How to fix 'TypeError: __init__() got an unexpected keyword argument 'sender''

Question

I am trying to create a django model instance with a django-rest-framework serializer ModelSerializer class. This is my Serializer code:

class MessageSerializer(serializers.ModelSerializer):
    class Meta:
        model = Message
        fields = ['sender', 'chat_room', 'content', 'sending_date']

and this is my view when I try to make a model instance out of it:

class SendMessage(APIView):
authentication_classes = [authentication.TokenAuthentication]
permission_classes = [permissions.IsAuthenticated]

def post(self, request):
    try:
        message_type = request.data['message_type']

        if message_type == ('text' or 'image' or 'audio'):

            if message_type == 'text':

                message_serializer = MessageSerializer(sender=request.user, chat_room=ChatRoom.objects.get(
                    id=request.data['chat_room_id']), content=MessageContent(text=request.data['text']))
                message = Message(message_serializer.data)

            elif message_type == 'image':
                message = MessageSerializer(sender=request.user.id, chat_room=request.data['chat_room_id'],
                                            content=MessageContent(image=request.FILES['image']))

            elif message_type == 'audio':
                message = MessageSerializer(sender=request.user.id, chat_room=request.data['chat_room_id'],
                                            content=MessageContent(image=request.FILES['image']))

            if message.chat_room.users.all().filter(id=request.user.id).exists():
                message.save()

                if message_type == 'image':
                    resize_photo(message.content.image, MessageContent.image_width, MessageContent.image_height)

                if message_type == 'audio':
                    if (not message.content.name.lower().endswith('mp4')) and os.get_size(message.content) > 25000:
                        message.delete()
                        raise FileSourceError

                message.save()
                return Response(status=status.HTTP_201_CREATED)
            else:
                return Response(status=status.HTTP_401_UNAUTHORIZED)

        else:
            return Response(status=status.HTTP_400_BAD_REQUEST)

    except KeyError or FileSourceError:
        return Response(status=status.HTTP_400_BAD_REQUEST)

This is my message model:

class Message(models.Model):
    sender = models.ForeignKey(User, related_name='sender', on_delete=models.CASCADE)

    chat_room = models.ForeignKey(ChatRoom, related_name='chat_room', on_delete=models.CASCADE)

    content = models.OneToOneField(MessageContent, on_delete=models.CASCADE)

    is_read_by = models.ManyToManyField(User, related_name="is_read_by")

    sending_date = models.DateTimeField(auto_now_add=True)

    class Meta:
        ordering = ('sending_date',)

However, when I run this code, I get

TypeError: init() got an unexpected keyword argument 'sender'

If I delete the sender argument I get

TypeError: init() got an unexpected keyword argument 'chat_room'

and so on. I checked if my ModelSerializer was making the right serializer fields with

print(repr(MessageSerializer()))

in the django python shell, and I got

MessageSerializer():
    sender = PrimaryKeyRelatedField(queryset=User.objects.all())
    chat_room = PrimaryKeyRelatedField(queryset=ChatRoom.objects.all())
    content = PrimaryKeyRelatedField(queryset=MessageContent.objects.all(), validators=[<UniqueValidator(queryset=Message.objects.all())>])
    sending_date = DateTimeField(read_only=True)

which means that my serializer has these fields (sender, chat_room, etc.) Why do I get this error and how do I fix this? Thank you for your time!

Solution

You are supposed to pass a Message model instance to MessageSerializer or a dict containing data with the keys specified in fields.

In case you want to pass a dict, pass the dict to data keyword.

message_dict = {'sender': request.user, 'chat_room': ChatRoom.objects.get(id=request.data['chat_room_id']), 'content': MessageContent(text=request.data['text'])}
message_serializer = MessageSerializer(data=message_dict)

if message_serializer.is_valid():
    message_serializer.save()

Make sure you have create method implemented in your MessageSerializer.