Merge pull request #261 from AlexejStukov/patch-8

move encoding from serialize to trigger_outbound

channels/binding/base.py

@@ -93,6 +93,13 @@ class Binding(object):
         """
         cls.trigger_outbound(instance, "delete")
 
+    @classmethod
+    def encode(cls, stream, payload):
+        """
+        Encodes stream + payload for outbound sending.
+        """
+        raise NotImplementedError()
+
     @classmethod
     def trigger_outbound(cls, instance, action):
         """
@@ -101,9 +108,13 @@ class Binding(object):
         self = cls()
         self.instance = instance
         # Check to see if we're covered
-        for group_name in self.group_names(instance, action):
-            group = Group(group_name)
-            group.send(self.serialize(instance, action))
+        payload = self.serialize(instance, action)
+        if payload != {}:
+            assert self.stream is not None
+            message = cls.encode(self.stream, payload)
+            for group_name in self.group_names(instance, action):
+                group = Group(group_name)
+                group.send(message)
 
     def group_names(self, instance, action):
         """
@@ -115,9 +126,7 @@ class Binding(object):
     def serialize(self, instance, action):
         """
         Should return a serialized version of the instance to send over the
-        wire (return value must be a dict suitable for sending over a channel -
-        e.g., to send JSON as a WebSocket text frame, you must return
-        {"text": json.dumps(instance_serialized_as_dict)}
+        wire (e.g. {"pk": 12, "value": 42, "string": "some string"})
         """
         raise NotImplementedError()
 

channels/binding/websockets.py

@@ -32,6 +32,9 @@ class WebsocketBinding(Binding):
     stream = None
 
     # Outbound
+    @classmethod
+    def encode(cls, stream, payload):
+        return WebsocketDemultiplexer.encode(stream, payload)
 
     def serialize(self, instance, action):
         payload = {
@@ -40,9 +43,7 @@ class WebsocketBinding(Binding):
             "data": self.serialize_data(instance),
             "model": self.model_label,
         }
-        # Encode for the stream
-        assert self.stream is not None
-        return WebsocketDemultiplexer.encode(self.stream, payload)
+        return payload
 
     def serialize_data(self, instance):
         """