"""
Various edge-cases for model managers.
"""
from django.db import models
class OnlyFred(models.Manager):
def get_query_set(self):
return super(OnlyFred, self).get_query_set().filter(name='fred')
class OnlyBarney(models.Manager):
def get_query_set(self):
return super(OnlyBarney, self).get_query_set().filter(name='barney')
class Value42(models.Manager):
def get_query_set(self):
return super(Value42, self).get_query_set().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 __unicode__(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 __unicode__(self):
return self.data
class Child2(AbstractBase1, AbstractBase2):
data = models.CharField(max_length=25)
def __unicode__(self):
return self.data
class Child3(AbstractBase1, AbstractBase3):
data = models.CharField(max_length=25)
def __unicode__(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 __unicode__(self):
return self.data
class Child5(AbstractBase3):
name = models.CharField(max_length=25)
default = OnlyFred()
objects = models.Manager()
def __unicode__(self):
return self.name
# Will inherit managers from AbstractBase1, but not Child4.
class Child6(Child4):
value = models.IntegerField()
# Will not inherit default manager from parent.
class Child7(Parent):
pass