Flex: How can I use the @ContextRoot in a Button or LinkButton

I'm trying to create a button that will simply link back to the context root. I noticed flex has a @ContextRoot attribute that appears to work only in certain cases. For example, if I try to use it in the following mxml:

<mx:Button label="Back to Root" click="navigateToURL(new URLRequest(@ContextRoot()), '_parent')"/>

I get the following error: Error: Attributes are not callable.

I can't seem to find this technique explained anywhere, is there another way?

Thanks for the help! Dave

From stackoverflow

• Well, the cleanest way I found was to use a function in the script block, and not use @ContextRoot like:

  private function goBacktoHompage():void
   {
    baseURL = Application.application.url;
    var tempUrl:String = baseURL.substr(7,baseURL.length);
    var tempUrlArr:Array = tempUrl.split("/");
    var contextRoot:String = tempUrlArr[1];
    var u:URLRequest = new URLRequest("/" + contextRoot);
    navigateToURL(u,"_parent");
   }
  

  I would assume there is an easier way that could use @ContextRoot, so any other answers that don't use relative paths would be welcomed!

  Thanks to these sites for the help:

  http://blog.devsandbox.co.uk/?p=174

  [Adobe help docs on passing arguments]

  -Dave

• Thanks to http://devgirl.wordpress.com/ for this solution! I think it is better than the Application.application.url solution:

  Use the HTTPService control:

  <mx:HTTPService id="home" url="@ContextRoot()"/> 
  

  And then in Action Script:

   navigateToURL(new URLRequest(home.url),"_parent");
  

  works like a charm!