david chan's blog

Web development has been moving towards faster and quicker deployment. Popular frameworks such as .NET 2.0 and Prototype.js allow for quick AJAX and web services development, but are rarely used together. Web services made with ASP.NET are usually used along-side with ASP.NET AJAX on ASP pages. However, if your site does not use ASP but you would still like to consume your ASP.NET web services with just JavaScript, then read on.

First, create your ASP.NET web service. Once you are finished, visit the Web.Config file and enter the following under the <system.web> node:

<webservices>
    <protocols>
        <add name="HttpGet" />
        <add name="HttpPost" />
    </protocols>
</webservices>

After that’s done with, view your web service’s .asmx file in a web browser. Click the name of a web service operation and you’ll be taken to the operation’s Invoke page. Scroll to the bottom and you can clearly see how to structure your header for calling your web service method using POST or GET:

You can now use Prototype or another JavaScript method to call the web service. An example AJAX call using POST with Prototype.js could be:

new Ajax.Request('/myws.asmx/HelloWorld',
    {
        method: 'post',
        postBody: 'strName=David',
        onSuccess: function(transport){
          var response = transport.responseText || "no response text";
          alert("Success! nn" + response);
        },
        onFailure: function(){ alert('Something went wrong...') }
    }