Mastering Ajax, Part 3: Advanced requests and responses in Ajax

Mastering Ajax, Part 3: Advanced requests and responses in Ajax: "Mastering Ajax, Part 3: Advanced requests and responses in Ajax

Gain a complete understanding of HTTP status codes, ready states, and the XMLHttpRequest object
developerWorks

Level: Introductory

Brett McLaughlin (brett@newInstance.com), Author and Editor, O'Reilly Media Inc.

14 Feb 2006

For many Web developers, making simple requests and receiving simple responses is all they'll ever need, but for developers who want to master Ajax, a complete understanding of HTTP status codes, ready states, and the XMLHttpRequest object is required. In this article, Brett McLaughlin will show you the different status codes and demonstrate how browsers handle each and he will showcase the lesser-used HTTP requests that you can make with Ajax.

In the last article in this series, I provided a solid introduction to the XMLHttpRequest object, the centerpiece of an Ajax application that handles requests to a server-side application or script, and also deals with return data from that server-side component. Every Ajax application uses the XMLHttpRequest object, so you'll want to be intimately familiar with it to make your Ajax applications perform and perform well.

In this article, I move beyond the basics in the last article and concentrate on more detail about three key parts of this request object:

* The HTTP ready state
* The HTTP status code
* The types of requests that you can make"