Signals¶

django-simple-history includes signals that help you provide custom behavior when saving a historical record. Arguments passed to the signals include the following:

instance¶

The source model instance being saved

history_instance¶

The corresponding history record

history_date¶

Datetime of the history record’s creation

history_change_reason¶

Freetext description of the reason for the change

history_user¶

The user that instigated the change

using¶

The database alias being used

To connect the signals to your callbacks, you can use the @receiver decorator:

from django.dispatch import receiver
from simple_history.signals import (
    pre_create_historical_record,
    post_create_historical_record
)

@receiver(pre_create_historical_record)
def pre_create_historical_record_callback(sender, **kwargs):
    print("Sent before saving historical record")

@receiver(post_create_historical_record)
def post_create_historical_record_callback(sender, **kwargs):
    print("Sent after saving historical record")