"""Generic models"""
from django.db import models
from model_utils.managers import InheritanceManager
from rest_framework.serializers import BaseSerializer
class SerializerModel(models.Model):
"""Base Abstract Model which has a serializer"""
@property
def serializer(self) -> BaseSerializer:
"""Get serializer for this model"""
raise NotImplementedError
class Meta:
abstract = True
class CreatedUpdatedModel(models.Model):
"""Base Abstract Model to save created and update"""
created = models.DateTimeField(auto_now_add=True)
last_updated = models.DateTimeField(auto_now=True)
class InheritanceAutoManager(InheritanceManager):
"""Object manager which automatically selects the subclass"""
def get_queryset(self):
return super().get_queryset().select_subclasses()
class InheritanceForwardManyToOneDescriptor(
models.fields.related.ForwardManyToOneDescriptor
):
"""Forward ManyToOne Descriptor that selects subclass. Requires InheritanceAutoManager."""
def get_queryset(self, **hints):
return self.field.remote_field.model.objects.db_manager(
hints=hints
).select_subclasses()
class InheritanceForeignKey(models.ForeignKey):
"""Custom ForeignKey that uses InheritanceForwardManyToOneDescriptor"""
forward_related_accessor_class = InheritanceForwardManyToOneDescriptor