940 lines
30 KiB
Haskell
940 lines
30 KiB
Haskell
{-# LANGUAGE MultiParamTypeClasses #-}
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{-# LANGUAGE FlexibleInstances #-}
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{-# LANGUAGE TypeSynonymInstances #-}
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{-# LANGUAGE FlexibleContexts #-}
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{-# LANGUAGE TypeFamilies #-}
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{-# LANGUAGE GeneralizedNewtypeDeriving #-}
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{-# LANGUAGE CPP #-}
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{-# LANGUAGE FunctionalDependencies #-}
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{-# LANGUAGE OverloadedStrings #-}
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{-# LANGUAGE QuasiQuotes #-}
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{-# LANGUAGE DeriveDataTypeable #-}
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---------------------------------------------------------
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--
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-- Module : Yesod.Handler
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-- Copyright : Michael Snoyman
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-- License : BSD3
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--
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-- Maintainer : Michael Snoyman <michael@snoyman.com>
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-- Stability : stable
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-- Portability : portable
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--
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-- Define Handler stuff.
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--
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---------------------------------------------------------
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module Yesod.Handler
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( -- * Type families
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YesodSubRoute (..)
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-- * Handler monad
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, GHandler
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-- ** Read information from handler
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, getYesod
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, getYesodSub
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, getUrlRender
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, getUrlRenderParams
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, getCurrentRoute
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, getRouteToMaster
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, getRequest
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, waiRequest
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, runRequestBody
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-- * Special responses
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-- ** Redirecting
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, RedirectUrl (..)
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, redirect
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, redirectWith
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, redirectToPost
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-- ** Errors
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, notFound
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, badMethod
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, permissionDenied
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, permissionDeniedI
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, invalidArgs
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, invalidArgsI
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-- ** Short-circuit responses.
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, sendFile
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, sendFilePart
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, sendResponse
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, sendResponseStatus
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, sendResponseCreated
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, sendWaiResponse
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-- * Setting headers
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, setCookie
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, getExpires
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, deleteCookie
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, setHeader
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, setLanguage
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-- ** Content caching and expiration
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, cacheSeconds
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, neverExpires
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, alreadyExpired
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, expiresAt
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-- * Session
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, SessionMap
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, lookupSession
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, lookupSessionBS
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, getSession
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, setSession
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, setSessionBS
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, deleteSession
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, clearSession
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-- ** Ultimate destination
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, setUltDest
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, setUltDestCurrent
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, setUltDestReferer
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, redirectUltDest
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, clearUltDest
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-- ** Messages
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, setMessage
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, setMessageI
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, getMessage
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-- * Helpers for specific content
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-- ** Hamlet
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, hamletToContent
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, hamletToRepHtml
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-- ** Misc
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, newIdent
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-- * Lifting
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, MonadLift (..)
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-- * i18n
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, getMessageRender
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-- * Per-request caching
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, CacheKey
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, mkCacheKey
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, cacheLookup
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, cacheInsert
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, cacheDelete
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-- * Internal Yesod
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, runHandler
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, YesodApp (..)
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, runSubsiteGetter
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, toMasterHandler
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, toMasterHandlerDyn
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, toMasterHandlerMaybe
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, localNoCurrent
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, HandlerData
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, ErrorResponse (..)
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, YesodAppResult (..)
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, handlerToYAR
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, yarToResponse
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, headerToPair
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) where
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import Prelude hiding (catch)
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import Yesod.Internal.Request
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import Yesod.Internal
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import Data.Time (UTCTime, getCurrentTime, addUTCTime)
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import Control.Exception hiding (Handler, catch, finally)
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import Control.Applicative
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import Control.Monad (liftM)
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import Control.Monad.IO.Class
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import Control.Monad.Trans.Class (MonadTrans)
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import qualified Control.Monad.Trans.Class
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import System.IO
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import qualified Network.Wai as W
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import qualified Network.HTTP.Types as H
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import Text.Hamlet
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#if MIN_VERSION_blaze_html(0, 5, 0)
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import qualified Text.Blaze.Html.Renderer.Text as RenderText
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#else
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import qualified Text.Blaze.Renderer.Text as RenderText
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#endif
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import qualified Data.Text as T
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import Data.Text.Encoding (encodeUtf8, decodeUtf8With)
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import Data.Text.Encoding.Error (lenientDecode)
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import qualified Data.Text.Lazy as TL
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import qualified Data.Map as Map
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import qualified Data.ByteString as S
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import Network.Wai.Parse (parseHttpAccept)
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import Yesod.Content
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import Data.Maybe (fromMaybe)
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import Web.Cookie (SetCookie (..), renderSetCookie)
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import Control.Arrow ((***))
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import qualified Network.Wai.Parse as NWP
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import Data.Monoid (mappend, mempty, Endo (..))
