How can I get jQuery to perform a synchronous, rather than asynchronous, Ajax request?

Question

I have a JavaScript widget which provides standard extension points. One of them is the beforecreate function. It should return false to prevent an

Answer 1

Keep in mind that if you're doing a cross-domain Ajax call (by using JSONP) - you can't do it synchronously, the async flag will be ignored by jQuery.

$.ajax({
    url: "testserver.php",
    dataType: 'jsonp', // jsonp
    async: false //IGNORED!!
});

For JSONP-calls you could use:

1. Ajax-call to your own domain - and do the cross-domain call server-side
2. Change your code to work asynchronously
3. Use a "function sequencer" library like Frame.js (this answer)
4. Block the UI instead of blocking the execution (this answer) (my favourite way)