如何将关闭事件绑定到window.open（）

Question

I have the following function to open a url in a window pop up:

function windowPopup(url, width, height) {
  // center 
  var left = (screen.width / 2) - (width / 2),
      top = (screen.height / 2) - (height / 2);

  handle=window.open(
    url,
    "",
    "menubar=no,toolbar=no,resizable=yes,scrollbars=yes,width=" + 
    width + ",height=" + height + ",top=" + top + ",left=" + left
  );
}

I want to be able to detect when this window is closed an execute some code. How can I use the handle in the function to bind an unload or close?

I want to know once the window has been closed after someone shares to twitter:

windowPopup("https://twitter.com/intent/tweet/?text=Check%20out%20this%20website!&url=https%3A%2F%2Fgoogle.com%2F", 500, 300);

Update

I updated with Lar's suggestion:

function windowPopup(url, width, height) {
  // center 
  var left = (screen.width / 2) - (width / 2),
      top = (screen.height / 2) - (height / 2);



  handle=window.open(
    url,
    "",
    "menubar=no,toolbar=no,resizable=yes,scrollbars=yes,width=" + 
    width + ",height=" + height + ",top=" + top + ",left=" + left
  );

  handle.onbeforeunload = function() {
    alert('Bye!');
  }

}

While this worked for some pop up windows it didn't work when i closed the twitter window...

Answer 1

You're looking for the beforeunload event:

handle.onbeforeunload = function() {
  console.log('Bye!');
}