Model Extensions

synopsis:

Model Extensions

Introduction

Django Extensions provides you a set of Abstract Base Classes for models that implements commonly used patterns like holding the model’s creation and last modification dates.

Database Model Extensions

  • ActivatorModel - Abstract Base Class that provides a status, activate_date, and deactivate_date fields.

The status field is an IntegerField whose value is chosen from a tuple of choices - active and inactive - defaulting to active. This model also exposes a custom manager, allowing the user to easily query for active or inactive objects.

E.g.: Model.objects.active() returns all instances of Model that have an active status.

  • TitleDescriptionModel - This Abstract Base Class model provides title and description fields.

The title field is CharField with a maximum length of 255 characters, non-nullable. description. On the other hand, description is a nullable TextField.

  • TimeStampedModel - An Abstract Base Class model that provides self-managed created and modified fields.

Both of the fields are customly defined in Django Extensions as CreationDateTimeField and ModificationDateTimeField. Those fields are subclasses of Django’s DateTimeField and will store the value of django.utils.timezone.now() on the model’s creation and modification, respectively

  • TitleSlugDescriptionModel - An Abstract Base Class model that, like the TitleDescriptionModel, provides title and description fields but also provides a self-managed slug field which populates from the title.

That field’s class is a custom defined AutoSlugField, based on Django’s SlugField. By default, it uses - as a separator, is unique and does not accept blank values. It is possible to customize slugify_function by defining your custom function within a model:

# models.py

from django.db import models

from django_extensions.db.models import TitleSlugDescriptionModel


class MyModel(TitleSlugDescriptionModel, models.Model):

    def slugify_function(self, content):
        """
        This function will be used to slugify
        the title (default `populate_from` field)
        """
        return content.replace('_', '-').lower()

See AutoSlugField docs for more details.