This project provides a @hook decorator as well as a base model and mixin to add lifecycle hooks flow to your Django models. Django's built-in approach to offering lifecycle hooks flow is Signals. However, my team often finds that Signals introduce unnecessary indirection and are at odds with Django's "fat models" approach.
Django Lifecycle Hooks Flow supports Python 3.5, 3.6, 3.7, 3.8 and 3.9, Django 2.0.x, 2.1.x, 2.2.x, 3.0.x, 3.1.x, and 3.2.x.
In short, you can write model code like this:
from django_lifecycle_flow import LifecycleModel, hook, BEFORE_UPDATE, AFTER_UPDATE
class Article(LifecycleModel):
contents = models.TextField()
updated_at = models.DateTimeField(null=True)
status = models.ChoiceField(choices=['draft', 'published'])
editor = models.ForeignKey(AuthUser)
@hook(BEFORE_UPDATE, when='contents', has_changed=True)
def on_content_change(self):
self.updated_at = timezone.now()
@hook(AFTER_UPDATE, when="status", was="draft", is_now="published")
def on_publish(self):
send_email(self.editor.email, "An article has published!")Instead of overriding save and __init__ in a clunky way that hurts readability:
# same class and field declarations as above ...
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._orig_contents = self.contents
self._orig_status = self.status
def save(self, *args, **kwargs):
if self.pk is not None and self.contents != self._orig_contents:
self.updated_at = timezone.now()
super().save(*args, **kwargs)
if self.status != self._orig_status:
send_email(self.editor.email, "An article has published!")Documentation: https://rsinger86.github.io/django-lifecycle
Tests are found in a simplified Django project in the /tests folder. Install the project requirements and do ./manage.py test to run them.
See License.