How do I disable the "Leave page" confirmation dialog in Firefox?-CodePudding

I have the following code in my Vue application for detecting when the user closes the tab:

onBeforeUnload() {
  window.onbeforeunload = null;
  return undefined;
}

Disabling the "Leave page" confirmation dialog works in Chrome, but not on Firefox. Why is that? How do I disable the confirmation dialog on Firefox?

Edit 1: Adding and removing beforeunload listeners

created() {
    window.addEventListener('beforeunload', this.onBeforeUnload);
},
beforeDestroy() {
    window.removeEventListener('beforeunload', this.onBeforeUnload);
}

CodePudding user response：

Changing my onBeforeUnload method to this fixed the problem:

onBeforeUnload(e) {
  window.onbeforeunload = () => {};
  delete e.returnValue;
}