Angularjs JSONP not working

Question

I might be missing something here but I can't make this JSONP request work, here is the code:

var url =  'http://' + server + '?callback=JSON_CALLBACK';
$http.jsonp(url)
    .success(function(data){
       console.log('success');
    })
    .error(function () {
      console.log('error')
    });

The request fires ok and I am getting the response (with header Content-Type:application/json) in this format:

    [{"id": "1", "name": "John Doe"},
     {"id": "2", "name": "Lorem ipsum"},
     {"id": "3", "name": "Lorem ipsum"}]

Can you see anything wrong? Maybe the format I should return from the server is not right? Angular fires the error callback without any error message besides the one I set ('error').

Answer 1

@TheHippo is correct the data should not just be a plain json response. Here is a working example of a JSONP request against a youtube endpoint in AngularJS.

A couple of things to note in this example:

• Angular's $http.jsonp converts the request querystring parameter from callback=JSON_CALLBACK to callback=angular.callbacks._0.
• When calling the youtube endpoint I needed to specify to the service that this is a JSONP request by using alt=json-in-script instead of alt=json in the querystring. This was found in their documentation.
• Compare the results of this url to this one to see the difference between JSON and JSONP response in your browser.
• Take a look at the Chrome Network Panel in Developer Tools to help compare and troubleshoot with your request/response.

I know this example is very specific but hopefully it helps!

Answer 2

JSONP requires you do wrap your data into a JavaScript function call. So technically you return a JavaScript file and not a Json file.

The data returned from server should similar to this:

// the name should match the one you add to the url
JSON_CALLBACK([
    {"id": "1", "name": "John Doe"},
    {"id": "2", "name": "Lorem ipsum"},
    {"id": "3", "name": "Lorem ipsum"}
]);

Edit: If some one else stumbles across problems with angular's JSONP please also read this answer to this question, it contains usefull informations about how angular handles the actual callback function.