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django/tests/modeltests/proxy_models/models.py

393 lines
12 KiB
Python

"""
By specifying the 'proxy' Meta attribute, model subclasses can specify that
they will take data directly from the table of their base class table rather
than using a new table of their own. This allows them to act as simple proxies,
providing a modified interface to the data from the base class.
"""
from django.contrib.contenttypes.models import ContentType
from django.db import models
# A couple of managers for testing managing overriding in proxy model cases.
class PersonManager(models.Manager):
def get_query_set(self):
return super(PersonManager, self).get_query_set().exclude(name="fred")
class SubManager(models.Manager):
def get_query_set(self):
return super(SubManager, self).get_query_set().exclude(name="wilma")
class Person(models.Model):
"""
A simple concrete base class.
"""
name = models.CharField(max_length=50)
objects = PersonManager()
def __unicode__(self):
return self.name
class Abstract(models.Model):
"""
A simple abstract base class, to be used for error checking.
"""
data = models.CharField(max_length=10)
class Meta:
abstract = True
class MyPerson(Person):
"""
A proxy subclass, this should not get a new table. Overrides the default
manager.
"""
class Meta:
proxy = True
ordering = ["name"]
objects = SubManager()
other = PersonManager()
def has_special_name(self):
return self.name.lower() == "special"
class ManagerMixin(models.Model):
excluder = SubManager()
class Meta:
abstract = True
class OtherPerson(Person, ManagerMixin):
"""
A class with the default manager from Person, plus an secondary manager.
"""
class Meta:
proxy = True
ordering = ["name"]
class StatusPerson(MyPerson):
"""
A non-proxy subclass of a proxy, it should get a new table.
"""
status = models.CharField(max_length=80)
# We can even have proxies of proxies (and subclass of those).
class MyPersonProxy(MyPerson):
class Meta:
proxy = True
class LowerStatusPerson(MyPersonProxy):
status = models.CharField(max_length=80)
class User(models.Model):
name = models.CharField(max_length=100)
def __unicode__(self):
return self.name
class UserProxy(User):
class Meta:
proxy = True
class UserProxyProxy(UserProxy):
class Meta:
proxy = True
# We can still use `select_related()` to include related models in our querysets.
class Country(models.Model):
name = models.CharField(max_length=50)
class State(models.Model):
name = models.CharField(max_length=50)
country = models.ForeignKey(Country)
def __unicode__(self):
return self.name
class StateProxy(State):
class Meta:
proxy = True
# Proxy models still works with filters (on related fields)
# and select_related, even when mixed with model inheritance
class BaseUser(models.Model):
name = models.CharField(max_length=255)
class TrackerUser(BaseUser):
status = models.CharField(max_length=50)
class ProxyTrackerUser(TrackerUser):
class Meta:
proxy = True
class Issue(models.Model):
summary = models.CharField(max_length=255)
assignee = models.ForeignKey(TrackerUser)
def __unicode__(self):
return ':'.join((self.__class__.__name__,self.summary,))
class Bug(Issue):
version = models.CharField(max_length=50)
reporter = models.ForeignKey(BaseUser)
class ProxyBug(Bug):
"""
Proxy of an inherited class
"""
class Meta:
proxy = True
class ProxyProxyBug(ProxyBug):
"""
A proxy of proxy model with related field
"""
class Meta:
proxy = True
class Improvement(Issue):
"""
A model that has relation to a proxy model
or to a proxy of proxy model
"""
version = models.CharField(max_length=50)
reporter = models.ForeignKey(ProxyTrackerUser)
associated_bug = models.ForeignKey(ProxyProxyBug)
class ProxyImprovement(Improvement):
class Meta:
proxy = True
__test__ = {'API_TESTS' : """
# The MyPerson model should be generating the same database queries as the
# Person model (when the same manager is used in each case).
>>> from django.db import DEFAULT_DB_ALIAS
>>> MyPerson.other.all().query.get_compiler(DEFAULT_DB_ALIAS).as_sql() == Person.objects.order_by("name").query.get_compiler(DEFAULT_DB_ALIAS).as_sql()
