A serializer mixin for Django REST Framework to expand object representations inline

• Python (2.7, 3.2, 3.3, 3.4, 3.5)
• Django (1.7, 1.8, 1.9)
• Django REST Framework (3.1, 3.2, 3.3)

Install using pip

pip install djangorestframework-expander

• Must inherit from ExpanderSerializerMixin
• Expandable fields are defined using the expandable_fields attribute on the serializer Meta class.
  • Key is the field name.
  • Value is the serializer class - e.g. MenuItemSerializer OR
  • Value is a 3 tuple of (class, args, kwargs) - e.g. (MenuItemSerializer, (), {'many': True})
• NOTE field does not have to appear in fields to appear in expandable_fields.
• Expansion is controlled using the expand URL paramter. e.g. /menu-items/?expand=menu
• Expand multiple fields with a comma. e.g. /menu-items/?expand=menu,price_bracket
• Expand nested fields by using a dot. e.g. /menu-items/?expand=menu.restaurant

from expander import ExpanderSerializerMixin


class RestaurantSerializer(ExpanderSerializerMixin, serializers.ModelSerializer):
    class Meta:
        model = Restaurant
        fields = ('id', 'title')


class MenuSerializer(ExpanderSerializerMixin, serializers.ModelSerializer):
    class Meta:
        model = Menu
        fields = ('id', 'restaurant', 'title')
        expandable_fields = {
            'restaurant': RestaurantSerializer,
        }

class PriceBracketSerializer(serializers.ModelSerializer):
    class Meta:
        model = PriceBracket
        fields = ('id', 'title')


class MenuItemSerializer(ExpanderSerializerMixin, serializers.ModelSerializer):
    class Meta:
        model = MenuItem
        fields = ('id', 'menu', 'title', 'description', 'price', 'price_bracket')
        expandable_fields = {
            'menu': MenuSerializer,
            'price_bracket': PriceBracketSerializer,
        }

Making a request for a menu item returns the usual results to start with.

GET /menu-items/1/

{
    "id": 1,
    "menu": 3,
    "title": "Breakfast",
    "description": "",
    "price": "3.50"
}

Expand menu

GET /menu-items/1/?expand=menu

{
    "id": 1,
    "menu": {
        "id": 3,
        "restaurant": 6,
        "title": "Breakfast"
    },
    "title": "Eggs",
    "description": "",
    "price": "3.50"
}

Expand nested

GET /menu-items/1/?expand=menu.restaurant

{
    "id": 1,
    "menu": {
        "id": 3,
        "restaurant": {
            "id": 6,
            "title": "Bob's Bed and Breakfast"
        },
        "title": "Breakfast"
    },
    "title": "Eggs",
    "description": "",
    "price": "3.50"
}