From 772563c46b4250e892c0611ed3a6cb44d1551a36 Mon Sep 17 00:00:00 2001
From: Michael Snoyman <michael@snoyman.com>
Date: Thu, 30 May 2013 08:31:24 +0300
Subject: [PATCH] lookupHeader/lookupHeaders

---
 yesod-core/Yesod/Core/Handler.hs | 17 +++++++++++++++++
 yesod-core/yesod-core.cabal      |  2 +-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/yesod-core/Yesod/Core/Handler.hs b/yesod-core/Yesod/Core/Handler.hs
index 3fd3cc91..f3b1799b 100644
--- a/yesod-core/Yesod/Core/Handler.hs
+++ b/yesod-core/Yesod/Core/Handler.hs
@@ -49,11 +49,13 @@ module Yesod.Core.Handler
     , lookupPostParam
     , lookupCookie
     , lookupFile
+    , lookupHeader
       -- **** Multi-lookup
     , lookupGetParams
     , lookupPostParams
     , lookupCookies
     , lookupFiles
+    , lookupHeaders
       -- * Responses
       -- ** Pure
     , respond
@@ -191,6 +193,7 @@ import           Yesod.Routes.Class            (Route)
 import Control.Failure (failure)
 import Blaze.ByteString.Builder (Builder)
 import Safe (headMay)
+import Data.CaseInsensitive (CI)
 
 get :: MonadHandler m => m GHState
 get = liftHandlerT $ HandlerT $ I.readIORef . handlerState
@@ -800,6 +803,20 @@ languages = reqLangs `liftM` getRequest
 lookup' :: Eq a => a -> [(a, b)] -> [b]
 lookup' a = map snd . filter (\x -> a == fst x)
 
+-- | Lookup a request header.
+--
+-- Since 1.2.2
+lookupHeader :: MonadHandler m => CI S8.ByteString -> m (Maybe S8.ByteString)
+lookupHeader = liftM listToMaybe . lookupHeaders
+
+-- | Lookup a request header.
+--
+-- Since 1.2.2
+lookupHeaders :: MonadHandler m => CI S8.ByteString -> m [S8.ByteString]
+lookupHeaders key = do
+    req <- waiRequest
+    return $ lookup' key $ W.requestHeaders req
+
 -- | Lookup for GET parameters.
 lookupGetParams :: MonadHandler m => Text -> m [Text]
 lookupGetParams pn = do
diff --git a/yesod-core/yesod-core.cabal b/yesod-core/yesod-core.cabal
index 9b9126de..177e3783 100644
--- a/yesod-core/yesod-core.cabal
+++ b/yesod-core/yesod-core.cabal
@@ -1,5 +1,5 @@
 name:            yesod-core
-version:         1.2.1
+version:         1.2.2
 license:         MIT
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>