Requirements

• Python 2.6/2.7/3.2/3.3 (3.x requires Django >=1.5)

• Django 1.2/1.3/1.4/1.5

Installation

1. Install from PyPI: pip install django-db-signals.

2. Add 'django_db_signals' to INSTALLED_APPS.

3. Enable the signals by adding to your models.py:

   import django_db_signals
   django_db_signals.enable()

Example

Let’s assume you’ve installed django-db-signals, and now you’d like to log a message each time the database is rolled back:

from django.db import signals
from django.dispatch import receiver
import logging

logger = logging.getLogger(__name__)

@reciever(signals.post_rollback)
def log_rollbacks(sender, **kwargs):
    # sender is a DatabaseWrapper object
    logger.info("A rollback occurred on database %s" %
                sender.alias)

Design

In the same way that Django settings are available via django.conf.settings attributes, signals are available via django.db.signals attributes. As such, attempting to import individual signals will fail:

>>> import django_db_signals
>>> django_db_signals.enable()

>>> from django.db import signals  # GOOD
>>> signals.pre_commit
<django.dispatch.dispatcher.Signal object at 0x1089c8b90>

>>> from django.db.signals import pre_commit  # BAD
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named signals

Troubleshooting

“I can import django.db.signals, but when I try to access a signal I get an AttributeError exception.”

You need to enable the signals via django_db_signals.enable()