Custom permissions in Django - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a custom permission class in Django REST Framework.

Django

from rest_framework.permissions import [1]

class IsOwnerPermission([1]):
    def has_object_permission(self, request, view, obj):
        return obj.owner == request.user

Drag options to blanks, or click blank then click option'

ABasePermission

BAllowAny

CIsAuthenticated

DDjangoModelPermissions

Attempts:

3 left

💡 Hint

Common Mistakes

Using IsAuthenticated or AllowAny as base class for custom permissions.

Not inheriting from any permission class.

The custom permission class should inherit from BasePermission to define custom logic.

2fill in blank

medium

Complete the code to check if the user is the owner of the object in the permission method.

Django

def has_object_permission(self, request, view, obj):
    return obj.[1] == request.user

Drag options to blanks, or click blank then click option'

Aauthor

Buser

Cowner

Dcreator

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'user' instead of 'owner' which may not exist on the object.

Using unrelated attribute names like 'creator' or 'author' without confirming model fields.

The permission checks if the owner attribute of the object matches the current user.

3fill in blank

hard

Fix the error in the permission class by completing the missing import statement.

Django

from rest_framework.permissions import [1], SAFE_METHODS

class IsAdminOrReadOnly([1]):
    def has_permission(self, request, view):
        if request.method in SAFE_METHODS:
            return True
        return request.user and request.user.is_staff

Drag options to blanks, or click blank then click option'

ADjangoModelPermissions

BIsAuthenticated

CAllowAny

DBasePermission

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to import BasePermission causes errors.

Using other permission classes that don't support custom logic.

The class should inherit from BasePermission and import it to define custom permission logic.

4fill in blank

hard

Fill both blanks to correctly apply the custom permission class to a Django REST Framework view.

Django

from rest_framework.views import APIView
from .permissions import [1]

class MyView(APIView):
    permission_classes = [[2]]

Drag options to blanks, or click blank then click option'

AIsOwnerPermission

BIsAdminOrReadOnly

CIsAuthenticated

DAllowAny

Attempts:

3 left

💡 Hint

Common Mistakes

Importing one permission but using another in the list.

Not using a list for permission_classes.

The custom permission IsOwnerPermission is imported and applied in the permission_classes list.

5fill in blank

hard

Fill all three blanks to create a custom permission that allows safe methods for everyone but restricts other methods to the object's owner.

Django

from rest_framework.permissions import BasePermission, SAFE_METHODS

class [1](BasePermission):
    def has_object_permission(self, request, view, obj):
        if request.method in [2]:
            return True
        return obj.[3] == request.user

Drag options to blanks, or click blank then click option'

AIsOwnerOrReadOnly

BSAFE_METHODS

Cowner

DIsAdminOrReadOnly

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong class names that don't match the logic.

Forgetting to check safe methods before owner.

Using incorrect attribute names for ownership.

The class IsOwnerOrReadOnly allows safe methods for all and restricts other methods to the object's owner.

Practice

1. What is the main purpose of creating a custom permission in Django?

easy

A. To control user access based on specific rules you define

B. To change the database schema automatically

C. To speed up the Django server response time

D. To create new database tables for users

Solution

1. Step 1: Understand what permissions do in Django

   Permissions control what users can or cannot do in the app.

2. Step 2: Identify the role of custom permissions

   Custom permissions let you define your own rules for user access beyond default ones.

3. Final Answer:

   To control user access based on specific rules you define -> Option A

4. Quick Check:

   Custom permissions = control user access [OK]

Hint: Custom permissions control access rules you create [OK]

Common Mistakes:

• Thinking permissions change database structure
• Confusing permissions with performance settings
• Believing permissions create new tables

2. Which method must you override when creating a custom permission class in Django REST Framework?

easy

A. save

B. get_queryset

C. has_permission

D. dispatch

Solution

1. Step 1: Recall the BasePermission class methods

   The main method to check access is has_permission.

2. Step 2: Confirm which method controls permission checks

   has_permission returns True or False to allow or deny access.

