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Django Rest Framework - creating without providing a foreign key value

I am building my first API with the Django-Rest-Framework and I am a bit stuck in the validation process. Hope this is a simple answer, but I could not understand it from a 6-part tutorial ...

I have a model:

class XYZMeta(models.Model):
    id = models.AutoField(primary_key=True)
    xyz_id = models.ForeignKey(XYZ)
    user_id = models.ForeignKey(User)
    field_name = models.CharField(blank=True, max_length=50)
    value = models.TextField(blank=True)

And serializer:

class XYZMetaSerializer(serializers.ModelSerializer):
    class Meta:
        model = XYZMeta
        fields = ('id', 'xyz_id', 'user_id', 'field_name', 'value')

And the view:

class XYZMetaViewSet(viewsets.ModelViewSet):
    """
    API endpoint that allows xyz metadata to be viewed or edited.
    """
    queryset = XYZMeta.objects.all()
    serializer_class = serializers.XYZMetaSerializer

    def perform_create(self, serializer):
        serializer.save(user_id=self.request.user)

When I send POST to create a new object, it works fine and uses the identifier of the authorized user, and not any value that I provide. Example:

> curl -X POST -H "Content-Type:application/json" -d '{"xyz_id":"12345",**"user_id":2**,"field_name":"abc","value":"abc comment"}' -u admin:admin http://mysite/xyzmeta/
{"id":2,"dealer_id":12345,**"user_id":1**,"field_name":"abc","value":"abc comment","create_date":"2015-02-22T23:32:27.928991Z"}

However, if I completely leave user_id (since it does not matter), I get the error message that is required for this field:

> curl -X POST -H "Content-Type:application/json" -d '{"xyz_id":"12345","field_name":"abc","value":"abc comment"}' -u admin:admin http://mysite/xyzmeta/
{"user_id":["This field is required."]}

How do I indicate that I want the user_id foreign key fields to be set programmatically during the creation process, and not need to provide a dummy value?

+4
3

: user_id

class XYZMetaSerializer(serializers.ModelSerializer):
    class Meta:
        model = XYZMeta
        fields = ('id', 'xyz_id', 'user_id', 'field_name', 'value')
        extra_kwargs = {
            'user_id': {'required': False}
        }

: alter request.data get_serializer(data=request.data).

class XYZMetaViewSet(viewsets.ModelViewSet):
    """
    API endpoint that allows xyz metadata to be viewed or edited.
    """
    queryset = XYZMeta.objects.all()
    serializer_class = serializers.XYZMetaSerializer

    def create(self, request, *args, **kwargs):
        request.data['user_id'] = request.user.id
        return super(self.__class__, self).create(request, *args, **kwargs)
+4

required=False user_id?

... - !

class XYZMetaSerializer(serializers.ModelSerializer):
    user_id = serializers.RelatedField(source='user_id', required=False)

    class Meta:
        [...]
+1

user_id , ViewSet perform_create:

class XYZMetaViewSet(viewsets.ModelViewSet):
    """
    API endpoint that allows xyz metadata to be viewed or edited.
    """
    queryset = XYZMeta.objects.all()
    serializer_class = serializers.XYZMetaSerializer

    def perform_create(self, serializer):
        serializer.save(user=self.request.user)
0

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