posdana lne_a:-,]j`_khkn9#na`# will not return the desired results, because there are no lne_a and _khkn fields. We could still achieve the same results using other means, but it would involve more code and more SQL statements.

Ê

UÊ *Àœ}À>““ˆ˜}ʜ̅iÀÊÊi‡ÊVœ““iÀViÊvi>ÌÕÀiÃÊLiVœ“iÃʓÕV…Ê“œÀiÊVœ“«ˆV>Ìi`°ÊœÀÊ example, a simple SQL statement like oaha_p&bnkilnk`q_po would not return the results we want. To get this data, we would need to make further SQL queries.

Ê

UÊ œ`iʓ>ˆ˜Ìi˜>˜ViÊLiVœ“iÃʓœÀiÊ`ˆvvˆVÕÌ°Ê iÛiœ«iÀÃÊ>ÀiÊv>“ˆˆ>ÀÊ܈̅Ê̅iÊÌÀ>`ˆÌˆœ˜>Ê way in which SQL statements interact with code. The advantages of the dynamic data approach are as follows:

Ê

UÊ 9œÕÊV>˜ÊVÀi>ÌiÊ`ޘ>“ˆVÊÌ>LiÃÊ>˜`Ê`>Ì>Êvˆi`ÃÊL>Ãi`ʜ˜Ê̅iÊ>ÌÌÀˆLÕÌiÃʜvÊ«Àœ`ÕVÌÃ°Ê Indeed, you can also create dynamic forms (although that isn’t our goal in this chapter’s example).

Ê

UÊ 9œÕÊV>˜ÊVÀi>ÌiÊ>Õ̜“>̈VÊÛ>ˆ`>̈œ˜ÊȘViÊޜÕÊ>ÀiÊVœ˜ÌÀœˆ˜}Ê̅iÊ`>Ì>ÊÌÞ«iʜvÊ̅iÊvˆi`°Ê (We won’t cover that feature in this chapter, but you can easily add it.)

Ê

UÊ 7…>ÌÊÜ>ؽÌÊ«À>V̈V>ÞÊ«œÃÈLiÊ«ÀiۈœÕÏÞÊÕȘ}ÊÃÌ>˜`>À`Ê-+ʓi̅œ`ÃʈÃʘœÜÊ«œÃÈble—namely, mixed data sets.

Our dynamic data field technique is recommended only if the ability to have dynamic fields is a core feature of your application. If you have several hundred brands or products, it’s still much better to create separate tables as and when needed, such as lnk`q_po[odkao, lnk`q_po[pahareoekjo, lnk`q_po[d]po, and so on (although, honestly, that solution isn’t that attractive either when the number of tables increases).

331


332

CH APT ER 12 N D YNA MIC DA TA FIEL DS

The Product Database Design Most of our tables will be metatablesâ&#x20AC;&#x201D;tables that hold data that describes other data. For example, the integer value 42 may numerically represent anything, but if we attach an attribute called lne_a to it, then 42 numerically represents price. The attribute is the metadata. As weâ&#x20AC;&#x2122;ve said, creating dynamic data fields is a complicated business. To achieve our aim, we have created nine tables, as shown in Figure 12-5.

Figure 12-5. Dynamic data fields schema


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

We will now describe the type of data each table will contain and show some examples. This will give you enough information to allow you to adapt the code to suit your own needs.

The field_type_groups Table The beah`[pula[cnkqlo table is used to group the different data types, as shown in the example in Figure 12-6. For example, a price field is a `a_ei]h field; a free-form text field, such as the description of a product, is a r]n_d]n type; and a drop-down field of brand names is an enumerated type. Table 12-1 describes the two fields in this table.

Figure 12-6. Sample data in the field_type_groups table

Table 12-1. The field_type_groups Table Fields

Field

Description

e`

Unique primary key field

pepha

Name of the field type

The field_type_values Table The beah`[pula[r]hqao table holds the actual data types, as shown in the example in Figure 12-7. Itâ&#x20AC;&#x2122;s used with the beah`[pula[cnkqlo table. It exists mainly for the benefit of enumerated types. Each field in this table is described in Table 12-2.

Figure 12-7. Sample data in the field_type_values table

Table 12-2. The field_type_values Table Fields

Field

Description

e`

Unique primary key field

pepha

Name of the data type

beah`[pula[cnkql[e`

Foreign key to beah`[pula[cnkqlo

333


334

CH APT ER 12 N D YNA MIC DA TA FIEL DS

The products Table Each product will have one entry in the lnk`q_po table, as shown in the example in Figure 12-8. All the other tables are ultimately used to support this single table. Table 12-3 shows the fields in the lnk`q_po table.

Figure 12-8. Sample data in the products table

Table 12-3. The products Table Fields

Field

Description

e`

Unique primary key field

pepha

Name of the product

lnk`q_p[beah`[cnkql[e`

Foreign key to lnk`q_p[beah`[cnkqlo

The products_product_groups Table The lnk`q_po[lnk`q_p[cnkqlo table links the lnk`q_po table and the lnk`q_p[cnkqlo table. The lnk`q_po and lnk`q_p[cnkqlo table have a many-to-many relationship: one product can Liœ˜}Ê̜ʓ>˜ÞÊ«Àœ`ÕVÌÊ}ÀœÕ«Ã]Ê>˜`Ê>Ê«Àœ`ÕVÌÊ}ÀœÕ«ÊV>˜ÊVœ˜Ì>ˆ˜Ê“>˜ÞÊ«Àœ`ÕVÌðÊ˜Ê >Ži]Ê this association is called has and belongs to many (HABTM). For example, - ʓi“œÀÞÊV>À`ÃÊ can be used in many devices, such as cameras and computers, and devices like cameras and Vœ“«ÕÌiÀÃÊV>˜ÊÌ>ŽiÊ`ˆvviÀi˜ÌÊÌÞ«iÃʜvÊ- ʓi“œÀÞÊV>À`ðʘÊiÝ>“«iʜvÊ̅iÊlnk`q_po[ lnk`q_p[cnkqlo table is shown in Figure 12-9. Each field is described in Table 12-4.

Figure 12-9. Sample data in the products_product_groups table

Table 12-4. The products_product_groups Table Fields

Field

Description

e`

Unique primary key field

lnk`q_p[e`

Foreign key to lnk`q_po

lnk`q_p[cnkql[e`

Foreign key to lnk`q_p[cnkqlo


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

The product_fields Table The lnk`q_p[beah`o table holds the name of the data fields, as shown in the example in Figure 12-10. Table 12-5 describes the four fields in this table.

Figure 12-10. Sample data in the product_fields table

Table 12-5. The product_fields Table Fields

Field

Description

e`

Unique primary key field

pepha

Name of the data field

beah`[pula[cnkql[e`

Foreign key to beah`[pula[cnkqlo

lnk`q_p[beah`[cnkql[e`

Foreign key to lnk`q_p[beah`[cnkqlo

The product_field_groups Table The lnk`q_p[beah`[cnkqlo table is essentially used to hold together the different data fields in the lnk`q_p[beah`o table, as shown in the example in Figure 12-11. Table 12-6 describes the fields in this table.

Figure 12-11. Sample data in the product_field_groups table

Table 12-6. The product_field_groups Table Fields

Field

Description

e`

Unique primary key field

pepha

Name of the grouping of the field (like a table name)

The product_field_values Table After the lnk`q_po table, lnk`q_p[beah`[r]hqao is the second most important table, as it holds the attribute data for each product. Figure 12-12 shows an example of the table. Each of its fields is described in Table 12-7.

335


336

CH APT ER 12 N D YNA MIC DA TA FIEL DS

Figure 12-12. Sample data in the product_field_values table

Table 12-7. The product_field_values Table Fields

Field

Description

e`

Unique primary key field

lnk`q_p[beah`[e`

Foreign key to lnk`q_p[beah`o

r]hqa

Value of the data itself—probably the most important field

beah`[pula[r]hqa[e`

Foreign key to beah`[pula[r]hqao

lnk`q_p[e`

Foreign key to lnk`q_po

The product_groups Table The lnk`q_p[cnkqlo table is one found in many other applications. It simply groups the products and puts the groups in a hierarchical structure. The lnk`q_p[cnkql[e` field points back to itself and is used to record the hierarchy structure. Figure 12-13 shows an example of this table. Each field in the lnk`q_p[cnkqlo table is described in Table 12-8.

Figure 12-13. Sample data in the product_groups table

Table 12-8. The product_groups Table Fields

Field

Description

e`

Unique primary key field

pepha

Name of the group of products

`ao_nelpekj

iÃVÀˆ«Ìˆœ˜ÊœvÊ̅iÊ}ÀœÕ«

lnk`q_p[cnkql[e`

Foreign key to lnk`q_p[cnkqlo

lnk`q_p[beah`[cnkql[e`

Foreign key to lnk`q_p[beah`[cnkqlo


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

The product_searches Table The lnk`q_p[oa]n_dao table holds the search criteria for each product group, as shown in the example in Figure 12-14. Table 12-9 describes the fields in this table. The fields that begin with r]hqa[ are used in price range search filtering. For example, if r]hqa[bnki is -,, and r]hqa[pk is 1,,, then one of the search fields would allow you to search for products with the price range between $100 and $500. You’ll see the code that uses these fields later in this chapter, in Listing 12-4 starting on line 39.

