# HG changeset patch
# User Branko Majic <branko@majic.rs>
# Date 2013-07-14 13:27:02
# Node ID 5c7da7c67a3edf4521f36224b262a804a7bff437
# Parent  5deeefd8d0fc753318a1848e0b7f859806982745

Noticket: Added a check for existing communications when attempting to move entity to a different project. Includes test of new functionality.

diff --git a/conntrackt/models.py b/conntrackt/models.py
--- a/conntrackt/models.py
+++ b/conntrackt/models.py
@@ -149,6 +149,26 @@ class Entity(models.Model):
 
         return reverse("entity", kwargs={'pk': self.pk})
 
+    def clean(self):
+        """
+        Performs additional validation checks on the submitted data. It will
+        verify the following:
+
+          - That entity is not linked to any other entity in case of project
+            change.
+        """
+
+        # Perform the check if entity is being updated.
+        if self.pk:
+            # Fetch the old data from database.
+            # @TODO: Is it better to do copying during __init__ instead?
+            old_object = Entity.objects.get(pk=1)
+
+            # Make sure that entity has no communications in current project if
+            # moving it around.
+            if self.project != old_object.project and (self.incoming_communications() or self.outgoing_communications()):
+                raise ValidationError("The entity cannot be moved to different project as long as it has valid communications with entities in current project.")
+
 
 class Interface(models.Model):
     """
diff --git a/conntrackt/tests/test_models.py b/conntrackt/tests/test_models.py
--- a/conntrackt/tests/test_models.py
+++ b/conntrackt/tests/test_models.py
@@ -117,6 +117,18 @@ class EntityTest(TestCase):
 
         self.assertEqual(entity.get_absolute_url(), "/conntrackt/entity/1/")
 
+    def test_project_move_constraints(self):
+        """
+        Tests if entity is prevented from being moved to different project in
+        case of existing communications.
+        """
+
+        entity = Entity.objects.get(pk=1)
+        new_project = Project.objects.get(pk=2)
+
+        entity.project = new_project
+        self.assertRaisesRegexp(ValidationError, "The entity cannot be moved to different project as long as it has valid communications with entities in current project." ,entity.clean)
+
 
 class InterfaceTest(TestCase):
     fixtures = ['test-data.json']