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import qualified Data.ByteString.Char8 as S8
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import Data.CaseInsensitive (CI)
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import qualified Data.CaseInsensitive as CI
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import Blaze.ByteString.Builder (toByteString)
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import Data.Text (Text)
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import Yesod.Message (RenderMessage (..))
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#if MIN_VERSION_blaze_html(0, 5, 0)
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import Text.Blaze.Html (toHtml, preEscapedToMarkup)
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#define preEscapedText preEscapedToMarkup
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#else
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import Text.Blaze (toHtml, preEscapedText)
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#endif
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import qualified Yesod.Internal.Cache as Cache
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import Yesod.Internal.Cache (mkCacheKey, CacheKey)
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import Data.Typeable (Typeable)
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import qualified Data.IORef as I
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import Control.Exception.Lifted (catch)
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import Control.Monad.Trans.Control
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import Control.Monad.Trans.Resource
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import Control.Monad.Base
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import Yesod.Routes.Class
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class YesodSubRoute s y where
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fromSubRoute :: s -> y -> Route s -> Route y
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data HandlerData sub master = HandlerData
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{ handlerRequest :: Request
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, handlerSub :: sub
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, handlerMaster :: master
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, handlerRoute :: Maybe (Route sub)
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, handlerRender :: Route master -> [(Text, Text)] -> Text
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, handlerToMaster :: Route sub -> Route master
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, handlerState :: I.IORef GHState
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}
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handlerSubData :: (Route sub -> Route master)
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-> (master -> sub)
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-> Route sub
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-> HandlerData oldSub master
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-> HandlerData sub master
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handlerSubData tm ts = handlerSubDataMaybe tm ts . Just
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handlerSubDataMaybe :: (Route sub -> Route master)
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-> (master -> sub)
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-> Maybe (Route sub)
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-> HandlerData oldSub master
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-> HandlerData sub master
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handlerSubDataMaybe tm ts route hd = hd
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{ handlerSub = ts $ handlerMaster hd
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, handlerToMaster = tm
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, handlerRoute = route
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}
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get :: GHandler sub master GHState
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get = do
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hd <- ask
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liftIO $ I.readIORef $ handlerState hd
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put :: GHState -> GHandler sub master ()
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put g = do
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hd <- ask
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liftIO $ I.writeIORef (handlerState hd) g
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modify :: (GHState -> GHState) -> GHandler sub master ()
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modify f = do
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hd <- ask
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liftIO $ I.atomicModifyIORef (handlerState hd) $ \g -> (f g, ())
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tell :: Endo [Header] -> GHandler sub master ()
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tell hs = modify $ \g -> g { ghsHeaders = ghsHeaders g `mappend` hs }
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-- | Used internally for promoting subsite handler functions to master site
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-- handler functions. Should not be needed by users.
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toMasterHandler :: (Route sub -> Route master)
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-> (master -> sub)
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-> Route sub
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-> GHandler sub master a
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-> GHandler sub' master a
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toMasterHandler tm ts route = local (handlerSubData tm ts route)
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-- | FIXME do we need this?
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toMasterHandlerDyn :: (Route sub -> Route master)
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-> GHandler sub' master sub
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-> Route sub
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-> GHandler sub master a
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-> GHandler sub' master a
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toMasterHandlerDyn tm getSub route h = do
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sub <- getSub
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local (handlerSubData tm (const sub) route) h
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class SubsiteGetter g m s | g -> s where
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runSubsiteGetter :: g -> m s
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instance (master ~ master'
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) => SubsiteGetter (master -> sub) (GHandler anySub master') sub where
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runSubsiteGetter getter = getter <$> getYesod
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instance (anySub ~ anySub'
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,master ~ master'
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) => SubsiteGetter (GHandler anySub master sub) (GHandler anySub' master') sub where
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runSubsiteGetter = id
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toMasterHandlerMaybe :: (Route sub -> Route master)
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-> (master -> sub)
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-> Maybe (Route sub)
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-> GHandler sub master a
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-> GHandler sub' master a
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toMasterHandlerMaybe tm ts route = local (handlerSubDataMaybe tm ts route)
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-- | A generic handler monad, which can have a different subsite and master
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-- site. We define a newtype for better error message.
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newtype GHandler sub master a = GHandler
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{ unGHandler :: HandlerData sub master -> ResourceT IO a
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}
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data GHState = GHState
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{ ghsSession :: SessionMap
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, ghsRBC :: Maybe RequestBodyContents
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, ghsIdent :: Int
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, ghsCache :: Cache.Cache
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, ghsHeaders :: Endo [Header]
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}
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type SessionMap = Map.Map Text S.ByteString
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-- | An extension of the basic WAI 'W.Application' datatype to provide extra
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-- features needed by Yesod. Users should never need to use this directly, as
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-- the 'GHandler' monad and template haskell code should hide it away.
