ajax

AJAX

AJAX = Asynchronous JavaScript and XML.

AJAX is a technique for creating fast and dynamic web pages.

AJAX allows web pages to be updated asynchronously by exchanging small amounts of data with the server behind the scenes. This means that it is possible to update parts of a web page, without reloading the whole page.

ASP.NET 2.0 AJAX

On June 28, 2005, Microsoft announced “ASP.NET 2.0 AJAX.” ASP.NET 2.0 AJAX is an AJAX-oriented .NET library that runs on .NET 2.0. Though ASP.NET 2.0 AJAX is an AJAX library and can be used to perform AJAX operations, it is really much more. ASP.NET 2.0 AJAX offers many of the same types of features of the server-side ASP.NET, but it is directed at the client side. Because ASP.NET 2.0 AJAX is fully integrated with ASP.NET, it provides rich integration with the services provided by ASP.NET.

ASP.NET 2.0 AJAX provides the following features (and much more):

•AJAX-style communications between client and server. This communication is over web services.

•Asynchronous communication. All client-to-server communication in the ASP.NET 2.0 AJAX framework is asynchronous.

•A set of server-side controls that enable rich client-side functionality.

•A set of client-side controls and classes that further enable client-side functionality.

•A framework for encapsulating client-logic through the creation of namespaces and classes.

•Cross browser support. Although there is no official matrix of web browsers that ASP.NET 2.0 AJAX supports, the latest versions of Internet Explorer, Firefox, and Safari are supported. In addition, Opera is thought to be supported; however, we have not been able to find an official statement from Microsoft regarding this.

 Disadvantage of AJAX-

•Search engines would not be able to index an AJAX application.

•The server information can not be accessed within AJAX.

•AJAX is not well integrated with any browser.

•ActiveX requests are enabled only in IE 5 and IE6

•Data of all requests is URL-encoded, which increases the size of the request.