Django Custom Permission Management And Permission Verification

In this tutorial, we will create custom permissions for a Django model and verify permissions for a specific view.

Prerequisites:

Basic knowledge of Python
Familiarity with Django framework
A Django project set up and running
A Django app with at least one model

Step 1: Create custom permissions for a model

1.1. In your Django app, open the models.py file and add a permissions option to the Meta class of the model you want to create custom permissions for. For this tutorial, we will create a custom permission called "can_publish" for a model named Article:

from django.db import models

class Article(models.Model):
    title = models.CharField(max_length=100)
    content = models.TextField()
    published = models.BooleanField(default=False)

    class Meta:
        permissions = [
            ("can_publish", "Can publish articles"),
        ]

Step 2: Verify custom permissions in a view

2.1. In your Django app, create a new view function or class-based view to handle publishing an article. In this example, we'll create a function-based view:

from django.http import HttpResponseForbidden
from django.shortcuts import get_object_or_404
from .models import Article

def publish_article(request, article_id):
    article = get_object_or_404(Article, id=article_id)

    if not request.user.has_perm('myapp.can_publish'):
        return HttpResponseForbidden("You don't have permission to publish articles")

    article.published = True
    article.save()

    return HttpResponse("Article published")

Replace 'myapp.can_publish' with the correct format for your app's name and permission.

Step 3: Configure URL patterns for the view

3.1. In your Django app, open the urls.py file, import the new view function, and add a URL pattern for it:

from django.urls import path
from . import views

urlpatterns = [
    # ...
    path('publish_article/<int:article_id>/', views.publish_article, name='publish_article'),
]

Step 4: Test the custom permission and permission verification

4.1. Run your Django development server:

python manage.py runserver

4.2. Assign the custom permission "can_publish" to a user or a group of users in the Django admin site.

4.3. Open your web browser and visit the URL for publishing an article:

http://127.0.0.1:8000/publish_article/1/

If you're logged in as a user with the "can_publish" permission, you should see the "Article published" message. Otherwise, you should see the "You don't have permission to publish articles" message.

And that's it! You've successfully created custom permissions for a Django model and verified permissions in a view. You can now create more custom permissions and permission checks to manage access to different parts of your application based on user roles and privileges.

Implementing custom permissions in Django: Django provides a robust permission system, but sometimes, custom permissions are needed. Define custom permissions by creating instances of django.contrib.auth.models.Permission and associating them with your models.

# myapp/models.py
from django.contrib.auth.models import Permission

class MyModel(models.Model):
    # Your model fields here

# Create a custom permission
custom_permission = Permission.objects.create(
    codename='can_custom_action',
    name='Can perform custom action',
)

Django custom permission verification example: Once custom permissions are created, use them in your views or other parts of your application to control access.

# myapp/views.py
from django.contrib.auth.decorators import permission_required

@permission_required('myapp.can_custom_action')
def custom_action_view(request):
    # Your view logic here

Django custom permission backend: Customize permission checks further by creating a custom permission backend. This involves implementing the get_all_permissions method in your custom backend.

# myapp/auth_backends.py
from django.contrib.auth.backends import BaseBackend

class CustomPermissionBackend(BaseBackend):
    def get_all_permissions(self, user, obj=None):
        # Your custom permission logic here
        return set(['myapp.can_custom_action'])

Update AUTHENTICATION_BACKENDS in settings.py to include your custom backend.