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newtype YesodApp = YesodApp
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{ unYesodApp
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:: (ErrorResponse -> YesodApp)
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-> Request
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-> [ContentType]
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-> SessionMap
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-> ResourceT IO YesodAppResult
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}
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data YesodAppResult
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= YARWai W.Response
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| YARPlain H.Status [Header] ContentType Content SessionMap
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data HandlerContents =
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HCContent H.Status ChooseRep
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| HCError ErrorResponse
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| HCSendFile ContentType FilePath (Maybe W.FilePart) -- FIXME replace FilePath with opaque type from system-filepath?
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| HCRedirect H.Status Text
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| HCCreated Text
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| HCWai W.Response
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deriving Typeable
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instance Show HandlerContents where
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show _ = "Cannot show a HandlerContents"
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instance Exception HandlerContents
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getRequest :: GHandler s m Request
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getRequest = handlerRequest `liftM` ask
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hcError :: ErrorResponse -> GHandler sub master a
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hcError = liftIO . throwIO . HCError
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runRequestBody :: GHandler s m RequestBodyContents
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runRequestBody = do
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x <- get
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case ghsRBC x of
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Just rbc -> return rbc
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Nothing -> do
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rr <- waiRequest
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rbc <- lift $ rbHelper rr
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put x { ghsRBC = Just rbc }
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return rbc
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rbHelper :: W.Request -> ResourceT IO RequestBodyContents
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rbHelper req =
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(map fix1 *** map fix2) <$> (NWP.parseRequestBody NWP.lbsSink req) -- FIXME allow control over which backend to use
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where
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fix1 = go *** go
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fix2 (x, NWP.FileInfo a b c) =
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(go x, FileInfo (go a) (go b) c)
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go = decodeUtf8With lenientDecode
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-- | Get the sub application argument.
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getYesodSub :: GHandler sub master sub
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getYesodSub = handlerSub `liftM` ask
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-- | Get the master site appliation argument.
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getYesod :: GHandler sub master master
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getYesod = handlerMaster `liftM` ask
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-- | Get the URL rendering function.
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getUrlRender :: GHandler sub master (Route master -> Text)
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getUrlRender = do
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x <- handlerRender `liftM` ask
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return $ flip x []
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-- | The URL rendering function with query-string parameters.
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getUrlRenderParams
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:: GHandler sub master (Route master -> [(Text, Text)] -> Text)
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getUrlRenderParams = handlerRender `liftM` ask
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-- | Get the route requested by the user. If this is a 404 response- where the
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-- user requested an invalid route- this function will return 'Nothing'.
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getCurrentRoute :: GHandler sub master (Maybe (Route sub))
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getCurrentRoute = handlerRoute `liftM` ask
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-- | Get the function to promote a route for a subsite to a route for the
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-- master site.
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getRouteToMaster :: GHandler sub master (Route sub -> Route master)
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getRouteToMaster = handlerToMaster `liftM` ask
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-- | Function used internally by Yesod in the process of converting a
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-- 'GHandler' into an 'W.Application'. Should not be needed by users.
