What are jQuery AJAX Events?

Ajax requests produce a number of different events that you can subscribe to. Let’s check the two types of events.

There are two types of events:

Local Events

These are callbacks that you can subscribe to within the Ajax request object.

   beforeSend: function(){
      // Handle the beforeSend event
   complete: function(){
     // Handle the complete event
   // ......

Global Events

These events are broadcast to all elements in the DOM, triggering any handlers which may be listening. You can listen for these events like so −

$("#loading").bind("ajaxSend", function(){
}).bind("ajaxComplete", function(){

Global events can be disabled, for a particular Ajax request, by passing in the global option, like so −

   url: "test.html",
   global: false,
   // ...

Here’s the full list of Ajax events. The ajaxStart and ajaxStop events are events that relate to all Ajax requests together.

  • ajaxStart (Global Event)- This event is broadcast if an Ajax request is started and no other Ajax requests are currently running.
  • beforeSend (Local Event)- This event, which is triggered before an Ajax request is started, allows you to modify the XMLHttpRequest object (setting additional headers, if need be.)
  • ajaxSend (Global Event)- This global event is also triggered before the request is run.
  • success (Local Event)- This event is only called if the request was successful (no errors from the server, no errors with the data).
  • ajaxSuccess (Global Event)- This event is also only called if the request was successful.
  • error (Local Event)- This event is only called if an error occurred with the request (you can never have both an error and a success callback with a request).
  • ajaxError (Global Event)- This global event behaves the same as the local error event.
  • complete (Local Event)- This event is called regardless of if the request was successful, or not. You will always receive a complete callback, even for synchronous requests.
  • ajaxComplete (Global Event)- This event behaves the same as the complete event and will be triggered every time an Ajax request finishes.
  • ajaxStop (Global Event-) This global event is triggered if there are no more Ajax requests being processed.

Updated on: 17-Feb-2020


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