Fetch realm emoji in initial register call & update using events

[neiljp]

We have preliminary support for realm emoji (custom emoji specific to an organization) via #710, but this has a few caveats (though perhaps minor, depending on the frequency of adding custom emoji vs each ZT session):

• We don't update the realm emoji ZT is aware of, using events available from the server
• We fetch using an API call after initial register, so even if we had updates, we might miss them between the two points - we should really just grab them out of the initial register() call (initial_data) instead

Working on this issue is a fairly good introduction to how the Zulip events API works. You'll likely want to review the events in the zulip documentation and existing code in model.py, which is where event handling occurs.

[mkp6781]

I am new to the codebase and this is my first issue.
From what I have understood, these are the changes I intend to make:

• add "realm_emoji" to fetch_event_types list
• change line 148 in __init__ models.py from custom_emoji_data = self.fetch_custom_emojis() to
  custom_emoji_data = self.initial_data['realm_emoji']

When a client starts up, a call to _update_initial_data()is made which in turn calls _register_desired_events() Here the list of events in fetch_event_types() gets registered to the event queue. Finally the initial_data is updated with values in the returned response .
Please correct me if I've gone wrong.

[neiljp]

@mkp6781 What you've described should replace the existing code and is related to the first part of this issue (title - the second bullet).

The second part (of title, the first bullet) - "update using events" - requires an event handler for that event type to update them as emoji are added and removed on the server, so that the application retains a current list.

[mkp6781]

 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)

This is the event handler code. However when I run pytest, it gives me a 'key error' saying no key 'realm_emoji'. Should I make any more changes to pass the tests?

[neiljp]

The Event type likely doesn't have that key at this point. You also should check whether it should have that key, based on the different types of events available from the Zulip API.

https://zulip.com/api/get-events#realm_emoji-update

You're just quoting a function here so I'm not sure what else you've written, but note that this method won't be triggered unless you map the function to the name of the event type, as with the other event handlers.

Also note that you likely need to adjust the event data to understand what change to make to the emoji data.

[mkp6781]

Pull request. #825

[mkp6781]

Pull request #827

[Ezio-Sarthak]

Hi @neiljp I am new to the codebase and this is my first issue. Could you please elaborate a bit what the issue is?

[mkp6781]

I have updated the pr. #827
Please do have a look and suggest any more changes that may be necessary.

[mkp6781]

@zulipbot claim

[neiljp]

@Ezio-Sarthak Someone is already working on this right now - have a look at other issues, explore the application and see what you think could be improved, and come and have a chat on chat.zulip.org in #zulip-terminal :)