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runHandler :: HasReps c
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=> GHandler sub master c
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-> (Route master -> [(Text, Text)] -> Text)
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-> Maybe (Route sub)
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-> (Route sub -> Route master)
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-> master
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-> sub
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-> YesodApp
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runHandler handler mrender sroute tomr master sub =
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YesodApp $ \eh rr cts initSession -> do
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let toErrorHandler e =
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case fromException e of
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Just x -> x
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Nothing -> InternalError $ T.pack $ show e
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istate <- liftIO $ I.newIORef GHState
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{ ghsSession = initSession
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, ghsRBC = Nothing
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, ghsIdent = 1
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, ghsCache = mempty
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, ghsHeaders = mempty
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}
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let hd = HandlerData
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{ handlerRequest = rr
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, handlerSub = sub
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, handlerMaster = master
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, handlerRoute = sroute
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, handlerRender = mrender
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, handlerToMaster = tomr
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, handlerState = istate
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}
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contents' <- catch (fmap Right $ unGHandler handler hd)
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(\e -> return $ Left $ maybe (HCError $ toErrorHandler e) id
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$ fromException e)
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state <- liftIO $ I.readIORef istate
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let finalSession = ghsSession state
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let headers = ghsHeaders state
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let contents = either id (HCContent H.status200 . chooseRep) contents'
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let handleError e = do
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yar <- unYesodApp (eh e) safeEh rr cts finalSession
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case yar of
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YARPlain _ hs ct c sess ->
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let hs' = appEndo headers hs
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in return $ YARPlain (getStatus e) hs' ct c sess
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YARWai _ -> return yar
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let sendFile' ct fp p =
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return $ YARPlain H.status200 (appEndo headers []) ct (ContentFile fp p) finalSession
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case contents of
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HCContent status a -> do
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(ct, c) <- liftIO $ a cts
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return $ YARPlain status (appEndo headers []) ct c finalSession
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HCError e -> handleError e
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HCRedirect status loc -> do
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let hs = Header "Location" (encodeUtf8 loc) : appEndo headers []
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return $ YARPlain
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status hs typePlain emptyContent
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finalSession
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HCSendFile ct fp p -> catch
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(sendFile' ct fp p)
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(handleError . toErrorHandler)
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HCCreated loc -> do
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let hs = Header "Location" (encodeUtf8 loc) : appEndo headers []
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return $ YARPlain
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H.status201
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hs
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typePlain
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emptyContent
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finalSession
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HCWai r -> return $ YARWai r
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safeEh :: ErrorResponse -> YesodApp
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safeEh er = YesodApp $ \_ _ _ session -> do
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liftIO $ hPutStrLn stderr $ "Error handler errored out: " ++ show er
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return $ YARPlain
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H.status500
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[]
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typePlain
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(toContent ("Internal Server Error" :: S.ByteString))
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session
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-- | Redirect to the given route.
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-- HTTP status code 303 for HTTP 1.1 clients and 302 for HTTP 1.0
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-- This is the appropriate choice for a get-following-post
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-- technique, which should be the usual use case.
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--
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-- If you want direct control of the final status code, or need a different
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-- status code, please use 'redirectWith'.
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redirect :: RedirectUrl master url => url -> GHandler sub master a
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redirect url = do
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req <- waiRequest
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let status =
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if W.httpVersion req == H.http11
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then H.status303
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else H.status302
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redirectWith status url
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-- | Redirect to the given URL with the specified status code.
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redirectWith :: RedirectUrl master url => H.Status -> url -> GHandler sub master a
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redirectWith status url = do
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urlText <- toTextUrl url
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liftIO $ throwIO $ HCRedirect status urlText
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ultDestKey :: Text
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ultDestKey = "_ULT"
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-- | Sets the ultimate destination variable to the given route.
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--
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-- An ultimate destination is stored in the user session and can be loaded
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-- later by 'redirectUltDest'.
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setUltDest :: RedirectUrl master url => url -> GHandler sub master ()
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setUltDest url = do
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urlText <- toTextUrl url
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setSession ultDestKey urlText
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-- | Same as 'setUltDest', but uses the current page.
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--
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-- If this is a 404 handler, there is no current page, and then this call does
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-- nothing.
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setUltDestCurrent :: GHandler sub master ()
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setUltDestCurrent = do
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route <- getCurrentRoute
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case route of
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Nothing -> return ()
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Just r -> do
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tm <- getRouteToMaster
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gets' <- reqGetParams `liftM` handlerRequest `liftM` ask
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setUltDest (tm r, gets')
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-- | Sets the ultimate destination to the referer request header, if present.
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--
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-- This function will not overwrite an existing ultdest.
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setUltDestReferer :: GHandler sub master ()
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setUltDestReferer = do
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mdest <- lookupSession ultDestKey
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maybe
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(waiRequest >>= maybe (return ()) setUltDestBS . lookup "referer" . W.requestHeaders)
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(const $ return ())
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mdest
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where
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setUltDestBS = setUltDest . T.pack . S8.unpack
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-- | Redirect to the ultimate destination in the user's session. Clear the
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-- value from the session.
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--
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-- The ultimate destination is set with 'setUltDest'.
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--
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-- This function uses 'redirect', and thus will perform a temporary redirect to
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-- a GET request.
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redirectUltDest :: RedirectUrl master url
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=> url -- ^ default destination if nothing in session
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-> GHandler sub master a
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redirectUltDest def = do
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mdest <- lookupSession ultDestKey
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deleteSession ultDestKey
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maybe (redirect def) redirect mdest
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-- | Remove a previously set ultimate destination. See 'setUltDest'.
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clearUltDest :: GHandler sub master ()
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clearUltDest = deleteSession ultDestKey
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msgKey :: Text
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msgKey = "_MSG"
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-- | Sets a message in the user's session.
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--
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-- See 'getMessage'.
