now builds with both yesod 1.2 and 1.1

Utility/WebApp.hs

@@ -178,7 +178,11 @@ lookupRequestField k req = fromMaybe "" . lookup k $ Wai.requestHeaders req
 
 {- Rather than storing a session key on disk, use a random key
  - that will only be valid for this run of the webapp. -}
+#if MIN_VERSION_yesod(1,2,0)
 webAppSessionBackend :: Yesod.Yesod y => y -> IO (Maybe Yesod.SessionBackend)
+#else
+webAppSessionBackend :: Yesod.Yesod y => y -> IO (Maybe (Yesod.SessionBackend y))
+#endif
 webAppSessionBackend _ = do
 	g <- newGenIO :: IO SystemRandom
 	case genBytes 96 g of
@@ -218,7 +222,11 @@ genRandomToken = do
  - Note that the usual Yesod error page is bypassed on error, to avoid
  - possibly leaking the auth token in urls on that page!
  -}
+#if MIN_VERSION_yesod(1,2,0)
 checkAuthToken :: (Monad m, Yesod.MonadHandler m) => (Yesod.HandlerSite m -> T.Text) -> m Yesod.AuthResult
+#else
+checkAuthToken :: forall t sub. (t -> T.Text) -> Yesod.GHandler sub t Yesod.AuthResult
+#endif
 checkAuthToken extractToken = do
 	webapp <- Yesod.getYesod
 	req <- Yesod.getRequest