Can to_representation() in Django Rest Framework access the normal fields

Question

The docs on using to_representation is somewhat short. This method is used by Django Rest Framework 3.0+ to change the representation of your data in an API.

Here' the documentation link:

http://www.django-rest-framework.org/api-guide/serializers/#overriding-serialization-and-deserialization-behavior

Here is my current code:

from django.forms.models import model_to_dict  class PersonListSerializer(serializers.ModelSerializer):      class Meta:         model = Person         fields = ('foo', 'bar',)      def to_representation(self, instance):         return model_to_dict(instance) 

When I do this code, it returns all fields in the model instead of the fields that I have specified above in class Meta: fields.

Is it possible to reference the class Meta: fields within the to_representation method?

Answer 1

DRF's ModelSerializer already has all the logic to handle that. In your case you shouldn't even need to customize to_representation. If you need to customize it, I would recommend to first call super and then customize the output:

class PersonListSerializer(serializers.ModelSerializer):     class Meta:         model = Person         fields = ('foo', 'bar',)      def to_representation(self, instance):         data = super(PersonListSerializer, self).to_representation(instance)         data.update(...)         return data 

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P.S. if you are interested to know how it works, the magic actually does not happen in ModelSerializer.to_representation. As a matter of fact, it does not even implement that method. Its implemented on regular Serializer. All the magic with Django models actually happens in get_fields which calls get_field_names which then considers the Meta.fields parameters...