jQuery: Handle fallback for failed AJAX Request

ajax, callback, jquery, json, wait

Solution

You will need to either use the lower level $.ajax call, or the ajaxError function. Here it is with the $.ajax method:

function update() {
  $.ajax({
    type: 'GET',
    dataType: 'json',
    url: url,
    timeout: 5000,
    success: function(data, textStatus ){
       alert('request successful');
    },
    fail: function(xhr, textStatus, errorThrown){
       alert('request failed');
    }
  });
}

EDIT I added a `timeout` to the `$.ajax` call and set it to five seconds.

Problem

Can jQuery provide a fallback for failed AJAX calls? This is my try: ``` function update() { var requestOK = false; $.getJSON(url, function(){ alert('request successful'); requestOK = true; }); if (!requestOK) { alert('request failed'); } } ``` Unfortunately, even if the callback function of the $.getJSON() method is called, i get the message 'request failed', before the callback function has the opportunity to set the requestOK variable. I think it's because the code runs in parallel. Is there a way to handle such situations? I thought about chaining or some way of waiting for the AJAX request, including its callback function. But how? Does anyone know how to do that?

Original source