Document library open file in application page

Question

Is it possible to handle the click event of a file in a sharepoint document library so that instead of opening the actual file, it opens an application page?

E.g. Open letter.xml goes to letter editor.aspx in layouts.

Answer 1

Here is an example JavaScript you can add to your custom masterpage:

<script type="text/javascript">
//<![CDATA[
function OpenPdfInNewWindow()
{
    try
    {
        var OpenPdfInNewWindowAnchors, OpenPdfInNewWindowAnchorsCounter;
        OpenPdfInNewWindowAnchors = document.getElementsByTagName('A');
        for (OpenPdfInNewWindowAnchorsCounter = 0; OpenPdfInNewWindowAnchorsCounter < OpenPdfInNewWindowAnchors.length; OpenPdfInNewWindowAnchorsCounter ++)
        {
            var OpenPdfInNewWindowAnchor = OpenPdfInNewWindowAnchors[OpenPdfInNewWindowAnchorsCounter].href.toLowerCase();
            if (OpenPdfInNewWindowAnchor.lastIndexOf(".pdf") != -1)
            {
                try
                {
                    if (OpenPdfInNewWindowAnchors[OpenPdfInNewWindowAnchorsCounter].onclick != "")
                    {
                        OpenPdfInNewWindowAnchors[OpenPdfInNewWindowAnchorsCounter].onclick = "";
                    }
                }
                catch (e) {}

                try
                {
                    OpenPdfInNewWindowAnchors[OpenPdfInNewWindowAnchorsCounter].setAttribute('target', "_blank");
                    OpenPdfInNewWindowAnchors[OpenPdfInNewWindowAnchorsCounter].href = L_Menu_BaseUrl + "/_layouts/pdfviewer.aspx?src=" + OpenPdfInNewWindowAnchor;
                }
                catch (e) {}
            }
        }
    }
    catch (e) {}
}

if (typeof(_spBodyOnLoadFunctionNames) != "undefined")
{
    if (_spBodyOnLoadFunctionNames != null)
    {
        _spBodyOnLoadFunctionNames.push("OpenPdfInNewWindow");
    }
}
//]]>
</script>

Though, you need to tweak it a little bit to fit your needs. You could also use jQuery but in my case I didn't want to rely on a third-party lib for such a simple task.

Answer 2

If you want a file to be open by making user to open it via "ECB" menu for an item then you can create custom action (check here for simple walkthrought http://codename-srini.blogspot.com/2010/04/using-custom-actions-in-sharepoint-2010.html) and check the respective location group setting name i.e. ECB (complete ref here : http://msdn.microsoft.com/en-us/library/ie/bb802730.aspx).

You can work with the UrlActions to redirect to a ASHX handler or _layouts page and open the file.