Figure 12-14. Sample data in the product_searches table

Table 12-9. The product_searches Table Fields

Field

Description

e`

Unique primary key field

lnk`q_p[beah`[e`

Foreign key to lnk`q_p[beah`o

beah`[pula[r]hqa[e`

Foreign key to beah`[pula[r]hqao

r]hqa[haoo

Used for price range filtering; filter for values less than this limit

r]hqa[bnki

Used for price range filtering; filter for values from this limit

r]hqa[pk

Used for price range filtering; filter for values to this limit

r]hqa[ikna

Used for price range filtering; filter for values more than this limit

Baking for This Application 1Ș}Ê >Ži½ÃÊ^]ga command, we generated all the models for this application automatically. Even more important is that we also created the associations in the models automatically. To generate the associations, we named the foreign key using the naming convention Wbknaecj[p]^ha[oejcqh]nY[e`. Regarding the controllers, we have baked only the products controller. In it, we will create two actions: the oa]n_d action for searching and the ]``@]p] action for adding a product. Because of the architecture of our tables, we cannot simply use the automatically generated ]`` action to add products. However, that ]`` action will still help us to some extent, as you’ll see when we discuss adding products later in this chapter. We have also baked some views, but again, only for the products.

337


338

CH APT ER 12 N D YNA MIC DA TA FIEL DS

Building the Product Search Feature One of the main objectives of our dynamic data field approach is to allow flexible product searches. Users can refine their search to a narrow set of desired attributes. For our search feature, we need to create the search form and code the search process.

Creating the Product Search Form Listing 12-2 shows the products controller for our application. Listing 12-2. The Products Controller (/app/controllers/products_controller.php) -68;ldl .6_h]ooLnk`q_po?kjpnkhhanatpaj`o=ll?kjpnkhhanw /6 06r]n j]ia9#Lnk`q_po#7 16r]n dahlano9]nn]u$#Dpih#(#Bkni#%7 26 36r]n qoao9]nn]u$#Lnk`q_p#(#Lnk`q_pOa]n_d#(#Lnk`q_pCnkql#( 46#Lnk`q_pBeah`R]hqa#(#Lnk`q_pBeah`#( 56#Beah`PulaR]hqao#%7 -,6 --6bqj_pekjoa]n_d$%w -.6 -/6eb$eooap$pdeo):l]n]ioW#bkni#YW#lnk`q_p[cnkql[e`#Y%%w -06 -16 oa]n_dNaoqhp9pdeo):Lnk`q_p):`kOa]n_d$ÂŁ pdeo):l]n]ioW#bkni#Y%7 -26 -36pdeo):oap$#oa]n_d[naoqhpo#( oa]n_dNaoqhp%7 -46y -56 .,6pdeo):[heopLnk`q_pOa]n_d$%7 .-6y ..6 ./6bqj_pekj[heopLnk`q_pOa]n_d$%w .06 .16++=ppdaikiajp(pdeoeod]n`_k`a`pk]`ab]qhpr]hqakb.26++^qpukqi]us]jppk_d]jcapdeopkukqnlnk`q_pcnkqle` .36 lnk`q_pCnkqlE`9#-#7 .46 .56eb$eooap$pdeo):l]ooa`=ncoW#lnk`q_pCnkqlE`#Y%%w /,6 lnk`q_pCnkqlE`9pdeo):l]ooa`=ncoW#lnk`q_pCnkqlE`#Y7 /-6y /.6 //6++Cappdaaj`jk`acnkql /06 lnk`q_pCnkql9pdeo):Lnk`q_pCnkql):bej`>uE`$ lnk`q_pCnkqlE`%7 /16


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

/26pdeo):oap$#lnk`q_p[cnkql#( lnk`q_pCnkql%7 /36 /46pdeo):oap$#lnk`q_p[beah`o#( /56pdeo):Lnk`q_pBeah`):oa]n_dBehpano$ lnk`q_pCnkql%%7 0,6y 0-6 0.6bqj_pekj]``@]p]$%w 0/6 006eb$ailpu$ pdeo):`]p]%%w 016 026 beah`@]p]9pdeo):`]p]W#Lnk`q_p#YW#`]p][beah`o#Y7 036 046bkna]_d$ beah`@]p]]o beah`R]h%w 056 1,6eb$eo[]nn]u$ beah`R]h%%w 1-6heop$ gau( r]hqa%9a]_d$ beah`R]h%7 1.6 1/6 beah`@]p].Olhep9atlhk`a$(( gau%7 106 lnk`q_p[beah`[e`9 beah`@]p].OlhepW,Y7 116 beah`[pula[r]hqa[e`9 beah`@]p].OlhepW-Y7 126y 136ahoaw 146 beah`@]p].Olhep9atlhk`a$(( beah`R]h%7 156 lnk`q_p[beah`[e`9 beah`@]p].OlhepW,Y7 2,6 beah`[pula[r]hqa[e`9 beah`@]p].OlhepW-Y7 2-6 r]hqa9£ pdeo):capBeah`PulaR]hqa$ beah`[pula[r]hqa[e`%7 2.6y 2/6 206 `]p]9]nn]u$%7 216 `]p]W#Lnk`q_pBeah`R]hqa#YW#lnk`q_p[beah`[e`#Y9£ lnk`q_p[beah`[e`7 226 `]p]W#Lnk`q_pBeah`R]hqa#YW#r]hqa#Y9 r]hqa7 236 `]p]W#Lnk`q_pBeah`R]hqa#YW#beah`[pula[r]hqa[e`#Y9£ beah`[pula[r]hqa[e`7 246 `]p]W#Lnk`q_pBeah`R]hqa#YW#lnk`q_p[e`#Y9£ pdeo):`]p]W#Lnk`q_p#YW#lnk`q_p[e`#Y7 256 3,6pdeo):Lnk`q_pBeah`R]hqa):_na]pa$ `]p]%7 3-6pdeo):Lnk`q_pBeah`R]hqa):o]ra$%7 3.6y 3/6y 306 316eb$eooap$pdeo):l]ooa`=ncoW#lnk`q_pBeah`CnkqlE`#Y%%w 326 336 lnk`q_pBeah`CnkqlE`9pdeo):£ l]ooa`=ncoW#lnk`q_pBeah`CnkqlE`#Y7 346

339


340

CH APT ER 12 N D YNA MIC DA TA FIEL DS

356++Hap#obej`]hhpda`]p]beah`o 4,6 lnk`q_pBeah`o9pdeo):Lnk`q_pBeah`):£ bej`=hh>uLnk`q_pBeah`CnkqlE`$ lnk`q_pBeah`CnkqlE`%7 4-6 4.6++Jatpsajaa`pdar]hqaonah]pejcpkpda`]p]beah`o 4/6bkna]_d$ lnk`q_pBeah`o]o" beah`%w 406 416 beah`PulaCnkqlE`9 beah`W#Beah`PulaCnkql#YW#e`#Y7 426 436 beah`PulaR]hqao9pdeo):£ Beah`PulaR]hqao):bej`=hh>uBeah`PulaCnkqlE`$ beah`PulaCnkqlE`%7 446 456 beah`W#Beah`PulaR]hqao#Y9 beah`PulaR]hqao7 5,6y 5-6 5.6pdeo):oap$#beah`[pula[r]hqao#( lnk`q_pBeah`o%7 5/6y 506 516 lnk`q_pE`9##7 526eb$eooap$pdeo):l]ooa`=ncoW#lnk`q_pE`#Y%%w 536 lnk`q_pE`9pdeo):l]ooa`=ncoW#lnk`q_pE`#Y7 546y 556 -,,6pdeo):oap$#lnk`q_p[e`#( lnk`q_pE`%7 -,-6 -,.6y -,/6 -,06bqj_pekjcapBeah`PulaR]hqa$ beah`[pula[r]hqa[e`%w -,16 -,26 naoqhp9##7 -,36 -,46 beah`PulaR]hqao9pdeo):Beah`PulaR]hqao):£ bej`>uE`$ beah`[pula[r]hqa[e`%7 -,56 --,6eb$ailpu$ beah`PulaR]hqao%%w ---6 --.6eb$eooap$ beah`PulaR]hqao£ WBeah`PulaR]hqaoYWpephaY%%w --/6 naoqhp9 beah`PulaR]hqaoWBeah`PulaR]hqaoYWpephaY7 --06y --16y --26 --36napqnj naoqhp7 --46y --56y -.,6;:


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

We have created a oa]n_d action in the products controller to handle searches, on line 11. Line 20 carries out the task of listing the product search fields in the [heopLnk`q_pOa]n_d method. On line 23, we find all the data fields for a particular product group. On line 27, we >ÃÃՓiÊ̅iÊ`iv>ՏÌÊ«Àœ`ÕVÌÊ}ÀœÕ«Ê ʈÃÊ-. If no lnk`q_pCnkqlE` value has been specified, then the products with a lnk`q_pCnkqlE` of - will be shown. In practice, this value would be passed to the function via the URL, maybe as a named parameter. For example, you may have a page with different product group types, and one URL might look like this: dppl6++hk_]hdkop+_d]lpan[-.+Lnk`q_po+oa]n_d+lnk`q_pCnkqlE`60.+ This URL would then list all the products with a lnk`q_pCnkqlE` value of 0.. Once we retrieve the lnk`q_pCnkqlE`, on line 30, we simply get details about the group for display in the view. Line 38 does the main work and fetches the product fields. Finding the search fields is carried out by the Lnk`q_pBeah` model, shown in Listing 12-3. Remember that the search fields are not hard-coded; they are generated dynamically. Listing 12-3. ProductField Model (/app/models/product_field.php) -68;ldl .6_h]ooLnk`q_pBeah`atpaj`o=llIk`ahw /6 06r]n j]ia9#Lnk`q_pBeah`#7 16 26r]n ^ahkjcoPk9]nn]u$ 36#Beah`PulaCnkql#9:]nn]u$#_h]ooJ]ia#9:#Beah`PulaCnkql#( 46#bknaecjGau#9:#beah`[pula[cnkql[e`#( 56#_kj`epekjo#9:##( -,6#beah`o#9:##( --6#kn`an#9:## -.6%( -/6#Lnk`q_pBeah`Cnkql#9:]nn]u$#_h]ooJ]ia#9:#Lnk`q_pBeah`Cnkql#( -06#bknaecjGau#9:#lnk`q_p[beah`[cnkql[e`#( -16#_kj`epekjo#9:##( -26#beah`o#9:##( -36#kn`an#9:## -46% -56%7 .,6 .-6r]n d]oI]ju9]nn]u$ ..6#Lnk`q_pBeah`R]hqa#9:]nn]u$#_h]ooJ]ia#9:#Lnk`q_pBeah`R]hqa#( ./6#bknaecjGau#9:#lnk`q_p[beah`[e`#( .06#`alaj`ajp#9:b]hoa( .16#_kj`epekjo#9:##( .26#beah`o#9:##( .36#kn`an#9:##( .46#heiep#9:##( .56#kbboap#9:##(

341


342

CH APT ER 12 N D YNA MIC DA TA FIEL DS

/,6#at_hqoera#9:##( /-6#bej`anMqanu#9:##( /.6#_kqjpanMqanu#9:## //6%( /06#Lnk`q_pOa]n_d#9:]nn]u$#_h]ooJ]ia#9:#Lnk`q_pOa]n_d#( /16#bknaecjGau#9:#lnk`q_p[beah`[e`#( /26#`alaj`ajp#9:b]hoa( /36#_kj`epekjo#9:##( /46#beah`o#9:##( /56#kn`an#9:##( 0,6#heiep#9:##( 0-6#kbboap#9:##( 0.6#at_hqoera#9:##( 0/6#bej`anMqanu#9:##( 006#_kqjpanMqanu#9:## 016% 026%7 036 046bqj_pekjoa]n_dBehpano$ oa]n_dBeah`%w 056 1,6++Sacappdabeah`onah]pejcpkpdeolnk`q_pcnkql 1-6 lnk`q_pBeah`o9]nn]u$%7 1.6 1/6eb$ oa]n_dBeah`W#Lnk`q_pCnkql#YW#lnk`q_p[beah`[cnkql[e`#Y%w 106 116 lnk`q_pBeah`CnkqlE`9£ oa]n_dBeah`W#Lnk`q_pCnkql#YW#lnk`q_p[beah`[cnkql[e`#Y7 126 136 beah`o9£ pdeo):bej`=hh>uLnk`q_pBeah`CnkqlE`$ lnk`q_pBeah`CnkqlE`%7 146 156bkna]_d$ beah`o]o lnk`q_p[beah`%w 2,6 2-6 lnk`q_pBeah`oWY9£ lnk`q_p[beah`W#Lnk`q_pBeah`#YW#e`#Y7 2.6y 2/6y 206 216++Jatp(bkna]_dbeah`(sacappdaoa]n_d_nepane](a*c*(heopkb 226++^n]j`j]iao(lne_an]jca(ap_* 236 beah`Nabeja9]nn]u$%7 246 256bkna]_d$ beah`o]o lnk`q_pBeah`%w 3,6 3-6 lnk`q_pBeah`E`9 lnk`q_pBeah`W#Lnk`q_pBeah`#YW#e`#Y7 3.6


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

3/6 beah`Oaha_pekj9ÂŁ pdeo):Lnk`q_pOa]n_d):bej`=hh>uLnk`q_pBeah`E`$ lnk`q_pBeah`E`%7 306 316 beah`R]hqao9]nn]u$%7 326 336bkna]_d$ beah`Oaha_pekj]o oaha_pekj%w 346 beah`R]hqaoWY9 oaha_pekj7 356y 4,6 4-6 lnk`q_pBeah`W#beah`[oaha_pekjo#Y9 beah`R]hqao7 4.6 4/6 beah`NabejaWY9 lnk`q_pBeah`7 406y 416 426napqnj beah`Nabeja7 436y 446 456y 5,6;: At the beginning of the file, we have created some associations that correspond to the diagram shown earlier in Figure 12-5. The important code begins on line 48 with the oa]n_dBehpano method. First, we get the fields relating to the product group, starting on line 53. Next, starting on line 69, we get the search criteria for each field. For example, if the field is about brand names, we need a list of all the brands. If it is a price field, we need to get the search range of the price field. Figure 12-15 shows an example of the form displaying these criteria.

Figure 12-15. The dynamic search form

343


344

CH APT ER 12 N D YNA MIC DA TA FIEL DS

Let’s now look at the view that corresponds to the search form, which is shown in Listing 12-4. The file is split into two sections: lines 1 through 105 list the search fields relating to the product group, and lines 107 through 140 list the products found. Listing 12-4. Search Action View (/app/views/products/index.ctp) -68;ldl .6 /6a_dkbkni):_na]pa$#Lnk`q_p#( 06]nn]u$#qnh#9:#+Lnk`q_po+oa]n_d+#%%7 16 26;: 36 468;ldla_dkbkni):_na]pa$#Lnk`q_p#%7;: 56 -,68;ldl --6 -.6eb$eooap$ lnk`q_p[cnkql%%w -/6 -06 lnk`q_p[cnkql[e`9 lnk`q_p[cnkqlW#Lnk`q_pCnkql#YW#e`#Y7 -16 -26a_dkbkni):de``aj$#lnk`q_p[cnkql[e`#( -36]nn]u$#j]ia#9:#lnk`q_p[cnkql[e`#( -46#r]hqa#9: lnk`q_p[cnkql[e`%%7 -56y .,6;: .-6 ..68;ldl ./6 .06eb$eooap$ lnk`q_p[cnkql%%w .16 .26++Heoppdalnk`q_pcnkql .36a_dk lnk`q_p[cnkqlW#Lnk`q_pCnkql#YW#pepha#Y7 .46y .56 /,6a_dk#8^n+:#7 /-6 /.6a_dk#8`ere`9lnk`q_p[oa]n_d:#7 //6 /06eb$eooap$ lnk`q_p[cnkql%%w /16 /26bkna]_d$ lnk`q_p[beah`o]o lnk`q_p[beah`%w /36 /46a_dk£ #8^:#* lnk`q_p[beah`W#Lnk`q_pBeah`#YW#pepha#Y*#8+^:8^n+:#7 /56 0,6 beah`[oaha_pekjo9 lnk`q_p[beah`W#beah`[oaha_pekjo#Y7 0-6


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

0.6bkna]_d$ beah`[oaha_pekjo]o beah`[r]hqa%w 0/6 006 pepha9 beah`[r]hqaW#Beah`PulaR]hqa#YW#pepha#Y7 016 e`9 beah`[r]hqaW#Lnk`q_pOa]n_d#YW#e`#Y7 026 lnk`q_p[beah`[e`9£ beah`[r]hqaW#Lnk`q_pOa]n_d#YW#lnk`q_p[beah`[e`#Y7 036 046eb$ pepha99#W@A?EI=HY#%w 056 1,6++Sap]gaepbnkipdan]jca 1-6 r]hqa[haoo9£ beah`[r]hqaW#Lnk`q_pOa]n_d#YW#r]hqa[haoo#Y7 1.6 1/6eb$ r]hqa[haoo%w 106 116a_dkbkni):_da_g^kt$##(£ ]nn]u$#j]ia#9:#beah`[oaha_pekjW#* lnk`q_p[beah`[e`*#YWY#(#r]hqa#9: e`%%7 126 136a_dk#8#* r]hqa[haoo*#8^n+:#7 146y 156 2,6 r]hqa[bnki9£ beah`[r]hqaW#Lnk`q_pOa]n_d#YW#r]hqa[bnki#Y7 2-6 2.6eb$ r]hqa[bnki%w 2/6 206a_dkbkni):_da_g^kt$##(]nn]u$£ #j]ia#9:#beah`[oaha_pekjW#* lnk`q_p[beah`[e`*#YWY#(#r]hqa#9: e`%%7 216 226a_dk r]hqa[bnki7 236 246 r]hqa[pk9£ beah`[r]hqaW#Lnk`q_pOa]n_d#YW#r]hqa[pk#Y7 256 3,6eb$ r]hqa[pk%w 3-6 3.6a_dk#)#* r]hqa[pk*#8^n+:#7 3/6y 306y 316 326 r]hqa[ikna9£ beah`[r]hqaW#Lnk`q_pOa]n_d#YW#r]hqa[ikna#Y7 336 346eb$ r]hqa[ikna%w 356a_dkbkni):_da_g^kt$##(]nn]u$£ #j]ia#9:#beah`[oaha_pekjW#* lnk`q_p[beah`[e`*#YWY#(#r]hqa#9: e`%%7 4,6