True
# The StatusPerson models should have its own table (it's using ORM-level
# inheritance).
>>> StatusPerson.objects.all().query.get_compiler(DEFAULT_DB_ALIAS).as_sql() == Person.objects.all().query.get_compiler(DEFAULT_DB_ALIAS).as_sql()
False
# Creating a Person makes them accessible through the MyPerson proxy.
>>> _ = Person.objects.create(name="Foo McBar")
>>> len(Person.objects.all())
1
>>> len(MyPerson.objects.all())
1
>>> MyPerson.objects.get(name="Foo McBar").id
1
>>> MyPerson.objects.get(id=1).has_special_name()
False
# Person is not proxied by StatusPerson subclass, however.
>>> StatusPerson.objects.all()
[]
# A new MyPerson also shows up as a standard Person
>>> _ = MyPerson.objects.create(name="Bazza del Frob")
>>> len(MyPerson.objects.all())
2
>>> len(Person.objects.all())
2
>>> _ = LowerStatusPerson.objects.create(status="low", name="homer")
>>> LowerStatusPerson.objects.all()
[<LowerStatusPerson: homer>]
# Correct type when querying a proxy of proxy
>>> MyPersonProxy.objects.all()
[<MyPersonProxy: Bazza del Frob>, <MyPersonProxy: Foo McBar>, <MyPersonProxy: homer>]
# Proxy models are included in the ancestors for a model's DoesNotExist and MultipleObjectsReturned
>>> try:
... MyPersonProxy.objects.get(name='Zathras')
... except Person.DoesNotExist:
... pass
>>> try:
... MyPersonProxy.objects.get(id__lt=10)
... except Person.MultipleObjectsReturned:
... pass
>>> try:
... StatusPerson.objects.get(name='Zathras')
... except Person.DoesNotExist:
... pass
>>> sp1 = StatusPerson.objects.create(name='Bazza Jr.')
>>> sp2 = StatusPerson.objects.create(name='Foo Jr.')
>>> try:
... StatusPerson.objects.get(id__lt=10)
... except Person.MultipleObjectsReturned:
... pass
# And now for some things that shouldn't work...
#
# All base classes must be non-abstract
>>> class NoAbstract(Abstract):
... class Meta:
... proxy = True
Traceback (most recent call last):
....
TypeError: Abstract base class containing model fields not permitted for proxy model 'NoAbstract'.
# The proxy must actually have one concrete base class
>>> class TooManyBases(Person, Abstract):
... class Meta:
... proxy = True
Traceback (most recent call last):
....
TypeError: Abstract base class containing model fields not permitted for proxy model 'TooManyBases'.
>>> class NoBaseClasses(models.Model):
... class Meta:
... proxy = True
Traceback (most recent call last):
....
TypeError: Proxy model 'NoBaseClasses' has no non-abstract model base class.
# A proxy cannot introduce any new fields
>>> class NoNewFields(Person):
... newfield = models.BooleanField()
... class Meta:
... proxy = True
Traceback (most recent call last):
....
FieldError: Proxy model 'NoNewFields' contains model fields.
# Manager tests.
>>> Person.objects.all().delete()
>>> _ = Person.objects.create(name="fred")
>>> _ = Person.objects.create(name="wilma")
>>> _ = Person.objects.create(name="barney")
>>> MyPerson.objects.all()
[<MyPerson: barney>, <MyPerson: fred>]
>>> MyPerson._default_manager.all()
[<MyPerson: barney>, <MyPerson: fred>]
>>> OtherPerson.objects.all()
[<OtherPerson: barney>, <OtherPerson: wilma>]
>>> OtherPerson.excluder.all()
[<OtherPerson: barney>, <OtherPerson: fred>]
>>> OtherPerson._default_manager.all()
[<OtherPerson: barney>, <OtherPerson: wilma>]
# Test save signals for proxy models
>>> from django.db.models import signals
>>> def make_handler(model, event):
... def _handler(*args, **kwargs):
... print u"%s %s save" % (model, event)
... return _handler
>>> h1 = make_handler('MyPerson', 'pre')
>>> h2 = make_handler('MyPerson', 'post')
>>> h3 = make_handler('Person', 'pre')
>>> h4 = make_handler('Person', 'post')
>>> signals.pre_save.connect(h1, sender=MyPerson)
>>> signals.post_save.connect(h2, sender=MyPerson)
>>> signals.pre_save.connect(h3, sender=Person)
>>> signals.post_save.connect(h4, sender=Person)
>>> dino = MyPerson.objects.create(name=u"dino")
MyPerson pre save
MyPerson post save
# Test save signals for proxy proxy models
>>> h5 = make_handler('MyPersonProxy', 'pre')
>>> h6 = make_handler('MyPersonProxy', 'post')
>>> signals.pre_save.connect(h5, sender=MyPersonProxy)
>>> signals.post_save.connect(h6, sender=MyPersonProxy)
>>> dino = MyPersonProxy.objects.create(name=u"pebbles")
MyPersonProxy pre save
MyPersonProxy post save
>>> signals.pre_save.disconnect(h1, sender=MyPerson)
>>> signals.post_save.disconnect(h2, sender=MyPerson)
>>> signals.pre_save.disconnect(h3, sender=Person)
>>> signals.post_save.disconnect(h4, sender=Person)
>>> signals.pre_save.disconnect(h5, sender=MyPersonProxy)
>>> signals.post_save.disconnect(h6, sender=MyPersonProxy)
