In so far as you are talking about background worker tasks, you are correct.
But those statements do not pertain to a websocket consumer that accepts connections from a browser. You can run an application without ever creating a worker task. (Again, I'll refer you to the channels-examples app for such a demonstration.) Ken On Sunday, February 25, 2018 at 5:04:13 AM UTC-5, muha...@swordfish.co.za wrote: > > While I'm at it, would you mind confirming if I understand the following > changes in channels 2.0 correctly ? > > 1) Channel names are not auto-detected and must be specified when running > a worker > 2) *runserver* no long starts up a worker by default, this has be done > manually > > On Sunday, February 25, 2018 at 2:56:45 AM UTC+2, muha...@swordfish.co.za > wrote: >> >> I'm still trying to find my way around channels 2.0, so I'm not sure if >> my implementation is incorrect or if this is a valid issue. I'm going to >> post as much info as possible in the hope that it will assist with finding >> the problem. >> >> I have a single page app which opens a JS websocket connection - with >> channels 1 I used to add a *session_key *to the querystring and that >> used to handle the authentication. >> >> I see this is no longer the case, so I now have a custom middleware class >> that sets the user object on the scope: >> >> from django.contrib.sessions.models import Session >> >> from users.models import User >> >> >> class QueryAuthMiddleware: >> >> def __init__(self, inner): >> # Store the ASGI application we were passed >> self.inner = inner >> >> def __call__(self, scope): >> # Look up user from query string (you should also do things like >> # check it's a valid user ID, or if scope["user"] is already >> populated) >> if scope.get("user", None) is None: >> session_obj = >> Session.objects.get(session_key=scope["query_string"].decode("utf-8").split("=")[1]) >> session_decoded = session_obj.get_decoded() >> >> scope["user"] = >> User.objects.get(id=session_decoded.get("_auth_user_id")) >> >> # Return the inner application directly and let it run >> everything else >> return self.inner(scope) >> >> >> >> >> This is in turn added to my routing (channels.py): >> >> from django.conf.urls import url >> from django.conf import settings >> from channels.routing import ProtocolTypeRouter, URLRouter, ChannelNameRouter >> >> from notifications.consumer import TestWebsocketConsumer, TestConsumer >> from notifications.middleware.query_auth_middleware import >> QueryAuthMiddleware >> >> ROOT_PATH = "" if settings.DEBUG else "/ws/" >> >> >> application = ProtocolTypeRouter({ >> >> "websocket": QueryAuthMiddleware( >> URLRouter([ >> url(f"^{ROOT_PATH}(?P<user_id>[-\w]+)/$", TestWebsocketConsumer), >> >> ]) >> ), >> >> "channel": ChannelNameRouter({ >> "user-notifications": TestConsumer, >> }) >> >> >> }) >> >> >> >> >> >> Here's my *consumers.py*: >> >> from asgiref.sync import async_to_sync >> from channels.consumer import SyncConsumer >> from channels.generic.websocket import WebsocketConsumer >> >> >> class TestWebsocketConsumer(WebsocketConsumer): >> def websocket_connect(self, message): >> >> async_to_sync(self.channel_layer.group_add)(str(self.scope["user"].id), >> "user-notifications") >> self.connect() >> >> >> class TestConsumer(SyncConsumer): >> def notification_handler(self, message): >> >> self.send( >> { >> "type": "websocket.send", >> "text": message["text"] >> } >> ) >> >> >> >> >> >> >> The idea of the app is that each user that logs in on the front end is >> able to receive messages meant only for them sent by the back end. I have >> been trying to test it like this: >> >> >>> channel_layer = get_channel_layer() >> >>> async_to_sync(channel_layer.send)("user-notifications", {"type": >> >>> "notification.handler", "text": "My Message"}) >> >> >> >> >> Here's the traceback in the *runworker* output: >> >> 2018-02-25 02:34:14,002 - INFO - runworker - Running worker for channels >> ['user-notifications'] >> ERROR:root:Exception inside application: You must implement >> application_send() >> File >> "/Users/muhammed/projects/xxx/lib/python3.6/site-packages/channels/consumer.py", >> >> line 54, in __call__ >> await await_many_dispatch([receive, self.channel_receive], >> self.dispatch) >> File >> "/Users/muhammed/projects/xxx/lib/python3.6/site-packages/channels/utils.py", >> >> line 48, in await_many_dispatch >> await dispatch(result) >> File >> "/Users/muhammed/projects/xxx/lib/python3.6/site-packages/asgiref/sync.py", >> line 110, in __call__ >> return await asyncio.wait_for(future, timeout=None) >> File >> "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/asyncio/tasks.py", >> >> line 333, in wait_for >> return (yield from fut) >> File >> "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/concurrent/futures/thread.py", >> >> line 55, in run >> result = self.fn(*self.args, **self.kwargs) >> File >> "/Users/muhammed/projects/xxx/lib/python3.6/site-packages/channels/db.py", >> line 13, in thread_handler >> return super().thread_handler(loop, *args, **kwargs) >> File >> "/Users/muhammed/projects/xxx/lib/python3.6/site-packages/asgiref/sync.py", >> line 125, in thread_handler >> return self.func(*args, **kwargs) >> File >> "/Users/muhammed/projects/xxx/lib/python3.6/site-packages/channels/consumer.py", >> >> line 99, in dispatch >> handler(message) >> File >> "/Users/muhammed/projects/xxx/my-app/app/notifications/consumer.py", line >> 18, in notification_handler >> "text": message["text"] >> File >> "/Users/muhammed/projects/xxx/lib/python3.6/site-packages/channels/consumer.py", >> >> line 107, in send >> self.base_send(message) >> File >> "/Users/muhammed/projects/xxx/lib/python3.6/site-packages/asgiref/sync.py", >> line 64, in __call__ >> return call_result.result() >> File >> "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/concurrent/futures/_base.py", >> >> line 405, in result >> return self.__get_result() >> File >> "/usr/local/Cellar/python3/3.6.1/Frameworks/Python.framework/Versions/3.6/lib/python3.6/concurrent/futures/_base.py", >> >> line 357, in __get_result >> raise self._exception >> File >> "/Users/muhammed/projects/xxx/lib/python3.6/site-packages/asgiref/sync.py", >> line 78, in main_wrap >> result = await self.awaitable(*args, **kwargs) >> File >> "/Users/muhammed/projects/xxx/lib/python3.6/site-packages/asgiref/server.py", >> >> line 71, in application_send >> raise NotImplementedError("You must implement application_send()") >> You must implement application_send() >> >> >> OS: MacOS High Sierra >> Python: 3.6.1 >> >> Django==2.0.2 >> channels==2.0.2 >> channels-redis==2.1.0 >> asgiref==2.1.6 >> daphne==2.0.4 >> >> Config from *settings.py:* >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> *# -- Channels DetailsCHANNEL_LAYERS = { "default": { "BACKEND": >> "channels_redis.core.RedisChannelLayer", "CONFIG": { "hosts": >> [("localhost", 6379)] } }}ASGI_APPLICATION = >> "myapp.settings.channels.application"* >> >> Any help would be appreciated. >> >> -- You received this message because you are subscribed to the Google Groups "Django users" group. 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