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javascriptsubmitonunload

Problem submitting form on window.unload

I am having a problem submitting form on window unload if form information has been updated (album.updated = true):

window.onunload = function(evnt) {
  if (album.updated) {
    var save = confirm('Do you want to save changes?');
    if (save) {
      alert('submitting form...');
      document.edit_photos.submit();
    }
  }
}

It alerts "submitting form" but nothing is saved. But when I do a regular submit with a Save button - it saves information. What could be wrong here?

Solution

  • You cannot reliably interact with the server from the unload event.

    Sending an AJAX request might be a little more reliable, but should also not be relied on.

    Instead, you should handle the onbeforeunload event and return "You have unsaved changes";.
    This will instruct the browser to show a confirmation dialog allowing the user to cancel the navigation. (After which he can save manually)