From bc8b25eb56bf4fcec3546c2ea28741189a519da5 Mon Sep 17 00:00:00 2001
From: Mark Haines <mark.haines@matrix.org>
Date: Wed, 9 Sep 2015 15:42:16 +0100
Subject: [PATCH] Allow users that have left the room to view the member list
 from the point they left

---
 synapse/handlers/room.py           | 36 ------------------------------
 synapse/rest/client/v1/room.py     | 18 ++++++++++-----
 tests/rest/client/v1/test_rooms.py |  4 ++--
 3 files changed, 15 insertions(+), 43 deletions(-)

diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index c5d1001b50..0ff816d53e 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -25,7 +25,6 @@ from synapse.api.constants import (
 from synapse.api.errors import StoreError, SynapseError
 from synapse.util import stringutils, unwrapFirstError
 from synapse.util.async import run_on_reactor
-from synapse.events.utils import serialize_event
 
 from collections import OrderedDict
 import logging
@@ -342,41 +341,6 @@ class RoomMemberHandler(BaseHandler):
                 if remotedomains is not None:
                     remotedomains.add(member.domain)
 
-    @defer.inlineCallbacks
-    def get_room_members_as_pagination_chunk(self, room_id=None, user_id=None,
-                                             limit=0, start_tok=None,
-                                             end_tok=None):
-        """Retrieve a list of room members in the room.
-
-        Args:
-            room_id (str): The room to get the member list for.
-            user_id (str): The ID of the user making the request.
-            limit (int): The max number of members to return.
-            start_tok (str): Optional. The start token if known.
-            end_tok (str): Optional. The end token if known.
-        Returns:
-            dict: A Pagination streamable dict.
-        Raises:
-            SynapseError if something goes wrong.
-        """
-        yield self.auth.check_joined_room(room_id, user_id)
-
-        member_list = yield self.store.get_room_members(room_id=room_id)
-        time_now = self.clock.time_msec()
-        event_list = [
-            serialize_event(entry, time_now)
-            for entry in member_list
-        ]
-        chunk_data = {
-            "start": "START",  # FIXME (erikj): START is no longer valid
-            "end": "END",
-            "chunk": event_list
-        }
-        # TODO honor Pagination stream params
-        # TODO snapshot this list to return on subsequent requests when
-        # paginating
-        defer.returnValue(chunk_data)
-
     @defer.inlineCallbacks
     def change_membership(self, event, context, do_auth=True):
         """ Change the membership status of a user in a room.
diff --git a/synapse/rest/client/v1/room.py b/synapse/rest/client/v1/room.py
index c9c27dd5a0..f4558b95a7 100644
--- a/synapse/rest/client/v1/room.py
+++ b/synapse/rest/client/v1/room.py
@@ -290,12 +290,18 @@ class RoomMemberListRestServlet(ClientV1RestServlet):
     def on_GET(self, request, room_id):
         # TODO support Pagination stream API (limit/tokens)
         user, _ = yield self.auth.get_user_by_req(request)
-        handler = self.handlers.room_member_handler
-        members = yield handler.get_room_members_as_pagination_chunk(
+        handler = self.handlers.message_handler
+        events = yield handler.get_state_events(
             room_id=room_id,
-            user_id=user.to_string())
+            user_id=user.to_string(),
+        )
 
-        for event in members["chunk"]:
+        chunk = []
+
+        for event in events:
+            if event["type"] != EventTypes.Member:
+                continue
+            chunk.append(event)
             # FIXME: should probably be state_key here, not user_id
             target_user = UserID.from_string(event["user_id"])
             # Presence is an optional cache; don't fail if we can't fetch it
@@ -308,7 +314,9 @@ class RoomMemberListRestServlet(ClientV1RestServlet):
             except:
                 pass
 
-        defer.returnValue((200, members))
+        defer.returnValue((200, {
+            "chunk": chunk
+        }))
 
 
 # TODO: Needs unit testing
diff --git a/tests/rest/client/v1/test_rooms.py b/tests/rest/client/v1/test_rooms.py
index 34ab47d02e..d50cfe4298 100644
--- a/tests/rest/client/v1/test_rooms.py
+++ b/tests/rest/client/v1/test_rooms.py
@@ -492,9 +492,9 @@ class RoomsMemberListTestCase(RestTestCase):
         self.assertEquals(200, code, msg=str(response))
 
         yield self.leave(room=room_id, user=self.user_id)
-        # can no longer see list, you've left.
+        # can see old list once left
         (code, response) = yield self.mock_resource.trigger_get(room_path)
-        self.assertEquals(403, code, msg=str(response))
+        self.assertEquals(200, code, msg=str(response))
 
 
 class RoomsCreateTestCase(RestTestCase):