wai-extra-2.0.0: Network/Wai/Middleware/Autohead.hs

{-# LANGUAGE OverloadedStrings #-}
-- | Automatically produce responses to HEAD requests based on the underlying
-- applications GET response.
module Network.Wai.Middleware.Autohead (autohead) where

import Network.Wai
import Network.Wai.Internal
import Data.Monoid (mempty)

autohead :: Middleware
autohead app req
    | requestMethod req == "HEAD" = do
        res <- app req { requestMethod = "GET" }
        case res of
            ResponseFile s hs _ _ -> return $ ResponseBuilder s hs mempty
            ResponseBuilder s hs _ -> return $ ResponseBuilder s hs mempty
            ResponseSource s hs _ -> return $ ResponseBuilder s hs mempty
    | otherwise = app req