cross domain jsonp callback is undefined

Question

I must be missing something here, because this seems like a very simple problem, but I've tried most of the solutions and haven't had any luck.

I am simply trying to create an ajax request cross-domain and store the result into a javascrip variable. I'm getting valid javascript, my callback is being fired, but my success never is.

I've tried: Setting jsonp: false with jsonpCallback: myCallback (as it stands now, below) Remobing jsonp: false and jsonpCallback: mcCallback and setting the url url?callback=? A few other things... point being, I'm doing something wrong and it's pretty basic

For the example below, I do get the alert('hello') but then I get parsererror in the console (coming from the error function)

Edit to add how it is now after reading a comment. Same issue, though. Sucess is not called

    $.ajax({
        url: 'http://localhost/faqservice/questions',
        type: 'GET',
        dataType: 'jsonp',
        error: function (x, t, r) { alert(x + t + r); },
        success: function (data) {
            alert('success');
        }
    });

How the question was originally

    $(document).ready(function () {
        $.ajax({
            type: "GET",
            url: "http://localhost/faqservice/questions",
            dataType: 'jsonp',
            jsonp: false,
            jsonpCallback: myCallback,
            error: function (httpReq, status, exception) {
                console.log(status);
            },
            success: function(data) {
                alert('success');
            }
        });
    });

    myCallback = function (data) {
        alert('hello');
    }

what does the server side response code look like? what are you using to send back the response to the client? — Jonathan Marzullo, Nov 07 '13 at 20:49
take a look at the this answer http://stackoverflow.com/questions/7167488/use-of-success-jsonpcallback-with-ajax-request — Rayweb_on, Nov 07 '13 at 20:51
Your server response should look like 'myCallback({"some":"data"})'. Is this the case? — Alex Schenkel, Nov 07 '13 at 20:51
The response is not wrapped in that myCallback, no. Just a plain json reponse — Tom, Nov 07 '13 at 20:53
Could it be because `myCallback` is not within the scope of `$.ajax()`? try: `var myCallback = function(data){ alert('hello'); }` — Phil Cross, Nov 07 '13 at 20:54
@Rayweb_on, I basically did a straight copy and paste from that answer and got the following error: `[object Object]parsererror jQuery3424723891473_90284732 was never called` (i.e., it went into the error function and not the success) The response still came in fine — Tom, Nov 07 '13 at 21:04
@Tom that's good then. That means your server simply needs to be updated to support JSONP now that your client-side code is correct. Your server should take the value of `$_GET["callback"]` and wrap your json string in it, for example, `jQuery3424723891473_90284732(YOURJSONHERE)` — Kevin B, Nov 07 '13 at 21:08
@KevinB thank you! I was not allowing it on the server side. Set up my WCF service like http://www.bendewey.com/blog/index.php/186/ and got a successful ajax call — Tom, Nov 07 '13 at 21:42

score 1 · Answer 1 · answered Mar 18 '15 at 20:22

As the notes said, your server must respond like 'myCallback({"some":"data"})'

not just the raw json: '{"some":"data"}'

jsonp is a bit strange, it's requested by inserting a script tag, cuz script tags CAN transfer cross-domain. Your server must supply JS code that'll do something when the response comes.
jQuery does most of the browser side for you. When it sends the request, it'll add on an argument like callback=jQuery17209078477467410266_1426708743857

Then it sets up a function of that name that'll take care of the response when it comes. Your server must take this string and construct the code like this: jQuery17209078477467410266_1426708743857({"data": "the"});

If you just pass the json, it'll execute like a big expression and be forgotten.

cross domain jsonp callback is undefined

1 Answers1