使用django rest框架时，如何强制将用户ID作为值？

Question

I want my rest api to be able to add objects, but there is a twist.

My model has a field that's called user which can either be None for anonymous users or the id of whoever sets it.

How can I enforce this in an elegant way?

Also if the user field is None I want the id of the new object to be stored in an array in the anonymous users session so it can be assigned if he ever decides to register.

Here is how I created the viewset:

class PointAPIView(viewsets.ModelViewSet):
    queryset = Point.objects.all()
    serializer_class = PointSerializer
    permission_classes = (IsOwnerOrReadOnly,)

I suspect that I have to write a custom create method is that right? If so how does it need to look like? The documentation only says that it's there, but not how it needs to be structured and what it needs to return. Can you show me an example of a dummy method where I can put my logic?

Thank you for your time!

EDIT: Because someone asked. The Model would look something like this:

class Point(models.Model):
  user = models.ForeignKey('auth.User')
  value = models.IntegerField()

Now the question is how I can force the user field to be request.user when creating a point object via the rest api.

Answer 1

In your PointSerializer override create method and get request object to extract current user and assign it to created point.

class PointSerializer(serializers.ModelSerializer):
     //point fields

    class Meta:
          model = Point
          fields = ('value','user')

    def create(self,validated_data):
        request = request = self.context['request']
        user = request.user
        point = Point.objects.create(value=validated_data['value'])
        point.user = user
        point.save()
        return point

Answer 2

not sure if you can nodify validated_data , if not you'd need to copy it over

def create(self, validated_data):
    request = self.context['request']
    user = request.user

    if user.is_authenticated():
        validated_data.update({
            'user': user.id
        })

    point = Point.objects.create(**validated_data)

    return point