On browser close, JavaScript does not always call a custom server side method (Asp.Net/C#)

Question

On browser close event, I am trying to call a server side method from JavaScript, to make some database table changes. I am doing this in the “onbeforeunload” event in JavaScript.

Most of the time, it is successfully calling the server side code and implementing the expected database table changes* . But sometimes, the Server side event does not get invoked. *

Does anyone have any experience with a similar requirement OR would be able to provide us any suggestions on how we can make sure that the Server side event gets invoked always without fail?

Answer 1

Aha, we had one of those problems a while back, where we absolutely needed to give our server notification that the window has closed. We noticed that only Firefox would obey requests made inside onbeforeunload . Finally, the solution is as follows:

$(window).unload(function () {
    $.ajax ({
        url: "...",
        data: "(what you want to send)",
        async: false                             // THIS
    });
});

What's more peculiar is that neither window.onunload nor window.onbeforeunload worked for us; not back then at least.