Firefox 4 onBeforeUnload custom message

javascript firefox firefox4
JoJo picture JoJo · Mar 22, 2011 · Viewed 48.5k times · Source

In Firefox 3, I was able to write a custom confirmation popup with:

window.onbeforeunload = function() {
   if (someCondition) {
      return 'Your stream will be turned off';
   }
}

Now in Firefox 4, it does not show my custom message. The default message that it provides is not even accurate to what my application does.

firefox 4 confirm

Can this default message be overridden?

Answer

ThiefMaster picture ThiefMaster · Mar 22, 2011

From MDN:

Note that in Firefox 4 and later the returned string is not displayed to the user. See Bug 588292.

This "Bug" is actually a (imho questionable) feature.. so there's no way to display the message in Firefox 4. If you think it should be changed, comment on that bug so the Firefox developers will know that people actually want to be able to show a custom string.

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