Question

How can populate a ddl list dynamically (cascading ddl) using jquery w/o ms ajax framework or jquery plugins? (where I work am very limited on the libraries I can use). I am using ASP.Net with jquery accessing an asmx webmethod. The $.ajax call to the web method looks like the following:

function getText() {
    $.ajax({
        type: "POST",
        url: "SearchFilters.asmx/HelloWorld",
        dataType: "html", // also tried "text"
        success: function(response) {
            alert(response);
            $("#ddlCase").html(response);
        }
    });
}

This return xml that looks like the following:

<?xml version="1.0" encoding="utf-8"?>
<string xmlns="http://tempuri.org/">&lt;option value='1'&gt;Hello World&lt;/option&gt;</string>

In the success function, the js only clears out the values of the ddl:

$("#ddlCase").html(response)

Can this be done? How can I decode the returned xml? What am I missing? Previously I attempted a datatype of json without success. Please refer to the following:

using JQuery .ajax, a Success method is not called when using jquery 'json' vs 'text'

Thanks! D

Answer 1

In the end the source of my issue was the lack of the [ScriptService] attribute on the class decoration. I changed to class declartion to:

[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[ScriptService]
public class SearchFilters : System.Web.Services.WebService {
    [WebMethod]
    public string HelloWorld() {
        return "";
    }
}

Using Fiddler I discovered the following error message was returned:

Only Web services with a [ScriptService] attribute on the class
definition can be called from script