Django Rest Framework, add object to request.data and then call serializer is_valid()

Question

I\'m wondering which is the best way to solve this, I have a nested serializer like this:

serializers.py:

class PaymentMethodSerializer(serializers.Model         


        

Answer 1

Suppose payment_type is ForeignKey field in a PaymentMethod model, with null=True because of required=False.
If you provide only a pk so you don't need serializer for it field, you can just write in fields, like all other fields.

class PaymentMethodSerializer(serializers.ModelSerializer):

    data = serializers.JSONField()

    class Meta:
        model = PaymentMethod
        fields = ('data', 'payment_type')

It will accept pk or None. If you want to provide special representation for your PaymentType model, you can override a to_representation() method.

class PaymentMethodSerializer(serializers.ModelSerializer):

    ...
    def to_representation(self, instance):
        representation = super(PaymentMethodSerializer, self).to_representation(instance)
        representation['payment_type'] = PaymentTypeSerializer(instance.payment_type).data
        return representation

Now it will use PaymentTypeSerializer for representation of related PaymentType model.
You can move you payment_type validation in a serializer though. Override to_internal_value, check provided PaymentType pk and throw an exception if it wrong and then catch that exception in a view.