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setMessage :: Html -> GHandler sub master ()
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|
setMessage = setSession msgKey . T.concat . TL.toChunks . RenderText.renderHtml
|
|
|
|
-- | Sets a message in the user's session.
|
|
--
|
|
-- See 'getMessage'.
|
|
setMessageI :: (RenderMessage y msg) => msg -> GHandler sub y ()
|
|
setMessageI msg = do
|
|
mr <- getMessageRender
|
|
setMessage $ toHtml $ mr msg
|
|
|
|
-- | Gets the message in the user's session, if available, and then clears the
|
|
-- variable.
|
|
--
|
|
-- See 'setMessage'.
|
|
getMessage :: GHandler sub master (Maybe Html)
|
|
getMessage = do
|
|
mmsg <- liftM (fmap preEscapedText) $ lookupSession msgKey
|
|
deleteSession msgKey
|
|
return mmsg
|
|
|
|
-- | Bypass remaining handler code and output the given file.
|
|
--
|
|
-- For some backends, this is more efficient than reading in the file to
|
|
-- memory, since they can optimize file sending via a system call to sendfile.
|
|
sendFile :: ContentType -> FilePath -> GHandler sub master a
|
|
sendFile ct fp = liftIO . throwIO $ HCSendFile ct fp Nothing
|
|
|
|
-- | Same as 'sendFile', but only sends part of a file.
|
|
sendFilePart :: ContentType
|
|
-> FilePath
|
|
-> Integer -- ^ offset
|
|
-> Integer -- ^ count
|
|
-> GHandler sub master a
|
|
sendFilePart ct fp off count =
|
|
liftIO . throwIO $ HCSendFile ct fp $ Just $ W.FilePart off count
|
|
|
|
-- | Bypass remaining handler code and output the given content with a 200
|
|
-- status code.
|
|
sendResponse :: HasReps c => c -> GHandler sub master a
|
|
sendResponse = liftIO . throwIO . HCContent H.status200
|
|
. chooseRep
|
|
|
|
-- | Bypass remaining handler code and output the given content with the given
|
|
-- status code.
|
|
sendResponseStatus :: HasReps c => H.Status -> c -> GHandler s m a
|
|
sendResponseStatus s = liftIO . throwIO . HCContent s
|
|
. chooseRep
|
|
|
|
-- | Send a 201 "Created" response with the given route as the Location
|
|
-- response header.
|
|
sendResponseCreated :: Route m -> GHandler s m a
|
|
sendResponseCreated url = do
|
|
r <- getUrlRender
|
|
liftIO . throwIO $ HCCreated $ r url
|
|
|
|
-- | Send a 'W.Response'. Please note: this function is rarely
|
|
-- necessary, and will /disregard/ any changes to response headers and session
|
|
-- that you have already specified. This function short-circuits. It should be
|
|
-- considered only for very specific needs. If you are not sure if you need it,
|
|
-- you don't.
|
|
sendWaiResponse :: W.Response -> GHandler s m b
|
|
sendWaiResponse = liftIO . throwIO . HCWai
|
|
|
|
-- | Return a 404 not found page. Also denotes no handler available.
|
|
notFound :: GHandler sub master a
|
|
notFound = hcError NotFound
|
|
|
|
-- | Return a 405 method not supported page.
|
|
badMethod :: GHandler sub master a
|
|
badMethod = do
|
|
w <- waiRequest
|
|
hcError $ BadMethod $ W.requestMethod w
|
|
|
|
-- | Return a 403 permission denied page.
|
|
permissionDenied :: Text -> GHandler sub master a
|
|
permissionDenied = hcError . PermissionDenied
|
|
|
|
-- | Return a 403 permission denied page.
|
|
permissionDeniedI :: RenderMessage master msg => msg -> GHandler sub master a
|
|
permissionDeniedI msg = do
|
|
mr <- getMessageRender
|
|
permissionDenied $ mr msg
|
|
|
|
-- | Return a 400 invalid arguments page.
|
|
invalidArgs :: [Text] -> GHandler sub master a
|
|
invalidArgs = hcError . InvalidArgs
|
|
|
|
-- | Return a 400 invalid arguments page.
|
|
invalidArgsI :: RenderMessage y msg => [msg] -> GHandler s y a
|
|
invalidArgsI msg = do
|
|
mr <- getMessageRender
|
|
invalidArgs $ map mr msg
|
|
|
|
------- Headers
|
|
-- | Set the cookie on the client.
|
|
|
|
setCookie :: SetCookie
|
|
-> GHandler sub master ()
|
|
setCookie = addHeader . AddCookie
|
|
|
|
-- | Helper function for setCookieExpires value
|
|
getExpires :: Int -- ^ minutes
|
|
-> IO UTCTime
|
|
getExpires m = do
|
|
now <- liftIO getCurrentTime
|
|
return $ fromIntegral (m * 60) `addUTCTime` now
|
|
|
|
|
|
-- | Unset the cookie on the client.
