yesod/Yesod/Widget.hs
2010-07-06 22:36:20 +03:00

164 lines
5.0 KiB
Haskell

{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE PackageImports #-}
{-# LANGUAGE FlexibleInstances #-}
module Yesod.Widget
( -- * Datatype
GWidget
, Widget
-- * Unwrapping
, widgetToPageContent
, applyLayoutW
-- * Creating
, newIdent
, setTitle
, addStyle
, addStylesheet
, addStylesheetRemote
, addScript
, addScriptRemote
, addHead
, addBody
-- * Manipulating
, wrapWidget
, extractBody
) where
-- FIXME add support for script contents
import Data.List (nub)
import Data.Monoid
import Control.Monad.Trans.Writer
import Control.Monad.Trans.State
import Yesod.Hamlet (Hamlet, hamlet, PageContent (..), Html)
import Yesod.Handler (Route, GHandler)
import Yesod.Yesod (Yesod, defaultLayout)
import Yesod.Content (RepHtml (..))
import Control.Applicative (Applicative)
import Control.Monad.IO.Class (MonadIO)
import Control.Monad.Trans.Class (lift)
import "MonadCatchIO-transformers" Control.Monad.CatchIO (MonadCatchIO)
data Location url = Local url | Remote String
deriving (Show, Eq)
locationToHamlet :: Location url -> Hamlet url
locationToHamlet (Local url) = [$hamlet|@url@|]
locationToHamlet (Remote s) = [$hamlet|$s$|]
newtype UniqueList x = UniqueList ([x] -> [x])
instance Monoid (UniqueList x) where
mempty = UniqueList id
UniqueList x `mappend` UniqueList y = UniqueList $ x . y
runUniqueList :: Eq x => UniqueList x -> [x]
runUniqueList (UniqueList x) = nub $ x []
toUnique :: x -> UniqueList x
toUnique = UniqueList . (:)
newtype Script url = Script { unScript :: Location url }
deriving (Show, Eq)
newtype Stylesheet url = Stylesheet { unStylesheet :: Location url }
deriving (Show, Eq)
newtype Title = Title { unTitle :: Html () }
newtype Style url = Style (Hamlet url)
deriving Monoid
newtype Head url = Head (Hamlet url)
deriving Monoid
newtype Body url = Body (Hamlet url)
deriving Monoid
newtype GWidget sub master a = GWidget (
WriterT (Body (Route master)) (
WriterT (Last Title) (
WriterT (UniqueList (Script (Route master))) (
WriterT (UniqueList (Stylesheet (Route master))) (
WriterT (Style (Route master)) (
WriterT (Head (Route master)) (
StateT Int (
GHandler sub master
))))))) a)
deriving (Functor, Applicative, Monad, MonadIO, MonadCatchIO)
instance Monoid (GWidget sub master ()) where
mempty = return ()
mappend x y = x >> y
type Widget y = GWidget y y
setTitle :: Html () -> GWidget sub master ()
setTitle = GWidget . lift . tell . Last . Just . Title
addHead :: Hamlet (Route master) -> GWidget sub master ()
addHead = GWidget . lift . lift . lift . lift . lift . tell . Head
addBody :: Hamlet (Route master) -> GWidget sub master ()
addBody = GWidget . tell . Body
newIdent :: GWidget sub master String
newIdent = GWidget $ lift $ lift $ lift $ lift $ lift $ lift $ do
i <- get
let i' = i + 1
put i'
return $ "w" ++ show i'
addStyle :: Hamlet (Route master) -> GWidget sub master ()
addStyle = GWidget . lift . lift . lift . lift . tell . Style
addStylesheet :: Route master -> GWidget sub master ()
addStylesheet = GWidget . lift . lift . lift . tell . toUnique . Stylesheet . Local
addStylesheetRemote :: String -> GWidget sub master ()
addStylesheetRemote =
GWidget . lift . lift . lift . tell . toUnique . Stylesheet . Remote
addScript :: Route master -> GWidget sub master ()
addScript = GWidget . lift . lift . tell . toUnique . Script . Local
addScriptRemote :: String -> GWidget sub master ()
addScriptRemote =
GWidget . lift . lift . tell . toUnique . Script . Remote
applyLayoutW :: (Eq (Route m), Yesod m)
=> GWidget sub m () -> GHandler sub m RepHtml
applyLayoutW w = widgetToPageContent w >>= fmap RepHtml . defaultLayout
widgetToPageContent :: Eq (Route master)
=> GWidget sub master ()
-> GHandler sub master (PageContent (Route master))
widgetToPageContent (GWidget w) = do
w' <- flip evalStateT 0
$ runWriterT $ runWriterT $ runWriterT $ runWriterT
$ runWriterT $ runWriterT w
let (((((((),
Body body),
Last mTitle),
scripts'),
stylesheets'),
Style style),
Head head') = w'
let title = maybe mempty unTitle mTitle
let scripts = map (locationToHamlet . unScript) $ runUniqueList scripts'
let stylesheets = map (locationToHamlet . unStylesheet)
$ runUniqueList stylesheets'
let head'' = [$hamlet|
$forall scripts s
%script!src=^s^
$forall stylesheets s
%link!rel=stylesheet!href=^s^
%style
^style^
^head'^
|]
return $ PageContent title head'' body
wrapWidget :: GWidget s m a
-> (Hamlet (Route m) -> Hamlet (Route m))
-> GWidget s m a
wrapWidget (GWidget w) wrap =
GWidget $ mapWriterT (fmap go) w
where
go (a, Body h) = (a, Body $ wrap h)
extractBody :: GWidget s m () -> GWidget s m (Hamlet (Route m))
extractBody (GWidget w) =
GWidget $ mapWriterT (fmap go) w
where
go ((), Body h) = (h, Body mempty)