jquery: how to cancel the specific ajaxSuccess handler from a global ajaxSuccess handler

Question

Hi all,

I would like to register a global ajaxSuccess handler, which would upon certain conditions cancel the specific ajaxSuccess handler of the caller functions.

Is there a way to achieve this?

Thanks in advance

Answer 1

Unfortunately there's not a way to do what you're after, not that way, you'll have to set a global variable or something some other route. If you look at how the jQuery success function works:

handleSuccess: function( s, xhr, status, data ) {
  // If a local callback was specified, fire it and pass it the data
  if ( s.success ) {
    s.success.call( s.context, data, status, xhr );
  }

  // Fire the global callback
  if ( s.global ) {
    jQuery.ajax.triggerGlobal( s, "ajaxSuccess", [xhr, s] );
  }
}

You can see it's just a matter of ordering, the local success handler always happens before the global event is fired, which triggers any $.ajaxSuccess() handlers. The easiest way to do what you're after is to call whatever function may cancel at the beginning of your local success handler, like this:

$.ajax({
  //options...
  success: function(data) {
    if(shouldIBeCanceled()) return;
    //rest of code...
  }
});

The alternative is editing jQuery core, or extending it which will yield somewhat unpredictable behavior for plugins, so I wouldn't go down that route, as it's likely to also introduce a new pain when upgrading as well.