How to know when a user has left the page and refreshed the page

I want to make an AJAX call before the user leaves the page (so basically before leaving the page and before refreshing the page)?

How can this be done. I was trying to search something with jQuery but didnt get anything.

I tried to use the following code -

window.onbeforeunload(function(){alert('before unload');});

But the alert box never appears when leaving the page(closing the browser tab) or refre开发者_JAVA百科shing the page.

How can this be accomplished?

You should try unload() from jquery:

$(window).unload(function(){
   //Do your call
   alert('before unload');
  });

oro you could use the beforeunload event. You should test it well because browser tend to imlement those things differently. taken from jquery documentation:

The exact handling of the unload event has varied from version to version of browsers. For example, some versions of Firefox trigger the event when a link is followed, but not when the window is closed. In practical usage, behavior should be tested on all supported browsers, and contrasted with the proprietary beforeunload event.

$(window).unload(function() {
    alert('Visitor left page');
});

Regarding the ajax call, you can do it, but you must set the async to false.

$.ajax({
   async: false,
   ...
 });

Your code is simply wrong. The unbeforeunload is used to ask the person if he really want to leave the page. You need unload.

window.onunload = function() {
  // Make your AJAX call

}

Better use jQuery.unload() method