Merge pull request django-polymorphic#63 from dannyshaw/fix-child-type-validation

Allow child type validation in memory

Author: vdboor

polymorphic_tree/models.py

@@ -174,6 +174,11 @@ def is_child_allowed(self, child):
  return False
 
  child_types = self.get_child_types()
+
+ # this allows tree validation to occur in the event the child model is not
+# yet created in db (ie. when django admin tries to validate)
+ child.pre_save_polymorphic()
+
  return not child_types or child.polymorphic_ctype_id in child_types
 
  def validate_move(self, target, position='first-child'):

polymorphic_tree/tests/models.py

@@ -145,3 +145,8 @@ class ModelMustBeChildRoot(PolymorphicMPTTModel):
 
 class ModelMustBeChild(ModelMustBeChildRoot):
  can_be_root = False
+
+class ModelRestrictedChildren(Base):
+ child_types = [
+ ModelX,
+ ]

polymorphic_tree/tests/test_models.py

@@ -35,6 +35,7 @@ class PolymorphicTests(TestCase):
  test_custom_pk()
  test_fix_getattribute()
  test_parent_link_and_related_name()
+ test_child_type_validation_in_memory()
 
  """
 
@@ -227,6 +228,21 @@ def test_node_type_checking(self):
  self.assertTrue(grandchild.is_leaf_node())
  self.assertFalse(grandchild.is_root_node())
 
+ def test_child_type_validation_in_memory(self):
+ root_node = ModelRestrictedChildren.objects.create(field_b='root')
+
+ valid_child = ModelX(field_b='valid_child', field_x='ModelX', parent=root_node)
+ valid_child.clean()
+
+ with self.assertRaises(ValidationError) as context:
+ invalid_child = ModelY(field_b='invalid_child', field_y='ModelY', parent=root_node)
+ invalid_child.clean()
+
+ self.assertTrue('a model restricted children does not allow model y as a child!'
+ in context.exception.args[0]['parent'])
+
+
+
  def test_tree_manager(self):
  # Having the tree manager correct is absolutely essential,
  # so our move validation is also triggered.