How to call a client side javascript function after a specific UpdatePanel has been loaded

Question

How is it possible to call a client side javascript method after a specific update panel has been loaded?

Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler) does not work for me because this will fire after ANY update panel finishes loading, and I can find no client side way to find which is the one

ScriptManager.GetCurrent(Page).AsyncPostBackSourceElementID AsyncPostBackSourceElementID does not work for me as this is a server side object, and i want Client Side

The ClientSide .Net framework must know which UpdatePanel it is updating in order to update the correct content. Surely there is a way to hook into this event?

Any help would be appreciated.

Solution 1

You can hook the PageRequestManager.beginRequest event and inspect the BeginRequestEventArgs.postBackElement property.

Note that it doesn't really give you the UpdatePanel, but the control inside of the UpdatePanel. That should be good enough, though.

Edit: Even better, the PageRequestManager.pageLoaded event gives you PageLoadedEventArgs.panelsUpdated (and panelsCreated) properties.

Solution 2

Thanks - both good answers. I went with the client side script "pageloaded" in the end. That is a fairly buried method that google did not reveal to me. For those who are interested, this code works with FireBug to give a good demo of the PageLoaded method working to find the updated panels:

<script type="text/javascript">
        $(document).ready(function() {
            panelsLoaded = 1;
            Sys.WebForms.PageRequestManager.getInstance().add_pageLoaded(PageLoaded)
        });

        function PageLoaded(sender, args) {
            console.log("I have occured " + panelsLoaded++ + " times!");

            var panelsCreated = args.get_panelsCreated();
            for (var i = 0; i < panelsCreated.length; i++) {
                console.log("Panels Updating: " + panelsCreated[i].id);
            }

            var panelsUpdated = args.get_panelsUpdated();
            for (var i = 0; i < panelsUpdated.length; i++) {
                console.log("Panels Updating: " + panelsUpdated[i].id);
            }
        }
    </script>

Solution 3

This may be your solution.

In the code behind for the UpdatePanel's OnLoad event, register a startup script.

string scriptText = "alert('Bar!');";

ScriptManager.RegisterStartupScript(this.Page, this.GetType(), "foo", scriptText, true);

Comments

[Michel]

This was extremely helpful. Thank you!

[bambams]

For some reason the add_pageLoaded method doesn't exist for me... :(

[Taylor K.]

Great solution, I've been searching for answers to this for a while now.