ASP.net Script Service consumption in javascript

Question

I have a script service in asp.net and I need to consume this WS from javascript using JSONP (Script tag injection; since it is cross domain, no $.ajax() call).

In this case, where the input to the web method is a complex structure, I have to create the input structure at the client. How does matching of the client-side structure to the Server side parameter happen?

To make the question a bit more clearer for the unapt answers given :-

Assume that I have somehow created the complex input and passed it to the Script Method. Now, how does the matching/vaidation of my input structure to the input parameter of the Script method happen (or in other words, what is the basis of the matching?)

Answer 1

In this case you will sending a JSON structure based on your discovery of the parameters. If it is same as what service accepts then your call will succeed else fail.

Answer 2

You can pass complex types to a webservice without using the Microsoft.Ajax framework. I wrote a little example using JQuery.

Assume you have the following C# class used as parameter for the webmethod:

namespace JQueryWebServiceTest
{
    public class TwoStringsTogether
    {
     public string StringA;
     public string StringB;
    }
}

The webmethod has the following signature:

TwoStringsTogether TransformTwoStringsTogether(TwoStringsTogether input)

You can call the method like this:

$.ajax({
    type: "POST",
    contentType: "application/json; charset=utf-8",
    url: "TestService.asmx/TransformTwoStringsTogether",
    data:"{" +
        "input: {" +
        "__type: 'JQueryWebServiceTest.TwoStringsTogether'," +
        "StringA: 'HalloA'," +
        "StringB: 'HalloB'" +
        "}" +
    "}",
    dataType: "json",
    success: SuccessCallback
});

Note the __type parameter, without that it won't work.