Add url parameter to css file in asp themes folder

Question

I have written a bit of code that helps with versioning of js files. Essentially it spins around the current script manager and appends the javascript file path with an md5

Answer 1

You can use a control adapter to neatly inject this behavior into the page as follows:

public class PageAdapter : System.Web.UI.Adapters.PageAdapter
{
    protected override void OnPreRender(System.EventArgs e)
    {
        foreach (var link in Page.Header.Controls.OfType().ToList())
            if (link.Attributes["type"].Equals("text/css", StringComparison.OrdinalIgnoreCase))
                if (link.Attributes["href"].Contains("/App_Themes/{0}/".Fill(Page.Theme), StringComparison.OrdinalIgnoreCase))
                   /* process link */

        base.OnPreRender(e);
    }
}

You can plug it in by saving the following as a *.browser file in the App_Browsers folder:

Overall, I think Control Adapters are a powerful AOP-like mechanism for injecting behavior into control/page life-cycles; they are almost entirely ignored in favor of traditional sub-classing.