|
|
--
|
|
-- Note: although the value used for key and path is 'Text', you should only
|
|
-- use ASCII values to be HTTP compliant.
|
|
deleteCookie :: Text -- ^ key
|
|
-> Text -- ^ path
|
|
-> GHandler sub master ()
|
|
deleteCookie a = addHeader . DeleteCookie (encodeUtf8 a) . encodeUtf8
|
|
|
|
|
|
-- | Set the language in the user session. Will show up in 'languages' on the
|
|
-- next request.
|
|
setLanguage :: Text -> GHandler sub master ()
|
|
setLanguage = setSession langKey
|
|
|
|
-- | Set an arbitrary response header.
|
|
--
|
|
-- Note that, while the data type used here is 'Text', you must provide only
|
|
-- ASCII value to be HTTP compliant.
|
|
setHeader :: Text -> Text -> GHandler sub master ()
|
|
setHeader a = addHeader . Header (encodeUtf8 a) . encodeUtf8
|
|
|
|
-- | Set the Cache-Control header to indicate this response should be cached
|
|
-- for the given number of seconds.
|
|
cacheSeconds :: Int -> GHandler s m ()
|
|
cacheSeconds i = setHeader "Cache-Control" $ T.concat
|
|
[ "max-age="
|
|
, T.pack $ show i
|
|
, ", public"
|
|
]
|
|
|
|
-- | Set the Expires header to some date in 2037. In other words, this content
|
|
-- is never (realistically) expired.
|
|
neverExpires :: GHandler s m ()
|
|
neverExpires = setHeader "Expires" "Thu, 31 Dec 2037 23:55:55 GMT"
|
|
|
|
-- | Set an Expires header in the past, meaning this content should not be
|
|
-- cached.
|
|
alreadyExpired :: GHandler s m ()
|
|
alreadyExpired = setHeader "Expires" "Thu, 01 Jan 1970 05:05:05 GMT"
|
|
|
|
-- | Set an Expires header to the given date.
|
|
expiresAt :: UTCTime -> GHandler s m ()
|
|
expiresAt = setHeader "Expires" . formatRFC1123
|
|
|
|
-- | Set a variable in the user's session.
|
|
--
|
|
-- The session is handled by the clientsession package: it sets an encrypted
|
|
-- and hashed cookie on the client. This ensures that all data is secure and
|
|
-- not tampered with.
|
|
setSession :: Text -- ^ key
|
|
-> Text -- ^ value
|
|
-> GHandler sub master ()
|
|
setSession k = setSessionBS k . encodeUtf8
|
|
|
|
-- | Same as 'setSession', but uses binary data for the value.
|
|
setSessionBS :: Text
|
|
-> S.ByteString
|
|
-> GHandler sub master ()
|
|
setSessionBS k = modify . modSession . Map.insert k
|
|
|
|
-- | Unsets a session variable. See 'setSession'.
|
|
deleteSession :: Text -> GHandler sub master ()
|
|
deleteSession = modify . modSession . Map.delete
|
|
|
|
-- | Clear all session variables.
|
|
--
|
|
-- Since: 1.0.1
|
|
clearSession :: GHandler sub master ()
|
|
clearSession = modify $ \x -> x { ghsSession = Map.empty }
|
|
|
|
modSession :: (SessionMap -> SessionMap) -> GHState -> GHState
|
|
modSession f x = x { ghsSession = f $ ghsSession x }
|
|
|
|
-- | Internal use only, not to be confused with 'setHeader'.
|
|
addHeader :: Header -> GHandler sub master ()
|
|
addHeader = tell . Endo . (:)
|
|
|
|
getStatus :: ErrorResponse -> H.Status
|
|
getStatus NotFound = H.status404
|
|
getStatus (InternalError _) = H.status500
|
|
getStatus (InvalidArgs _) = H.status400
|
|
getStatus (PermissionDenied _) = H.status403
|
|
getStatus (BadMethod _) = H.status405
|
|
|
|
-- | Some value which can be turned into a URL for redirects.
|
|
class RedirectUrl master a where
|
|
-- | Converts the value to the URL and a list of query-string parameters.
|
|
toTextUrl :: a -> GHandler sub master Text
|
|
|
|
instance RedirectUrl master Text where
|
|
toTextUrl = return
|
|
|
|
instance RedirectUrl master String where
|
|
toTextUrl = toTextUrl . T.pack
|
|
|
|
instance RedirectUrl master (Route master) where
|
|
toTextUrl url = do
|
|
r <- getUrlRender
|
|
return $ r url
|
|
|
|
instance (key ~ Text, val ~ Text) => RedirectUrl master (Route master, [(key, val)]) where
|
|
toTextUrl (url, params) = do
|
|
r <- getUrlRenderParams
|
|
return $ r url params
|
|
|
|
localNoCurrent :: GHandler s m a -> GHandler s m a
|
|
localNoCurrent =
|
|
local (\hd -> hd { handlerRoute = Nothing })
|
|
|
|
-- | Lookup for session data.
