filtering improved withing the transformer

1. stream.takeWhile will cancel on first failure
2. rename `event` and `events` to `name` and `names` to match IDL

example/lib/main.dart

@@ -329,9 +329,9 @@ class _MyAppState extends State<MyApp> {
   );
 
   Widget createChannelSubscribeButton() => FlatButton(
-    onPressed: (_realtimeChannelState==ably.ChannelState.attached)?() {
+    onPressed: (_realtimeChannelState==ably.ChannelState.attached && channelMessageSubscription==null)?() {
       ably.RealtimeChannel channel = _realtime.channels.get("test-channel");
-      Stream<ably.Message> messageStream = channel.subscribe();
+      Stream<ably.Message> messageStream = channel.subscribe(name: 'message-data');
       channelMessageSubscription = messageStream.listen((ably.Message message){
         print("Channel message recieved: $message\n"
           "\tisNull: ${message.data == null}\n"
@@ -352,6 +352,9 @@ class _MyAppState extends State<MyApp> {
     onPressed: (channelMessageSubscription!=null)?() async {
       await channelMessageSubscription.cancel();
       print("Channel messages ubsubscribed");
+      setState((){
+        channelMessageSubscription = null;
+      });
     }:null,
     child: Text('Unsubscribe'),
   );

lib/src/impl/realtime/channels.dart

@@ -134,22 +134,27 @@ class RealtimePlatformChannel extends PlatformObject implements spec.RealtimeCha
 
   @override
   Stream<spec.Message> subscribe({
-    String event,
-    List<String> events
+    String name,
+    List<String> names
   }) {
     Stream<spec.Message> stream = listen(PlatformMethod.onRealtimeChannelMessage, _payload).transform<spec.Message>(
       StreamTransformer.fromHandlers(
         handleData: (dynamic value, EventSink<spec.Message> sink){
           spec.Message message = value as spec.Message;
-          sink.add(message);
+          if (names!=null){
+            if(names.contains(message.name)){
+              sink.add(message);
+            }
+          } else if (name!=null) {
+            if(message.name==name){
+              sink.add(message);
+            }
+          } else {
+            sink.add(message);
+          }
         }
       )
     );
-    if (events!=null && events.isNotEmpty){
-      return stream.takeWhile((spec.Message _message) => events.contains(_message.name));
-    } else if (event!=null) {
-      return stream.takeWhile((spec.Message _message) => _message.name==event);
-    }
     return stream;
   }
 

lib/src/spec/realtime/channels.dart

@@ -35,8 +35,8 @@ abstract class RealtimeChannel extends EventEmitter<ChannelEvent, ChannelStateCh
     dynamic data
   });
   Stream<Message> subscribe({
-    String event,
-    List<String> events,
+    String name,
+    List<String> names,
   });
   void setOptions(ChannelOptions options);
 }