Gfrktyl

I have project on Django wich use Django Channels. I use Django Channel for sending notifications to users who are subscribed to articles changes (adding/editing/deleting comments on article).

So I've chosen this way of realization: every group of channels is an article and when changes happen, script sends notification to relevant groups. My code works correctly but I have some doubts if my choice of way of realization is most appropriate for this task. I need advice what is the best practice in my case?

Solution:

consumers.py

from channels.generic.websocket import AsyncJsonWebsocketConsumer

from channels.db import database_sync_to_async

from project.apps.account.models import UserStatus

from .models import CommentSubscribe





class CommentNotificationConsumer(AsyncJsonWebsocketConsumer):



    async def connect(self):

        await self.accept()

        if not self.scope['user'].is_anonymous:

            groups = await database_sync_to_async(self.get_users_subscription)()

            await database_sync_to_async(self.change_user_status)(True)

            await self.add_subscriptions(groups)



    async def add_subscriptions(self, groups):

        for group in groups:

            await self.channel_layer.group_add(

                'article_{0}'.format(group.article_id),

                self.channel_name

            )



    async def receive_json(self, content, **kwargs):

        command = content.get('command', None)

        article_id = content.get('article_id', None)

        if command == 'subscribe':

            await self.subscribe(article_id)

        elif command == 'unsubscribe':

            await self.unsubscribe(article_id)

        else:

            await self.send_json({

                'error': 'unknown command'

            })



    async def disconnect(self, code):

        await database_sync_to_async(self.change_user_status)(False)



    async def send_notification(self, action):

        await self.send_json(action)



    async def subscribe(self, article_id):

        await self.channel_layer.group_add(

            'article_{0}'.format(article_id),

            self.channel_name

        )



    async def unsubscribe(self, article_id):

        await self.channel_layer.group_discard(

            'article_{0}'.format(article_id),

            self.channel_name

        )



    def get_users_subscription(self):

        return CommentSubscribe.objects.filter(

            user=self.scope['user']

        )



    def change_user_status(self, online):

        return UserStatus.objects.filter(

            user=self.scope['user']

        ).update(online=online)

views.py

from .notify import send_comment_notification



class CreateComment(CreateView):



    ...



    def form_valid(self, form):

        ...

        super().form_valid(form)

        send_comment_notification('create', article_id)





class UpdateComment(UpdateView):



    ...



    def form_valid(self, form):

        ...

        super().form_valid(form)

        send_comment_notification('update', article_id)





class DeleteComment(DeleteView):



    ...



    def delete(self, request, *args, **kwargs):

        ...

        send_comment_notification('delete', article_id)

notify.py

...



def send_comment_notification(action, article_id):

    channel_layer = get_channel_layer()

    group_name = 'article_{0}'.format(article_id)

    async_to_sync(channel_layer.group_send)(

        group_name,

        {

            'type': 'send.notification',

            'data': {

                'action': action

            }

        }

    )