|
|
lookupSession :: Text -> GHandler s m (Maybe Text)
|
|
lookupSession = (fmap . fmap) (decodeUtf8With lenientDecode) . lookupSessionBS
|
|
|
|
-- | Lookup for session data in binary format.
|
|
lookupSessionBS :: Text -> GHandler s m (Maybe S.ByteString)
|
|
lookupSessionBS n = do
|
|
m <- liftM ghsSession get
|
|
return $ Map.lookup n m
|
|
|
|
-- | Get all session variables.
|
|
getSession :: GHandler sub master SessionMap
|
|
getSession = liftM ghsSession get
|
|
|
|
handlerToYAR :: (HasReps a, HasReps b)
|
|
=> master -- ^ master site foundation
|
|
-> sub -- ^ sub site foundation
|
|
-> (Route sub -> Route master)
|
|
-> (Route master -> [(Text, Text)] -> Text) -- route renderer
|
|
-> (ErrorResponse -> GHandler sub master a)
|
|
-> Request
|
|
-> Maybe (Route sub)
|
|
-> SessionMap
|
|
-> GHandler sub master b
|
|
-> ResourceT IO YesodAppResult
|
|
handlerToYAR y s toMasterRoute render errorHandler rr murl sessionMap h =
|
|
unYesodApp ya eh' rr types sessionMap
|
|
where
|
|
ya = runHandler h render murl toMasterRoute y s
|
|
eh' er = runHandler (errorHandler' er) render murl toMasterRoute y s
|
|
types = httpAccept $ reqWaiRequest rr
|
|
errorHandler' = localNoCurrent . errorHandler
|
|
|
|
yarToResponse :: YesodAppResult -> [(CI H.Ascii, H.Ascii)] -> W.Response
|
|
yarToResponse (YARWai a) _ = a
|
|
yarToResponse (YARPlain s hs _ c _) extraHeaders =
|
|
case c of
|
|
ContentBuilder b mlen ->
|
|
let hs' = maybe finalHeaders finalHeaders' mlen
|
|
in W.ResponseBuilder s hs' b
|
|
ContentFile fp p -> W.ResponseFile s finalHeaders fp p
|
|
ContentSource body -> W.ResponseSource s finalHeaders body
|
|
where
|
|
finalHeaders = extraHeaders ++ map headerToPair hs
|
|
finalHeaders' len = ("Content-Length", S8.pack $ show len)
|
|
: finalHeaders
|
|
|
|
httpAccept :: W.Request -> [ContentType]
|
|
httpAccept = parseHttpAccept
|
|
. fromMaybe mempty
|
|
. lookup "Accept"
|
|
. W.requestHeaders
|
|
|
|
-- | Convert Header to a key/value pair.
|
|
headerToPair :: Header
|
|
-> (CI H.Ascii, H.Ascii)
|
|
headerToPair (AddCookie sc) =
|
|
("Set-Cookie", toByteString $ renderSetCookie $ sc)
|
|
headerToPair (DeleteCookie key path) =
|
|
( "Set-Cookie"
|
|
, S.concat
|
|
[ key
|
|
, "=; path="
|
|
, path
|
|
, "; expires=Thu, 01-Jan-1970 00:00:00 GMT"
|
|
]
|
|
)
|
|
headerToPair (Header key value) = (CI.mk key, value)
|
|
|
|
-- | Get a unique identifier.
|
|
newIdent :: GHandler sub master Text
|
|
newIdent = do
|
|
x <- get
|
|
let i' = ghsIdent x + 1
|
|
put x { ghsIdent = i' }
|
|
return $ T.pack $ 'h' : show i'
|
|
|
|
-- | Redirect to a POST resource.
|
|
--
|
|
-- This is not technically a redirect; instead, it returns an HTML page with a
|
|
-- POST form, and some Javascript to automatically submit the form. This can be
|
|
-- useful when you need to post a plain link somewhere that needs to cause
|
|
-- changes on the server.
|
|
redirectToPost :: RedirectUrl master url => url -> GHandler sub master a
|
|
redirectToPost url = do
|
|
urlText <- toTextUrl url
|
|
hamletToRepHtml [hamlet|
|
|
$newline never
|
|
$doctype 5
|
|
|
|
<html>
|
|
<head>
|
|
<title>Redirecting...
