Adding Ajax [ペーパーバック]

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The book title delivers a vital clue. "Adding Ajax" has a special, limited focus that may be right up your alley -- if you are evaluating enhancing existing Web applications by adding Ajax effects. Developers looking to evaluate building an Ajax-based application architecture from the ground up may not be satisfied.

The book itself is a fast read. That is not because of lack of content -- there is plenty of that! Still, Shelley Powers has organized the information so that most of the chapters can be read out of order, as independently as possible from the others. Chapter 5, which deals with accordion menus, tabbed paging, and overlays with Ajax and common script libraries can be skipped if you are most interested in user updates of live data in Chapter 6 without a problem.

The author cites known experts for related material (like Jeremy Keith and Eric Meyer) and gives lots of URLs for follow-up material.

The book is pretty much practice-oriented and contains lots of code. That leads to my one quibble: there is a lot of code here that does not seem to be available in downloadable form. Some people would find it convenient to have the code examples in a way that could be immediately tested on a server. Re-typing is a drag. The O'Reilly page for this book has a *very* impressive Table of Contents, with content previews -- but no code download.

Other than that, this is a very fine book.
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Ajax can be added to existing web applications without redoing everything - and ADDING AJAX by Shelley Powers is the perfect web programmer's guide to doing so with ease. Chapters not only cover methods of adding Ajax, but how to use Ajax to enhance an application, how to work with Ajax libraries and interactive elements, and how to understand the effects Ajax has on Web applications. Any web programmer's collection should have ADDING AJAX: it discusses easy integration of Ajax into existing systems and operations.

The book describes a number of ways in which Ajax changes the traditional state of the web. However, to start with the author describes what you need to do to prepare yourself for Ajax. I especially like the Start Clean section in which Shelly claims that the default CSS values are not necessarily good. For example, link underlining in a-tag is not always a good idea. I have heard this concept of starting from a clean sheet a number of times, it is a popular idea in the design community.

Also in the first chapter the author introduces the notion of Progressive enhancement, a web development methodology. Basically it says that the web site should work in various environments, even in the simplest. The idea is to make sure that your web site is still accessible on various devices after adding new features to it. The author stresses the concept of accessibility throughout the book. Indeed, web is an open platform for everybody - people in developing world, people with disabilities, etc.

Then there is a chapter on various web frameworks. The author explains the tradeoffs associated with using them. Obviously, a web framework often includes features you don't need and that increases the loading time of your page, an important issue for people with slower connections. Among the frameworks, Prototype offers the best value. Its goal is to provide a cross-browser layer while staying quite minimal in size.

In Chapter 4 the book describes interactive effects that Ajax allows to add, for example instant previews, fade ins and outs, etc. Then it describes the widgets that Ajax allows one to use: accordion, tabs, overlays. After that, the book deals with more complex issues such as in-place editing and live validation which requires interacting with a server. Besides home-grown solutions that book mentions a variety of web frameworks and tools, for example JotForm - a nice framework for building forms and putting them on your web site. JotForm simplifies life of web developers.

A special chapter is dedicated to advanced effects such as using Ajax with SVG. Finally, the author explains how to build mashups using web APIs. In this chapter the author explains the tradeoffs of using client-side and server-side mashups and explains how to implement a mashup in a non-scripting environment. Despite the fact that this is a book on Ajax the case in which Javascript is disabled is also dealt with. The reason is that many people prefer to browse unfamiliar sites without Javascript, the author claims.

Despite all its gorgeous content the book has drawbacks. The main disadvantage is that it is a bit hackish in nature. For example, there are well defined Javascript design patterns which the book does not mention. Instead, it offers its solutions as functions or snippets of code that the web developers are supposed to paste wherever appropriate. If next editions of the book are to appear it needs to take an object-oriented approach to all the beauty that it has developed.