345


346

CH APT ER 12 N D YNA MIC DA TA FIEL DS

4-6a_dk#:#* r]hqa[ikna*#8^n+:#7 4.6y 4/6y 406ahoaw 416 426++Bknkn`ej]nuheopo(a*c*^n]j`j]iao 436 e`9 beah`[r]hqaW#Lnk`q_pOa]n_d#YW#e`#Y7 446 456a_dkbkni):_da_g^kt$##(]nn]u$£ #j]ia#9:#beah`[oaha_pekjW#* lnk`q_p[beah`[e`*#YWY#(#r]hqa#9: e`%%7 5,6 5-6a_dk£ beah`[r]hqaW#Beah`PulaR]hqa#YW#pepha#Y*#8^n+:#7 5.6y 5/6y 506 516a_dk#8^n+:#7 526y 536 546a_dkbkni):aj`$#Oq^iep#%7 556y -,,6 -,-6a_dk#8+`er:#7 -,.6 -,/6 -,06 -,16;: -,26 -,368^n+: -,468dnse`pd9-,,!_khkn9111111: -,568^n+: --,6 ---68;ldl --.6 --/6eb$eooap$ oa]n_d[naoqhpo%%w --06 --16bkna]_d$ oa]n_d[naoqhpo]o ][naoqhp%w --26 --36 lnk`q_p[beah`o9 ][naoqhpW#lnk`q_p[beah`o#Y7 --46 --56eb$eooap$ lnk`q_p[beah`oW,YW#Lnk`q_p#YW#pepha#Y%%w -.,6 lnk`q_p[pepha9 lnk`q_p[beah`oW,YW#Lnk`q_p#YW#pepha#Y7 -.-6a_dk#8l:#* lnk`q_p[pepha*#8+l:#7 -..6y -./6 -.06bkna]_d$ lnk`q_p[beah`o]o lnk`q_p[beah`%w -.16


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

-.26 beah`[pepha9 lnk`q_p[beah`W#Lnk`q_pBeah`#YW#pepha#Y7 -.36 -.46osep_d$ beah`[pepha%w -.56 -/,6_]oa#Lnk`q_p>n]j`#6 -/-6a_dk#8l:8^:>n]j`68+^:#* lnk`q_p[beah`£ W#Lnk`q_pBeah`R]hqa#YW#r]hqa#Y*#8+l:#7 -/.6^na]g7 -//6 -/06_]oa#Lnk`q_pLne_a#6 -/16a_dk#8l:8^:Lne_a68+^:#* lnk`q_p[beah`£ W#Lnk`q_pBeah`R]hqa#YW#r]hqa#Y*#8+l:#7 -/26^na]g7 -/36y -/46y -/56y -0,6y -0-6 -0.6;: ˆ˜iÃÊ£ÓÊ̜ʣ™Êȓ«ÞÊÃ̜ÀiÊ̅iÊ«Àœ`ÕVÌÊ}ÀœÕ«Ê ʈ˜Ê>ʅˆ``i˜Êvˆi`]ÊÜÊ̅>ÌÊ܅i˜ÊÜiÊ«iÀform the search, we know on which product group we’re searching. The eb statement on line Ó{ÊiV…œiÃÊ̅iʘ>“iʜvÊ̅iÊ«Àœ`ÕVÌÊ}ÀœÕ«pvœÀÊiÝ>“«i]Ê*>Ó>Ê/6ðÊ"˜Êˆ˜iÊÎÈ]Ê̅iÊLˆ}ʜÕÌiÀÊ bkna]_d loop goes through each field and displays the relevant filter input box and the label that goes with it. Inside the big bkna]_d loop on line 42, we have an eb statement on line 48 that decides on the data type of the data field. If it’s a decimal, we assume it’s a price range filter. We then go through the r]hqa[ variables to find what kind of range we should display. If it’s not a decimal, we assume it’s an enumerated list, like brand names or shoe sizes. We then go into the ahoa block on line 84, where we echo a check box and the title of the field type.

Processing the Search In the previous section, we showed you how the search form was created. We’ll now explain how the search actually works. Referring to the products controller in Listing 12-2, on line 15, you can see that all the work to search for the products is done within the Lnk`q_p model. The code for the Lnk`q_p model is shown in Listing 12-5. Listing 12-5. Product Model (/app/models/product.php) -68;ldl .6_h]ooLnk`q_patpaj`o=llIk`ahw /6 06r]n j]ia9#Lnk`q_p#7 16 26r]n ^ahkjcoPk9]nn]u$ 36#Lnk`q_pBeah`Cnkql#9:]nn]u$#_h]ooJ]ia#9:#Lnk`q_pBeah`Cnkql#(

347


348

CH APT ER 12 N D YNA MIC DA TA FIEL DS

46#bknaecjGau#9:#lnk`q_p[beah`[cnkql[e`#( 56#_kj`epekjo#9:##( -,6#beah`o#9:##( --6#kn`an#9:## -.6% -/6%7 -06 -16r]n d]oI]ju9]nn]u$ -26#Lnk`q_pBeah`R]hqa#9:]nn]u$#_h]ooJ]ia#9:#Lnk`q_pBeah`R]hqa#( -36#bknaecjGau#9:#lnk`q_p[e`#( -46#`alaj`ajp#9:b]hoa( -56#_kj`epekjo#9:##( .,6#beah`o#9:##( .-6#kn`an#9:##( ..6#heiep#9:##( ./6#kbboap#9:##( .06#at_hqoera#9:##( .16#bej`anMqanu#9:##( .26#_kqjpanMqanu#9:## .36% .46%7 .56 /,6r]n d]o=j`>ahkjcoPkI]ju9]nn]u$ /-6#Lnk`q_pCnkql#9:]nn]u$#_h]ooJ]ia#9:#Lnk`q_pCnkql#( /.6#fkejP]^ha#9:#lnk`q_po[lnk`q_p[cnkqlo#( //6#bknaecjGau#9:#lnk`q_p[e`#( /06#]ook_e]pekjBknaecjGau#9:#lnk`q_p[cnkql[e`#( /16#qjemqa#9:pnqa( /26#_kj`epekjo#9:##( /36#beah`o#9:##( /46#kn`an#9:##( /56#heiep#9:##( 0,6#kbboap#9:##( 0-6#bej`anMqanu#9:##( 0.6#`ahapaMqanu#9:##( 0/6#ejoanpMqanu#9:## 006% 016%7 026 036bqj_pekj`kOa]n_d$ bkniR]hqao%w 046 056 naoqhp9]nn]u$%7 1,6 1-6 lnk`q_pCnkqlE`9 bkniR]hqaoW#lnk`q_p[cnkql[e`#Y7 1.6 1/6eb$eooap$ bkniR]hqaoW#beah`[oaha_pekj#Y%%w 106


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

116 naoqhp9pdeo):capBeah`Oaha_pekj$ 126 lnk`q_pCnkqlE`( 136 bkniR]hqaoW#beah`[oaha_pekj#Y%7 146 156++Sajaa`pk]``pdabeah`ejbkni]pekjpka]_dlnk`q_p 2,6 naoqhp9pdeo):]``Beah`Ejbkni]pekj$ naoqhp%7 2-6y 2.6 2/6napqnj naoqhp7 206y 216 226bqj_pekj]``Beah`Ejbkni]pekj$ lnk`q_po%w 236 246bkna]_d$ lnk`q_po]o" _qnnajp[lnk`q_p%w 256 3,6 lnk`q_pE`9 _qnnajp[lnk`q_pW#e`#Y7 3-6 3.6 lnk`q_pBeah`o9pdeo):Lnk`q_pBeah`R]hqa):ÂŁ bej`=hh>uLnk`q_pE`$ lnk`q_pE`%7 3/6 306 _qnnajp[lnk`q_pW#lnk`q_p[beah`o#Y9 lnk`q_pBeah`o7 316y 326 336napqnj lnk`q_po7 346y 356 4,6bqj_pekjcapOa]n_d?nepane]$ beah`Oaha_pekj%w 4-6 4.6 oaha_pekjBh]p9]nn]u$%7 4/6 406 e`t9,7 416 426bkna]_d$ beah`Oaha_pekj]o" _qnnajpOaha_pekj%w 436 446bkn$ e`t.9,7 e`t.8oevakb$ _qnnajpOaha_pekj%7 e`t.''%w 456 5,6 oaha_pekjR]hqa9 _qnnajpOaha_pekjW e`t.Y7 5-6 5.6 omh9oaha_p&bnkilnk`q_p[oa]n_dao 5/6sdana 506e`9# oaha_pekjR]hqa# 5167 526 536 oa]n_do9pdeo):mqanu$ omh%7 546 556 oaha_pekjBh]pW e`tYW e`t.Y9 oa]n_doW,Y7 -,,6y -,-6

