Working distinction between single and multiplayer game

Application.hs

@@ -1,4 +1,5 @@
-{-# LANGUAGE TypeFamilies, QuasiQuotes, TemplateHaskell, OverloadedStrings #-}
+{-# LANGUAGE TypeFamilies, QuasiQuotes, TemplateHaskell, OverloadedStrings,
+             MultiParamTypeClasses #-}
 
 module Application where
 
@@ -29,4 +30,6 @@ instance Yesod Tfoo where
       addScript $ StaticR $ StaticRoute ["scripts","jquery.wiggle.js"] []
     hamletToRepHtml $(hamletFile "templates/layout.hamlet")
 
+instance RenderMessage Tfoo FormMessage where
+  renderMessage _ _ = defaultFormMessage
 

Tfoo/Handlers/Root.hs

@@ -14,8 +14,9 @@ import Tfoo.Helpers.Game
 import Data.Text as T
 import Data.List as L
 import Data.Maybe as M
-import Control.Monad
 
+import Control.Monad
+import Control.Applicative
 import Control.Concurrent.MVar
 
 import Yesod
@@ -34,6 +35,10 @@ postGamesR :: Handler RepHtml
 postGamesR = do
     tfoo <- getYesod
     id   <- liftIO $ newGame tfoo
+    Just single <- runInputPost $ Just <$> iopt hiddenField (T.pack "single")
+    if isJust single
+      then setupComputerPlayer id
+      else return ()
     redirect $ GameR id
 
 getGameR :: Int -> Handler RepHtml

Tfoo/Helpers/Game.hs

@@ -71,3 +71,7 @@ playerAuthorizations :: Handler [Player]
 playerAuthorizations = do
   authorizations <- lookupSession $ pack "players"
   return $ fromMaybe [] $ fmap (words . unpack) authorizations
+
+setupComputerPlayer :: Int -> Handler ()
+setupComputerPlayer id = do
+      return ()

templates/index.hamlet

@@ -6,10 +6,9 @@
     \ Play ↓ or <a target=_blank href=https://github.com/nbartlomiej/tfoo>view source</a>.
   <div .play>
     <form method=post action=@{GamesR}>
-      <input type=hidden name=humans value=1>
+      <input type=hidden name=single value=true>
       <input type=submit value="VS. Computer">
     <form method=post action=@{GamesR}>
-      <input type=hidden name=humans value=2>
       <input type=submit value="VS. Human">
 
 <div #social_media_wrapper>