I want to store some information in localstorage of a browser when the page is refreshed or the user exits the page for future use. I figured that I'd use some JavaScript to detect the event and store the state of the page visit.
Now my predicament is: shall I use Onbeforeunload or Onunload method to accomplish this objective?
Why not register it with both just to be on the safe side? Just have the listener do a check to see if the data's stored yet and exit early.
Here's a quick example using event properties:
window.onunload = window.onbeforeunload = (function(){
var didMyThingYet=false;
return function(){
if (didMyThingYet) return;
didMyThingYet=true;
// do your thing here...
}
}());
Or you could use attachEvent:
(function(){
var didMyThingYet=false;
function listener (){
if (didMyThingYet) return;
didMyThingYet=true;
// do your thing here...
}
window.attachEvent(onbeforeunload, listener);
window.attachEvent(onunload, listener);
}());
