Client.hs

-- | a very simple interface for acting as an HTTP client. This is mostly used for things like "Happstack.Server.Proxy". You are more likely to want a library like http-enumerator <http://hackage.haskell.org/package/http-enumerator>.
module Happstack.Server.Client where

import Happstack.Server.Internal.Handler    (parseResponse, putRequest)
import Happstack.Server.Internal.Types      (Response, Request, getHeader, readDec')
import Data.Maybe                           (fromJust)
import qualified Data.ByteString.Char8      as B
import qualified Data.ByteString.Lazy.Char8 as L 
import Network                              (PortID(PortNumber), connectTo, withSocketsDo)
import System.IO                            (BufferMode(NoBuffering), hFlush, hSetBuffering)

-- | Sends the serialized request to the host defined in the request
-- and attempts to parse response upon arrival.
getResponse :: Request -> IO (Either String Response)
getResponse rq = withSocketsDo $ do
  let (hostName,p) = span (/=':') $ fromJust $ fmap B.unpack $ getHeader "host" rq 
      portInt = if null p then 80 else readDec' $ tail p
      portId = PortNumber $ toEnum $ portInt
  h <- connectTo hostName portId 
  hSetBuffering h NoBuffering

  putRequest h rq
  hFlush h

  inputStr <- L.hGetContents h
  return $ parseResponse inputStr