django-api-mixins 0.1.0

A collection of useful mixins for Django REST Framework ViewSets and APIViews

django-api-mixins

A collection of useful mixins for Django REST Framework ViewSets and APIViews to simplify common API patterns.

Features

• APIMixin: Dynamic serializer selection based on action (create, update, list, retrieve)
• ModelMixin: Automatic filter field generation for Django models
• RelationshipFilterMixin: Automatic filtering for reverse relationships and direct fields
• RoleBasedFilterMixin: Role-based queryset filtering for multi-tenant applications

Installation

pip install django-api-mixins

Requirements

• Python 3.8+
• Django 3.2+
• Django REST Framework 3.12+

Quick Start

APIMixin

Use different serializers for different actions (create, update, list, retrieve):

from rest_framework import viewsets
from django_api_mixins import APIMixin

class UserViewSet(APIMixin, viewsets.ModelViewSet):
    queryset = User.objects.all()
    serializer_class = UserSerializer  # Default serializer
    create_serializer_class = UserCreateSerializer  # For POST requests
    update_serializer_class = UserUpdateSerializer  # For PUT/PATCH requests
    list_serializer_class = UserListSerializer  # For GET list requests
    retrieve_serializer_class = UserDetailSerializer  # For GET detail requests

The mixin also automatically handles list data in requests:

# POST /api/users/
# Body: [{"name": "User1"}, {"name": "User2"}]
# Automatically sets many=True for list data

ModelMixin

Automatically generate filter fields for all model fields:

from django.db import models
from django_api_mixins import ModelMixin

class Product(models.Model, ModelMixin):
    name = models.CharField(max_length=100)
    price = models.DecimalField(max_digits=10, decimal_places=2)
    created_at = models.DateTimeField(auto_now_add=True)
    is_active = models.BooleanField(default=True)

# Automatically generates filter fields:
# - name: exact, in, isnull
# - price: exact, in, isnull, gte, lte
# - created_at: exact, in, isnull, gte, lte
# - is_active: exact, in, isnull

Use in your ViewSet with Django Filter Backend:

from rest_framework import viewsets
from django_filters.rest_framework import DjangoFilterBackend
from django_api_mixins import ModelMixin

class ProductViewSet(viewsets.ModelViewSet):
    queryset = Product.objects.all()
    filter_backends = [DjangoFilterBackend]
    filterset_fields = Product.get_filter_fields()  # Use auto-generated fields

Filter related models:

# Get filter fields for a related model
filter_fields = Product.get_filter_fields_for_related_model('category')
# Returns: {'category__name': [...], 'category__id': [...], ...}

# Get filter fields for a foreign key field
filter_fields = Order.get_filter_fields_for_foreign_fields('product')
# Returns: {'product__name': [...], 'product__price': [...], ...}

RelationshipFilterMixin

Automatically apply filters for reverse relationships and direct fields:

from rest_framework import viewsets
from django_api_mixins import RelationshipFilterMixin

class OrderViewSet(RelationshipFilterMixin, viewsets.ModelViewSet):
    queryset = Order.objects.all()
    
    # Define which reverse relationship filters to allow
    reverse_relation_filters = [
        'customer__name',
        'customer__email',
        'product__category__name',
    ]
    
    # Define which filters support list/array values
    listable_filters = ['customer__id', 'product__id']

Important: Place the mixin BEFORE the ViewSet class:

# ✅ Correct
class OrderViewSet(RelationshipFilterMixin, viewsets.ModelViewSet):
    pass

# ❌ Wrong
class OrderViewSet(viewsets.ModelViewSet, RelationshipFilterMixin):
    pass

Usage examples:

# Filter by customer name
GET /api/orders/?customer__name=John

# Filter by multiple customer IDs (listable filter)
GET /api/orders/?customer__id=1,2,3
# or
GET /api/orders/?customer__id=[1,2,3]

# Filter by product category
GET /api/orders/?product__category__name=Electronics

RoleBasedFilterMixin

Automatically filter querysets based on user roles:

from rest_framework import viewsets
from django_api_mixins import RoleBasedFilterMixin

class OrderViewSet(RoleBasedFilterMixin, viewsets.ModelViewSet):
    queryset = Order.objects.all()
    
    # Required: field name to filter on
    role_filter_field = 'operator_type'
    
    # Optional: roles that see all data
    admin_roles = ['admin', 'super_admin']
    
    # Optional: roles that see no data
    excluded_roles = ['guest']
    
    # Optional: custom role to field value mapping
    role_mapping = {
        'custom_role': 'custom_value',
        'manager': 'MGR',
    }

Important: Place the mixin BEFORE the ViewSet class:

# ✅ Correct
class OrderViewSet(RoleBasedFilterMixin, viewsets.ModelViewSet):
    pass

# ❌ Wrong
class OrderViewSet(viewsets.ModelViewSet, RoleBasedFilterMixin):
    pass

How it works:

1. Extracts the user's role from user.role.name
2. Admin roles see all data (no filtering)
3. Excluded roles see no data (empty queryset)
4. Other roles are filtered by role_filter_field = role_name (or mapped value)

Example:

# User with role.name = 'operator'
# Model has operator_type field
# Automatically filters: Order.objects.filter(operator_type='operator')

# User with role.name = 'admin'
# Sees all orders (no filtering)

# User with role.name = 'guest'
# Sees no orders (queryset.none())

FieldLookup Enum

The package includes a FieldLookup enum for consistent lookup naming:

from django_api_mixins import FieldLookup

FieldLookup.EXACT      # "exact"
FieldLookup.ICONTAINS  # "icontains"
FieldLookup.CONTAINS   # "contains"
FieldLookup.ISNULL     # "isnull"
FieldLookup.GTE        # "gte"
FieldLookup.LTE        # "lte"
FieldLookup.IN         # "in"

Combining Mixins

You can combine multiple mixins:

from rest_framework import viewsets
from django_api_mixins import (
    APIMixin,
    RelationshipFilterMixin,
    RoleBasedFilterMixin,
)

class OrderViewSet(
    RelationshipFilterMixin,
    RoleBasedFilterMixin,
    APIMixin,
    viewsets.ModelViewSet
):
    queryset = Order.objects.all()
    serializer_class = OrderSerializer
    create_serializer_class = OrderCreateSerializer
    
    role_filter_field = 'operator_type'
    reverse_relation_filters = ['customer__name', 'product__category__name']
    listable_filters = ['customer__id']

Note: The order of mixins matters! Place filtering mixins before the ViewSet class.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT License - see LICENSE file for details.

Support

For issues, questions, or contributions, please visit the GitHub repository.