Model mixins

synopsis:

Model mixins in django-boost

UUIDModelMixin

Mixins that replace id from AutoField to UUIDField

from django.db import models
from django_boost.models.mixins import UUIDModelMixin

class Stock(UUIDModelMixin):
    name = models.CharField(max_length=128)
    count = models.IntegerField()

TimeStampModelMixin

from django.db import models
from django_boost.models.mixins import TimeStampModelMixin

class Stock(TimeStampModelMixin):
    name = models.CharField(max_length=128)
    count = models.IntegerField()

The fields created_at and updated_at are added.

The following fields are automatically added to the above model.

created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)

Combine

from django.db import models
from django_boost.models.mixins import UUIDModelMixin, TimeStampModelMixin

class Stock(UUIDModelMixin,TimeStampModelMixin):
    name = models.CharField(max_length=128)
    count = models.IntegerField()

Model mixins can also be combined in this way.

LogicalDeletionMixin

from django.db import models
from django_boost.models.mixins import LogicalDeletionMixin

class Store(LogicalDeletionMixin):
    name = models.CharField(max_length=128)

The field deleted_at is added to hold the date of the logical deletion.

Also, some methods are provided to distinguish between logically deleted items.

By default, the deletion process for models that inherit from this class is a logical deletion.

If you want to do physical deletion, please pass hard=True as a delete method argument.

Logical deletion follows Django’s deletion collector for normal delete behavior: CASCADE, PROTECT, SET_NULL, delete signals, queryset restrictions, and the (count, details) return value are preserved. Related models that do not inherit LogicalDeletionMixin are physically deleted when Django’s cascade handling deletes them, because they have no deleted_at field to update.

Store.objects.delete() # logical deletion.

Store.objects.delete(hard=True) # physical deletion.

If you want to specify when the object was logically deleted, pass deleted_at. This is available on model instances, querysets, and managers.

from django.utils.timezone import now

deleted_at = now()

store.delete(deleted_at=deleted_at)
Store.objects.filter(name="Store 1").delete(deleted_at=deleted_at)
Store.objects.delete(deleted_at=deleted_at)

all method will get all the data as usual, including the logically deleted items.

To retrieve items that have not been logically removed, you can use the alive method.

If you want to retrieve only the logically deleted items, you can use the dead method.

Store.objects.alive() # get not logically deleted items queryset.

Store.objects.dead() # get logically deleted items queryset.

To filter by when items were logically deleted, deleted_since, deleted_before and deleted_between are available on both the manager and the queryset. All three compare against local calendar days (midnight to midnight in the current time zone). deleted_since and deleted_between are inclusive of the day boundaries they name; deleted_before excludes the named day itself. Both bounds of deleted_between are optional: omitting one leaves that side of the range open, and omitting both returns all logically deleted items.

from datetime import date

Store.objects.deleted_since(7) # deleted within the past 7 calendar days, today inclusive.

Store.objects.deleted_before(date(2024, 1, 1)) # deleted before the start of that day.

Store.objects.deleted_between(date(2024, 1, 1), date(2024, 1, 31)) # deleted on or between those days.