yesod/Yesod/Hamlet.hs
2010-04-23 12:29:20 -07:00

86 lines
2.7 KiB
Haskell

{-# LANGUAGE TypeSynonymInstances #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE QuasiQuotes #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Yesod.Hamlet
( -- * Hamlet library
Hamlet
, hamlet
, HtmlContent (..)
-- * Convert to something displayable
, hamletToContent
, hamletToRepHtml
-- * Page templates
, PageContent (..)
-- * data-object
, HtmlObject
)
where
import Text.Hamlet
import Text.Hamlet.Monad (outputHtml)
import Yesod.Content
import Yesod.Handler
import Yesod.Definitions
import Data.Convertible.Text
import Data.Object
import Control.Arrow ((***))
-- | Content for a web page. By providing this datatype, we can easily create
-- generic site templates, which would have the type signature:
--
-- > PageContent url -> Hamlet url IO ()
data PageContent url = PageContent
{ pageTitle :: HtmlContent
, pageHead :: Hamlet url IO ()
, pageBody :: Hamlet url IO ()
}
-- FIXME some typeclasses for the stuff below?
-- | Converts the given Hamlet template into 'Content', which can be used in a
-- Yesod 'Response'.
hamletToContent :: Hamlet (Routes master) IO () -> GHandler sub master Content
hamletToContent h = do
render <- getUrlRenderMaster
return $ ContentEnum $ go render
where
go render iter seed = do
res <- runHamlet h render seed $ iter' iter
case res of
Left x -> return $ Left x
Right ((), x) -> return $ Right x
iter' iter seed text = iter seed $ cs text
-- | Wraps the 'Content' generated by 'hamletToContent' in a 'RepHtml'.
hamletToRepHtml :: Hamlet (Routes master) IO () -> GHandler sub master RepHtml
hamletToRepHtml = fmap RepHtml . hamletToContent
instance Monad m => ConvertSuccess String (Hamlet url m ()) where
convertSuccess = outputHtml . Unencoded . cs
instance Monad m
=> ConvertSuccess (Object String HtmlContent) (Hamlet url m ()) where
convertSuccess (Scalar h) = outputHtml h
convertSuccess (Sequence s) = template () where
template = [$hamlet|
%ul
$forall s' s
%li ^s^|]
s' _ = map cs s
convertSuccess (Mapping m) = template () where
template :: Monad m => () -> Hamlet url m ()
template = [$hamlet|
%dl
$forall pairs pair
%dt $pair.fst$
%dd ^pair.snd^|]
pairs _ = map (cs *** cs) m
instance ConvertSuccess String HtmlContent where
convertSuccess = Unencoded . cs
type HtmlObject = Object String HtmlContent
instance ConvertSuccess (Object String String) HtmlObject where
convertSuccess = fmap cs