AJAX - The introduction

AJAX

Asynchronous JavaScript + XML, is not a new technology or a new programming language, but a new way to use existing standards. It is a term coined in 2005 by Jesse James Garrett, which describes a "new" approach to using a number of existing technologies together, including: HTML or XHTML, Cascading Style Sheets, JavaScript, The Document Object Model, XML, XSLT, and the XMLHttpRequest object. It is a new technique for creating better, faster, and more interactive web applications

When these technologies are combined in the AJAX model, web applications are able to make quick, incremental updates to the user interface without reloading the entire browser page. This makes the application faster and more responsive to user actions.

With AJAX, a JavaScript can communicate directly with the server, with the XMLHttpRequest object. With this object, a JavaScript can trade data with a web server, without reloading the page.

AJAX uses asynchronous data transfer (HTTP requests) between the browser and the web server, allowing web pages to request small bits of information from the server instead of whole pages.

The AJAX technique makes Internet applications smaller, faster and more user-friendly.

Ajax isn’t a technology. It’s really several technologies, each flourishing in its own right, coming together in powerful new ways. Ajax incorporates:

• standards-based presentation using XHTML and CSS;
• dynamic display and interaction using the Document Object Model;
• data interchange and manipulation using XML and XSLT;
• asynchronous data retrieval using XMLHttpRequest;
• and JavaScript binding everything together.

The classic web application model works like this: Most user actions in the interface trigger an HTTP request back to a web server. The server does some processing — retrieving data, crunching numbers, talking to various legacy systems — and then returns an HTML page to the client. It’s a model adapted from the Web’s original use as a hypertext medium.

Although we are just beginning to realize its full potential, the proven success of famous AJAX-based projects like Google Maps, Google suggest or gmail are few real time examples which signifies that this is not just another media hype, but rather a promising technology that may change web-applications as we know them.

The biggest challenges in creating Ajax applications are not technical. The core Ajax technologies are mature, stable, and well understood. Instead, the challenges are for the designers of these applications: to forget what we think we know about the limitations of the Web, and begin to imagine a wider, richer range of possibilities.

Ajax has changed the face of the web forever. Save for some of the browser enhancements and a few other technologies, I dare to say that it’s had the most significant impact on the way we use the internet in its short life