django rest framework - how do you flatten nested data?

Question

I have a \'through\' model governing a many to many relationship and i want to be able to return the \'through\' model and the target model as flat data, as opposed to havin

Answer 1

combining ekuusela's answer and this example from the DRF documentatation, you can also control which fields (from the nested object) you want to display.
Your serializer would look like this

class UserDetailsSerializer(serializers.ModelSerializer):
    """User model with Profile. Handled as a single object, profile is flattened."""

    profile = ProfileSerializer()

    def __init__(self, *args, **kwargs):
        self.allow_fields = kwargs.pop('fields', None)
        super(ProfileSerializer, self).__init__(*args, **kwargs)

    class Meta:
        model = User
        fields = ('username', 'email', 'profile')

    def to_representation(self, instance):
        representation = super().to_representation(instance)
        profile_representation = representation.pop('profile')
        representation.update(profile_representation)

        if self.allow_fields is not None:
            # Drop any fields that are not specified in the `fields` argument.
            allowed = set(self.allow_fields)
            existing = set(representation)
            for field_name in existing - allowed:
                representation.pop(field_name)
        return representation

And you would instantiate your Serializer as if it was only a singe Model

serializer = UserDetailsSerializer(user, fields=('username', 'email','profile_field1', 'profile_field2'))