Events & Signals

Event-Driven Architecture

Use Django signals to decouple business logic and trigger actions on model events (e.g., post_save, pre_delete).

• Define signal handlers in signals.py or relevant app modules.
• Connect signals in apps.py or via ready() method.

Example:

from django.db.models.signals import post_save
from django.dispatch import receiver
from .models import User

@receiver(post_save, sender=User)
def send_welcome_email(sender, instance, created, **kwargs):
    if created:
        # Send welcome email
        pass

Naming Conventions

• Use descriptive names for signal handlers (e.g., send_welcome_email).
• Group related signals and handlers by app or feature.

Organization

• Place signal handlers in signals.py or a dedicated module.
• Document signal usage and side effects for maintainability.

Best Practices

• Avoid heavy logic in signal handlers; use services for complex operations.
• Disconnect signals in tests to avoid side effects.
• Write tests for signal handlers and event-driven workflows.