django-rest-serializer-field-permissions 3.0a1

Field-by-field serializer permissions for Django Rest Framework.

django-rest-serializer-field-permissions

Add field-by-field permission classes to your serializer fields that look like this:

  class PersonSerializer(FieldPermissionSerializerMixin, LookupModelSerializer):

      # Only allow authenticated users to retrieve family and given names
      family_names = serializers.CharField(permission_classes=(IsAuthenticated(), ))
      given_names = serializers.CharField(permission_classes=(IsAuthenticated(), ))

      # Allow all users to retrieve nick name
      nick_name = serializers.CharField(permission_classes=(AllowAll(), ))

Complete Tutorial

This example builds on the example Django REST Framework API in the DRF 3.8 documentation. Please make sure that you have completed that tutorial before beginning this one.

Install this module into your environment:

  $ pip install django-rest-serializer-field-permissions==2.0a1

Install this module into Django by adding it to your INSTALLED_APPS.

  INSTALLED_APPS = (
  # ...
      'rest_framework_serializer_field_permissions',
  # ...
  )

Then add the included middleware to any position in your MIDDLEWARE.

  MIDDLEWARE = [
  # ...
      'rest_framework_serializer_field_permissions.middleware.RequestMiddleware' 
  # ...
  ]

Now you can add retrieve permissions to individual fields. You must import the modules and classes shown below, mix FieldPermissionSerializerMixin as the leftmost parent to your serializers, and then define your fields using the provided drop-in field classes.

For example, modify the root urls.py you created in the DRF tutorial with the following code:

from django.conf.urls import url, include
from django.contrib.auth.models import User
from rest_framework import routers, serializers, viewsets

from rest_framework_serializer_field_permissions import fields                                      # <--
from rest_framework_serializer_field_permissions.serializers import FieldPermissionSerializerMixin  # <--
from rest_framework_serializer_field_permissions.permissions import IsAuthenticated                 # <--

# Serializers define the API representation.
class UserSerializer(FieldPermissionSerializerMixin, serializers.HyperlinkedModelSerializer):       # <--
    class Meta:
        model = User
        fields = ('url', 'username', 'email', 'is_staff')

    email = fields.EmailField(permission_classes=(IsAuthenticated(), ))                             # <--

# ViewSets define the view behavior.
class UserViewSet(viewsets.ModelViewSet):
    queryset = User.objects.all()
    serializer_class = UserSerializer

# Routers provide an easy way of automatically determining the URL conf.
router = routers.DefaultRouter()
router.register(r'users', UserViewSet)

# Wire up our API using automatic URL routing.
# Additionally, we include login URLs for the browsable API.
urlpatterns = [
    url(r'^', include(router.urls)),
    url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework'))
]

Now, only authenticated users will be able to retrieve your users' emails. You can confirm this by creating a superuser account, if you haven't already, and visiting http://localhost:8000/users/ as both an authenticated user and an unauthenticated visitor.

Alternately, you could have restricted retrieve access to the username field with the code:

    username = fields.CharField(permission_classes=(IsAuthenticated(), ))

You can define your own permissions classes that operate on any aspect of the incoming request, and you can specify multiple rpermission_classes on a field: all provided permissions must be satisfied for the visitor to retrieve the given field.

Use

Installation

Install the module in your Python distribution or virtualenv:

$ pip install django-rest-serializer-field-permissions

Add the application to your INSTALLED_APPS:

  INSTALLED_APPS = (
  ...
  'rest_framework_serializer_field_permissions',
  ...
  )

Adding Permissions

In your serializers, mix FieldPermissionSerializerMixin into your serializer classes, as the left-most parent. The fields provided by rest_framework_serializer_field_permissions.fields accept permission_classes which operate in typical DRF fashion:

  from rest_framework import serializers

  from rest_framework_serializer_field_permissions import fields
  from rest_framework_serializer_field_permissions.serializers import FieldPermissionSerializerMixin
  from rest_framework_serializer_field_permissions.permissions import IsAuthenticated

  class UserSerializer(FieldPermissionSerializerMixin, serializers.HyperlinkedModelSerializer):
    class Meta:
        model = User
        fields = ('url', 'username', 'email', 'is_staff')

    email = fields.EmailField(permission_classes=(IsAuthenticated(), ))

The FieldPermissionSerializerMixin may be mixed with any DRF serializer class, not just ModelSerializer.

You can write your own permission classes by sub-classing BaseFieldPermission in permissions.py.

How it Works

The FieldPermissionSerializerMixin provides its own fields property, which DRF serializers call to get a list of their own fields. The amended fields property checks for permission-bearing fields, forces them to check their permissions against the request, and scrubs from the return any fields which fail their permission checks.

Compatibility

This package is tested for compatibility against the following software versions:

• Django Rest Framework 3.11
• Django 2.1, 3.0
• Python 3.7

This package may incidentally be compatible with other similar versions of the above software. See tox.ini for specific minor versions tested.

Additional Requirements

None

Todo

• Integration tests

Getting Involved

Feel free to open pull requests or issues. GitHub is the canonical location of this project.

Here's the general sequence of events for contribution:

1. Open an issue in the issue tracker.
2. In any order:

• Submit a pull request with a failing test that demonstrates the issue/feature.
• Get acknowledgement/concurrence.

3. Submit pull request that passes your test in (2). Include documentation, if appropriate.