onbeforeunload wait for ajax result

Question

Is it possible for onbeforeunload() function to wait for ajax result and move to a jsp based on the resultvalue or atleast show a message before unloading?

Answer 1

AFAIK, it is not possible. onbeforeunload has very limited functionality, otherwise malicious sites could stop you from leaving their site.

Addendum: It is possible to show a message like 'You are leaving this page'. In that case, the beforeunload() function must return a string.

Example

window.onbeforeunload = function() {
   return 'Are you sure about that?';
}