How do I catch an Ajax query post error?

Question

I would like to catch the error and show the appropriate message if the Ajax request fails.

My code is like the following, but I could not manage to catch the failing Ajax request.

function getAjaxData(id) {      $.post("status.ajax.php", {deviceId : id}, function(data){          var tab1;          if (data.length>0) {             tab1 = data;         }         else {             tab1 = "Error in Ajax";         }          return tab1;     }); } 

I found out that, "Error in Ajax" is never executed when the Ajax request failed.

How do I handle the Ajax error and show the appropriate message if it fails?

Answer 1

Since jQuery 1.5 you can use the deferred objects mechanism:

$.post('some.php', {name: 'John'})     .done(function(msg){  })     .fail(function(xhr, status, error) {         // error handling     }); 

Another way is using .ajax:

$.ajax({   type: "POST",   url: "some.php",   data: "name=John&location=Boston",   success: function(msg){         alert( "Data Saved: " + msg );   },   error: function(XMLHttpRequest, textStatus, errorThrown) {      alert("some error");   } });