Updating database data from websocket - django

Question

I would like to update database data from a websocket. Specifically, when a user connects to a websocket, I would like to update a field in one of my models with the timestamp of when the user connected.
However, with the logic I have implemented, I am getting this error:
Exception inside application: __init__() takes 1 positional argument but 2 were given
Traceback (most recent call last):
File "C:\Users\15512\anaconda3\lib\site-packages\channels\staticfiles.py", line 44, in __call__
return await self.application(scope, receive, send)
File "C:\Users\15512\anaconda3\lib\site-packages\channels\routing.py", line 71, in __call__
return await application(scope, receive, send)
File "C:\Users\15512\anaconda3\lib\site-packages\channels\security\websocket.py", line 37, in __call__
return await self.application(scope, receive, send)
File "C:\Users\15512\Desktop\django-project\peerplatform\signup\middleware.py", line 47, in __call__
return await super().__call__(scope, receive, send)
File "C:\Users\15512\anaconda3\lib\site-packages\channels\middleware.py", line 26, in __call__
return await self.inner(scope, receive, send)
File "C:\Users\15512\anaconda3\lib\site-packages\channels\sessions.py", line 47, in __call__
return await self.inner(dict(scope, cookies=cookies), receive, send)
File "C:\Users\15512\anaconda3\lib\site-packages\channels\sessions.py", line 263, in __call__
return await self.inner(wrapper.scope, receive, wrapper.send)
File "C:\Users\15512\anaconda3\lib\site-packages\channels\auth.py", line 185, in __call__
return await super().__call__(scope, receive, send)
File "C:\Users\15512\anaconda3\lib\site-packages\channels\middleware.py", line 26, in __call__
return await self.inner(scope, receive, send)
File "C:\Users\15512\anaconda3\lib\site-packages\channels\routing.py", line 150, in __call__
return await application(
File "C:\Users\15512\anaconda3\lib\site-packages\channels\consumer.py", line 94, in app
return await consumer(scope, receive, send)
File "C:\Users\15512\anaconda3\lib\site-packages\channels\consumer.py", line 58, in __call__
await await_many_dispatch(
File "C:\Users\15512\anaconda3\lib\site-packages\channels\utils.py", line 51, in await_many_dispatch
await dispatch(result)
File "C:\Users\15512\anaconda3\lib\site-packages\channels\consumer.py", line 73, in dispatch
await handler(message)
File "C:\Users\15512\Desktop\django-project\peerplatform\signup\consumers.py", line 34, in websocket_connect
result = (await self.update_timestamp(group_name))
File "C:\Users\15512\anaconda3\lib\site-packages\asgiref\sync.py", line 414, in __call__
ret = await asyncio.wait_for(future, timeout=None)
File "C:\Users\15512\anaconda3\lib\asyncio\tasks.py", line 455, in wait_for
return await fut
File "C:\Users\15512\anaconda3\lib\concurrent\futures\thread.py", line 57, in run
result = self.fn(*self.args, **self.kwargs)
File "C:\Users\15512\anaconda3\lib\site-packages\channels\db.py", line 13, in thread_handler
return super().thread_handler(loop, *args, **kwargs)
File "C:\Users\15512\anaconda3\lib\site-packages\asgiref\sync.py", line 455, in thread_handler
return func(*args, **kwargs)
File "C:\Users\15512\Desktop\django-project\peerplatform\signup\consumers.py", line 108, in update_timestamp
serializer_class = UpdateProfileView(request)
TypeError: __init__() takes 1 positional argument but 2 were given
This is what I have tried, this is in my consumers.py and is the function called when a user connects to the websocket:
class PracticeConsumer(AsyncWebsocketConsumer):
async def websocket_connect(self, event):
...
group_name = username_id
result = (await self.update_timestamp(group_name))
await self.channel_layer.group_add(
'{}'.format(group_name),
self.channel_name
)
await self.accept()
...
#database_sync_to_async
def update_timestamp(self, user_id):
time = timezone.now().isoformat()
request = dict({'method': 'PUT', 'connected_timestamp': time, 'user.id': self.user_id})
serializer_class = UpdateProfileView(request)
return User.objects.filter(user__id=user_id).values()
This is how my UpdateProfileView is written out:
class UpdateProfileView(generics.UpdateAPIView):
queryset = User.objects.all()
serializer_class = UpdateUserSerializer
def profile(request):
if request.method == 'PUT':
try:
user = User.objects.get(id=request.user.id)
serializer_user = UpdateUserSerializer(user, many=True)
if serializer_user.is_valid():
serializer_user.save()
return Response(serializer_user)
except User.DoesNotExist:
return Response(data='no such user!', status=status.HTTP_400_BAD_REQUEST)

Answer 1

The error is because you need a self in the UpdateProfileView's profile function, like: def profile(self, request):
But! from what I'm seeing they usually use the function update and not profile
Example
Also I updated to use filter().first(), it will return None if it doesn't find one. Try/Catch is sorta gross imo
class UpdateProfileView(generics.UpdateAPIView):
queryset = User.objects.all()
serializer_class = UpdateUserSerializer
def update(self, request, *args, **kwargs):
if request.method == 'PUT':
user = User.objects.filter(id=request.user.id).first()
# # but `request.user` is a User Object!- You don't need to filter for it!
# user = request.user
if user:
serializer_user = UpdateUserSerializer(user, many=True)
if serializer_user.is_valid():
serializer_user.save()
return Response(serializer_user)
else:
return Response(data='no such user!', status=status.HTTP_400_BAD_REQUEST)python