|
|
<body onload="document.getElementById('form').submit()">
|
|
<form id="form" method="post" action=#{urlText}>
|
|
<noscript>
|
|
<p>Javascript has been disabled; please click on the button below to be redirected.
|
|
<input type="submit" value="Continue">
|
|
|] >>= sendResponse
|
|
|
|
-- | Converts the given Hamlet template into 'Content', which can be used in a
|
|
-- Yesod 'Response'.
|
|
hamletToContent :: HtmlUrl (Route master) -> GHandler sub master Content
|
|
hamletToContent h = do
|
|
render <- getUrlRenderParams
|
|
return $ toContent $ h render
|
|
|
|
-- | Wraps the 'Content' generated by 'hamletToContent' in a 'RepHtml'.
|
|
hamletToRepHtml :: HtmlUrl (Route master) -> GHandler sub master RepHtml
|
|
hamletToRepHtml = liftM RepHtml . hamletToContent
|
|
|
|
-- | Get the request\'s 'W.Request' value.
|
|
waiRequest :: GHandler sub master W.Request
|
|
waiRequest = reqWaiRequest `liftM` getRequest
|
|
|
|
getMessageRender :: RenderMessage master message => GHandler s master (message -> Text)
|
|
getMessageRender = do
|
|
m <- getYesod
|
|
l <- reqLangs `liftM` getRequest
|
|
return $ renderMessage m l
|
|
|
|
cacheLookup :: CacheKey a -> GHandler sub master (Maybe a)
|
|
cacheLookup k = do
|
|
gs <- get
|
|
return $ Cache.lookup k $ ghsCache gs
|
|
|
|
cacheInsert :: CacheKey a -> a -> GHandler sub master ()
|
|
cacheInsert k v = modify $ \gs ->
|
|
gs { ghsCache = Cache.insert k v $ ghsCache gs }
|
|
|
|
cacheDelete :: CacheKey a -> GHandler sub master ()
|
|
cacheDelete k = modify $ \gs ->
|
|
gs { ghsCache = Cache.delete k $ ghsCache gs }
|
|
|
|
ask :: GHandler sub master (HandlerData sub master)
|
|
ask = GHandler return
|
|
|
|
local :: (HandlerData sub' master' -> HandlerData sub master)
|
|
-> GHandler sub master a
|
|
-> GHandler sub' master' a
|
|
local f (GHandler x) = GHandler $ \r -> x $ f r
|
|
|
|
-- | The standard @MonadTrans@ class only allows lifting for monad
|
|
-- transformers. While @GHandler@ and @GWidget@ should allow lifting, their
|
|
-- types do not express that they actually are transformers. This replacement
|
|
-- class accounts for this.
|
|
class MonadLift base m | m -> base where
|
|
lift :: base a -> m a
|
|
instance (Monad m, MonadTrans t) => MonadLift m (t m) where
|
|
lift = Control.Monad.Trans.Class.lift
|
|
instance MonadLift (ResourceT IO) (GHandler sub master) where
|
|
lift = GHandler . const
|
|
|
|
-- Instances for GHandler
|
|
instance Functor (GHandler sub master) where
|
|
fmap f (GHandler x) = GHandler $ \r -> fmap f (x r)
|
|
instance Applicative (GHandler sub master) where
|
|
pure = GHandler . const . pure
|
|
GHandler f <*> GHandler x = GHandler $ \r -> f r <*> x r
|
|
instance Monad (GHandler sub master) where
|
|
return = pure
|
|
GHandler x >>= f = GHandler $ \r -> x r >>= \x' -> unGHandler (f x') r
|
|
instance MonadIO (GHandler sub master) where
|
|
liftIO = GHandler . const . lift
|
|
instance MonadBase IO (GHandler sub master) where
|
|
liftBase = GHandler . const . lift
|
|
instance MonadBaseControl IO (GHandler sub master) where
|
|
data StM (GHandler sub master) a = StH (StM (ResourceT IO) a)
|
|
liftBaseWith f = GHandler $ \reader ->
|
|
liftBaseWith $ \runInBase ->
|
|
f $ liftM StH . runInBase . (\(GHandler r) -> r reader)
|
|
restoreM (StH base) = GHandler $ const $ restoreM base
|
|
|
|
instance MonadUnsafeIO (GHandler sub master) where
|
|
unsafeLiftIO = liftIO
|
|
instance MonadThrow (GHandler sub master) where
|
|
monadThrow = liftIO . throwIO
|
|
instance MonadResource (GHandler sub master) where
|
|
allocate a = lift . allocate a
|
|
register = lift . register
|
|
release = lift . release
|
|
resourceMask = lift . resourceMask
|