model: Fetch emoji using events

Fetching emoji using events ensures that emoji updates are not missed.
Initial state of emoji is updated from initial_data.

Author: mkp6781

zulipterminal/model.py

@@ -53,7 +53,9 @@
     'stream_id': int,
     'stream_ids': List[int],  # NOTE: replaces 'stream_id' in ZFL 35 for peer*
     'value': bool,
-    'message_ids': List[int]  # Present when subject of msg(s) is updated
+    'message_ids': List[int],  # Present when subject of msg(s) is updated
+    # realm emoji:
+    'realm_emoji': Dict[str, Any]
 }, total=False)  # Each Event will only have a subset of these
 
 EditPropagateMode = Literal['change_one', 'change_all', 'change_later']
@@ -103,6 +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]
@@ -145,7 +148,7 @@ def __init__(self, controller: Any) -> None:
         for name, data in unicode_emoji_data.items():
             data['type'] = 'unicode_emoji'
         typed_unicode_emoji_data = cast(NamedEmojiData, unicode_emoji_data)
-        custom_emoji_data = self.fetch_custom_emojis()
+        custom_emoji_data = self.initial_data['realm_emoji']
         zulip_extra_emoji = {
                 'zulip': {'code': 'zulip', 'type': 'zulip_extra_emoji'}
         }  # type: NamedEmojiData
@@ -1086,6 +1089,13 @@ 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_emojis = event['realm_emoji']
+        self.active_emoji_data.update(realm_emojis)
+
     def _update_rendered_view(self, msg_id: int) -> None:
         """
         Helper method called by various _handle_* methods
@@ -1143,6 +1153,7 @@ def _register_desired_events(self, *, fetch_data: bool=False) -> str:
             'muted_topics',
             'realm_user',  # Enables cross_realm_bots
             'realm_user_groups',
+            'realm_emoji',
             # zulip_version and zulip_feature_level are always returned in
             # POST /register from Feature level 3.
             'zulip_version',