Callback function for JSONP with jQuery AJAX

Question

I didn't quite understand how to work with the callback for the ajax function of jQuery.

I have the following code in the JavaScript:

try {     $.ajax({         url: 'http://url.of.my.server/submit?callback=?',         cache: false,         type: 'POST',         data: $("#survey").serialize(),         dataType: "jsonp",         timeout: 200,         crossDomain: true,         jsonp: 'jsonp_callback',         success: function (data, status) {             mySurvey.closePopup();         },         error: function (xOptions, textStatus) {             mySurvey.closePopup();         }     }); } catch (err) {     mySurvey.closePopup(); } 

And on the server side (AppEngine / Python) I get the value of the callback parameter and respond with

self.response.headers['Content-Type'] = 'application/json; charset=utf-8' self.response.out.write(callback + '({"msg": "ok"});') 

But then I get an "Error: jQuery152042227689944248825_1317400799214 is not a function" in the browser console.

What is the proper way to handle this? Right now I get the results that I need, but the fact that I know it's not right is bothering me.

Answer 1

This is what I do on mine

$(document).ready(function() {   if ($('#userForm').valid()) {     var formData = $("#userForm").serializeArray();     $.ajax({       url: 'http://www.example.com/user/' + $('#Id').val() + '?callback=?',       type: "GET",       data: formData,       dataType: "jsonp",       jsonpCallback: "localJsonpCallback"     });   });  function localJsonpCallback(json) {   if (!json.Error) {     $('#resultForm').submit();   } else {     $('#loading').hide();     $('#userForm').show();     alert(json.Message);   } }