Closing tab/browser or save our docks?

Question

JavaScript

There is a web interface with which you have to work with data for a long time. Data is saved by clicking. Autosave doesn't work for certain reasons. How, when closing the browser / tab, to display a message that they say “Have you saved the data on this page?”.

I remember that in the old JS textbooks there were a lot of such examples. On the forums they wrote that it was not necessary to do this (at least on ordinary sites). But now I can’t find an example of how to implement this.

Answer 1

Use window.onbeforeunload

Answer 2

For the opera, try it, I don’t remember what exactly, but somehow I struggled.
And then I just needed to send an event that the tab was closed, but most likely you can’t stop it.

if(window.opera){
  document.body.addEventListener('_close', ajaxUnload(), false);
  history.navigationMode = 'compatible';
  window.onunload =ajaxUnload;
}

Answer 3

But what about document.body.onunload?

Answer 4

window.onclose?

Answer 5

Opera does not support this type of event. Closing a tab or browser is not tracked in Opera.

Answer 6

You can confirm-ohm to suspend the closure. Those. ask: do you really need to close the page?