All update related events now pass in the previous state.

discord/server.py

@@ -30,6 +30,7 @@ from .member import Member
 from .channel import Channel
 from .enums import ServerRegion, Status
 from .mixins import Hashable
+import copy
 
 class Server(Hashable):
     """Represents a Discord server.
@@ -94,11 +95,12 @@ class Server(Hashable):
     def _update_voice_state(self, data):
         user_id = data.get('user_id')
         member = utils.find(lambda m: m.id == user_id, self.members)
+        before = copy.copy(member)
         if member is not None:
             ch_id = data.get('channel_id')
             channel = utils.find(lambda c: c.id == ch_id, self.channels)
             member.update_voice_state(voice_channel=channel, **data)
-        return member
+        return before, member
 
     def _from_data(self, guild):
         self.name = guild.get('name')

discord/state.py

@@ -148,8 +148,10 @@ class ConnectionState:
         if server is not None:
             channel_id = data.get('id')
             channel = utils.find(lambda c: c.id == channel_id, server.channels)
-            channel.update(server=server, **data)
-            self.dispatch('channel_update', channel)
+            if channel is not None:
+                old_channel = copy.copy(channel)
+                channel.update(server=server, **data)
+                self.dispatch('channel_update', old_channel, channel)
 
     def parse_channel_create(self, data):
         is_private = data.get('is_private', False)
@@ -275,14 +277,16 @@ class ConnectionState:
         if server is not None:
             role_id = data['role']['id']
             role = utils.find(lambda r: r.id == role_id, server.roles)
-            role.update(**data['role'])
-            self.dispatch('server_role_update', role)
+            if role is not None:
+                old_role = copy.copy(role)
+                role.update(**data['role'])
+                self.dispatch('server_role_update', old_role, role)
 
     def parse_voice_state_update(self, data):
         server = self._get_server(data.get('guild_id'))
         if server is not None:
-            updated_member = server._update_voice_state(data)
-            self.dispatch('voice_state_update', updated_member)
+            updated_members = server._update_voice_state(data)
+            self.dispatch('voice_state_update', *updated_members)
 
     def parse_typing_start(self, data):
         channel = self.get_channel(data.get('channel_id'))

docs/api.rst

@@ -226,11 +226,12 @@ to handle it, which defaults to print a traceback and ignore the exception.
 
     :param channel: The :class:`Channel` that got added or deleted.
 
-.. function:: on_channel_update(channel)
+.. function:: on_channel_update(before, after)
 
     Called whenever a channel is updated. e.g. changed name, topic, permissions.
 
-    :param channel: The :class:`Channel` that got updated.
+    :param before: The :class:`Channel` that got updated with the old info.
+    :param after: The :class:`Channel` that got updated with the updated info.
 
 .. function:: on_member_join(member)
               on_member_remove(member)
@@ -296,11 +297,12 @@ to handle it, which defaults to print a traceback and ignore the exception.
     :param server: The :class:`Server` that was created or deleted.
     :param role: The :class:`Role` that was created or deleted.
 
-.. function:: on_server_role_update(role)
+.. function:: on_server_role_update(before, after)
 
     Called when a :class:`Role` is changed server-wide.
 
-    :param role: The :class:`Role` that was updated.
+    :param before: The :class:`Role` that updated with the old info.
+    :param after: The :class:`Role` that updated with the updated info
 
 .. function:: on_server_available(server)
               on_server_unavailable(server)
@@ -310,7 +312,7 @@ to handle it, which defaults to print a traceback and ignore the exception.
 
     :param server: The :class:`Server` that has changed availability.
 
-.. function:: on_voice_state_update(member)
+.. function:: on_voice_state_update(before, after)
 
     Called when a :class:`Member` changes their voice state.
 
@@ -321,7 +323,8 @@ to handle it, which defaults to print a traceback and ignore the exception.
     - A member is muted or deafened by their own accord.
     - A member is muted or deafened by a server administrator.
 
-    :param member: The :class:`Member` whose voice state changed.
+    :param before: The :class:`Member` whose voice state changed prior to the changes.
+    :param after: The :class:`Member` whose voice state changed after the changes.
 
 .. function:: on_typing(channel, user, when)
 
@@ -341,6 +344,7 @@ Utility Functions
 
 .. autofunction:: discord.utils.find
 
+.. autofunction:: discord.utils.get
 
 Enumerators
 ------------