Ajax Basics

 

The traditional website uses a page-based model. That's to say, you view a page, then do something - click a link, submit a form or some such - and wait for another page, or a page refresh.

 

That's unlike your desktop applications. In those, your actions cause changes within the current windows, dialog boxes and such like, in real time.

 

Ajax is a combination of techniques that allows us to offer similar types of responses from our web-based applications. It does this by using a JavaScript gadget called the XMLHTTPRequest object.

 

This object is capable of exchanging communications with the server in the background while your user continues to browse your site. A few simple JavaScript routines can then be used to process the returned data and offer it to your user without a page refresh.

 

Ajax stands for Asynchronous JavaScript And XML. This may suggest that Ajax requires the use of XML to function, but in fact the technique can be very valuable even without the added complexity of XML.

 

This site contains lots of information about how Ajax works, including code snippets, tutorials, and complete projects (more to follow soon). However, suggestions for content are always welcome!