www.it-ebooks.info Professional Ajax 2 nd Edition Nicholas C. Zakas Jeremy McPeak Joe Fawcett 01_109496 ffirs.qxd 2/5/07 6:41 PM Page i www.it-ebooks.info 01_109496 ffirs.qxd 2/5/07 6:41 PM Page i www.it-ebooks.info Professional Ajax 2 nd Edition Nicholas C. Zakas Jeremy McPeak Joe Fawcett 01_109496 ffirs.qxd 2/5/07 6:41 PM Page i www.it-ebooks.info Professional Ajax, 2nd Edition Published by Wiley Publishing, Inc. 10475 Crosspoint Boulevard Indianapolis, IN 46256 www.wiley.com Copyright © 2007 by Wiley Publishing, Inc., Indianapolis, Indiana Published simultaneously in Canada ISBN: 978-0-470-10949-6 Manufactured in the United States of America 10 9 8 7 6 5 4 3 2 1 Library of Congress Cataloging-in-Publication Data:˙ Zakas, Nicholas C. Professional Ajax / Nicholas C. Zakas, Jeremy McPeak, Joe Fawcett. 2nd ed. p. cm. Includes index. ISBN-13: 978-0-470-10949-6 (paper/website) ISBN-10: 0-470-10949-1 (paper/website) 1. Ajax (Web site development technology) 2. Web sites Design Computer programs. 3. JavaScript (Computer pro- gram language) 4. Asynchronous transfer mode. 5. World Wide Web. I. McPeak, Jeremy, 1979- II. Fawcett, Joe, 1962- III. Title. TK5105.8885.A52Z35 2007 005.13'3 dc22 2006103094 No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600. Requests to the Publisher for permission should be addressed to the Legal Department, Wiley Publishing, Inc., 10475 Crosspoint Blvd., Indianapolis, IN 46256, (317) 572-3447, fax (317) 572-4355, or online at http://www.wiley.com/go/permissions. 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All other trademarks are the property of their respective owners. Wiley Publishing, Inc., is not associated with any product or vendor mentioned in this book. Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be avail- able in electronic books. 01_109496 ffirs.qxd 2/5/07 6:41 PM Page ii www.it-ebooks.info To mom, dad, Greg, Yiayia, and the rest of my family and friends who have supported me throughout my cross-country move. —Nicholas C. Zakas To the love of my life, Starla. Thank you for your love, patience, and encouragement. —Jeremy McPeak To my parents, Sheila and William, who instilled in me a love of reading. Thank you! —Joe Fawcett 01_109496 ffirs.qxd 2/5/07 6:41 PM Page iii www.it-ebooks.info About the Authors Nicholas C. Zakas has a BS in Computer Science from Merrimack College and an MBA from Endicott College. He is the author of Professional JavaScript for Web Developers (Wiley 2005) as well as several online articles. Nicholas works for Yahoo! as a frontend engineer and has worked in web development for more than 6 years, during which time he has helped develop web solutions in use at some of the largest companies in the world. Nicholas can be reached through his web site at www.nczonline.net. Jeremy McPeak began tinkering with web development as a hobby in 1998. Currently working in the IT department of a school district, Jeremy has experience developing web solutions with JavaScript, PHP, and C#. He has written several online articles covering topics such as XSLT, WebForms, and C#. He is also co-author of Beginning JavaScript, 3rd Edition (Wiley 2007). Jeremy can be reached through his web site at www.wdonline.com. Joe Fawcett started programming in the 1970s and briefly worked in IT upon leaving full-time educa- tion. He then pursued a more checkered career before returning to software development in 1994. In 2003 he was awarded the title of Microsoft Most Valuable Professional in XML for community contribu- tions and technical expertise. He currently works in London as a developer for FTC Kaplan, a leading international provider of accountancy and business training, where he specializes in systems integration. 01_109496 ffirs.qxd 2/5/07 6:41 PM Page iv www.it-ebooks.info Credits Senior Acquisitions Editor Jim Minatel Senior Development Editor Kevin Kent Technical Editor Alexei Gorkov Production Editor Angela Smith Copy Editor Jeri Freedman Editorial Manager Mary Beth Wakefield Production Manager Tim Tate Vice President and Executive Group Publisher Richard Swadley Vice President and Executive Publisher Joseph B. Wikert Graphics and Production Specialists Sean Decker Jennifer Mayberry Amanda Spagnuolo Alicia B. South Quality Control Technician Rob Springer Project Coordinator Bill Ramsey Proofreading Christopher Jones Indexing Johnna VanHoose Dinse Anniversary Logo Design Richard Pacifico 01_109496 ffirs.qxd 2/5/07 6:41 PM Page v www.it-ebooks.info Acknowledgments It takes many people to create a book such as this, and as such, we’d like to thank some people for their contributions to this work. First and foremost, thanks to everyone at Wiley for their support: to Jim Minatel for starting the process once again, and Kevin Kent for putting up with all of the last-minute changes and course diversions throughout the process. Also, a thanks to our technical editor, Alexei Gorkov, for doing a fantastic job keeping us honest. Last, a big thanks to those who provided feedback pre-publication including Peter Frueh, Adam Moore, Jenny Han, Matt Sweeney, Tyson Guskiken, Steve Carlson, and especially Hedger Wang, who suggested adding the chapter on request management. 