What changed in jQuery 1.9 to cause a $.ajax call to fail with syntax error

Question

I\'m making a REST DELETE call, which returns a 204. In jQuery 1.8.3 this works, and hits the request.done callback. But if I use 1.9 it goes to request.fail with a parsererror

Answer 1

I was having a very similar problem, and you helped my find my answer - so thank you. My solution, however is slightly different, so I figured I would share it.

As stated in the question, on the JQuery website it says:

Prior to 1.9, an ajax call that expected a return data type of JSON or JSONP would consider a return value of an empty string to be a success case, but return a null to the success handler or promise. As of 1.9, an empty string returned for JSON data is considered to be malformed JSON (because it is); this will now throw an error. Use the error handler to catch such cases.

I was passing JSON data to a method on my server with "void" as a return type because I did not need to do anything with returned data in the success function. You can no longer return null when passing JSON in an AJAX request in JQuery 1.9 +. This was possible in previous versions of JQuery however.

To stop getting an error and get the success function to fire instead, you must simply return valid JSON in your AJAX request. It doesn't matter what you pass, as long as it's valid, because (in my case anyways) you are not using the returned data.