Merge "Add a TimestampedObject mixin"

oslo_versionedobjects/base.py

@@ -715,6 +715,18 @@ class ComparableVersionedObject(object):
         return NotImplemented
 
 
+class TimestampedObject(object):
+    """Mixin class for db backed objects with timestamp fields.
+
+    Sqlalchemy models that inherit from the oslo_db TimestampMixin will include
+    these fields and the corresponding objects will benefit from this mixin.
+    """
+    fields = {
+        'created_at': obj_fields.DateTimeField(nullable=True),
+        'updated_at': obj_fields.DateTimeField(nullable=True),
+    }
+
+
 class VersionedObjectDictCompat(object):
     """Mix-in to provide dictionary key access compatibility
 

oslo_versionedobjects/tests/test_objects.py

@@ -23,6 +23,7 @@ import mock
 from oslo_context import context
 from oslo_serialization import jsonutils
 from oslo_utils import timeutils
+import testtools
 from testtools import matchers
 
 from oslo_versionedobjects import base
@@ -2441,3 +2442,42 @@ class TestListObjectConcat(test.TestCase):
             return [] + obj
 
         self.assertRaises(TypeError, add, list1)
+
+
+class TestTimestampedObject(test.TestCase):
+    """Test TimestampedObject mixin.
+
+    Do this by creating an object that uses the mixin and confirm that the
+    added fields are there and in fact behaves as the DateTimeFields we desire.
+    """
+
+    def setUp(self):
+        super(TestTimestampedObject, self).setUp()
+
+        @base.VersionedObjectRegistry.register_if(False)
+        class MyTimestampedObject(base.VersionedObject,
+                                  base.TimestampedObject):
+            fields = {
+                'field1': fields.Field(fields.String()),
+            }
+
+        self.myclass = MyTimestampedObject
+        self.my_object = self.myclass(field1='field1')
+
+    def test_timestamped_has_fields(self):
+        self.assertEqual('field1', self.my_object.field1)
+        self.assertIn('updated_at', self.my_object.fields)
+        self.assertIn('created_at', self.my_object.fields)
+
+    def test_timestamped_holds_timestamps(self):
+        now = timeutils.utcnow(with_timezone=True)
+        self.my_object.updated_at = now
+        self.my_object.created_at = now
+        self.assertEqual(now, self.my_object.updated_at)
+        self.assertEqual(now, self.my_object.created_at)
+
+    def test_timestamped_rejects_not_timestamps(self):
+        with testtools.ExpectedException(ValueError, '.*parse date.*'):
+            self.my_object.updated_at = 'a string'
+        with testtools.ExpectedException(ValueError, '.*parse date.*'):
+            self.my_object.created_at = 'a string'