Response.hs

-----------------------------------------------------------------------------
-- |
-- Module      :  HSP.Data.Response
-- Copyright   :  (c) Niklas Broberg 2004,
-- License     :  BSD-style (see the file LICENSE.txt)
-- 
-- Maintainer  :  Niklas Broberg, d00nibro@dtek.chalmers.se
-- Stability   :  experimental
-- Portability :  requires undecidable and overlapping instances
--
-- Defines the Response object available to HSP pages.
-----------------------------------------------------------------------------
module HSP.Data.Response (
	  Response		-- ^ The Response type is abstract
	, initResponse		-- ^ :: IO Response
	, setOutgoingHeader	-- ^ :: Response -> String -> String -> IO ()
	, getHeaders 		-- ^ :: Response -> IO [(String, String)]
	) where

import Data.IORef

data Response = Response {
		  outHeaders :: IORef [(String, String)]
			 }

-- | Set a header in the outgoing response.
setOutgoingHeader :: Response -> String -> String -> IO ()
setOutgoingHeader resp hdn hdv =
	modifyIORef (outHeaders resp) ((hdn,hdv):)
	
-- | Initialise a blank response.
initResponse = do ref <- newIORef []
		  return $ Response { outHeaders = ref }

-- | Get all set headers.
getHeaders :: Response -> IO [(String, String)]
getHeaders = readIORef . outHeaders