1.9. Summary

This chapter introduced you to the basic premise of Ajax. Short for Asynchronous JavaScript + XML, the term Ajax was coined by Jesse James Garrett in an article posted on the Adaptive Path, LLC web site. The article introduced Ajax as a new user interaction model for web applications in which full page loads are no longer necessary.

This chapter also explored the evolution of the Web in relation to the development of technologies that enable Ajax to be a reality today. Ajax owes its existence to the introduction of both JavaScript and frames into web browsers, which made asynchronous data retrieval using JavaScript theoretically possible in Netscape Navigator 2.0. Throughout the evolution of new web technologies, Ajax methodologies such as the hidden frame technique developed. The introduction of iframes and XMLHttp really pushed Ajax development forward.

Although Ajax can be used to accomplish many things, it is best used to enhance the user experience rather than providing cool effects. This chapter discussed several Ajax principles, all circling back to the requirements of the user being paramount to anything else in web application development.

Several of the most popular Ajax applications were also discussed, including Google Suggest, Gmail, Google Maps, Yahoo! News, and the Bitflux Blog.

Finally, the chapter covered the controversy surrounding Ajax, Garrett's article, and Ajax's place on the Web. Some feel that the popularization of Ajax will lead to an overall lack of accessibility, whereas others question Garrett's motive for writing the now-famous article. As with all approaches, Ajax is at its best when used in a logical enhancement to a well-designed web application.