Capture the close event of popup window in JavaScript

Question

I need to perform some action before a popup window(using window.open ) closes.

Something like will be good:

var new_window = window.open('some url') new_window.onBeforeUnload = function(){ my code} 

How can I achieve that?

Answer 1

While the accepted answer is correct for same origins I found a solution for cross origin popups:

var win = window.open('http://www.google.com');  var timer = setInterval(function() {      if(win.closed) {         clearInterval(timer);         alert('closed');     } }, 1000); 

Source: atashbahar.com

For those considering using it.

Even Facebook is using this "hack" in their Javascript SDK.

You can verify this by having a look at their code. Just search for .closed in https://connect.facebook.net/en_US/sdk.js.

Answer 2

Your example will work as long as the pop-up window url is in the same domain as the parent page, and you change the event to all lowercase:

var new_window = window.open('some url') new_window.onbeforeunload = function(){ /* my code */ }