Django Softdelete Mixin

What is it

django-softdelete-mixin is a simple Django package that contains some mixins which implement soft delete for Django ORM.

Requirements

• Python 3.6+
• Django 3.1+ (related_objects function has break changes in django/django@26c66f45)

Installation

Install from github.

pip install git+https://github.com/ZhaoQi99/django-softdelete-mixin.git
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Quick example

from django_softdelete_mixin.models import SoftDeleteModel

class Article(SoftDeleteModel):
    title = models.CharField(max_length=100)

# Example of use
>>> a1 = Article.objects.create(title='django')
>>> a2 = Article.objects.create(title='python')
>>> a3 = Article.objects.create(title='javascript')
>>> a4 = Article.objects.create(title='golang')

# soft deletion of object
>>> a1.delete()
(1, {'app.Article': 1})
>>> Article.objects.count()
3
>>> Article.objects.filter(title='python').delete()
(1, {'app.Article': 1})
>>> Article.objects.count()
2

# Django default manager
>>> Article.src_objects.count()
4

# only soft delete self without `on_delete` behavior
>>> a3.delete(soft=False, only_self=True)
ValueError: `soft` can't be False when `only_self` is True
>>> a3.delete(only_self=True)
(1, {'app.Article': 1})

# hard deletion of object
>>> a4.delete(soft=False)  
(1, {'app.Article': 1})
>>> Article.objects.all().delete(soft=False)
(0, {})

Usage

Model

Use the abstract model SoftDeleteModel for adding one field:

• deleted - is a CharField, shows weather of a deletion state of object

Use the abstract model BaseModel for adding another two fields in addition to is_deleted:

• create_at - is a DateTimeField, shows the time of creation of object
• update_at - is a DateTimeField, shows the time of last update of object

from django_softdelete_mixin.models import SoftDeleteModel, BaseModel

class YourModel(SoftDeleteModel):
    pass

class YourModel(BaseModel):
    pass

QuerySet

• ModelName.objects.all() - returns all objects except deleted ones
• ModelName.src_objects.all() - returns all objects

Delete

• ModelName.objects.all().delete() - soft delete all objects
• ModelName.objects.all().delete(soft=False) - hard delete all objects
• ModelName.objects.all().delete(only_self=True) - only soft delete self without on_delete behavior
• ModelName.src_objects.delete() - hard delete all objects(including soft deleted)

Mixins

from django_softdelete_mixin.mixins import SoftDeleteManagerMixin,SoftDeleteQuerySetMixin

# For inherited model
class YourOwnManager(SoftDeleteManagerMixin, SomeParentManagerClass):
    pass

class YourOwnQuerySet(SoftDeleteQuerySetMixin, SomeParentQuerySetClass):
    pass

Unique

class Test(BaseModel):
    name = models.CharField(max_length=100)
    class Meta:
        unique_together = (
            ('name', 'deleted'),
        )

In Django REST framework:

from django_softdelete_mixin.constant import UN_DELETE

class TestSerializer(serializers.ModelSerializer):
    deleted = serializers.HiddenField(default=UN_DELETE)

    class Meta:
        model = Test
        fields = "__all__"
        extra_kwargs = {
            "deleted": {"write_only": True},
        }
        validators = [
            serializers.UniqueTogetherValidator(
                queryset=Test.objects.all(),
                fields=("name", "deleted"),
                message="XXX已存在"
            )
        ]

Custom

QuerySet

from django_softdelete_mixin.query import SoftDeleteQuerySet

class YourOwnQuerySet(SoftDeleteQuerySet):
    pass

Manager

from django_softdelete_mixin.manager import SoftDeleteManager

class YourOwnManager(SoftDeleteManager):
    pass

Important

According to the official documentation Managers | Django documentation | Django, if you want to add extra managers to your Model class, you must use the following two methods to to ensure that the default_manager is SoftDeleteManager.

class YourModel(SoftDeleteModel):
    title = models.CharField(max_length=100)

    class Meta:
        default_manager_name  = "objects"

or

class ExtraManager(models.Model):
    other_objects = YourOwnManager()

    class Meta:
        abstract = True

class YourModel(SoftDeleteModel, ExtraManager):
    title = models.CharField(max_length=100)

Bug

Querying in the opposite direction using ForeignKey

Use the following solutions to solve:

from django_softdelete_mixin.constant import UN_DELETE
role = Role.objects.first()
role.user_set.filter(role_user__deleted=UN_DELETE)

License

GNU General Public License v3.0

Author

• Qi Zhao([email protected])