Easy application of decorators to Bindings (#281)

* Added get_handler

Added a get_handler method that applies decorators to the consumer-classmethod

* added imports for decorators

* Added get_handler to WebsocketBinding

* Fixed missing import

* channel_session_user defaults to True

* removed user-transfer from http

would only work in a connect-method

* removed unused import

channels/binding/base.py

@@ -6,6 +6,7 @@ from django.apps import apps
 from django.db.models.signals import post_save, post_delete
 
 from ..channel import Group
+from ..auth import channel_session, channel_session_user
 
 
 class BindingMetaclass(type):
@@ -62,6 +63,10 @@ class Binding(object):
 
     fields = None
 
+    # Decorators
+    channel_session_user = True
+    channel_session = False
+
     @classmethod
     def register(cls):
         """
@@ -158,7 +163,23 @@ class Binding(object):
         # Run incoming action
         self.run_action(self.action, self.pk, self.data)
 
-    consumer = trigger_inbound
+    @classmethod
+    def get_handler(cls):
+        """
+        Adds decorators to trigger_inbound.
+        """
+        handler = cls.trigger_inbound
+        if cls.channel_session_user:
+            return channel_session_user(handler)
+        elif cls.channel_session:
+            return channel_session(handler)
+        else:
+            return handler
+
+    @classmethod
+    def consumer(cls, message, **kwargs):
+        handler = cls.get_handler()
+        handler(message, **kwargs)
 
     def deserialize(self, message):
         """

channels/binding/websockets.py

@@ -5,6 +5,7 @@ from django.core.serializers.json import DjangoJSONEncoder
 
 from .base import Binding
 from ..generic.websockets import WebsocketDemultiplexer
+from ..sessions import enforce_ordering
 
 
 class WebsocketBinding(Binding):
@@ -32,6 +33,10 @@ class WebsocketBinding(Binding):
 
     stream = None
 
+    # Decorators
+    strict_ordering = False
+    slight_ordering = False
+
     # Outbound
     @classmethod
     def encode(cls, stream, payload):
@@ -58,6 +63,20 @@ class WebsocketBinding(Binding):
         return json.loads(data)[0]['fields']
 
     # Inbound
+    @classmethod
+    def get_handler(cls):
+        """
+        Adds decorators to trigger_inbound.
+        """
+        # Get super-handler
+        handler = super(WebsocketBinding, cls).get_handler()
+        # Ordering decorators
+        if cls.strict_ordering:
+            return enforce_ordering(handler, slight=False)
+        elif cls.slight_ordering:
+            return enforce_ordering(handler, slight=True)
+        else:
+            return handler
 
     def deserialize(self, message):
         """