""" Various edge-cases for model managers. """ from django.contrib.contenttypes.fields import GenericForeignKey, GenericRelation from django.contrib.contenttypes.models import ContentType from django.db import models class OnlyFred(models.Manager): def get_queryset(self): return super().get_queryset().filter(name="fred") class OnlyBarney(models.Manager): def get_queryset(self): return super().get_queryset().filter(name="barney") class Value42(models.Manager): def get_queryset(self): return super().get_queryset().filter(value=42) class AbstractBase1(models.Model): name = models.CharField(max_length=50) class Meta: abstract = True # Custom managers manager1 = OnlyFred() manager2 = OnlyBarney() objects = models.Manager() class AbstractBase2(models.Model): value = models.IntegerField() class Meta: abstract = True # Custom manager restricted = Value42() # No custom manager on this class to make sure the default case doesn't break. class AbstractBase3(models.Model): comment = models.CharField(max_length=50) class Meta: abstract = True class Parent(models.Model): name = models.CharField(max_length=50) manager = OnlyFred() def __str__(self): return self.name # Managers from base classes are inherited and, if no manager is specified # *and* the parent has a manager specified, the first one (in the MRO) will # become the default. class Child1(AbstractBase1): data = models.CharField(max_length=25) def __str__(self): return self.data class Child2(AbstractBase1, AbstractBase2): data = models.CharField(max_length=25) def __str__(self): return self.data class Child3(AbstractBase1, AbstractBase3): data = models.CharField(max_length=25) def __str__(self): return self.data class Child4(AbstractBase1): data = models.CharField(max_length=25) # Should be the default manager, although the parent managers are # inherited. default = models.Manager() def __str__(self): return self.data class Child5(AbstractBase3): name = models.CharField(max_length=25) default = OnlyFred() objects = models.Manager() def __str__(self): return self.name class Child6(Child4): value = models.IntegerField() class Child7(Parent): objects = models.Manager() # RelatedManagers class RelatedModel(models.Model): test_gfk = GenericRelation( "RelationModel", content_type_field="gfk_ctype", object_id_field="gfk_id" ) exact = models.BooleanField(null=True) def __str__(self): return str(self.pk) class RelationModel(models.Model): fk = models.ForeignKey(RelatedModel, models.CASCADE, related_name="test_fk") m2m = models.ManyToManyField(RelatedModel, related_name="test_m2m") gfk_ctype = models.ForeignKey(ContentType, models.SET_NULL, null=True) gfk_id = models.IntegerField(null=True) gfk = GenericForeignKey(ct_field="gfk_ctype", fk_field="gfk_id") def __str__(self): return str(self.pk)