/tests/modeltests/generic_relations/models.py
Python | 80 lines | 44 code | 21 blank | 15 comment | 0 complexity | d436b497bddc69ebe8948bb989795ee3 MD5 | raw file
Possible License(s): BSD-3-Clause
- """
- 34. Generic relations
- Generic relations let an object have a foreign key to any object through a
- content-type/object-id field. A ``GenericForeignKey`` field can point to any
- object, be it animal, vegetable, or mineral.
- The canonical example is tags (although this example implementation is *far*
- from complete).
- """
- from django.contrib.contenttypes import generic
- from django.contrib.contenttypes.models import ContentType
- from django.db import models
- class TaggedItem(models.Model):
- """A tag on an item."""
- tag = models.SlugField()
- content_type = models.ForeignKey(ContentType)
- object_id = models.PositiveIntegerField()
- content_object = generic.GenericForeignKey()
- class Meta:
- ordering = ["tag", "content_type__name"]
- def __unicode__(self):
- return self.tag
- class ValuableTaggedItem(TaggedItem):
- value = models.PositiveIntegerField()
- class Comparison(models.Model):
- """
- A model that tests having multiple GenericForeignKeys
- """
- comparative = models.CharField(max_length=50)
- content_type1 = models.ForeignKey(ContentType, related_name="comparative1_set")
- object_id1 = models.PositiveIntegerField()
- content_type2 = models.ForeignKey(ContentType, related_name="comparative2_set")
- object_id2 = models.PositiveIntegerField()
- first_obj = generic.GenericForeignKey(ct_field="content_type1", fk_field="object_id1")
- other_obj = generic.GenericForeignKey(ct_field="content_type2", fk_field="object_id2")
- def __unicode__(self):
- return u"%s is %s than %s" % (self.first_obj, self.comparative, self.other_obj)
- class Animal(models.Model):
- common_name = models.CharField(max_length=150)
- latin_name = models.CharField(max_length=150)
- tags = generic.GenericRelation(TaggedItem)
- comparisons = generic.GenericRelation(Comparison,
- object_id_field="object_id1",
- content_type_field="content_type1")
- def __unicode__(self):
- return self.common_name
- class Vegetable(models.Model):
- name = models.CharField(max_length=150)
- is_yucky = models.BooleanField(default=True)
- tags = generic.GenericRelation(TaggedItem)
- def __unicode__(self):
- return self.name
- class Mineral(models.Model):
- name = models.CharField(max_length=150)
- hardness = models.PositiveSmallIntegerField()
- # note the lack of an explicit GenericRelation here...
- def __unicode__(self):
- return self.name