From cb5945f96cc76d71f81cc878a6d20a54f47cd511 Mon Sep 17 00:00:00 2001
From: Blake Eggleston <bdeggleston@gmail.com>
Date: Wed, 6 Mar 2013 20:41:13 -0800
Subject: [PATCH] renaming the value manager's initial_value field to
 previous_value

---
 cqlengine/columns.py                   | 14 ++++++++++++--
 cqlengine/tests/model/test_model_io.py |  2 +-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/cqlengine/columns.py b/cqlengine/columns.py
index fe7ad9e3..67d9212a 100644
--- a/cqlengine/columns.py
+++ b/cqlengine/columns.py
@@ -12,12 +12,22 @@ class BaseValueManager(object):
     def __init__(self, instance, column, value):
         self.instance = instance
         self.column = column
-        self.initial_value = copy(value)
+        self.previous_value = copy(value)
         self.value = value
 
     @property
     def deleted(self):
-        return self.value is None and self.initial_value is not None
+        return self.value is None and self.previous_value is not None
+
+    @property
+    def changed(self):
+        """
+        Indicates whether or not this value has changed.
+
+        :rtype: boolean
+
+        """
+        return self.value != self.previous_value
 
     def getval(self):
         return self.value
diff --git a/cqlengine/tests/model/test_model_io.py b/cqlengine/tests/model/test_model_io.py
index f94b5964..4c40e2be 100644
--- a/cqlengine/tests/model/test_model_io.py
+++ b/cqlengine/tests/model/test_model_io.py
@@ -62,7 +62,7 @@ class TestModelIO(BaseCassEngTestCase):
 
         tm2 = TestModel.objects(id=tm.pk).first()
         assert tm2.text is None
-        assert tm2._values['text'].initial_value is None
+        assert tm2._values['text'].previous_value is None
 
 
     def test_a_sensical_error_is_raised_if_you_try_to_create_a_table_twice(self):