349


350

CH APT ER 12 N D YNA MIC DA TA FIEL DS

-,.6 e`t''7 -,/6y -,06 -,16napqnj oaha_pekjBh]p7 -,26y -,36 -,46bqj_pekjcapBeah`Oaha_pekj$ lnk`q_pCnkqlE`( beah`Oaha_pekj%w -,56 --,6 naoqhp9]nn]u$%7 ---6 --.6++Cap]hhlnk`q_posepdejpdacnkql --/6 lnk`q_po9pdeo):Lnk`q_pCnkql):bej`>uE`$ lnk`q_pCnkqlE`%7 --06 --16 oa]n_d?nepane]o9pdeo):capOa]n_d?nepane]$ beah`Oaha_pekj%7 --26 --36++Jkss]hgpdnkqcda]_dlnk`q_ppkbehpankqp --46++]__kn`ejcpkqoanoaha_pekj --56 -.,6bkna]_d$ lnk`q_poW#Lnk`q_p#Y]o _qnnajpLnk`q_p%w -.-6 -..6 lnk`q_pE`9 _qnnajpLnk`q_pW#e`#Y7 -./6 lnk`q_pBeah`CnkqlE`9 _qnnajpLnk`q_p£ W#lnk`q_p[beah`[cnkql[e`#Y7 -.06 -.16 omh9oaha_p&bnkilnk`q_p[beah`o -.26ejjanfkejlnk`q_p[beah`[r]hqao£ kjlnk`q_p[beah`[r]hqao*lnk`q_p[beah`[e`9lnk`q_p[beah`o*e` -.36ejjanfkejbeah`[pula[r]hqaokj£ beah`[pula[r]hqao*e`9lnk`q_p[beah`[r]hqao*beah`[pula[r]hqa[e` -.46sdana -.56lnk`q_p[beah`o*lnk`q_p[beah`[cnkql[e`9£ #* lnk`q_pBeah`CnkqlE`*#]j` -/,6lnk`q_p[beah`[r]hqao*lnk`q_p[e`9#* lnk`q_pE`*# -/-67 -/.6 -//6 lnk`q_pBeah`o9pdeo):mqanu$ omh%7 -/06 -/16 pklHarahI]p_dao9,7 -/26 -/36++S]hgpdnkqcda]_dbeah` -/46bkna]_d$ lnk`q_pBeah`o]o beah`%w -/56 -0,6++Jksi]p_d]c]ejoppdaoaha_pekj -0-6++Pklharahcnkqloiqopi]p_dsepd]j=J@ -0.6++a*c*(^n]j`(lne_a(ap_* -0/6++Sdehaoa_kj`harahcnkqloi]p_dsepd]jKN -006++a*c*(L]j]okje_(Okju(ap_* -016


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

-026++Op]npsepdpklharah -036bkn$ e`t9,7 e`t8oevakb$ oa]n_d?nepane]o%7 e`t''%w -046 -056 oq^Haraho9 oa]n_d?nepane]oW e`tY7 -1,6 oq^HarahI]p_dejc9,7 -1-6 -1.6++Oq^harah -1/6bkn$ e`t.9,7 e`t.8oevakb$ oq^Haraho%7 e`t.''%w -106 -116eb$$ oq^HarahoW e`t.Y£ W#lnk`q_p[oa]n_dao#YW#lnk`q_p[beah`[e`#Y99 -126$ beah`£ W#lnk`q_p[beah`[r]hqao#YW#lnk`q_p[beah`[e`#Y%%% -136w -146++Qoanoaha_pa`pdeobeah`pkbehpan -156++?da_geboaha_pekji]p_daopdeobeah` -2,6 -2-6eb$£ beah`W#beah`[pula[r]hqao#YW#pepha#Y99#W@A?EI=HY#%w -2.6 -2/6 r]hqaHaoo9£ oq^HarahoW e`t.YW#lnk`q_p[oa]n_dao#YW#r]hqa[haoo#Y7 -206 -216eb$ r]hqaHaoo%w -226eb$ beah`£ W#lnk`q_p[beah`[r]hqao#YW#r]hqa#Y8 r]hqaHaoo%w -236 oq^HarahI]p_dejc9-7 -246y -256y -3,6 -3-6 r]hqaBnki9 oq^Haraho£ W e`t.YW#lnk`q_p[oa]n_dao#YW#r]hqa[bnki#Y7 -3.6 r]hqaPk9 oq^Haraho£ W e`t.YW#lnk`q_p[oa]n_dao#YW#r]hqa[pk#Y7 -3/6 -306eb$$ r]hqaBnki%""$ r]hqaPk%%w -316eb$$ beah`£ W#lnk`q_p[beah`[r]hqao#YW#r]hqa#Y: r]hqaBnki%"" -326$ beah`£ W#lnk`q_p[beah`[r]hqao#YW#r]hqa#Y8 r]hqaPk%% -336w -346 oq^HarahI]p_dejc9-7 -356y -4,6y -4-6 -4.6 r]hqaIkna9 oq^Haraho£ W e`t.YW#lnk`q_p[oa]n_dao#YW#r]hqa[ikna#Y7 -4/6

351


352

CH APT ER 12 N D YNA MIC DA TA FIEL DS

-406eb$ r]hqaIkna%w -416eb$ beah`£ W#lnk`q_p[beah`[r]hqao#YW#r]hqa#Y: r]hqaIkna%w -426 oq^HarahI]p_dejc9-7 -436y -446y -456y -5,6ahoaw -5-6 -5.6++Eblh]eje`oaha_pekj(a*c*(^n]j`j]iao( ap_* -5/6eb$ beah`£ W#lnk`q_p[beah`[r]hqao#YW#beah`[pula[r]hqa[e`#Y99 -506 oq^Haraho£ W e`t.YW#lnk`q_p[oa]n_dao#YW#beah`[pula[r]hqa[e`#Y%w -516 -526 oq^HarahI]p_dejc9-7 -536y -546y -556y .,,6y .,-6 .,.6++?kqjpdksi]ju .,/6eb$ oq^HarahI]p_dejc%w .,06 pklHarahI]p_dao''7 .,16y .,26y .,36y .,46 .,56eb$ pklHarahI]p_dao99oevakb$ oa]n_d?nepane]o%%w .-,6 naoqhpWY9 _qnnajpLnk`q_p7 .--6y .-.6y .-/6 .-06napqnj naoqhp7 .-16y .-26 .-36y .-46;:


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

The search starts with `kOa]n_d on line 47. Starting on line 55, the capBeah`Oaha_pekj method gets the fields that were selected. As you may notice, we have used some raw SQL queries, which is sometimes necessary with such a complex system. The capBeah`Oaha_pekj method also does the work of finding the products. On line 113, we first get all the products within the product group. Next, on line 115, we get the search criteria that the user selected. Then, beginning on line 120, we walk through each product and check it against the search criteria. On line 125, we get all the data fields for the product. Then, on line 138, we take each field and try to match it against the search criteria values. i̽ÃÊVœ˜Ãˆ`iÀÊ̅iÊiÝ>“«iÊŜܘÊi>ÀˆiÀʈ˜Êʈ}ÕÀiʣӇ£x°ÊvÊ>ÊÕÃiÀÊÃiiVÌÃÊ*>˜>ܘˆVÊ>˜`Ê Ì…iÊ«ÀˆViÊÀ>˜}iÊxääq£äää]Ê̅>Ìʓi>˜ÃÊÅiÊÜ>˜ÌÃÊ̜Êvˆ˜`Ê*>˜>ܘˆVÊ*>Ó>Ê/6Ãʈ˜Ê̅iÊ«ÀˆViÊ range of $500 to $1,000. However, if the user also selects Samsung, that means she wants to vˆ˜`Ê*>˜>ܘˆVʜÀÊ->“Ã՘}Ê*>Ó>Ê/6Ãʈ˜Ê̅iÊ«ÀˆViÊÀ>˜}iʜvÊfxääÊ̜Êf£]äää°Ê-ˆ˜ViÊÜiÊV>˜not use an ordinary OAHA?P statement with =J@ and KN operators in the SDANA clause, we need to write the code to perform the equivalent functionality of these two operators. This is done from line 147 to line 212.

Adding a Product The process of adding a product is carried out in two stages: we add entries in the lnk`q_po and lnk`q_po[lnk`q_p[cnkqlo tables and then add the product data. (This could be combined into one step, but we’ll leave that as an exercise for those who are interested.)

Creating Table Entries First, we need to create an entry in the lnk`q_po table. This is quite simple, as we will use the action +Lnk`q_po+]`` that we baked, as mentioned earlier in the chapter. (We have not altered any of the baked code.) Figure 12-16 shows an example of the form, where we are adding >Ê*>˜>ܘˆVÊÊ ‡Ê7"7Ê«Àœ`ÕVÌ° The important point regarding the lnk`q_po table is the relationship it has with the lnk`q_p[cnkqloÊÌ>Li°Ê ÕÀˆ˜}Ê̅iÊL>Žˆ˜}Ê«ÀœViÃÃ]Ê >ŽiÊ}i˜iÀ>Ìi`Ê̅iÊÀiiÛ>˜ÌÊ>ÃÜVˆ>̈œ˜ÃÊ vœÀÊÕÃ°Ê iV>ÕÃiʈÌʎ˜œÜÃÊ>LœÕÌÊ̅iÊ>ÃÜVˆ>̈œ˜Ã]Ê >ŽiÊ܈Ê>Õ̜“>̈V>ÞÊV>ÀÀÞʜÕÌʓ>˜Þʜ«iÀ>tions for us, including the following: Ê

UÊ ˜Ê̅iÊۈiÜʜvÊ>˜Ê]`` action, a multiselect field is automatically generated so users can select more than one entry in the product group, as shown in Figure 12-16.

Ê

UÊ ÕÀˆ˜}Ê̅iÊÃ>ÛiÊ«ÀœViÃÃ]Êi˜ÌÀˆiÃÊvœÀÊ̅iʜ̅iÀÊÌ>LiÃÊ>ÀiÊ>Õ̜“>̈V>ÞÊVÀi>Ìi`°Ê˜Ê Figure 12-16, we have selected two product groups. The model’s o]ra method will actually create three records: one for the lnk`q_po table and two for the lnk`q_po[ lnk`q_p[cnkqlo link table.

