Code showing how to make dynamic serializer fields in Django Rest Framework

drf_serializer_override.py

# serializers.py
class CategorySerializer(serializers.ModelSerializer):
    class Meta:
        model = Category
        fields = ('id', 'name')


class TagSerializer(serializers.ModelSerializer):
    class Meta:
        model = Tag
        fields = ('id', 'name')
        
        
class EventSerializer(serializers.ModelSerializer):
    def __init__(self, *args, **kwargs):
        super(EventSerializer, self).__init__(*args, **kwargs)
        request = kwargs['context']['request']
        if request.method == 'GET':
            # this returns the serializer objects for GET actions
            # else, it returns the pk (which is what we need when we POST)
            self.fields.update({"category": CategorySerializer()})
            self.fields.update({"tags": TagSerializer(many=True)})
    
    class Meta:
        model = Event
        fields = (
            'id',
            'title',
            'category',
            'tags',
            'description',
            'event_date',
            'location',
        )
   
# views.py
class EventAPIView(generics.ListCreateAPIView):
    serializer_class = EventSerializer