Question

I am trying to block the unload event for a page until I get a response from the server for an async json call initiated by the client.

To make it clear, the scenario is the following: I need to save the user changes into a database when they close the browser. While doing so, I will show a small div and hide it when we’re done (hiding it doesn’t matter, the page will already be gone!)

In code, this is pretty much what I am trying to do.
PS: I don’t want to use alert()

  
  window.onbeforeunload = function () {

        var requestURL = "../foo/Save";
        $("#dvMsg").show();

        $.getJSON(
            requestURL,
            {
                changeId: 1,
                userId: 1
            },
                function (data) { 
                    // hide the dvMsg 
                    $("#dvMsg").show();
                    // page should be safe to unload
                });

        };

The problem is the nature of the async call i.e. it will not block and the page will be unloaded before we get the response.

Any ideas?

Thanks!

Answer 1

I don’t think this can be done at all if the event is asynchronous.

Why not make it synchronous? That’s probably your best chance to get it through.