[BUG] got an unexpected keyword argument 'instance'

[Maciek Niemczyk]

Describe the bug
The lib fails to instantiate and transmit the object
It fails with the error:
raise TypeError("%s() got an unexpected keyword argument '%s'" % (cls.name, kwarg))
TypeError: Economics() got an unexpected keyword argument 'instance'

To Reproduce
Steps to reproduce the behavior:
Adopt first example like consumer.py:

class LiveConsumer(ListModelMixin, GenericAsyncAPIConsumer):
    queryset = models.Economics.objects.all()
    serializer_class = serializers.Economics
    permission_classes = (permissions.IsAuthenticated,)

index.hml script:

    const request_id = "{{ request.sessions.session_key }}";

    const liveSocket = new WebSocket(
        'ws://'
        + window.location.host
        + '/ws/project/'
    );

    liveSocket.onopen = function() {
        console.log('WebSockets connection onopen');
        liveSocket.send(JSON.stringify({
            action: "list",
            request_id: request_id,
        }));
    };

model.py:

class Economics(models.Model):
    time_stamp = models.DateTimeField()
    cost_capex = models.DecimalField(
        max_digits=20, decimal_places=4, default=None, null=True
    )
 ... WITHOUT INIT

serializer:

class EconomicsSerializer(serializers.ModelSerializer):
    class Meta:
        model = Economics
        exclude = []
        depth = 1

and routing.py:

websocket_urlpatterns = [
    re_path(r"ws/project/$", consumers.LiveConsumer.as_asgi()),
]

Expected behavior
the result of the table is passed as list over the websocet to index.html

LOG

30/03/2022 14:29:26 [ERROR] daphne.server: Exception inside application: Economics() got an unexpected keyword argument 'instance'
Traceback (most recent call last):
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/staticfiles.py", line 44, in __call__
    return await self.application(scope, receive, send)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/routing.py", line 71, in __call__
    return await application(scope, receive, send)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/sessions.py", line 47, in __call__
    return await self.inner(dict(scope, cookies=cookies), receive, send)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/sessions.py", line 263, in __call__
    return await self.inner(wrapper.scope, receive, wrapper.send)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/auth.py", line 185, in __call__
    return await super().__call__(scope, receive, send)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/middleware.py", line 26, in __call__
    return await self.inner(scope, receive, send)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/routing.py", line 150, in __call__
    return await application(
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/consumer.py", line 94, in app
    return await consumer(scope, receive, send)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/consumer.py", line 58, in __call__
    await await_many_dispatch(
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/utils.py", line 51, in await_many_dispatch
    await dispatch(result)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/consumer.py", line 73, in dispatch
    await handler(message)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/generic/websocket.py", line 194, in websocket_receive
    await self.receive(text_data=message["text"])
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/generic/websocket.py", line 257, in receive
    await self.receive_json(await self.decode_json(text_data), **kwargs)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/djangochannelsrestframework/consumers.py", line 180, in receive_json
    await self.handle_action(action, request_id=request_id, **content)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/djangochannelsrestframework/consumers.py", line 175, in handle_action
    await self.handle_exception(exc, action=action, request_id=request_id)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/djangochannelsrestframework/consumers.py", line 135, in handle_exception
    raise exc
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/djangochannelsrestframework/consumers.py", line 168, in handle_action
    response = await method(request_id=request_id, action=action, **kwargs)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/djangochannelsrestframework/decorators.py", line 85, in async_f
    result, status = await database_sync_to_async(func)(self, *args, **_kwargs)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/asgiref/sync.py", line 414, in __call__
    ret = await asyncio.wait_for(future, timeout=None)
  File "/opt/homebrew/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/asyncio/tasks.py", line 442, in wait_for
    return await fut
  File "/opt/homebrew/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/lib/python3.9/concurrent/futures/thread.py", line 58, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/channels/db.py", line 13, in thread_handler
    return super().thread_handler(loop, *args, **kwargs)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/asgiref/sync.py", line 455, in thread_handler
    return func(*args, **kwargs)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/djangochannelsrestframework/mixins.py", line 139, in list
    serializer = self.get_serializer(
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/djangochannelsrestframework/generics.py", line 128, in get_serializer
    return serializer_class(*args, **kwargs)
  File "/Users/maciek/programming/suena/Python/suena/lib/python3.9/site-packages/django/db/models/base.py", line 507, in __init__
    raise TypeError("%s() got an unexpected keyword argument '%s'" % (cls.__name__, kwarg))
TypeError: Economics() got an unexpected keyword argument 'instance'
30/03/2022 14:29:26 [DEBUG] daphne.ws_protocol: WebSocket closed for ['127.0.0.1', 53218]
30/03/2022 14:29:26 [INFO] django.channels.server: WebSocket DISCONNECT /ws/project/ [127.0.0.1:53218]

• OS: [e.g. Ubuntu]
  -macOS
• Version [e.g. 18.04]
  Monterey

Additional context
By the way, the error is independent from the model (which is implied by the error massage) - It happens no matter which Model I try to use:

raise TypeError("%s() got an unexpected keyword argument '%s'" % (cls.__name__, kwarg))
TypeError: Preset() got an unexpected keyword argument 'instance'

[Matthaus Woolard]

@Macilias sorry for the delay to get back to you on this.

looking over your code it looks like your referencing the the model Economics as the serializer_class rather than EconomicsSerializer

your consumer should be:

class LiveConsumer(ListModelMixin, GenericAsyncAPIConsumer):
    queryset = models.Economics.objects.all()
    serializer_class = serializers.EconomicsSerializer
    permission_classes = (permissions.IsAuthenticated,)