Calling ASMX Web Service from Javascript

Question

I want to call a webservice from javascript.

This is my code:

    var method="GetStock";
    var url = "http://www.mywebsite.ro/ServiceGetStock.asmx";
    $.ajax({
        type: "POST",
        url: url + "/GetStock",
        data: "{variant_id='1'}",
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: OnSuccessCall,
        error: OnErrorCall
    });

    function OnSuccessCall(response) {
        alert(response.d);
    }


    function OnErrorCall(response) {
        alert(response.status + " " + response.statusText);
    }

My ServiceGetStock.asmx code:

 [WebMethod]
    public string GetStock(int variant_id)
    {
        try
        {

            ProductVariant variant = ProductVariantManager.GetProductVariantByID(variant_id);

            return variant.Stock.ToString();
        }
        catch (Exception ex)
        {
            return ex.Message;
        }
    }

I got the error message:

POST http://www.mywebsite.ro/ServiceGetStock.asmx/GetStock 500 (Internal Server Error)

[UPDATE]

I forgot to mention that I added in webconfig of project(with webservice) because I got the error:

XMLHttpRequest cannot load http://www.mywebsite.ro/ServiceGetStock.asmx/HelloWorld. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http:// localhost:11300' is therefore not allowed access.

  <httpProtocol>
          <customHeaders>
              <add name="Access-Control-Allow-Origin" value="*" />
              <add name="Access-Control-Allow-Headers" value="Content-Type" />
          </customHeaders>
  </httpProtocol>

Use Fiddler (fiddler2.com) to emulate the `POST` request (using the Composer tab) and take a look at your response - this will tell you specifically the detailed error message you're actually receiving. — Mike Marks, Jan 22 '14 at 14:41
500 is a server-side error. Have you debugged the server-side code? Also, `"{id='1'}"` isn't valid json, and `id` != `variant_id`. I'd imagine that matters. — Jason P, Jan 22 '14 at 14:42
Ok. I changed id into variant_id. It was my mistake. But I got the same error. — POIR, Jan 22 '14 at 14:44
And you can always attach your Visual Studio debugger to your running process, so when you hit the AJAX call, if you place a breakpoint inside your web method, it *SHOULD* hit. If it doesn't, then there's likely something off about how you're passing in the variable `variant_id`. — Mike Marks, Jan 22 '14 at 14:44
Again, your data string is not valid json. Try `data: JSON.stringify({variant_id: 1})` — Jason P, Jan 22 '14 at 14:46
@Otix, one more thing, is the web service on the same server as your website that's making the AJAX call (I'm assuming it is)? — Mike Marks, Jan 22 '14 at 14:46
My method is correct. But I cannot debug the function GetStock because my webservice is online.(http://www.mywebsite.com/ServiceGetStock.aspx) — POIR, Jan 22 '14 at 14:47
I think you'll also have a problem if `variant.Stock.ToString()` doesn't generate json (which it probably shouldn't). — Jason P, Jan 22 '14 at 14:47
I'm telling you, use Fiddler. Fiddler is great. I've ran into similar problems like this and Fiddler tells you EVERYTHING about the HTTP response/errors that come about as a result of a POST/PUT/GET/etc. — Mike Marks, Jan 22 '14 at 14:50
I'm pretty sure that my webservice is correct. One hour ago I tried to connect with C# and I succeed. — POIR, Jan 22 '14 at 14:52
@Otix try adding `[ScriptMethod (ResponseFormat = ResponseFormat.Json)]` to your web-method — RononDex, Jan 22 '14 at 15:49

score 15 · Answer 1 · edited Jun 02 '14 at 07:13

Ok guys. I found the problem. When an ASMX file is created, you must read all comments lines. To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.

 //[System.Web.Script.Services.ScriptService]

So the GetStock function is:

  [WebMethod]
     [ScriptMethod(ResponseFormat = ResponseFormat.Json)]
    public string GetStock(string variant_id)
    {
        SendEmail.SendErrorMail("in"+ variant_id);

        try
        {

            ProductVariant variant = ProductVariantManager.GetProductVariantByID(Convert.ToInt32(variant_id));

            return variant.Stock.ToString();
        }
        catch (Exception ex)
        {
            return ex.Message;
        }
    }

and the Ajax code is:

   var url = "http://www.mywebsite.ro/ServiceGetStock.asmx";
    $.ajax({
        type: "POST",
        url: url + "/GetStock",
        data: "{variant_id:'1'}",
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: OnSuccessCall,
        error: OnErrorCall
    });

    function OnSuccessCall(response) {
        alert(response.d);
    }


    function OnErrorCall(response) {
        alert(response.status + " " + response.statusText);
    }

Problem solved! Thanks all for tips.......

Going directly to this: `http://myserver:123/WServ/EDt.asmx/HelloWorld` displays the xml. But when I do the above I already get a `0 error`. Any idea why? — Si8, Jan 19 '17 at 21:22
Here is my question: http://stackoverflow.com/questions/41752213/why-is-asmx-giving-an-error-when-pulling-data-from-client-script — Si8, Jan 20 '17 at 10:59
Do you have to use absolute url? Relative link is not working out for you? — FrenkyB, Jul 23 '20 at 09:33

score 0 · Answer 2 · answered Dec 06 '17 at 05:39

0

use dataType: "jsonp", instead of dataType: "json", jsonp is for cross domian webservice. hope it will help.

answered Dec 06 '17 at 05:39

user3922209

29
3

Calling ASMX Web Service from Javascript

2 Answers2

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