Receiver decorator in Django - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the receiver decorator from Django signals.

Django

from django.dispatch import [1]

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

Areceiver

Bsignal

Cconnect

Dsend

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'signal' instead of 'receiver' for import.

Trying to import 'connect' which is a method, not a decorator.

The receiver decorator is imported from django.dispatch to connect functions to signals.

2fill in blank

medium

Complete the code to decorate the function so it listens to the post_save signal.

Django

@receiver([1])
def my_handler(sender, instance, **kwargs):
    pass

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

Apost_delete

Bpre_save

Cpost_save

Dpre_delete

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'pre_save' which runs before saving.

Confusing delete signals with save signals.

The post_save signal triggers after a model instance is saved, so the function listens to it.

3fill in blank

hard

Fix the error in the decorator to correctly listen to the signal from the User model.

Django

@receiver(post_save, sender=[1])
def user_saved(sender, instance, **kwargs):
    print('User saved')

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

Aauth.User

Bmodels.User

Cuser

DUser

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string like 'auth.User' instead of the User class.

Using lowercase 'user' which is undefined.

The sender must be the User model class, usually imported as 'User', not a string or module path.

4fill in blank

hard

Fill both blanks to connect a function to the pre_delete signal for the Article model.

Django

@receiver([1], sender=[2])
def article_deleted(sender, instance, **kwargs):
    print('Article deleted')

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

Apre_delete

Bpost_save

CArticle

DUser

Attempts:

3 left

💡 Hint

Common Mistakes

Using post_save signal which is unrelated to deletion.

Using User model instead of Article.

Use pre_delete signal and the Article model class as sender to listen before an article is deleted.

5fill in blank

hard

Fill all three blanks to create a receiver for the m2m_changed signal on the tags field of the Post model.

Django

@receiver([1], sender=[2].tags.through)
def tags_changed(sender, instance, action, **kwargs):
    if action == [3]:
        print('Tags updated')

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

Am2m_changed

BPost

C'post_add'

Dpost_save

Attempts:

3 left

💡 Hint

Common Mistakes

Using post_save signal which does not track m2m changes.

Using 'pre_add' instead of 'post_add' for action.

Using wrong sender model.

The m2m_changed signal listens to many-to-many changes; sender is Post.tags.through; action 'post_add' means tags were added.