Adding internal Base64 type to transparently handle bytes encoding

Fixes #26

core/gogol-core.cabal

@@ -36,7 +36,8 @@ library
     ghc-options:       -Wall
 
     exposed-modules:
-          Network.Google.Data.JSON
+          Network.Google.Data.Base64
+        , Network.Google.Data.JSON
         , Network.Google.Data.Numeric
         , Network.Google.Data.Time
         , Network.Google.Prelude
@@ -58,6 +59,7 @@ library
         , http-media           >= 0.6
         , http-types           >= 0.8.6
         , lens                 >= 4.4
+        , memory               >= 0.8
         , resourcet            >= 1.1
         , scientific           >= 0.3
         , servant              >= 0.4.4

core/src/Network/Google/Data/Base64.hs

@@ -0,0 +1,53 @@
+{-# LANGUAGE DeriveDataTypeable         #-}
+{-# LANGUAGE DeriveGeneric              #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+
+-- |
+-- Module      : Network.Google.Data.Base64
+-- Copyright   : (c) 2013-2016 Brendan Hay
+-- License     : Mozilla Public License, v. 2.0.
+-- Maintainer  : Brendan Hay <[email protected]>
+-- Stability   : provisional
+-- Portability : non-portable (GHC extensions)
+--
+module Network.Google.Data.Base64
+    ( Base64 (..)
+    , _Base64
+    ) where
+
+import           Control.Lens             (Iso', iso)
+import           Data.Aeson               (FromJSON (..), ToJSON (..))
+import qualified Data.ByteArray.Encoding  as BA
+import           Data.ByteString          (ByteString)
+import qualified Data.ByteString.Char8    as BS8
+import           Data.Data                (Data, Typeable)
+import           Data.Hashable
+import qualified Data.Text.Encoding       as Text
+import           GHC.Generics             (Generic)
+import           Network.Google.Data.JSON (parseJSONText, toJSONText)
+import           Web.HttpApiData          (FromHttpApiData (..),
+                                           ToHttpApiData (..))
+
+-- | Base64 encoded binary data.
+--
+-- Encoding\/decoding is automatically deferred to serialisation and deserialisation
+-- respectively.
+newtype Base64 = Base64 { unBase64 :: ByteString }
+    deriving (Eq, Read, Ord, Data, Typeable, Generic)
+
+instance Hashable Base64
+
+_Base64 :: Iso' Base64 ByteString
+_Base64 = iso unBase64 Base64
+
+instance ToHttpApiData Base64 where
+    toQueryParam = Text.decodeUtf8 . toHeader
+    toHeader     = BA.convertToBase BA.Base64 . unBase64
+
+instance FromHttpApiData Base64 where
+    parseQueryParam = parseHeader . Text.encodeUtf8
+    parseHeader     = either fail (pure . Base64) . BA.convertFromBase BA.Base64
+
+instance Show     Base64 where show      = show . BS8.unpack . unBase64
+instance FromJSON Base64 where parseJSON = parseJSONText "Base64"
+instance ToJSON   Base64 where toJSON    = toJSONText

core/src/Network/Google/Prelude.hs

@@ -10,27 +10,28 @@ module Network.Google.Prelude
     ( module Export
     ) where
 
-import           Control.Lens                as Export (Lens', lens, mapping,
-                                                        ( # ), (^.), _Just)
-import           Data.Data                   as Export (Data, Typeable)
-import           Data.Hashable               as Export
-import           Data.HashMap.Strict         as Export (HashMap)
-import           Data.Int                    as Export (Int32, Int64)
-import           Data.Maybe                  as Export
-import           Data.Monoid                 as Export (mempty, (<>))
-import           Data.Proxy                  as Export
-import           Data.Text                   as Export (Text)
-import           Data.Time                   as Export (Day, TimeOfDay, UTCTime)
-import           Data.Word                   as Export (Word32, Word64, Word8)
-import           GHC.Generics                as Export (Generic)
-import           Network.Google.Data.JSON    as Export
-import           Network.Google.Data.Numeric as Export
-import           Network.Google.Data.Time    as Export
-import           Network.Google.Types        as Export
-import           Network.HTTP.Client         as Export (RequestBody)
-import           Numeric.Natural             as Export (Natural)
-import           Prelude                     as Export hiding (product)
-import           Servant.API                 as Export hiding (getResponse)
-import           Servant.Utils.Links         as Export hiding (Link)
-import           Web.HttpApiData             as Export (FromHttpApiData (..),
-                                                        ToHttpApiData (..))
+import Control.Lens        as Export (Lens', lens, mapping, ( # ), (^.), _Just)
+import Data.ByteString     as Export (ByteString)
+import Data.Data           as Export (Data, Typeable)
+import Data.Hashable       as Export
+import Data.HashMap.Strict as Export (HashMap)
+import Data.Int            as Export (Int32, Int64)
+import Data.Maybe          as Export
+import Data.Monoid         as Export (mempty, (<>))
+import Data.Proxy          as Export
+import Data.Text           as Export (Text)
+import Data.Time           as Export (Day, TimeOfDay, UTCTime)
+import Data.Word           as Export (Word32, Word64, Word8)
+import GHC.Generics        as Export (Generic)
+import Network.HTTP.Client as Export (RequestBody)
+import Numeric.Natural     as Export (Natural)
+import Prelude             as Export hiding (product)
+import Servant.API         as Export hiding (getResponse)
+import Servant.Utils.Links as Export hiding (Link)
+import Web.HttpApiData     as Export (FromHttpApiData (..), ToHttpApiData (..))
+
+import Network.Google.Data.Base64  as Export
+import Network.Google.Data.JSON    as Export
+import Network.Google.Data.Numeric as Export
+import Network.Google.Data.Time    as Export
+import Network.Google.Types        as Export