jQuery Deferred object centralized global error handler

Question

Errors that happen inside Deferred object throws a warning in to the console and not getting noticed in:

    window.addEventListener("error", function(e) {
       // Global handler
    });

How to make centralized error handler work for all errors including Deferred object?

I am using most recent jQuery 3.3.1 and couldn't find woking solution.

Answer 1

After reading jQuery 3.3.1 (line 3605) , they actually have implemented $.Deferred.exceptionHook to be called when deferred object fails.

And for your case, you just need to implement it like,

$.Deferred.exceptionHook = function (err, stackTrace) {
  // 'err' is what you throw in your deferred's catch.
  window.dispatchEvent( new CustomEvent('error', {
    detail: err
  }) );
}

Here's some simple example.

 $.Deferred.exceptionHook = function (err, stackTrace) { // 'err' is what you throw in your deferred's catch. $("#errorMessage").text(err); } $.when( $.ajax( "https://example.com" ) // This should fail since SO is sandboxed. ).then(function successFn() { alert("Impossible thing is happening"); }, function failFn() { throw "A nice error"; }); 

 <script src="https://code.jquery.com/jquery-3.3.1.js"></script> <p id="errorMessage"> </p> 

Answer 2

If you're using jquery for ajax requests you could do:

$(document).ajaxError(function(){
   console.log(arguments);
}