Marco Valsecchi

Calling ASP.net AJAX services from jQuery with unknown generic parameters

16 marzo 2010 • ⏲️ 1 min.

I love REST web applications and I must thank Dave Ward with his Encosia blog that introduced me to this kind of architecture.

Recently I had to do a function in common script that calls some web services and I used json object approach to solve this (see Simplify calling ASP.NET AJAX services from jQuery for more info).

All worked fine but I had to pass different params to different services without making custom class for every specific javascript object.


Example:

var data = new Object();
data.Param1Int = 1;
data.Param2String = "hello";
data.Param3Decimal = 2.5;

var param = new Object();
param.p = data;

$.ajax({
   url: '/Service.asmx/DoSomething',
   data: JSON.stringify(param),
   success: function(msg){ ... }
});

This is the jQuery AJAX call to my service… and in this case I need to pass three params.

I could pass to the “DoSomething” service the “data” object directly and in this case ASP.net expects a method like this:

[WebMethod]
public string DoSomething(Int32 Param1Int, String Param2String, Decimal Param2Decimal)
{ ... }

But if I need to add another param or I don’t know exactly how they are?

So I wrapped the “data” object in another one… “param” with his member “p”.
In this case my web method changed in:

[WebMethod]
public String DoSomething(Dictionary<string, string> p)
{
   Int32 Param1Int = Convert.ToInt32(p["Param1Int"]);
   String Param2String = Convert.ToString(p["Param2String"]);
   Decimal Param3Decimal = Convert.Todecimal(p["Param3Decimal"]);
   ...
}

With Dictionary-based parameters you can pass to your web service every kind and as many params as you want.


Marco Valsecchi

Marco Valsecchi

"Man is still the most extraordinary computer of all" (J.F. Kennedy)