django/tests/regressiontests/model_inheritance_regress/models.py

"""
Regression tests for Model inheritance behaviour.
"""

from django.db import models

class Place(models.Model):
    name = models.CharField(max_length=50)
    address = models.CharField(max_length=80)

    class Meta:
        ordering = ('name',)
        
    def __unicode__(self):
        return u"%s the place" % self.name

class Restaurant(Place):
    serves_hot_dogs = models.BooleanField()
    serves_pizza = models.BooleanField()

    def __unicode__(self):
        return u"%s the restaurant" % self.name

class ItalianRestaurant(Restaurant):
    serves_gnocchi = models.BooleanField()

    def __unicode__(self):
        return u"%s the italian restaurant" % self.name

class ParkingLot(Place):
    # An explicit link to the parent (we can control the attribute name).
    parent = models.OneToOneField(Place, primary_key=True, parent_link=True)
    capacity = models.IntegerField()

    def __unicode__(self):
        return u"%s the parking lot" % self.name

__test__ = {'API_TESTS':"""
# Regression for #7350, #7202
# Check that when you create a Parent object with a specific reference to an existent
# child instance, saving the Parent doesn't duplicate the child. 
# This behaviour is only activated during a raw save - it is mostly relevant to 
# deserialization, but any sort of CORBA style 'narrow()' API would require a
# similar approach.

# Create a child-parent-grandparent chain
>>> place1 = Place(name="Guido's House of Pasta", address='944 W. Fullerton')
>>> place1.save_base(raw=True)
>>> restaurant = Restaurant(place_ptr=place1, serves_hot_dogs=True, serves_pizza=False)
>>> restaurant.save_base(raw=True)
>>> italian_restaurant = ItalianRestaurant(restaurant_ptr=restaurant, serves_gnocchi=True)
>>> italian_restaurant.save_base(raw=True)

# Create a child-parent chain with an explicit parent link
>>> place2 = Place(name='Main St', address='111 Main St')
>>> place2.save_base(raw=True)
>>> park = ParkingLot(parent=place2, capacity=100)
>>> park.save_base(raw=True)

# Check that no extra parent objects have been created.
>>> Place.objects.all()
[<Place: Guido's House of Pasta the place>, <Place: Main St the place>]

>>> dicts = Restaurant.objects.values('name','serves_hot_dogs')
>>> [sorted(d.items()) for d in dicts]
[[('name', u"Guido's House of Pasta"), ('serves_hot_dogs', True)]]

>>> dicts = ItalianRestaurant.objects.values('name','serves_hot_dogs','serves_gnocchi')
>>> [sorted(d.items()) for d in dicts]
[[('name', u"Guido's House of Pasta"), ('serves_gnocchi', True), ('serves_hot_dogs', True)]]

>>> dicts = ParkingLot.objects.values('name','capacity')
>>> [sorted(d.items()) for d in dicts]
[[('capacity', 100), ('name', u'Main St')]]

# You can also update objects when using a raw save.
>>> place1.name = "Guido's All New House of Pasta"
>>> place1.save_base(raw=True)

>>> restaurant.serves_hot_dogs = False
>>> restaurant.save_base(raw=True)

>>> italian_restaurant.serves_gnocchi = False
>>> italian_restaurant.save_base(raw=True)

>>> place2.name='Derelict lot'
>>> place2.save_base(raw=True)

>>> park.capacity = 50
>>> park.save_base(raw=True)

# No extra parent objects after an update, either.
>>> Place.objects.all()
[<Place: Derelict lot the place>, <Place: Guido's All New House of Pasta the place>]

>>> dicts = Restaurant.objects.values('name','serves_hot_dogs')
>>> [sorted(d.items()) for d in dicts]
[[('name', u"Guido's All New House of Pasta"), ('serves_hot_dogs', False)]]

>>> dicts = ItalianRestaurant.objects.values('name','serves_hot_dogs','serves_gnocchi')
>>> [sorted(d.items()) for d in dicts]
[[('name', u"Guido's All New House of Pasta"), ('serves_gnocchi', False), ('serves_hot_dogs', False)]]

>>> dicts = ParkingLot.objects.values('name','capacity')
>>> [sorted(d.items()) for d in dicts]
[[('capacity', 50), ('name', u'Derelict lot')]]

# If you try to raw_save a parent attribute onto a child object,
# the attribute will be ignored.

>>> italian_restaurant.name = "Lorenzo's Pasta Hut"
>>> italian_restaurant.save_base(raw=True)

# Note that the name has not changed
# - name is an attribute of Place, not ItalianRestaurant
>>> dicts = ItalianRestaurant.objects.values('name','serves_hot_dogs','serves_gnocchi')
>>> [sorted(d.items()) for d in dicts]
[[('name', u"Guido's All New House of Pasta"), ('serves_gnocchi', False), ('serves_hot_dogs', False)]]

"""}