353


354

CH APT ER 12 N D YNA MIC DA TA FIEL DS

Figure 12-16. The add product form

Entering Product Data Now we have created an entry in the lnk`q_po table for the new product, and we have also created two entries in the lnk`q_po[lnk`q_p[cnkqlo table. So, we know to which product group the product belongs. However, we still need to enter the actual data for the product, such as its price and specific attributes. For this task, we need to write specific code. Figure 12-17 shows the form that lists the products. Most of what you see in Figure 12-17 ˆÃÊL>Ži`°Ê/…iÊiÝVi«Ìˆœ˜ÊˆÃÊ̅iÊ``Ê >Ì>ʏˆ˜ŽÊˆ˜Ê̅iʓˆ``iʜvÊ̅iÊV̈œ˜ÃÊVœÕ“˜°ÊœÀÊi>V…Ê product, we need to add the data for the product attributes. For example, clicking the Add

>Ì>ʏˆ˜ŽÊvœÀÊ̅iÊ*>˜>ܘˆVÊÊ ‡Ê7"7Êi˜ÌÀÞÊ܈ÊÌ>ŽiÊޜÕÊ̜Ê̅iÊvœÀ“ÊŜܘʈ˜Êʈ}ÕÀiʣӇ£n°


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

Figure 12-17. Listing of the products

Figure 12-18. Adding data for a product

355


356

CH APT ER 12 N D YNA MIC DA TA FIEL DS

/…iÊ``Ê >Ì>ʏˆ˜ŽÊˆÃʈ˜Ê̅iÊvœœÜˆ˜}ÊvœÀ“>Ì\ +Lnk`q_po+]``@]p]+lnk`q_pE`62+lnk`q_pBeah`CnkqlE`6. As you can see from the link, there is an ]``@]p] action in the products controller (shown earlier in Listing 12-2). We pass into the action two named parameters: lnk`q_pE` and lnk`q_pBeah`CnkqlE`* The code for the ]``@]p] action is shown on line 42 in Listing 12-2. When the product data is returned, it goes into the eb statement on line 44 in Listing 12-2. To give you a better understanding of the code, the following is an example of the pdeo):`]p] variable as used on line 44: -6=nn]u .6$ /6WLnk`q_pY9:=nn]u 06$ 16W`]p][beah`oY9:=nn]u 26$ 36W,Y9:/(0 46W-Y9:=nn]u 56$ -,6W0(1Y9:1, --6% -.6 -/6W.Y9:=nn]u -06$ -16W1(1Y9:4 -26% -36 -46% -56 .,6Wlnk`q_p[e`Y9:2 .-6% ..6 ./6% In this listing, the Lnk`q_p key has two elements: `]p][beah`o and lnk`q_p[e`. We need the lnk`q_p[e` so we know to which product the data is attached. The `]p][beah`o element contains the product data itself. The numeric order in the `]p][beah`o element is not important; the important part is the value. If the value is an array (see line 50 in Listing 12-2), then the key is composed of two values in the format Wlnk`q_p[beah`[e`(beah`[pula[r]hqa[e`Y. Thus, we have all the information we need about the data: the data itself, the data type, and the field it is. If the value is not an array, then it’s coming from a select list (in our example, the brand names). In this case, we will just have the Wlnk`q_p[beah`[e`(beah`[pula[r]hqa[e`Y pair. It won’t have a value, since we already know the value, as it is in the enumerated list. Remember that the data fields are not hard-coded, so they don’t actually exist in the database as real data columns. As far as the database is concerned, these fields are just data. The view that generated Figure 12-18 is shown in Listing 12-6. The form simply sends the data back to itself in the ]``@]p] action. In the products controller in Listing 12-2, the data starts getting processed on line 44 onward.


C H A P T E R 1 2 N D Y N A M I C D A T A F I E LD S

Listing 12-6. AddData View (/app/views/products/add_data.ctp) -68`er_h]oo9lnk`q_pobkni: .68;ldla_dkbkni):_na]pa$#Lnk`q_p#(]nn]u$£ #qnh#9:#+Lnk`q_po+]``@]p]#%%7;: /68beah`oap: 068hacaj`:8;ldl[[$#=``Lnk`q_p@]p]#%7;:8+hacaj`: 168;ldl 26 36eb$eooap$ beah`[pula[r]hqao%%w 46 56bkna]_d$ beah`[pula[r]hqao]o beah`%w -,6 --6 beah`PulaR]hqao9 beah`W#Beah`PulaR]hqao#Y7 -.6 -/6 lnk`q_pBeah`E`9 beah`W#Lnk`q_pBeah`#YW#e`#Y7 -06 lnk`q_pBeah`Pepha9 beah`W#Lnk`q_pBeah`#YW#pepha#Y7 -16 lnk`q_pBeah`Pepha[.9hks$ lnk`q_pBeah`Pepha%7 -26 lnk`q_pBeah`Pepha[.9n$( -36[( -46 lnk`q_pBeah`Pepha[.%7 -56 .,6a_dk#8`er_h]oo9bkni[beah`:#7 .-6 ..6a_dk lnk`q_pBeah`Pepha*#"j^ol76"j^ol7#7 ./6 .06++?da_gpulakb`]p] .16eb$oevakb$ beah`PulaR]hqao%99-%w .26 .36++Capbeah`pular]hqae` .46 Beah`PulaR]hqaE`9£ beah`W#Beah`PulaR]hqao#YW,YW#Beah`PulaR]hqao#YW#e`#Y7 .56 /,6++Ep#o]^]oe_`]p]pulahegaejpkn]opnejc /-6++]j`jkp]heopkb`]p]epaio /.6 //6a_dkbkni):ejlqp$##(]nn]u$#h]^ah#9:b]hoa( /06#`er#9:b]hoa( /16#j]ia#9:£ #`]p]WLnk`q_pYW`]p][beah`oYWYW#* lnk`q_pBeah`E`*#(#* Beah`PulaR]hqaE`*#Y#%%7 /26a_dk#8^n+:#7 /36y /46ahoaw /56++Sa#hh]ooqiaep#o]heopkb`]p]epaio 0,6++Hap#oc]pdanpda`]p]pkcapdan 0-6 heopEpaio9]nn]u$%7 0.6bkna]_d$ beah`PulaR]hqao]o beah`R]hqa%w 0/6

357


358

CH APT ER 12 N D YNA MIC DA TA FIEL DS

006 e`9 beah`R]hqaW#Beah`PulaR]hqao#YW#e`#Y7 016 pepha9£ beah`R]hqaW#Beah`PulaR]hqao#YW#pepha#Y7 026 036 heopEpaioW lnk`q_pBeah`E`*#(#* e`Y9 pepha7 046y 056 1,6a_dkbkni):oaha_p$##( 1-6 heopEpaio( 1.6jqhh( 1/6]nn]u$£ #j]ia#9:#`]p]WLnk`q_pYW`]p][beah`oYWY#%%7 106a_dk#8^n+:#7 116y 126 136a_dk#8+`er:#7 146y 156y 2,6 2-6;: 2.68+beah`oap: 2/68;ldla_dkbkni):de``aj$#lnk`q_p[e`#( 206]nn]u$#r]hqa#9: lnk`q_p[e`%%7;: 216 2268;ldla_dkbkni):aj`$#Oq^iep#%7;: 2368+`er:

Summary Now that we’re at the end of the chapter, we hope you are still with us. As we said at the beginning of the chapter, our design is quite complex because we are essentially trying to do some of the job that the SQL engine usually does for us. Essentially, we have carried out some ÀiÃi>ÀV…Ê>˜`Ê`iÛiœ«“i˜ÌÊܜÀŽ°Ê˜`Ê>œ˜}Ê̅iÊÜ>Þ]ÊÜi½ÛiÊÕÃi`Ê >Ži½ÃÊʅ>Ç>˜`‡Liœ˜}Ç to-many association, as well as raw queries using the mqanu function. By stepping out of the ˜œÀ“]ÊÜiÊV>˜ÊÃiiʅœÜÊ >ŽiÊÀi뜘`ÃÊ̜ʘiÜʈ`i>ð This chapter contains the skeleton of an application. You can take the code in numerous directions. For example, in the lnk`q_p[cnkqlo table, instead of using a single lnk`q_p[cnkql[ e` field to represent a hierarchical tree structure, you could use the preorder tree traversal algorithm (see dppl6++sss*oepalkejp*_ki+]npe_ha+dean]n_de_]h)`]p])`]p]^]se). This ordering method allows you to fetch all products with certain attributes under a complete branch. For example, you can list all televisions between the price range of $500 and $1,000. You can achieve the same result using a single lnk`q_p[cnkql[e` field, but it would involve more code and more SQL statements. Additionally, you might add a back-end administration area, where administrators can easily manage products, product groups, and search criteria.


C HAPTER

13

Captcha N

owadays, most developers would not leave any web forms open to unlimited submission. Some safety measure must be put in place to prevent web forms from being used for spamming. While some people focus on building creative web sites and extending the capability of the Internet, others spend considerable amount of time trying to crack and compromise the information on web sites. Spamming is a huge problem. A recent statistic from Sophos research revealed that during the first quarter of 2008, 96.5 percent of all e-mail was spam (dppl6++sss*okldko*_ki+lnaookbbe_a+jaso+]npe_hao+.,,4+,3+`enpu`kvfqh,4*dpih%! Spambots are everywhere. They simply engage in the process of filling out web forms as if they were customers. For example, a spambot could send thousands of spontaneous e-mail messages by filling out your contact form or your blog comment form, if that form is not protected. You’ve probably encountered web sites where you’re required to interpret some obfuscated characters and input them for validation when a web form is submitted. You will most often see this type of protection on high-profile sites like Google’s Gmail and Yahoo! Mail. This fuzzy character output is called a Captcha. In this chapter, we will briefly look at the various types of Captchas used as a means of protecting web forms. We’ll then focus on the ASCII Art Captcha technique and implement an ASCII Art Captcha component.

