AJAX is hot, hot, hot! Why? It's simple. With AJAX, internet developers and designers can create web-based applications that look and feel like desktop applications. These are responsive, highly-interactive applications that represent a new breed called "Rich Internet Applications" (RIA). This book is a guide to designing, implementing, and debugging AJAX applications. The book begins by comparing and contrasting the traditional web application lifecycle with that of an AJAX application. It then covers core AJAX technology, including the XMLHTTPRequest object, and describes various methods for "consuming" data returned by it. Because AJAX represents a fundamentally new way of creating web applications, the book is careful to explore usability guidelines for AJAX developers. This is followed by a series of use cases that show how specific problems are solved in both the pre-AJAX and post-AJAX worlds. The book ends with a chapter on debugging AJAX applications, along with appendices that cover toolkits that greatly simplify AJAX development. All of the server-side examples presented in the book will be written in PHP, the most popular langauage for server-side web programming.
Understanding AJAX is a very in-depth look at some of the technologies used in modern web design. In reading this book, you will come to understand the pros and cons of using AJAX in a web site and exactly what happens between the browser and the web server.
You will get a sense of what can and can't be done using AJAX and how to get around the problems caused by the many web browser clients in use at this time. You will also come to understand how to make the user's browser do much of the work that your server used to do. Understanding AJAX also dives into the usage of many open source script libraries to make coding a modern website much easier. From adding DHTML effects to using a single page for your entire site, you will get a feel for what is possible.