AJAX is a set of web development techniques that are actually interrelated. In fact, the terminology is abbreviation for Asynchronous JavaScript and XML. Using these techniques on client-side, asynchronous web applications are developed. As such, this tool allows web applications to send and retrieve data from a (background) server, without affecting the display and behavior of an existing page.

Component elements

Interestingly, AJAX is not one single technology. Rather, it is a combination of technologies. It includes

  • CSS and HTML – to facilitate ‘mark up’ and style information
  • JavaScript and XMLHTTPRequest – facilitate a method for asynchronous data exchange between server and browser
  • DOM – accessed in combination with JavaScript to facilitate user interaction and dynamic display, etc.

This set of technology is widely used in various web form applications. In fact, the particular web forms reveal the following features.

  • Partial updating of a webpage that updates only the portion of a page that has changed
  • Presence of common UI elements, like progress indicator, pop-up windows and tooltips, etc.
  • Auto-generated proxy classes that ease the process of calling various web service methods from client script
  • Multi browser support, including Mozilla Firefox, Apple Safari and Internet Explorer, etc.

Architecture for the applications

AJAX web applications compose of either a

  • Client-only solution or
  • Client and server solution

A client-only solution makes extensive use of Microsoft AJAX Library, but does not use the server controls defined in ASP.NET. The AJAX library enables AJAX applications to perform all processing on the client side.

On the other hand, the client and server solution uses both AJAX library and the ASP.NET server controls.

The functionalities those are included in client-script libraries and server components with .NET framework 4 are as follows

  • Microsoft Ajax client and server architecture
  • ASP.NET AJAX Server and Client Architecture

Control Toolkit

AJAX Control Toolkit possesses controls that can be used to build impressively responsive and interactive (AJAX-enabled) web applications and is an Open Source project. Interestingly, these controls do not summon knowledge of JavaScript or AJAX. Rather, these are designed using a string of concepts that are familiar with ASP.NET Web Form Applications. Using this Control Toolkit it is easy to build Ajax-enabled ASP.NET Web Forms applications and ASP.NET MVC Web applications by dragging the controls from the Visual Studio Toolbox to an existing page.