AJAX Introduction
admin May 21st, 2009
AJAX or Asynchronous JavaScript and XML is a very useful tool for web programming, allowing you to create rich, dynamic web site components.
Typically one characteristic of web applications has been that, for a web application to function, a whole web page file would have to be loaded across the web. This made dynamic browser based applications perform very slowly, with limited levels of interactivity.
AJAX was developed with the view to overcome this, by allowing of sections of a web page displayed in a browser window to be modified /refreshed without a complete web page access.
AJAX is actually a number of technologies working together:
(a) Javascript
(b) XML - which is a markup language that can define a set of languages for use with structured data.
Any developer can create an XML-based language with its own set of markup tags, to suit the particular application.
(c) Cascading Style Sheets [CSS], which is a W3C standard providing web developers with greater control over how web pages are displayed in browsers. CSS supports the concept of the seperation of content from code, with CSS formatting script usually installed in .css files, saved together with, but seperated from the actual xHTML pages.