How to detect if a user leaves a page in PHP

Question

There is this function which i want to execute in case the user leaves a particular page. This function will basically change all of the data within a certain column in my database. So in case the user leaves this page, i want this function to be performed by the system. Is there a way to detect if the user already left the page.

Thanks!

Answer 1

With 100% reliability, no, it's not possible. Since leaving a particular page is a client-side operation, you have 0 control over what the client does. You can register an onbeforeunload handler via Javascript and hope that the client browser supports it. But again, support for this isn't universal.

Answer 2

You can't do this in php but you could use the javascript function onbeforeunload, here an example

<script type="text/javascript">
  window.onbeforeunload = confirmExit;
  function confirmExit()
  {
    return "You have attempted to leave this page.  If you have made any changes to the fields without clicking the Save button, your changes will be lost.  Are you sure you want to exit this page?";
  }
</script>

Answer 3

You can't do that using PHP since it's a server-side language. You will need to use JavaScript.