yesod/yesod-core/Yesod/Core/Class/Dispatch.hs
2013-03-14 07:32:40 +02:00

58 lines
2.0 KiB
Haskell

{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE ViewPatterns #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE FlexibleContexts #-}
module Yesod.Core.Class.Dispatch where
import Yesod.Routes.Class
import qualified Network.Wai as W
import Yesod.Core.Types
import Yesod.Core.Content
import Yesod.Core.Class.Yesod
import Yesod.Core.Class.Handler
import Yesod.Core.Internal.Request (textQueryString)
import Yesod.Core.Internal.Run
import Control.Monad.Trans.Control (MonadBaseControl)
-- | This class is automatically instantiated when you use the template haskell
-- mkYesod function. You should never need to deal with it directly.
class Yesod site => YesodDispatch site where
yesodDispatch :: YesodRunnerEnv site -> W.Application
class YesodSubDispatch sub m where
yesodSubDispatch
:: (m TypedContent
-> YesodRunnerEnv (HandlerSite m)
-> Maybe (Route (HandlerSite m))
-> W.Application)
-> (HandlerSite m -> sub)
-> (Route sub -> Route (HandlerSite m))
-> YesodRunnerEnv (HandlerSite m)
-> W.Application
instance YesodSubDispatch WaiSubsite master where
yesodSubDispatch _ toSub _ YesodRunnerEnv { yreSite = site } req =
app req
where
WaiSubsite app = toSub site
-- | A helper function for creating YesodSubDispatch instances, used by the
-- internal generated code.
subHelper :: Monad m
=> (HandlerT parent m TypedContent
-> YesodRunnerEnv parent
-> Maybe (Route parent)
-> W.Application)
-> (parent -> child)
-> (Route child -> Route parent)
-> HandlerT child (HandlerT parent m) TypedContent
-> YesodRunnerEnv parent
-> Maybe (Route child)
-> W.Application
subHelper parentRunner getSub toMaster handlert env route =
parentRunner base env (fmap toMaster route)
where
base = stripHandlerT (fmap toTypedContent handlert) getSub toMaster route