Snaplets.hs

{-# LANGUAGE EmptyDataDecls #-}
{-# LANGUAGE PackageImports #-}

module Snaplets where

import "monads-fd" Control.Monad.State
import Data.ByteString (ByteString)
import Data.Dynamic
import Data.Map (Map)
import Snap.Types


------------------------------------------------------------------------------
-- snaplet object brokerage
data SnapletBroker


------------------------------------------------------------------------------
require :: (Typeable a) =>
           SnapletBroker  -- ^ object broker
        -> ByteString     -- ^ id of resource, e.g. \"com.snapframework.user\" 
        -> Maybe a
require = undefined


------------------------------------------------------------------------------
register :: (Typeable a) =>
            SnapletBroker  -- ^ object broker
         -> ByteString     -- ^ id of snaplet
         -> [ByteString]   -- ^ ids of resources exported
         -> a              -- ^ object
         -> SnapletBroker
register = undefined


------------------------------------------------------------------------------
data SnapletConfig = SnapletConfig
    { mountPoint    :: ByteString
    , dataDirectory :: FilePath
    , snapletId     :: ByteString
    , broker        :: SnapletBroker
    , configuration :: Map ByteString ByteString }


------------------------------------------------------------------------------
data SnapletState snaplet


------------------------------------------------------------------------------
class (Typeable a) => SnapletClass a where
    initialize                        :: SnapletConfig -> IO a
    destroy                           :: a -> IO ()
    reload                            :: a -> IO a
    getHandler                        :: a -> Maybe (Snap ())

    setupDirectoryWithDefaultSettings :: FilePath -> IO a
    provides                          :: a -> [ByteString]
    depends                           :: a -> [ByteString]