README.md

Django Finite State Machine Log

Automatic logging for the excellent Django FSM package.

Installation

First, install the package with pip. This will automatically install any dependencies you may be missing

pip install django-fsm-log

With Python 2.7 Django 1.4+ is supported, with Python 3.3 Django 1.5+ is supported.

Then migrate the app to create the database table

python manage.py migrate django_fsm_log

Usage

The app will listen for django_fsm.signals.post_transition to be fired and create a new record for each transition.

To query logs simply

from django_fsm_log.models import StateLog
StateLog.objects.all()
# ...all recorded logs...

for_ Manager Method

For convenience there is a custom for_ manager method to easily filter on the generic foreign key

from my_app.models import Article
from django_fsm_log.models import StateLog

article = Article.objects.all()[0]

StateLog.objects.for_(article)
# ...logs for article...

by Decorator

We found that our transitions are commonly called by a user, so we've added a decorator to make logging that painless

from django.db import models
from django_fsm.db.fields import FSMField, transition
from django_fsm_log.decorators import fsm_log_by

class Article(models.Model):

    state = FSMField(default='draft', protected=True)

    @fsm_log_by
    @transition(field=state, source='draft', target='submitted')
    def submit(self, by=None):
        pass

Then every time the transition is called with the by kwarg set, it will be logged

article = Article.objects.create()
article.submit(by=some_user) # StateLog.by will be some_user

Advanced Usage

You can change the behaviour of this app by turning on caching for StateLog records. Simply add DJANGO_FSM_LOG_USE_CACHE = True to your project's settings file. By default your project's 'default' cache backend will be used to store this data. If you wish to use a different cache backend, add DJANGO_FSM_LOG_CACHE_BACKEND = 'custom_backend' to your settings file.

When caching is on, you can access the StateLog record before the transition takes place, and before it has been persisted to the database.

from django_fsm_log.models import StateLog
article = Article.objects.get(...)
pending_state_log = StateLog.objects.get_pending_for_object(article)

This pending StateLog object is available after the django_fsm.signals.pre_transition signal is fired, but is deleted from the cache after django_fsm.signals.post_transition is fired.

Running Tests

./runtests.py