Added m2o_recursive and m2o_recursive2 model unit tests/examples

git-svn-id: http://code.djangoproject.com/svn/django/trunk@356 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/testapp/models/__init__.py

@@ -1 +1,3 @@
-__all__ = ['basic', 'repr', 'custom_methods', 'many_to_one', 'many_to_many', 'ordering', 'lookup', 'get_latest', 'm2m_intermediary', 'one_to_one']
+__all__ = ['basic', 'repr', 'custom_methods', 'many_to_one', 'many_to_many',
+           'ordering', 'lookup', 'get_latest', 'm2m_intermediary', 'one_to_one',
+           'm2o_recursive', 'm2o_recursive2']

tests/testapp/models/m2m_intermediary.py

@@ -4,9 +4,10 @@
 For many-to-many relationships that need extra fields on the intermediary
 table, use an intermediary model.
 
-In this example, an article can have multiple reporters, and each
+In this example, an ``Article`` can have multiple ``Reporter``s, and each
-article-reporter combination (a "Writer") has a "position" field, which
+``Article``-``Reporter`` combination (a ``Writer``) has a ``position`` field,
-specifies the reporter's position for the given article (e.g. "Staff writer").
+which specifies the ``Reporter``'s position for the given article (e.g. "Staff
+writer").
 """
 
 from django.core import meta

tests/testapp/models/m2o_recursive.py

@@ -0,0 +1,48 @@
+"""
+11. Relating an object to itself, many-to-one
+
+To define a many-to-one relationship between a model and itself, use
+``ForeignKey('self')``.
+
+In this example, a ``Category`` is related to itself. That is, each
+``Category`` has a parent ``Category``.
+
+Because of this recursive relationship, we need to tell Django what the
+relationships should be called. Set ``rel_name`` for this, and set
+``related_name`` to designate what the reverse relationship is called.
+"""
+
+from django.core import meta
+
+class Category(meta.Model):
+    module_name = 'categories'
+    fields = (
+        meta.CharField('name', maxlength=20),
+        meta.ForeignKey('self', null=True,
+            rel_name='parent', related_name='child'),
+    )
+
+    def __repr__(self):
+        return self.name
+
+API_TESTS = """
+# Create a few Category objects.
+>>> r = categories.Category(id=None, name='Root category', parent_id=None)
+>>> r.save()
+>>> c = categories.Category(id=None, name='Child category', parent_id=r.id)
+>>> c.save()
+
+>>> r.get_child_list()
+[Child category]
+>>> r.get_child(name__startswith='Child')
+Child category
+>>> r.get_parent()
+Traceback (most recent call last):
+    ...
+CategoryDoesNotExist
+
+>>> c.get_child_list()
+[]
+>>> c.get_parent()
+Root category
+"""

tests/testapp/models/m2o_recursive2.py

@@ -0,0 +1,51 @@
+"""
+12. Relating a model to another model more than once
+
+In this example, a ``Person`` can have a ``mother`` and ``father`` -- both of
+which are other ``Person`` objects.
+
+Because a ``Person`` has multiple relationships to ``Person``, we need to
+distinguish the relationships. Set ``rel_name`` to tell Django what the
+relationship should be called, because ``Person`` has two relationships to the
+same model. Also, set ``related_name`` to designate what the reverse
+relationship is called.
+"""
+
+from django.core import meta
+
+class Person(meta.Model):
+    fields = (
+        meta.CharField('full_name', maxlength=20),
+        meta.ForeignKey('self', null=True, rel_name='mother',
+            related_name='mothers_child'),
+        meta.ForeignKey('self', null=True, rel_name='father',
+            related_name='fathers_child'),
+    )
+
+    def __repr__(self):
+        return self.full_name
+
+API_TESTS = """
+# Create two Person objects -- the mom and dad in our family.
+>>> dad = persons.Person(id=None, full_name='John Smith Senior', mother_id=None, father_id=None)
+>>> dad.save()
+>>> mom = persons.Person(id=None, full_name='Jane Smith', mother_id=None, father_id=None)
+>>> mom.save()
+
+# Give mom and dad a kid.
+>>> kid = persons.Person(id=None, full_name='John Smith Junior', mother_id=mom.id, father_id=dad.id)
+>>> kid.save()
+
+>>> kid.get_mother()
+Jane Smith
+>>> kid.get_father()
+John Smith Senior
+>>> dad.get_fathers_child_list()
+[John Smith Junior]
+>>> mom.get_mothers_child_list()
+[John Smith Junior]
+>>> kid.get_mothers_child_list()
+[]
+>>> kid.get_fathers_child_list()
+[]
+"""