Suggested solution for #8

As I think the `SaslHandler's might change relatively frequently
depending on the value of `ConnectionState', I hereby suggest that the
handler value passed to `session' is changed from `[SaslHandler]' to
`(ConnectionState -> [SaslHandler]'.

Most people would probably just do `\_ -> scramSha1...', but I guess
the extra flexibility this provides makes up for the slightly more
complicated API.

source/Network/Xmpp.hs

@@ -167,6 +167,7 @@ module Network.Xmpp
                , AuthIllegalCredentials
                , AuthOtherFailure )
   , SaslHandler
+  , ConnectionState(..)
   ) where
 
 import Network.Xmpp.Concurrent

source/Network/Xmpp/Concurrent.hs

@@ -42,6 +42,8 @@ import           Network.Xmpp.Tls
 import           Network.Xmpp.Types
 import           Network.Xmpp.Utilities
 
+import           Control.Monad.State.Strict
+
 runHandlers :: (TChan Stanza) -> [StanzaHandler] -> Stanza -> IO ()
 runHandlers _    []        _   = return ()
 runHandlers outC (h:hands) sta = do
@@ -162,17 +164,18 @@ writeWorker stCh writeR = forever $ do
 -- third parameter is a 'Just' value, @session@ will attempt to authenticate and
 -- acquire an XMPP resource.
 session :: HostName                          -- ^ The hostname / realm
-        -> Maybe ([SaslHandler], Maybe Text) -- ^ SASL handlers and the desired
-                                             -- JID resource (or Nothing to let
+        -> Maybe (ConnectionState -> [SaslHandler] , Maybe Text)
+           -- ^ SASL handlers and the desired JID resource (or Nothing to let
            -- the server decide)
         -> SessionConfiguration              -- ^ configuration details
         -> IO (Either XmppFailure Session)
 session realm mbSasl config = runErrorT $ do
     stream <- ErrorT $ openStream realm (sessionStreamConfiguration config)
     ErrorT $ tls stream
+    cs <- liftIO $ withStream (gets streamConnectionState) stream
     mbAuthError <- case mbSasl of
         Nothing -> return Nothing
-        Just (handlers, resource) -> ErrorT $ auth handlers resource stream
+        Just (handlers, resource) -> ErrorT $ auth (handlers cs) resource stream
     case mbAuthError of
         Nothing -> return ()
         Just _  -> throwError XmppAuthFailure

source/Network/Xmpp/Internal.hs

@@ -31,7 +31,6 @@ module Network.Xmpp.Internal
   , pushIQ
   , SaslHandler
   , StanzaID(..)
-  , ConnectionState(..)
   , Stanza(..)
   , TlsBehaviour(..)
  )