Using jquery jsonp returns error callback function was not called

Question

I have the following working example, I'm trying to get http://detectlanguage.com via a jquery request. Since this will be a cross-domain request I'm using jsonp.

Here is a link in MSDN with a similar request where it's infered that jsonp is the way to go.

Everything's fine, except the page throws an error Error: myCallback was not called, the response I get from server is the following:

{"data":
  {"detections":[
    {"language":"ca",
     "isReliable":false,
     "confidence":0.14992503748125938
    },
    {"language":"en",
     "isReliable":false,
     "confidence":0.00 8103727714748784
    }]
   }
}

I've been searching all day in stackoverflow for answers regarding jsonp but haven't got it to work yet.

Any help is very much appreciated

UPDATED

Including AJAX call

$.ajax({
    url: 'http://ws.detectlanguage.com/0.2/detect',
    data: {
        q: $('#hi').val(),
        key:'demo'
    },
    jsonpCallback: 'myCallback',
    dataType: "jsonp",
    success: myCallback,
    error: function(e,i,j){
         $('#results').html(j)
    }
});

I also have a javascript function called myCallback:

function myCallback(response){
    alert(response.data)
}

Doesn't seem like its a jsonp that is coming back from the service you called. — PSL, Oct 14 '13 at 00:37
Hello, good morning. Thank you for your responses. I've updated the question to include the ajax from the fiddle. Also I'm including a link in the web where it kind of hints that jsonp is the way to go. Please take a look at the fiddle included in the question. — Jose R, Oct 14 '13 at 12:46

Saranya · Answer 1 · 2013-10-17T10:16:12.950

The response doesnot seem to be jsonp, the jsonp response should be a javascript. Below is the code that works for me.

ajax request:

 $.ajax({
            crossDomain: true,
            type:"GET",
            contentType: "application/json; charset=utf-8",
            async:false,
            url: "http://<your service url here>/HelloWorld?callback=?",
            data: {projectID:1},
            dataType: "jsonp",                
            jsonpCallback: 'fnsuccesscallback'
        });

server side code returning jsonp (c#):

 public void HelloWorld(int projectID,string callback)
    {

        String s = "Hello World !!";
        StringBuilder sb = new StringBuilder();
        JavaScriptSerializer js = new JavaScriptSerializer();
        sb.Append(callback + "(");
        sb.Append(js.Serialize(s));
        sb.Append(");");
        Context.Response.Clear();
        Context.Response.ContentType = "application/json";
        Context.Response.Write(sb.ToString());
        Context.Response.End();
    }

so much searching. so many days beating my head against a wall. And for some reason, this did it. THANK YOU! — deebs, Jul 17 '17 at 19:48

score 0 · Answer 2 · answered Mar 24 '14 at 11:32

I also spend a very long time looking around SO for a response. The solution for me had to do with the service, not ajax calls or jQuery. Specifically, the service needs to be set up to allow cross-domain access using this setting in web.config:

<system.serviceModel>
<bindings>
  <webHttpBinding>
    <binding name="webHttpBindingWithJsonP" crossDomainScriptAccessEnabled="true" />
  </webHttpBinding>
</bindings>  

...

  <endpoint address="../YourService.svc"
  binding="webHttpBinding"
  bindingConfiguration="webHttpBindingWithJsonP"
  contract="YourServices.IYourService"
  behaviorConfiguration="webBehavior" />

Using jquery jsonp returns error callback function was not called

2 Answers2