205 lines
6.3 KiB
Haskell
205 lines
6.3 KiB
Haskell
{-# LANGUAGE QuasiQuotes #-}
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-- | The basic typeclass for a Yesod application.
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module Yesod.Yesod
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( Yesod (..)
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, YesodSite (..)
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, simpleApplyLayout
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, getApproot
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, toWaiApp
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, basicHandler
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) where
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import Yesod.Response
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import Yesod.Request
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import Yesod.Definitions
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import Yesod.Hamlet
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import Yesod.Handler hiding (badMethod)
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import qualified Data.ByteString as B
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import qualified Data.ByteString.Char8 as B8
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import Data.Convertible.Text
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import Control.Arrow ((***))
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import Data.Maybe (fromMaybe)
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import Web.Mime
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import Web.Encodings (parseHttpAccept)
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import Web.Routes (Site (..), encodePathInfo, decodePathInfo)
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import Data.List (intercalate)
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import qualified Network.Wai as W
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import Network.Wai.Middleware.CleanPath
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import Network.Wai.Middleware.ClientSession
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import Network.Wai.Middleware.Jsonp
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import Network.Wai.Middleware.MethodOverride
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import Network.Wai.Middleware.Gzip
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import qualified Network.Wai.Handler.SimpleServer as SS
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import qualified Network.Wai.Handler.CGI as CGI
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import System.Environment (getEnvironment)
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class YesodSite y where
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getSite :: Site (Routes y) (String -> YesodApp -> y -> YesodApp)
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class YesodSite a => Yesod a where
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-- | The encryption key to be used for encrypting client sessions.
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encryptKey :: a -> IO Word256
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encryptKey _ = getKey defaultKeyFile
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-- | Number of minutes before a client session times out. Defaults to
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-- 120 (2 hours).
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clientSessionDuration :: a -> Int
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clientSessionDuration = const 120
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-- | Output error response pages.
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errorHandler :: Yesod y => a -> ErrorResponse -> Handler y ChooseRep
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errorHandler _ = defaultErrorHandler
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-- | Applies some form of layout to <title> and <body> contents of a page. FIXME: use a Maybe here to allow subsites to simply inherit.
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applyLayout :: a
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-> PageContent url -- FIXME not so good, should be Routes y
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-> Request
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-> Hamlet url IO ()
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applyLayout _ p _ = [$hamlet|
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!!!
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%html
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%head
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%title $pageTitle$
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^pageHead^
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%body
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^pageBody^
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|] p
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-- | Gets called at the beginning of each request. Useful for logging.
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onRequest :: a -> Request -> IO ()
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onRequest _ _ = return ()
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-- | An absolute URL to the root of the application. Do not include
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-- trailing slash.
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approot :: a -> Approot
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-- | A convenience wrapper around 'simpleApplyLayout for HTML-only data.
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simpleApplyLayout :: Yesod master
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=> String -- ^ title
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-> Hamlet (Routes sub) IO () -- ^ body
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-> GHandler sub master RepHtml
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simpleApplyLayout t b = do
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let pc = PageContent
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{ pageTitle = cs t
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, pageHead = return ()
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, pageBody = b
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}
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y <- getYesodMaster
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rr <- getRequest
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content <- hamletToContent $ applyLayout y pc rr
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return $ RepHtml content
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getApproot :: Yesod y => Handler y Approot
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getApproot = approot `fmap` getYesod
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simpleApplyLayout' :: Yesod master
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=> String -- ^ title
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-> Hamlet (Routes sub) IO () -- ^ body
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-> GHandler sub master ChooseRep
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simpleApplyLayout' t = fmap chooseRep . simpleApplyLayout t
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defaultErrorHandler :: Yesod y => ErrorResponse -> Handler y ChooseRep
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defaultErrorHandler NotFound = do
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r <- waiRequest
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simpleApplyLayout' "Not Found" $ [$hamlet|
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%h1 Not Found
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%p $helper$
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|] r
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where
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helper = Unencoded . cs . W.pathInfo
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defaultErrorHandler PermissionDenied =
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simpleApplyLayout' "Permission Denied" $ [$hamlet|
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%h1 Permission denied|] ()
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defaultErrorHandler (InvalidArgs ia) =
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simpleApplyLayout' "Invalid Arguments" $ [$hamlet|
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%h1 Invalid Arguments
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%dl
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$forall ias pair
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%dt $pair.fst$
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%dd $pair.snd$
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|] ()
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where
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ias _ = map (cs *** cs) ia
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defaultErrorHandler (InternalError e) =
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simpleApplyLayout' "Internal Server Error" $ [$hamlet|
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%h1 Internal Server Error
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%p $cs$
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|] e
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defaultErrorHandler (BadMethod m) =
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simpleApplyLayout' "Bad Method" $ [$hamlet|
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%h1 Method Not Supported
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%p Method "$cs$" not supported
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|] m
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toWaiApp :: Yesod y => y -> IO W.Application
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toWaiApp a = do
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key' <- encryptKey a
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let mins = clientSessionDuration a
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return $ gzip
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$ jsonp
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$ methodOverride
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$ cleanPath
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$ \thePath -> clientsession encryptedCookies key' mins
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$ toWaiApp' a thePath
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toWaiApp' :: Yesod y
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=> y
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-> [B.ByteString]
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-> [(B.ByteString, B.ByteString)]
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-> W.Request
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-> IO W.Response
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toWaiApp' y resource session env = do
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let site = getSite
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method = B8.unpack $ W.methodToBS $ W.requestMethod env
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types = httpAccept env
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pathSegments = filter (not . null) $ cleanupSegments resource
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eurl = parsePathSegments site pathSegments
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render u = approot y ++ '/'
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: encodePathInfo (fixSegs $ formatPathSegments site u)
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rr <- parseWaiRequest env session
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onRequest y rr
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print pathSegments
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let ya = case eurl of
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Left _ -> runHandler (errorHandler y NotFound) y Nothing render
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Right url -> handleSite site render url method
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(badMethod method) y
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let url' = either (const Nothing) Just eurl
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let eh er = runHandler (errorHandler y er) y url' render
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unYesodApp ya eh rr types >>= responseToWaiResponse
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cleanupSegments :: [B.ByteString] -> [String]
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cleanupSegments = decodePathInfo . intercalate "/" . map B8.unpack
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httpAccept :: W.Request -> [ContentType]
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httpAccept = map contentTypeFromBS
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. parseHttpAccept
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. fromMaybe B.empty
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. lookup W.Accept
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. W.requestHeaders
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-- | Runs an application with CGI if CGI variables are present (namely
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-- PATH_INFO); otherwise uses SimpleServer.
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basicHandler :: Int -- ^ port number
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-> W.Application -> IO ()
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basicHandler port app = do
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vars <- getEnvironment
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case lookup "PATH_INFO" vars of
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Nothing -> do
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putStrLn $ "http://localhost:" ++ show port ++ "/"
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SS.run port app
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Just _ -> CGI.run app
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badMethod :: String -> YesodApp
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badMethod m = YesodApp $ \eh req cts
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-> unYesodApp (eh $ BadMethod m) eh req cts
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fixSegs :: [String] -> [String]
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fixSegs [] = []
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fixSegs [x]
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| any (== '.') x = [x]
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| otherwise = [x, ""] -- append trailing slash
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fixSegs (x:xs) = x : fixSegs xs
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