django-model-logging

Logging for changes made to Django model instances.

Installation

pip install django-model-logging

Add model_logging to your INSTALLED_APPS.

Usage

Low-level use

from model_logging.models import LogEntry

LogEntry.objects.log(
    log_entry_creator,
    operation,
    model,
    user,
    json_data,
)

The parameters are as follows:

• log_entry_creator: The user who made this change.
• operation: One of LogEntry.OPERATION_ADDED, LogEntry.OPERATION_REMOVED, or LogEntry.OPERATION_MODIFIED.
• model: The path to the model being logged (e.g. 'users.models.User').
• user: The user to which the model instance belongs.
• json_data: A full or partial JSON representation of data on the model instance.

Medium-level use

To add methods to a view(set) that can be used to straightforwardly log changes:

from model_logging.views import LoggingMethodMixin

class AViewOrViewset(LoggingMethodMixin, ModelViewSet):
    def _get_logging_user(self):
        # Override this method to return a suitable
        # value for the `user` parameter above.
        return self.instance.user  # or similar

    def extra_data(self):
        # Overriding this isn't mandatory, it's just a hook
        return {'any additional data': 'you wish to log'}

The class now has access to the following:

def log(self, operation, data):
    # A simplified version of LogEntry.objects.log,
    # with some parameters pre-filled. The return
    # value of extra_data() will be added to the
    # supplied data.

def _log_on_create(self, serializer):
    # Log a LogEntry.OPERATION_ADDED change, using
    # the log() method above.

def _log_on_update(self, serializer):
    # Log a LogEntry.OPERATION_MODIFIED change, using
    # the log() method above.

def _log_on_destroy(self, instance):
    # Log a LogEntry.OPERATION_DELETED change, using
    # the log() method above.

More abstract still:

High-level use

A viewset can log its own changes!

from model_logging.views import LoggingViewSetMixin

class AVeryShinyViewSet(LoggingViewSetMixin, ModelViewSet):
    def _get_logging_user(self):
        # Override this method to return a suitable
        # value for the `user` parameter above.
        return self.instance.user  # or similar

    def extra_data(self):
        # Overriding this isn't mandatory, it's just a hook
        return {'any additional data': 'you wish to log'}

This mixin is a wrapper around LoggingMethodMixin that calls the appropriate logging methods during perform_create, perform_update and perform_destroy.