[web-devel] Yesod: Dynamic subdomains

Hi, I am building a Yesod web app which should support dynamic subdomains. I.e. a user registers as "foobar" on http://www.example.com and can afterwards access her content via http://foobar.example.com Is this possible at all? I am wondering, because the server name is somehow hard coded in Settings.hs as approot. If it is possible: How do I access the domain name in a handler function? Thanks! Timo