Files
thrillwiki_django_no_react/backend/apps/reviews/signals.py

32 lines
1.1 KiB
Python

from django.db.models import Avg
from django.db.models.signals import post_delete, post_save
from django.dispatch import receiver
from .models import Review
@receiver(post_save, sender=Review)
@receiver(post_delete, sender=Review)
def update_average_rating(sender, instance, **kwargs):
"""
Update the average rating of the content object when a review is saved or deleted.
"""
content_object = instance.content_object
if not content_object:
# If content object doesn't exist (orphaned review?), skip
return
# Check if the content object has an 'average_rating' field
if not hasattr(content_object, "average_rating"):
return
# Calculate new average
# We query the Review model filtering by content_type and object_id
avg_rating = Review.objects.filter(content_type=instance.content_type, object_id=instance.object_id).aggregate(
Avg("rating")
)["rating__avg"]
# Update field
content_object.average_rating = avg_rating or 0 # Default to 0 if no reviews
content_object.save(update_fields=["average_rating"])