Captcha Implementations The term Captcha was coined in 2000 by Luis von Ahn, Manuel Blum, Nicholas J. Hopper, and John Langford. It is a shortened acronym for Completely Automated Public Turing Test to Tell Computers and Humans Apart. The purpose of a Captcha is to prevent automatic form submission by spambots or similar intrusion programs. In 1950, the brain behind the advent of Captcha, Professor Alan Turing, wrote an article called “Imitation Game” to describe how machines can demonstrate intelligence similar to humans. In 1997, Alta Vista created an early spam-blocking measure. Now Captchas are common. There is even a company (reCAPTCHA, at dppl6++na_]lp_d]*jap+) that offers Captcha security as a web service. Figure 13-1 shows an example of a reCAPTCHA Captcha box.

359


360

CH APT ER 13 N CA P TC HA

Figure 13-1. A reCAPTCHA box

Captcha Types There are different types of Captchas and consequently many ways of implementing them. This presents us with many options when it comes to blocking spammers from using robots for submitting web forms. The following list describes some of the common implementations of Captcha designed to completely block automatic programs from web form submission. Alphanumeric images: The most common Captcha implementation is the appearance of a random selection of distorted images made up of alphanumeric values. As humans, we can easily recognize distorted image characters, but spambots cannot. It’s more challenging for spambots to crack the Captcha when the image characters are overlapping or distorted with lines across the characters. Picture images: Another Captcha implementation uses a set of various images, such as animal images (a bird, a fish, an elephant, and so on) or furniture (table and chairs, for instance). You’re expected to recognize the objects by their names and enter their names into an input box. Audio: This technique involves embedding an audio (sound) to pronounce some words or random letters and digits. You’re expected to type the words into an input box. Unfortunately, this requires some audio player, which not everyone has. Also, it makes things difficult for people with hearing problems. Question/answer: A question-and-answer technique involves asking a user a question. If it’s a difficult question, some potential users may be blocked from form submission. Math problems: Using this technique, you are given a mathematical question (such as 56 minus 30), and you are expected to input the resulting value before you can submit the web form. ASCII Art: This technique displays a set of fonts that are created from a combination of characters artistically designed to form gigantic versions of some keyboard characters (A–Z, 0–9, @, and so on). This set of fonts is called the ASCII Art characters. The Captcha implementation presented in this chapter uses ASCII Art, so we’ll take a closer look at that approach.


C H A P T E R 1 3 N C A P T C H A

ASCII Art Captcha Although most of the standard Captchas on the Internet display graphic characters, users sometimes find it difficult to decipher all the characters correctly, perhaps due to their screen resolution, sight, or both. Many people find it is easier to recognize ASCII Art characters compared to their graphic counterparts.

NNote ASCII Art is the creation of images by using the strokes of the characters defined by the ASCII Standard as lines and shading. It is a mini-industry in itself. For more information, just search for “ASCII Art” on the Internet. You can start by going to dppl6++_dneo*_ki+]o_ee+ for some enlightening information.

As new ways of protecting web information are evolving, so are techniques for cracking that protection. Spammers are finding ways of decoding them, typically using optical character recognition (OCR) programs. Not many web forms use ASCII Art, so many deciphering spambot programs find it difficult to decode. Another advantage ASCII Art Captchas have over graphics-based Captchas has to do with external libraries. Some of the graphics-based Captchas rely on PHP extensions (for example, the PHP GD library). The ASCII Art Captchas do not rely on any external library for their operation. They simply rely on your design of the characters. One of the major characteristics of a Captcha is its look and feel. It includes the overlapping of characters and lines that touch the characters. To some extent, this characteristic is dependent on the spacing between characters and the fonts of the individual characters. One of the advantages of using ASCII characters is that you have total control over the look and feel of the characters. ASCII Art Captchas offer a very strong way of thwarting spambots. First, the spambot would need to decipher which keyboard characters are used to compose a single individual character. A single font character could combine some hash () characters, some pipe (x) characters, a few ampersands ("), and so on. Additionally, spambots face the problems of determining the start and end of characters, actual borders or coordinates of each character, and the position of the random text, as well as distinguishing the background noise from the character. In our ASCII Art Captcha implementation outlined in this chapter, our array of fonts will define all characters of the alphabet from A–Z and the numbers 0–9. With this array of fonts, you can modify the characters to suit your own preferences. Here is an example of a constructed font character:        This is clearly a letter T. It’s constructed using a combination of the hash () and exclamation point () characters.

361


362

CH APT ER 13 N CA P TC HA

A Captcha Component Now we will take you through implementing an ASCII Art Captcha. This technique will involve the creation of an array of fancy fonts (ASCII Art) using our own custom keyboard character combinations. Our Captcha characters will be randomly drawn from the array of the ASCII Art fonts, distorted, and finally displayed on a simple web form. The Captcha program will be rolled into a component, so that it can be reused when required in other Cake applications. Table 13-1 describes the properties of the ASCII Art Captcha component. Table 13-1. The Properties of the Captcha Component

Property

Description

bkjpo

Consists of ASCII Art characters. Each character is built by putting together some keyboard characters to form a whole character. You can create your own pattern of characters to replace these fonts. As the name implies, the individual characters of the fonts are determined from the standard alphanumeric values A–Z and 0–9.

jkeoa?d]no

Defines a set of characters that includes a dash $-) character stored as an array that is used as the background of ASCII Art characters.

jqi^an?d]n

A numeric value that must be greater than zero. It’s used to determine the total number of characters in the CAPTCHA string text.

Of course, you can add to the list of the properties—for example, include background coloring—to intensify security.

The ASCII Art Component Class Our component class is named =o_ee=npo?kilkjajp. Listing 13-1 shows the properties in this class. Listing 13-1. The Beginning of the AsciiArtsComponent Class (app/controllers/components/ascii_ captcha.php) 8;ldl _h]oo=o_ee=npo?kilkjajpatpaj`oK^fa_pw r]n jkeoa?d]no9]nn]u$##(9()(6%7 r]n ]o_eeBkjpo9]nn]u$%7 r]n jqi^an?d]n927 ;: The =o_ee=npo?kilkjajp class contains three properties: Ê

UÊ jkeoa?d]no is assigned an array of four ASCII characters: $##(9()(6%. These characters are randomly used to distort the Captcha characters.

Ê

UÊ ]o_eeBkjpo is initially assigned an empty array. This property will later contain a list of all the defined ASCII Art characters for A–Z and 0–9.

Ê

UÊ jqi^an?d]n is assigned an integer 2, which specifies the total number of characters that will constitute the Captcha.


C H A P T E R 1 3 N C A P T C H A

Now that we’ve dealt with the component properties, let’s look at the functionality that we’ll implement to build the ASCII Art Captcha. This functionality includes generating random text from the ASCII character fonts, distorting the randomly generated text, and writing the text to the screen. Next up in our component class is Cake’s op]npql function, as shown in Listing 13-2. Listing 13-2. AsciiArtsComponent’s Startup Method bqj_pekjop]npql$" _kjpnkhhan%w pdeo):`]p]9_kjpnkhhan):`]p]7 y You should be familiar with the op]npql method by now. In this case, it gives the =o_ee=npo?kilkjajp access to the properties of its parent controller, which is the ?]lp_d]?kjpnkhhan object. For example, it enables you to access a form object data $ pdeo):`]ta) submitted to a controller within a component. Next, the ejepe]heva method performs a similar task to the ^abknaBehpan method of the controller. This method contains logic that must be run before any component functionality is run. We initialize the bkjpo property with a set of ASCII Art characters. This bkjp property contains an array of the ASCII Art characters that we created from different sets of characters. For example, Listing 13-3 shows the first two elements of the bkjpo array. Listing 13-3. AsciiArtsComponent’s Initialize Method bqj_pekjejepe]heva$%w bkjpoW#=#Y9 <<< <<)<< <<)))<< <<))))<< <<<<<<<<< <<)))<< <<)))))<<7 bkjpoW#>#Y9 <<<<<<<< <<))))))<< <<)))))<< <<<<<<<<< <<))))))<< <<)))))<< <<<<<<<<<7 ++Kpdan]hld]^ap_d]n]_panobkhhks*** y

