Source Code: Microsoft ASP.NET AJAX the Series Part 5 - Call Web Service With JavaScript
This is the fifth in a series of blog posts about Microsoft ASP.NET AJAX, a new web development technology from Microsoft.
Click these links to view previous posts in this series: Post 1, Post 2, Post 3, and Post 4
This post introduces the Microsoft Ajax asynchronous communication layer and demonstrates how to use it to call a web service, from a client, using JavaScript.
Asynchronous Communication Layer
The asynchronous communication layer is the foundation for very responsive client Web application presentation.
The layer enables more separation between the business and data tiers on the server and the presentation tier on the client. It makes it easier to do more processing client side. In this context, the browser has full control of the presentation tier and provides a rich and responsive user interface, while the server performs the business and data tier tasks.
The layer exposes functionality for browser asynchronous behavior provided by the XMLHTTP object as a set of APIs that JavaScript functions can use from any browser to call Web service methods on the server. The XMLHTTP object enables the browser to send asynchronous HTTP requests and return data that can be processed in client script.
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Asynchronous postbacks and partial-page rendering
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Invoke methods in Web services implemented as .asmx files
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Invoke specifically enabled ASP.NET page methods
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Supports a variety of serialization formats for passing data between the browser and the server
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Optimize Web service interactions by pre-loading and caching JavaScript proxies used to communicate with the Web services on a server
About the Source Code
The source code includes a Web service whose proxy class is used by the browser and an ASP.NET Web page containing client script that calls a page method and a web service. Here is a screen shot of the web page:

The source code included with this post (see download link above) demonstrates how to call a web service with JavaScript. Additional comments about the process are included in the example page and source code.
The source code was created with ASP.NET AJAX 1.0 Beta 2 which is available at -> The Official Microsoft ASP.NET AJAX Website
The next post in this series will explore the Microsoft Ajax Page Manager object.
For more information and FREE Microsoft ASP.NET Ajax installers visit -> The Official Microsoft ASP.NET AJAX Website
mike mcintyre http://www.getdotnetcode.com