addStaticContentExternal

yesod-default/Yesod/Default/Util.hs

@@ -0,0 +1,43 @@
+{-# LANGUAGE OverloadedStrings #-}
+-- | Various utilities used in the scaffolded site.
+module Yesod.Default.Util
+    ( addStaticContentExternal
+    ) where
+
+import Control.Monad.IO.Class (liftIO)
+import qualified Data.ByteString.Lazy as L
+import Data.Text (Text, pack, unpack)
+import Yesod.Core -- purposely using complete import so that Haddock will see addStaticContent
+import Control.Monad (unless)
+import System.Directory (doesFileExist, createDirectoryIfMissing)
+
+-- | An implementation of 'addStaticContent' which stores the contents in an
+-- external file. Files are created in the given static folder with names based
+-- on a hash of their content. This allows expiration dates to be set far in
+-- the future without worry of users receiving stale content.
+addStaticContentExternal
+    :: (L.ByteString -> Either a L.ByteString) -- ^ javascript minifier
+    -> (L.ByteString -> String) -- ^ hash function to determine file name
+    -> FilePath -- ^ location of static directory. files will be placed within a "tmp" subfolder
+    -> ([Text] -> Route master) -- ^ route constructor, taking a list of pieces
+    -> Text -- ^ filename extension
+    -> Text -- ^ mime type
+    -> L.ByteString -- ^ file contents
+    -> GHandler sub master (Maybe (Either Text (Route master, [(Text, Text)])))
+addStaticContentExternal minify hash staticDir toRoute ext' _ content = do
+    liftIO $ createDirectoryIfMissing True statictmp
+    exists <- liftIO $ doesFileExist fn'
+    unless exists $ liftIO $ L.writeFile fn' content'
+    return $ Just $ Right (toRoute ["tmp", pack fn], [])
+  where
+    fn, statictmp, fn' :: FilePath
+    -- by basing the hash off of the un-minified content, we avoid a costly
+    -- minification if the file already exists
+    fn = hash content ++ '.' : unpack ext'
+    statictmp = staticDir ++ "/tmp/"
+    fn' = statictmp ++ fn
+
+    content' :: L.ByteString
+    content'
+        | ext' == "js" = either (const content) id $ minify content
+        | otherwise = content

yesod-default/yesod-default.cabal

@@ -14,15 +14,20 @@ description:     Convenient wrappers for your the configuration and
                  execution of your yesod application
 
 library
-    build-depends:   base       >= 4   && < 5
-                   , yesod-core >= 0.9 && < 0.10
-                   , cmdargs    >= 0.8 && < 0.9
-                   , warp       >= 0.4 && < 0.5
-                   , wai        >= 0.4 && < 0.5
-                   , wai-extra  >= 0.4 && < 0.5
+    build-depends:   base              >= 4   && < 5
+                   , yesod-core        >= 0.9 && < 0.10
+                   , cmdargs           >= 0.8 && < 0.9
+                   , warp              >= 0.4 && < 0.5
+                   , wai               >= 0.4 && < 0.5
+                   , wai-extra         >= 0.4 && < 0.5
+                   , bytestring        >= 0.9 && < 0.10
+                   , transformers      >= 0.2 && < 0.3
+                   , text              >= 0.9 && < 1.0
+                   , directory         >= 1.0 && < 1.2
 
     exposed-modules: Yesod.Default.Config
                    , Yesod.Default.Main
+                   , Yesod.Default.Util
 
     ghc-options:     -Wall
 

yesod/scaffold/Foundation.hs.cg

@@ -23,19 +23,18 @@ import Yesod.Auth
 import Yesod.Auth.OpenId
 import Yesod.Auth.Email
 import Yesod.Default.Config
+import Yesod.Default.Util (addStaticContentExternal)
 import Yesod.Logger (Logger, logLazyText)
 import qualified Settings
-import System.Directory
 import qualified Data.ByteString.Lazy as L
 import Database.Persist.~importGenericDB~
 import Settings (hamletFile, cassiusFile, luciusFile, juliusFile, widgetFile)
 import Model
 import Data.Maybe (isJust)
-import Control.Monad (join, unless)
+import Control.Monad (join)
 import Network.Mail.Mime
 import qualified Data.Text.Lazy.Encoding
 import Text.Jasmine (minifym)
-import qualified Data.Text as T
 import Web.ClientSession (getKey)
 import Text.Blaze.Renderer.Utf8 (renderHtml)
 import Text.Hamlet (shamlet)
@@ -104,21 +103,7 @@ instance Yesod ~sitearg~ where
     -- and names them based on a hash of their content. This allows
     -- expiration dates to be set far in the future without worry of
     -- users receiving stale content.
-    addStaticContent ext' _ content = do
-        let fn = base64md5 content ++ '.' : T.unpack ext'
-        let content' =
-                if ext' == "js"
-                    then case minifym content of
-                            Left _ -> content
-                            Right y -> y
-                    else content
-        let statictmp = Settings.staticDir ++ "/tmp/"
-        liftIO $ createDirectoryIfMissing True statictmp
-        let fn' = statictmp ++ fn
-        exists <- liftIO $ doesFileExist fn'
-        unless exists $ liftIO $ L.writeFile fn' content'
-        return $ Just $ Right (StaticR $ StaticRoute ["tmp", T.pack fn] [], [])
-
+    addStaticContent = addStaticContentExternal minifym base64md5 Settings.staticDir (StaticR . flip StaticRoute [])
 
 -- How to run database actions.
 instance YesodPersist ~sitearg~ where