Question

While specifing background image urls in css can we get the value from a config entry.

Today my server name is http://imageserver , tomorrow it may change to http://imagecacheserver.

How can i change at one place so that there is no need to change in all the css files.

On the .net side , i get the server url from appsettings.

Answer 1

Are you using .Net MVC? Even if you’re using WebForms you can incorporate MVC (just have a quick Google).

Anyway, if so you could put in a UrlRoute in Global.asax

routes.MapRoute(
                "ImageHandler",
                "images/{*fileName}",
                new { controller = "ImageHandler", action = "Handle", fileName = "" } 
            );

Then just add an ‘ImageHandler’ controller that does the following:

public class ImageHandlerController : Controller
    {
        public ActionResult Handle(string fileName)
        {
            return Redirect("http://myactualserver.com/imageshere/" + fileName);
        }

    }

This will then redirect all HTTP GET requests from /images/* to the dynamic Url. Of course you can then just “jazz-up” the method above to use the Url that you have in your AppSettings rather than the hard-coded string. You may also want to HtmlEncode ‘fileName’ to be safe.

So your CSS code can now just use background-image: url("/images/blah.jpg") regardless of where the files actually are.