Permission required decorator in Django - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the @permission_required decorator in Django?

It restricts access to a view so that only users with a specific permission can use it. If the user lacks the permission, they are redirected or shown an error.

beginner

How do you specify which permission a Django view requires using @permission_required?

You pass the permission as a string argument in the format 'app_label.permission_codename' to the decorator.

intermediate

What happens if a user without the required permission tries to access a view decorated with @permission_required?

By default, the user is redirected to the login page. You can change this behavior by setting the raise_exception=True argument to show a 403 Forbidden error instead.

beginner

Write a simple example of using @permission_required to require the permission polls.can_vote on a view.

from django.contrib.auth.decorators import permission_required

@permission_required('polls.can_vote')
def vote(request):
    # view code here
    pass

intermediate

Can @permission_required be used with class-based views in Django?

Not directly. You can use the PermissionRequiredMixin from django.contrib.auth.mixins to enforce permissions on class-based views.

What argument format does @permission_required expect for the permission?

A 'permission_codename'

B 'permission_codename.app_label'

C 'app_label.permission_codename'

D 'app_label'

The permission must be specified as 'app_label.permission_codename', for example 'polls.can_vote'.

What does setting raise_exception=True in @permission_required do?

A Redirects to login page

B Raises a 403 Forbidden error

C Grants permission automatically

D Logs the user out

Setting raise_exception=True causes Django to raise a 403 Forbidden error instead of redirecting.

Which import is needed to use @permission_required?

A from django.contrib.auth.decorators import permission_required

B from django.shortcuts import permission_required

C from django.views.decorators import permission_required

D from django.contrib.auth.mixins import permission_required

The decorator is imported from django.contrib.auth.decorators.

If you want to protect a class-based view with permissions, what should you use?

A No protection needed

B @permission_required decorator

C login_required decorator

D PermissionRequiredMixin

PermissionRequiredMixin is designed for class-based views to enforce permissions.

What happens if an anonymous user accesses a view with @permission_required?

A They are redirected to login page

B They get access anyway

C They see a 404 error

D They get a 500 server error

Anonymous users are redirected to the login page by default.

Explain how the @permission_required decorator works in Django and how you use it in a function-based view.

Think about how you protect a view so only certain users can use it.

Describe the difference between using @permission_required and PermissionRequiredMixin in Django.

Consider the type of view you want to protect.