JavaScript + onbeforeunload

Question

I have a query regarding my application. Whenever user closes browser window accidentally I\'d want to do some clean up operations before that. I have used onunload event bu

Answer 1

This works:

window.onbeforeunload = function(){
    console.log('closing shared worker port...');
    return 'Take care now, bye-bye then.';
  };

This is handy if, for instance you're working with SharedWorkers and you need to tell the worker that there is one less port to manage -- otherwise, you could end up refreshing one browser tab and get something like a "Successfully connected with: 10 other tabs" because the one tab is keeping the worker alive while the other tab's refreshes keep pushing new port connections to you array.

Hope this helps.