Question

I’m trying to use __doPostBack to pass some data from client to server side. I’m not very expierenced with JS, but when debugging in Firebug something wierd is happening. I’ll show my code first.

<script type="text/javascript">
function BeginDownload() {
        var temp = $("#waterwheel-carousel-horizon").CurrentSelectedImg().toString()
        __doPostBack("ImgDownload", temp);
}
</script>

Here’s the relevant jquery I’m attempting to call.

// Relevant Waterwheel jquery code.
$.fn.CurrentSelectedImg = function () {
        return data.currentCenterItem.data().index; };
$.fn.waterwheelCarousel = function (options) {

        // override the default options with user defined options
        options = $.extend({}, $.fn.waterwheelCarousel.defaults, options || {});

        return $(this).each(function () {

            /* These are univeral values that are used throughout the plugin. Do not modify them
            * unless you know what you're doing. Most of them feed off the options
            * so most customization can be achieved by modifying the options values */
            var data = {
                itemsContainer: $(this).find(".carousel-images"),
                totalItems: $(this).find(".carousel-images img").length,
                containerWidth: $(this).width(),
                containerHeight: $(this).height(),
                currentCenterItem: null,
                items: [],
                itemDistances: [],
                waveDistances: [],
                itemWidths: [],
                itemHeights: [],
                itemOpacities: [],
                carouselRotationsLeft: 0,
                currentlyMoving: false,
                itemsAnimating: 0,
                currentSpeed: options.speed,
                intervalTimer: null
            };

            // Setup the carousel
            beforeLoaded();
            // Preload the images. Once they are preloaded, the passed in function
            // will be called and the carousel will be setup
            preload(function () {
                setupDistanceArrays();
                setupCarousel();
                setupStarterRotation();
            });

And the code behind the scenes. It’s not being reached at the moment.

// This code is currently not reached, but I put it here for completion.
#region EventTarget
private string EventTarget
{
    get{
        return Request.Form["__EVENTTARGET"].ToString().ToUpper();
    }            
}
#endregion EventTarget

#region HandlePostBack
void HandlePostBack()
{
    switch (EventTarget)
    {
        case "ImgDownload":
            DownloadImage(EventArgs);
            break;
    }
}
#endregion HandlePostBack

private void DownloadImage(string index)
{
    string test = index;
}

Ultimately what happens is that I click the linkbutton and firebug jumps to the first line of code, but before it even finishes that function it suddenly jumps to __doPostBack function’s code before I even pass in the variables. Why is this happening?

I should also mention I’m doing this in DNN if that makes a difference. I think the problem might be the way I formed that jquery function or how I’m calling it.

Answer 1

Found the problem. I just had to move where my jquery was placed in the code. I think it just wasn’t inside some bracket so it couldn’t see data. Lack of intellisense and disorganized code strikes again! Now to write that download function.