The competition among Ajax programming books has gotten all the more fierce with Prentice Hall's excellent Understanding Ajax. While many Ajax texts are good at covering a handful of advanced Ajax-related topics, this one starts at the beginning and covers every necessary aspect of Ajax programming in just the right amount of detail.

Writing analysis

Understanding Ajax is divided into three parts: an Ajax introduction, case studies dealing with Ajax libraries, and appendices that explain popular Ajax libraries in depth. The first section is among the best introductions to Ajax that I've yet read; every concept, term, and technique is explained simply, then shown in a small but operational example. Once the basic concept is established, the author ventures further into more complex uses and alternative approaches.

In terms of content quality, this book is easy to follow and understand. The code samples are perfectly conceived and formed, and for the most part will actually work in your Web browser. Where appropriate, the author builds on previous examples so that you can see your little program evolve as you expand your knowledge of the subject. I was particularly impressed by chapter 4, which offered a no-holds-barred discussion of the challenges of developing with Ajax and implementing Ajax techniques into current sites and applications. The lack of Ajax cheerleading is refreshing, to say the least.

The writing style may be easy to follow, but the editing isn't on the same level. Typographical and punctuation errors litter the book, usually near the beginning of chapters.

Putting the book to the test

The book states that you must be familiar with JavaScript, HTML, and CSS in order to get the most benefit from it. That immediately put me off because I've read many technical books that start out with an admonition that the reader be "familiar with" or "competent in" certain key technologies, only to discover that what the author really meant to say was, "you must be a guru." Understanding Ajax is among the minority of programming books that don't assume you know everything, and when it says that you must have some degree of competence with JavaScript, HTML, and CSS, it means that you should know the basics of how to code your own Web page -- how to build a cascading style sheet, how to use HTML tags, the basics of object-oriented programming, and how to create and implement a JavaScript function.

Understanding Ajax covers development in Internet Explorer 6 and Firefox 1.5. It occasionally mentions Opera, Konqueror, and Safari, and completely ignores the subject of mobile and handheld browsers. I wasn't too pleased with these omissions because they make that terrible assumption that everyone who has a computer uses Microsoft Windows.

Though I have pages of notes on this book, the last thing I'll say about it as that it includes a whole chapter that walks you through building an entirely Ajax-based "support ticket" Web application, broken up into appropriate sections, and using techniques the book has previously taught. I can comfortably say that you can learn how to develop with Ajax by reading and following Understanding Ajax.

Summary and conclusions

Understanding Ajax is among the best books to learn Ajax programming from that I've seen so far. It's thorough without being dry, the author intuitively knows just how far to go into a subject to teach it to you without running off on some wild tangent, and every piece of relevant information -- browser-specific performance issues, debugging using popular software tools, error logging, integration with PHP-based applications, usability in user interface design -- is included. Definitely recommended for prospective Ajax Web developers.

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Copyright 2007 JEM Electronic Media, Inc. No reprints without written permission.