model: Add event handling for realm emoji.

This commit adds event handler for update of realm emoji within a
ZT session. The generate_all_emoji_data() function unpacks the three
emoji dictionaries in the priority order given by
zulip extra emoji>realm emoji>unicode emoji

Tests added.

Fixes #809

Author: mkp6781

tests/model/test_model.py

@@ -177,6 +177,7 @@ def test_register_initial_desired_events(self, mocker, initial_data):
             'subscription',
             'typing',
             'update_message_flags',
+            'realm_emoji',
         ]
         fetch_event_types = [
             'realm',
@@ -2033,6 +2034,45 @@ def test_process_realm_emoji_data(self, mocker, model,
 
         assert fetched_custom_emojis == custom_emojis
 
+    @pytest.mark.parametrize('response', [
+        ({
+            "last_event_id": -1,
+            "msg": "",
+            "queue_id": "1517975029:0",
+            "realm_emoji": {
+                "100": {
+                    "id": "100",
+                    "name": "urwid",
+                    "deactivated": True
+                },
+                "1": {
+                    "id": "1",
+                    "name": "green_tick",
+                    "deactivated": False
+                },
+                "202020": {
+                    "id": "202020",
+                    "name": "joker",
+                    "deactivated": True
+                },
+            },
+            "result": "success",
+            "zulip_feature_level": 2,
+            "zulip_version": "2.1.0"
+        })
+    ])
+    def test__handle_update_emoji_event(self, mocker, model,
+                                        response):
+        model._handle_update_emoji_event(response)
+        # For an already active emoji which has been deactivated
+        with pytest.raises(KeyError):
+            model.active_emoji_data['urwid']
+        # For a newly created custom emoji.
+        new_added_emoji = model.active_emoji_data['green_tick']['code']
+        assert new_added_emoji == response['realm_emoji']['1']['id']
+        # For deactivated custom emoji with same name as unicode emoji
+        assert model.active_emoji_data['joker']['type'] == 'unicode_emoji'
+
     # Use LoopEnder with raising_event to cause the event loop to end without
     # processing the event
     class LoopEnder(Exception):

zulipterminal/model.py

@@ -105,6 +105,7 @@ def __init__(self, controller: Any) -> None:
             ('subscription', self._handle_subscription_event),
             ('typing', self._handle_typing_event),
             ('update_message_flags', self._handle_update_message_flags_event),
+            ('realm_emoji', self._handle_update_emoji_event),
         ])  # type: OrderedDict[str, Callable[[Event], None]]
 
         self.initial_data = {}  # type: Dict[str, Any]
@@ -1135,6 +1136,15 @@ def _handle_update_message_flags_event(self, event: Event) -> None:
             set_count(list(message_ids_to_mark & indexed_message_ids),
                       self.controller, -1)
 
+    def _handle_update_emoji_event(self, event: Event) -> None:
+        """
+        Handle update of emoji
+        """
+        realm_emoji_update = event['realm_emoji']
+        all_emoji_data = self.generate_all_emoji_data(realm_emoji_update)
+        self.active_emoji_data = OrderedDict(sorted(all_emoji_data.items(),
+                                                    key=lambda e: e[0]))
+
     def _update_rendered_view(self, msg_id: int) -> None:
         """
         Helper method called by various _handle_* methods