yesod/Yesod/Helpers/Static.hs
Michael Snoyman d1618eb3d0 hlint applied
2010-01-27 09:40:39 +02:00

65 lines
2.0 KiB
Haskell

{-# LANGUAGE TypeSynonymInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
---------------------------------------------------------
--
-- Module : Yesod.Helpers.Static
-- Copyright : Michael Snoyman
-- License : BSD3
--
-- Maintainer : Michael Snoyman <michael@snoyman.com>
-- Stability : Unstable
-- Portability : portable
--
-- Serve static files from a Yesod app.
--
-- This is most useful for standalone testing. When running on a production
-- server (like Apache), just let the server do the static serving.
--
---------------------------------------------------------
module Yesod.Helpers.Static
( serveStatic
, FileLookup
, fileLookupDir
) where
import System.Directory (doesFileExist)
import Control.Monad
import Yesod
import Data.List (intercalate)
type FileLookup = FilePath -> IO (Maybe (Either FilePath Content))
-- | A 'FileLookup' for files in a directory. Note that this function does not
-- check if the requested path does unsafe things, eg expose hidden files. You
-- should provide this checking elsewhere.
--
-- If you are just using this in combination with serveStatic, serveStatic
-- provides this checking.
fileLookupDir :: FilePath -> FileLookup
fileLookupDir dir fp = do
let fp' = dir ++ '/' : fp
exists <- doesFileExist fp'
if exists
then return $ Just $ Left fp'
else return Nothing
serveStatic :: FileLookup -> Verb -> [String]
-> Handler y [(ContentType, Content)]
serveStatic fl Get fp = getStatic fl fp
serveStatic _ _ _ = notFound
getStatic :: FileLookup -> [String] -> Handler y [(ContentType, Content)]
getStatic fl fp' = do
when (any isUnsafe fp') notFound
let fp = intercalate "/" fp'
content <- liftIO $ fl fp
case content of
Nothing -> notFound
Just (Left fp'') -> sendFile (typeByExt $ ext fp'') fp''
Just (Right bs) -> return [(typeByExt $ ext fp, cs bs)]
where
isUnsafe [] = True
isUnsafe ('.':_) = True
isUnsafe _ = False