add framing protocol for websockets

1 files changed, 8 insertions, 13 deletions

diff --git a/SessionID.hs b/SessionID.hs
index 8bf8f7d..449f58c 100644
--- a/SessionID.hs
+++ b/SessionID.hs
@@ -14,9 +14,6 @@ import System.FilePath
 import System.IO
 import System.Directory
 import Network.Wai.Handler.Warp (Port)
-import Network.WebSockets hiding (Message)
-import qualified Data.Aeson
-import Data.Maybe
 import Data.List
 import Data.UUID
 import Data.UUID.V4
@@ -28,17 +25,15 @@ import Control.Exception
 newtype SessionID = SessionID FilePath
 	deriving (Show, Eq, Ord, Generic)
 
+-- | Custom JSON deserialization so we can check smart constructor
+-- to verify it's legal.
+instance FromJSON SessionID where
+	parseJSON v = verify =<< genericParseJSON defaultOptions v
+	  where
+		verify (SessionID unverified) = 
+			maybe (fail "illegal SessionID") return
+				(mkSessionID unverified)
 instance ToJSON SessionID
-instance FromJSON SessionID
-
-instance WebSocketsData SessionID where
-	-- fromDataMessage = fromLazyByteString . fromDataMessage
-	fromLazyByteString b =
-		-- Down't trust a legal SessionID to be deserialized;
-		-- use smart constructor to verify it's legal.
-		let SessionID unverified = fromMaybe (error "bad SessionID serialization") (Data.Aeson.decode b)
-		in fromMaybe (error "illegal SessionID") (mkSessionID unverified)
-	toLazyByteString = Data.Aeson.encode
 
 -- | Smart constructor that enforces legal SessionID contents.
 --