Skip to main content

Declarative model lifecycle hooks.

Project description

Django Lifecycle Hooks

Package version Python versions Python versions PyPI - Django Version

This project provides a @hook decorator as well as a base model and mixin to add lifecycle hooks to your Django models. Django's built-in approach to offering lifecycle hooks 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 supports:

  • Python 3.7, 3.8, 3.9, 3.10, 3.11, and 3.12
  • Django 2.2, 3.2, 4.0, 4.1, 4.2, and 5.0

In short, you can write model code like this:

from django_lifecycle 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

Source Code: https://github.com/rsinger86/django-lifecycle


Changelog

See Changelog

Testing

Tests are found in a simplified Django project in the /tests folder. Install the project requirements and do ./manage.py test to run them.

License

See License.

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

django-lifecycle-1.2.3.tar.gz (11.8 kB view hashes)

Uploaded Source

Built Distribution

django_lifecycle-1.2.3-py3-none-any.whl (13.9 kB view hashes)

Uploaded Python 3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page