hakyll/src/Hakyll/Web/Template/Context.hs
2012-11-10 18:11:46 +01:00

79 lines
2.4 KiB
Haskell

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module Hakyll.Web.Template.Context
( Context
, field
, defaultContext
, bodyField
, urlField
, pathField
, categoryField
, titleField
) where
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import Control.Applicative (empty, (<|>))
import Control.Arrow
import System.FilePath (takeBaseName, takeDirectory)
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import Hakyll.Core.Compiler
import Hakyll.Core.Identifier
import Hakyll.Web.Page.Internal
import Hakyll.Web.Urls
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type Context a = Compiler (String, (Identifier a, a)) String
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field :: String -> Compiler (Identifier a, a) String -> Context a
field key value = arr checkKey >>> (empty ||| value)
where
checkKey (k, x)
| k /= key = Left ()
| otherwise = Right x
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defaultContext :: Context Page
defaultContext =
bodyField "body" <|>
urlField "url" <|>
pathField "path" <|>
categoryField "category" <|>
titleField "title" <|>
missingField
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bodyField :: String -> Context Page
bodyField key = field key $ arr snd
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urlField :: String -> Context a
urlField key = field key $ fst ^>> getRouteFor >>^ maybe empty toUrl
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pathField :: String -> Context a
pathField key = field key $ arr $ toFilePath . fst
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categoryField :: String -> Context a
categoryField key = pathField key >>^ (takeBaseName . takeDirectory)
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titleField :: String -> Context a
titleField key = pathField key >>^ takeBaseName
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missingField :: Context a
missingField = arr $ \(k, _) -> "$" ++ k ++ "$"