363


364

CH APT ER 13 N CA P TC HA

Listing 13-3 shows the created ASCII Art characters for the first two elements (A and B) of the bkjpo array variable $ bkjpoW#=#Y(Å** bkjpoW#V#Y( bkjpoW#,#Y(Å** bkjpoW#5#Y%. In total, the bkjpo array contains 36 elements. We are going to randomly draw a number of characters from this array, based on the jqi^an?d]n property of the component. Next in this class is the cap?]lp_d] method, which returns a Captcha string, as shown in Listing 13-4. Listing 13-4. AsciiArtsComponent’s getCaptcha() Method bqj_pekjcap?]lp_d]$%w  naoqhp9]nn]u$%7  _]lp_d]?d]no9]nn]u[n]j`$pdeo):]o_eeBkjpo(pdeo):jqi^an?d]n%7 bkn$ e`t9,7 e`t8oevakb$ _]lp_d]?d]no%7 e`t''%w  _]l?d]n9 _]lp_d]?d]noW e`tY7  naoqhpW _]l?d]nY9pdeo):]o_eeBkjpoW _]l?d]nY7 y  naoqhp9pdeo):]``Jkeoa$ naoqhp%7 napqnj naoqhp7 y The first statement in this method initializes the naoqhp variable with an empty array. This variable will eventually contain the final result of this function. Next, we use the PHP function ]nn]u[n]j` to randomly select a list of characters from this function’s first argument, pdeo):]o_eeBkjts. The total number of characters selected is determined by the second argument, pdeo):jqi^an?dar, which has a default value of 2. In this case, a set of six randomly selected characters is stored in the _]lp_d]?d]no array variable. Next, we use a bkn loop to store each character in _]l?d]n variable. That variable is used as a key to pull the corresponding ASCII Art characters from the ]o_eeBkjpo array, and then stored in the naoqhp array variable. The bkn loop’s maximum iteration is based on the number of elements in the _]lp_d]?d]no array variable. Finally, we use the ]``Jkeoa method to distort the ASCII Art characters and return the final Captcha result to be used in the ?]lp_d]?kjpnkhhan object. The next method in our component class is ]``Jkeoa, which takes an array of the randomly selected ASCII Art characters and returns a distorted version of the character, as shown in Listing 13-5. Listing 13-5. AsciiArtsComponent’s addNoise() Method bqj_pekj]``Jkeoa$ _]lp_d]Opnejco%w  naoqhp9]nn]u$%7 bkna]_d$ _]lp_d]Opnejco]o _]l?d]n9: ]o_ee%w bkn$ e`t9,7 e`t8opnhaj$ ]o_ee%7 e`t''%w


C H A P T E R 1 3 N C A P T C H A

eb$ ]o_eeW e`tY99##%w  jkeoa?d]n9]nn]u[n]j`$pdeo):jkeoa?d]no(-%7  ]o_eeW e`tY9pdeo):jkeoa?d]noW jkeoa?d]nY7 y y  ]o_ee9opn[nalh]_a$_dn$-/%(##( ]o_ee%7  naoqhpW _]l?d]nY9 ]o_ee7 y napqnj naoqhp7 y y ;: In Listing 13-5, we first set the naoqhp variable to an empty array. Next, we use the bkna]_d loop to iterate the list of the ASCII Art characters stored in _]lp_d]Opnejco, and then use an inner bkn loop to iterate each ASCII Art character and check whether a character is empty or a whitespace character. If a character is a whitespace character, the program randomly selects a replacement character from the jkeoa?d]no array variable. The final ]o_ee character is stored and returned as the naoqhp array variable. Now that we are finished with the =o_ee=npo?kilkjajp properties and methods, let’s move to the controller that employs the services of this component to provide security against a spambot’s submission of our sample form.

The Captcha Controller Next, we will create the ?]lp_d]?kjpnkhhan class that displays a form to test our Captcha. It starts as shown in Listing 13-6. Listing 13-6. The Beginning of the CaptchaController Class (app/controllers/captcha_ controller.php) 8;ldl _h]oo?]lp_d]?kjpnkhhanatpaj`o=ll?kjpnkhhanw r]n j]ia9#?]lp_d]#7 r]n qoao9]nn]u$#?]lp_d]#%7 r]n dahlano9]nn]u$#Bkni#(#Dpih#(#Oaooekj#%7 r]n _kilkjajpo9]nn]u$#Oaooekj#(#NamqaopD]j`han#(#=o_ee=npo#%7 In Listing 13-6, we declare the helpers and components to aid some of the functions implemented in the controller. Notice that we’ve included our =o_ee=npo component. Next in the controller is the ^abknaBehpan function, which is invoked before any of the controller functionality is called to set the heading information for our screen, as shown in Listing 13-7.

365


366

CH APT ER 13 N CA P TC HA

Listing 13-7. CaptchaController’s beforeFilter Method bqj_pekj^abknaBehpan$%w  ]_pekjDa]`ejc9#=O?EE=npo?=LP?D=#7  ]_pekjOhkc]j9#Lha]oabehhej=O?EE=npopatp#7 pdeo):oap$_kil]_p$#]_pekjDa]`ejc#(#]_pekjOhkc]j#%%7 y Next, we will create the ej`at function, which renders a simple HTML form to do a Captcha test, as shown in Listing 13-8. Listing 13-8. CaptchaController’s index Function bqj_pekjej`at$%w  _]lp_d]9pdeo):=o_ee=npo):cap?]lp_d]$%7  opnejc9eilhk`a$(]nn]u[gauo$ _]lp_d]%%7 pdeo):Oaooekj):snepa$#opnejc#( opnejc%7 pdeo):oap$_kil]_p$#_]lp_d]#(#opnejc#%%7 y The ej`at method starts by setting the _]lp_d] array variable with the list of ASCII Art characters retrieved by using the cap?]lp_d] method of the =o_ee=npo?kilkjajpo object. Next, using the PHP eilhk`a function, we obtain all the keys of the elements of the _]lp_d] array variable with an empty string; this is the ASCII value of the Captcha characters. We then store the keys in the opnejc variable written to a string Oaooekj variable. We will use the characters stored in a Oaooekj object to validate the input a user has entered on a web form. We then make the _]lp_d] and opnejc variables available to the ]ll+reaso+_]lp_d]+ej`at*_pl view code, which is shown in Listing 13-9. Listing 13-9. The Captcha Test View (app/views/captcha/index.ctp) 8beah`oap: 8hacaj`:8;ldl[[$ ]_pekjDa]`ejc%7;:8+hacaj`: 8;9 ]_pekjOhkc]j7;: 8^n+: 8;ldl a$8lna:8p]^ha:8pn:%7 bkna]_d$ _]lp_d]]o gau9: r]h%w a$#8p`opuha9bkjp)oeva6-,lt7:#* r]h*#8+p`:#%7 y a$8+pn:8+p]^ha:8lna:%7 a_dkbkni):_na]pa$#?]lp_d]#(]nn]u$#qnh#9:#+_]lp_d]+_da_g#%%7 a_dkbkni):annkn$#?]lp_d]*patp#%7 a_dkbkni):ejlqp$#?]lp_d]*patp#(]nn]u$£ #e`#9:#patp#(#h]^ah#9:#Patp6#(#oeva#9:#1,#(£ #i]thajcpd#9:#.11#(#annkn#9:b]hoa%%7 a_dkbkni):aj`$]nn]u$#h]^ah#9:#Oq^iep#%%7 ;: 8+beah`oap:


C H A P T E R 1 3 N C A P T C H A

In Listing 13-9, the page heading and slogan were rendered using the variables set in the ^abknaBehpan method of the controller. Next, we use the bkna]_d loop to display the ASCII Art characters stored in the _]lp_d] array variable. Finally, we create a Captcha form containing an input text field to accept user input. The user is expected to correctly enter the ASCII Art character displayed above the input element. The view is shown in Figure 13-2.

Figure 13-2. The Captcha test form When a user clicks the Submit button, the form submission is handled by the _da_g function declared in the component, as shown in Listing 13-10. Listing 13-10. The check() Function in the CaptchaController Class (app/controllers/captcha_ controller.php) bqj_pekj_da_g$%w eb$ailpu$ pdeo):`]p]W#?]lp_d]#YW#patp#Y%%w eb$ pdeo):`]p]W#?]lp_d]#YW#patp#Y99pdeo):Oaooekj):na]`$#opnejc#%%w pdeo):Oaooekj):oapBh]od$ [[$#8d-:Ukqd]raajpana`pdanecdp_d]n]_pano8+d-:#(pnqa%%7 pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7

367


368

CH APT ER 13 N CA P TC HA

yahoaw pdeo):Oaooekj):oapBh]od$ [[$#Ukqd]raajpana`pdasnkjc_d]n]_pano*Lha]oapnu]c]ej*#(pnqa%%7 pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 y yahoaw pdeo):Oaooekj):oapBh]od$ [[$#Ukqjaa`pkajpanpda_knna_p_d]n]_pano*£ Lha]oapnu]c]ej*#(pnqa%%7 pdeo):na`ena_p$]nn]u$#]_pekj#9:#ej`at#%%7 y y In the _da_g function, we first check if the submitted data $ pdeo):`]p]W#?]lp_d]#Y W#patp#Y% is not empty. If it’s empty, the appropriate error message is stored in the Oaooekj object, and the Captcha form is displayed with the preset error message. If it’s not empty, we first check if the input value entered by the user is equal to the ASCII Art characters stored in the Oaooekj object. If they are not equal, the error message is set, using the oapBh]od method of the Oaooekj object. Otherwise, the success message is set for display in the Captcha view, as shown in Figure 13-3.

Figure 13-3. The screen showing the success message


C H A P T E R 1 3 N C A P T C H A

Summary In this chapter, we addressed the need to thwart spammers when collecting information using web forms. We concentrated on safeguarding form data against machine-code intruders such as spambots, who can act like humans and fill in web forms. We took a brief look at the various types of Captchas that can be implemented. We chose to implement an ASCII Art Captcha. We created an ASCII Art component. This component contains properties and functionality that enable our Captcha controller to create a simple human test via a web form that randomly displays a set of ASCII Art characters on the screen. Finally, appropriate messages are displayed after a user has entered text. There are many possible ways you can improve on our Captcha component. Here are some suggestions: Ă&#x160;