# A proxy has the same content type as the model it is proxying for (at the
# storage level, it is meant to be essentially indistinguishable).
>>> ctype = ContentType.objects.get_for_model
>>> ctype(Person) is ctype(OtherPerson)
True
>>> MyPersonProxy.objects.all()
[<MyPersonProxy: barney>, <MyPersonProxy: dino>, <MyPersonProxy: fred>, <MyPersonProxy: pebbles>]
>>> u = User.objects.create(name='Bruce')
>>> User.objects.all()
[<User: Bruce>]
>>> UserProxy.objects.all()
[<UserProxy: Bruce>]
>>> UserProxyProxy.objects.all()
[<UserProxyProxy: Bruce>]
# Proxy objects can be deleted
>>> u2 = UserProxy.objects.create(name='George')
>>> UserProxy.objects.all()
[<UserProxy: Bruce>, <UserProxy: George>]
>>> u2.delete()
>>> UserProxy.objects.all()
[<UserProxy: Bruce>]
# We can still use `select_related()` to include related models in our querysets.
>>> country = Country.objects.create(name='Australia')
>>> state = State.objects.create(name='New South Wales', country=country)
>>> State.objects.select_related()
[<State: New South Wales>]
>>> StateProxy.objects.select_related()
[<StateProxy: New South Wales>]
>>> StateProxy.objects.get(name='New South Wales')
<StateProxy: New South Wales>
>>> StateProxy.objects.select_related().get(name='New South Wales')
<StateProxy: New South Wales>
>>> contributor = TrackerUser.objects.create(name='Contributor',status='contrib')
>>> someone = BaseUser.objects.create(name='Someone')
>>> _ = Bug.objects.create(summary='fix this', version='1.1beta',
... assignee=contributor, reporter=someone)
>>> pcontributor = ProxyTrackerUser.objects.create(name='OtherContributor',
... status='proxy')
>>> _ = Improvement.objects.create(summary='improve that', version='1.1beta',
... assignee=contributor, reporter=pcontributor,
... associated_bug=ProxyProxyBug.objects.all()[0])
# Related field filter on proxy
>>> ProxyBug.objects.get(version__icontains='beta')
<ProxyBug: ProxyBug:fix this>
# Select related + filter on proxy
>>> ProxyBug.objects.select_related().get(version__icontains='beta')
<ProxyBug: ProxyBug:fix this>
# Proxy of proxy, select_related + filter
>>> ProxyProxyBug.objects.select_related().get(version__icontains='beta')
<ProxyProxyBug: ProxyProxyBug:fix this>
# Select related + filter on a related proxy field
>>> ProxyImprovement.objects.select_related().get(reporter__name__icontains='butor')
<ProxyImprovement: ProxyImprovement:improve that>
# Select related + filter on a related proxy of proxy field
>>> ProxyImprovement.objects.select_related().get(associated_bug__summary__icontains='fix')
<ProxyImprovement: ProxyImprovement:improve that>
Proxy models can be loaded from fixtures (Regression for #11194)
>>> from django.core import management
>>> management.call_command('loaddata', 'mypeople.json', verbosity=0)
>>> MyPerson.objects.get(pk=100)
<MyPerson: Elvis Presley>
"""}