2008-09-02 17:04:54 +08:00
|
|
|
"""
|
|
|
|
Various edge-cases for model managers.
|
|
|
|
"""
|
|
|
|
|
|
|
|
from django.db import models
|
|
|
|
|
2011-10-14 05:34:56 +08:00
|
|
|
|
2008-09-02 17:04:54 +08:00
|
|
|
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
|