3. Final Answer:

   has_permission -> Option C

4. Quick Check:

   Permission check method = has_permission [OK]

Hint: Override has_permission to define access rules [OK]

Common Mistakes:

• Using get_queryset which filters data, not permissions
• Confusing save method with permission checks
• Using dispatch which is for request handling

3. Given this custom permission class, what will be the result if a user is not authenticated?

from rest_framework.permissions import BasePermission

class IsAuthenticatedCustom(BasePermission):
    def has_permission(self, request, view):
        return request.user and request.user.is_authenticated

medium

A. Code raises an error due to missing return

B. Access is denied because user is not authenticated

C. Access is granted regardless of authentication

D. Access is granted only if user is staff

Solution

1. Step 1: Analyze the has_permission method logic

   It returns True only if request.user exists and is authenticated.

2. Step 2: Consider the case when user is not authenticated

   Then request.user.is_authenticated is False, so method returns False denying access.

3. Final Answer:

   Access is denied because user is not authenticated -> Option B

4. Quick Check:

   Unauthenticated user = access denied [OK]

Hint: Check if user.is_authenticated is True to allow access [OK]

Common Mistakes:

• Assuming access is granted without authentication
• Thinking code raises error due to return statement
• Confusing staff status with authentication

4. Identify the error in this custom permission class:

from rest_framework.permissions import BasePermission

class IsOwnerPermission(BasePermission):
    def has_permission(self, request, view):
        return request.user == view.get_object().owner

medium

A. Missing import for request module

B. No return statement in has_permission

C. Incorrect comparison operator used

D. Using has_permission instead of has_object_permission for object check

Solution

1. Step 1: Understand permission methods roles

   has_permission checks general access; has_object_permission checks per object.

2. Step 2: Identify misuse of has_permission for object ownership

   Comparing user to object owner requires has_object_permission, not has_permission.

3. Final Answer:

   Using has_permission instead of has_object_permission for object check -> Option D

4. Quick Check:

   Object checks need has_object_permission [OK]

Hint: Use has_object_permission for per-object access checks [OK]

Common Mistakes:

• Confusing has_permission with has_object_permission
• Assuming import errors cause this issue
• Thinking comparison operator is wrong

5. You want to create a custom permission that allows access only if the user is authenticated and the HTTP method is safe (GET, HEAD, OPTIONS). Which is the correct implementation?

hard

A. class SafeAndAuthenticated(BasePermission):
def has_permission(self, request, view):
return request.user.is_authenticated and request.method in ['GET', 'HEAD', 'OPTIONS']

B. class SafeAndAuthenticated(BasePermission):
def has_permission(self, request, view):
return request.user.is_authenticated or request.method in ['GET', 'HEAD', 'OPTIONS']

C. class SafeAndAuthenticated(BasePermission):
def has_permission(self, request, view):
return not request.user.is_authenticated and request.method in ['GET', 'HEAD', 'OPTIONS']

D. class SafeAndAuthenticated(BasePermission):
def has_permission(self, request, view):
return request.user.is_authenticated and request.method not in ['GET', 'HEAD', 'OPTIONS']

Solution

1. Step 1: Understand the requirement

   User must be authenticated AND method must be safe (GET, HEAD, OPTIONS).

2. Step 2: Analyze each option's logic

   class SafeAndAuthenticated(BasePermission): def has_permission(self, request, view): return request.user.is_authenticated and request.method in ['GET', 'HEAD', 'OPTIONS'] uses AND with correct method list; others use OR, NOT, or wrong method checks.

3. Final Answer:

   class SafeAndAuthenticated(BasePermission): def has_permission(self, request, view): return request.user.is_authenticated and request.method in ['GET', 'HEAD', 'OPTIONS'] -> Option A

4. Quick Check:

   Use AND for combined conditions [OK]

Hint: Use AND to combine authentication and method checks [OK]

Common Mistakes:

• Using OR instead of AND allowing wrong access
• Checking for methods incorrectly with NOT
• Allowing unauthenticated users by mistake