Professional ASP.NET 3.5 Security, Membership, and Role Management with C# and VB

17.2. ASP.NET AJAX Application Services

The previous section served as an overview of the ASP.NET application services that were initially introduced with ASP.NET 2.0 and still constitute a solid block in ASP.NET 3.5. The ASP.NET application services are not only used by ASP.NET applications but also by several other clients like Windows and AJAX client applications. This chapter focuses mainly on discussing how an AJAX client application can make use of the ASP.NET application services from the client-side by writing client-side JavaScript code to access the different functionalities of these services.

An AJAX client application is an ASP.NET application enabled with AJAX features so that it gives its users a better user experience with higher response rate in processing requests. To create an ASP.NET AJAX application, simply create a new ASP.NET application, configure the application's web.config configuration file with ASP.NET AJAX 3.5 configuration sections and finally, add a reference to a Base Class Library (BCL) that encapsulates the AJAX functionality needed for the application to function properly.

The ASP.NET AJAX library allows .aspx pages to call web service methods from the client-side using JavaScript code. For security reasons, AJAX client applications exchange data with the server-side web services, including the ASP.NET application services, over HTTP using POST requests. This behavior can be overridden to use GET requests, but it is recommended to use POST requests ...