Dynamically include or exclude Serializer class fields

Question

In my User profile model I've included a show_email field explicitly. So, to add this feature to my API, the UserSerializer class looks like this:

class UserSerializer(serializers.ModelSerializer):
    email = serializers.SerializerMethodField('show_email')

    def show_email(self, user):
        return user.email if user.show_email else None

    class Meta:
        model = django.contrib.auth.get_user_model()
        fields = ("username", "first_name", "last_name", "email")

But I don't really like it. I think it would be a lot cleaner if the field email would be completely excluded from the serializer output it show_email is False, instead showing that ugly "email": null thing.

How could I do that?

Answer 1

You could do this in your API view by overriding the method returning the response, i.e. the "verb" of the API view. For example, in a ListAPIView you would override get():

class UserList(generics.ListAPIView):
    model = django.contrib.auth.get_user_model()
    serializer_class = UserSerializer

    def get(self, request, *args, **kwargs):
        response = super(UserList, self).get(request, *args, **kwargs)
        for result in response.data['results']:
            if result['email'] is None:
                result.pop('email')
        return response

You would probably want to add some more checking for attributes, but that's the gist of how it could be done. Also, I would add that removing fields from some results may cause issues for the consuming application if it expects them to be present for all records.