01_109496 ffirs.qxd 2/5/07 6:41 PM Page vi www.it-ebooks.info Contents Introduction xv Chapter 1: What Is Ajax? 1 Ajax Is Born 2 The Evolution of the Web 2 JavaScript 2 Frames 3 The Hidden Frame Technique 3 Dynamic HTML and the DOM 3 Iframes 4 XMLHttp 4 The Real Ajax 5 Ajax Principles 6 Technologies behind Ajax 6 Who Is Using Ajax? 7 Google Suggest 7 Gmail 8 Google Maps 9 A9 10 Yahoo! News 11 Bitflux Blog 12 Confusion and Controversy 13 Ajax and Web 2.0 14 Summary 15 Chapter 2: Ajax Basics 17 HTTP Primer 17 HTTP Requests 18 HTTP Responses 20 Ajax Communication Techniques 21 The Hidden Frame Technique 21 XMLHttp Requests (XHR) 37 Ajax with Images 50 Dynamic Script Loading 59 Cache Control 63 Summary 63 02_109496 ftoc.qxd 2/5/07 6:46 PM Page vii www.it-ebooks.info [...]... 416 Using DWR DWR Example More about dwr.xml Summary of DWR 416 419 424 427 Ajax. NET Professional 427 Using Ajax. NET Professional Type Conversion Session Access Ajax. NET Professional Example Summary of Ajax. NET Professional Summary 427 429 430 431 436 436 Chapter 14: ASP.NET AJAX Extensions (Atlas) Requirements and Setup The AJAX Client Library 437 438 438 Accessing the Client Tools with ASP NET Accessing... creating Ajax widgets that can be included in your web site 13 Ajax Frameworks Covers three Ajax frameworks: JPSPAN for PHP, DWR for Java/JSP, and Ajax. NET for the NET framework Each of these frameworks attempts to automate some part of the Ajax development process 14 ASP.NET AJAX Extensions (Atlas) Introduces ASP.NET AJAX Extensions (formerly called Atlas) and how they can simplify the creation of Ajax. .. explores how to manage all of the requests inside of an Ajax application Ajax debugging techniques are also discussed, including the popular FireBug and Fiddler utilities The last part of the book walks through the creation of two full-fledged Ajax web applications The first, FooReader.NET, is an Ajax- powered RSS reader The second, called AjaxMail, is an Ajax- enabled email system Both of these applications... Second Edition (Wiley 2004) and Professional JavaScript for Web Developers (Wiley Publishing, Inc., 2005) What This Book Covers Professional Ajax provides a developer-level tutorial of Ajax techniques, patterns, and use cases The book begins by exploring the roots of Ajax, covering how the evolution of the web and new technologies directly led to the development of Ajax techniques A detailed discussion... as to when each should be used 3 Ajax Patterns Focuses on design patterns using Ajax There are a variety of ways to incorporate Ajax into web sites and web applications; these have been organized into a handful of design patterns that describe best practices for Ajax incorporation 4 Ajax Libraries Explores three popular Ajax libraries: the Yahoo! Connection Manager, Prototype, and jQuery The different... pressing Enter The LiveSearch Ajax functionality is just an enhancement to the overall site and isn’t required to search 12 www.it-ebooks.info What Is Ajax? Figure 1-7 Confusion and Controversy Despite the popularity of the term Ajax, it has been met with its fair share of dissenters and controversy Some believe that Ajax is an aberration of what the Web was moving toward before Ajax entered the picture... Contents The $.post() Method POST Example The load() Method The $ .ajax( ) Method The ajaxStart() and ajaxStop() Methods Limitations Summary 120 120 122 123 124 124 125 Chapter 5: Request Management Priority Queues The RequestManager Object Request Description Objects Queuing Requests Sending Requests Cancelling Requests Age-Based Promotion Handling Ajax Patterns Using RequestManager Summary 127 127 131 132... Summary 97 Chapter 4: Ajax Libraries 99 The Yahoo! Connection Manager 99 Setup Basic Requests The Callback Object Monitoring and Managing Requests Form Interaction File Uploads GET Example POST Example Additional Features Limitations 99 100 100 104 104 105 106 107 108 108 Prototype 109 The Ajax. Request Object The Options Object GET Example POST Example The Ajax. Updater Object The Ajax. Responders Object... server, the Ajax model provides an intermediate layer — what Garrett calls an Ajax engine — to handle this communication An Ajax engine is really just a JavaScript object or function that is called whenever information needs to be requested from the server Instead of the traditional model of providing a link to another resource (such as another web page), each link makes a call to the Ajax engine,... between the traditional and Ajax web application models Traditional Web Application Model Web Browser HTML, Images, CSS, JavaScript Data HTTP Request Query/Data Request Database Web Server Ajax Web Application Model Web Browser HTML, CSS Data Data HTTP Request Query/Data Request Ajax Engine User Interface JavaScript Call Database Web Server Figure 1-1 5 www.it-ebooks.info Chapter 1 Ajax Principles As a new . 427 Ajax. NET Professional 427 Using Ajax. NET Professional 427 Type Conversion 429 Session Access 430 Ajax. NET Professional Example 431 Summary of Ajax. NET. and the DOM 3 Iframes 4 XMLHttp 4 The Real Ajax 5 Ajax Principles 6 Technologies behind Ajax 6 Who Is Using Ajax? 7 Google Suggest 7 Gmail 8 Google Maps