Auto-closing SharePoint pop-up window after exporting to Excel

Recently I was working on a utility to export SharePoint list view data to a CSV file.. The logic was to open an application page using SharePoint's dialog framework, do the export logic in page-load of that application page and finally close the pop-up..

I thought closing the pop-up after completion would be fairly simple. I thought I can just use

Response.Write("<script type='text/javascript'>window.frameElement.commitPopup();</script>");

after process completion. But here was the challenge..To save the CSV data, I had to use the following code:


HttpContext context = HttpContext.Current;
context.Response.Clear();
context.Response.Write(csvData.ToString());
context.Response.ContentType = "text/csv";
context.Response.AppendHeader("Content-Disposition", "attachment; filename=" + fileName + ".csv");
context.Response.Flush();
context.Response.End();


The problem was, after changing the content type of Response to "text/csv", it was not possible to execute any JavaScript from server code to close the pop-up window..

After trying many options, I was about to give up when I found this method definition on MSDN..

SP.UI.ModalDialog.commonModalDialogClose(dialogResult, returnVal);

Closes the most recently opened modal dialog with the specified dialog result and return value.

Now, the solution was simple.. All I had to do was to set a cookie in the server side after process completion, and in the parent page, run a timer job every few seconds in JavaScript to check for the same cookie, and if found, delete the cookie, stop the timer and close the pop-up..

Note: To process the cookie in JavaScript I used this great library, because of which it turned out to be just a single line of code..
http://code.google.com/p/cookies/

Here is the complete code..

Javascript to open and close the pop-up:

function OpenPopUp() {
    var oUrl =  'http://mysite/_layouts/SPExcelExport/SPExcelExport.aspx;
    var options = {
        title: 'Excel Export',
        allowMaximize: false,
        showClose: true,
        width: 300,
        height: 90
    };
    SP.UI.ModalDialog.commonModalDialogOpen(oUrl, options, null, null);//Open pop-up
    var millisecondsToWait = 2000; //Run every 2 seconds to check for cookie
    var intrvl = setInterval(function () {
        if (jaaulde.utils.cookies.get('csvexportcookie') != null) { //check if cookie is found
            jaaulde.utils.cookies.del('csvexportcookie'); //Delete the cookie
            SP.UI.ModalDialog.commonModalDialogClose(1, 1); //Close the pop-up
            clearInterval(intrvl);//Clear timer 
        }
    }, millisecondsToWait);
};

Server side code in the pop-up page:


HttpCookie oCookie = new HttpCookie("csvexportcookie", "completed"); //Set the Cookie
Response.Cookies.Add(oCookie);

HttpContext context = HttpContext.Current; //Write the CSV data to current response
context.Response.Clear();
context.Response.Write(csvData.ToString());
context.Response.ContentType = "text/csv";
context.Response.AppendHeader("Content-Disposition", "attachment; filename=" + fileName + ".csv");
context.Response.Flush();
context.Response.End();

That was it.. Problem solved!