Subscription to tasks and listening on / instead of /task-id

[dmfigol]

Awesome project, kudos.
It would be great if the client could create a single WebSocket connection to / instead of /task-id, subscribe to task or tasks and then receive events.

[jjl]

That would be nice.

We don't actually use wscelery anymore since we stopped using celery, but we'd be happy to take patches.

[kalouantonis]

I agree with you, this was on our project roadmap before we moved away from celery.

If you'd like to have a look, you'd need to handle messages in the on_message handler here: https://github.com/johan-sports/wscelery/blob/master/wscelery/websocket.py#L43, removing task_id from the parameters expected here https://github.com/johan-sports/wscelery/blob/master/wscelery/websocket.py#L39 and moving the code that adds the event listener here https://github.com/johan-sports/wscelery/blob/master/wscelery/websocket.py#L41

I was thinking something along the lines of:

class WebSocketHandler(tornado.websocket.WebSocketHandler):
    def initialize(self, events, allow_origin=None):
        self.events = events
        self.listeners = []
        self.allow_origin = allow_origin

    def check_origin(self, origin):
        if not self.allow_origin:
            return super().check_origin(origin)
        match = re.match(self.allow_origin, origin)
        return match is not None

    def _handle_event(self, event):
        self.write_message(parse_event(event))


    def on_message(self, task_id):
        self.listeners.append(task_id)
        self.events.add_listener(task_id, self._handle_event)
       
    def on_close(self):
        map(self.events.remove_listener, self.listeners)

I don't have time to make these changes and test that the behaviour works as expected, but PR's are more than welcome.

[soer7022]

@kalouantonis what are you using instead of Celery? I find that all of the frontends for Celery are hopelessly outdated...

[antoniskalou]

Hey @soer7022, I'm using elixir/erlang nowadays to complete the same tasks without the need for a framework so to speak.

I'd be happy to add maintainers to this project, if anyone is interested, and if @johan-sports agrees.