Add 'changes' attribute to models

The 'changes' attribute returns a dictionary representing the state
of any top-level properties that have been changed since the object
was instantiated.

Bump version to v0.4.0

3 files changed, 17 insertions, 1 deletions

diff --git a/setup.py b/setup.py
index e20c6e1..019e556 100644
--- a/setup.py
+++ b/setup.py
@@ -11,7 +11,7 @@ def parse_requirements():
 
 setuptools.setup(
     name='warlock',
-    version='0.3.1',
+    version='0.4.0',
     description='Python object model built on top of JSON schema',
     author='Brian Waldon',
     author_email='bcwaldon@gmail.com',
diff --git a/test/test_core.py b/test/test_core.py
index 3502712..bc2828c 100644
--- a/test/test_core.py
+++ b/test/test_core.py
@@ -69,3 +69,12 @@ class TestCore(unittest.TestCase):
         self.assertEqual(sweden['name'], 'Sweden')
         sweden['name'] = 'Finland'
         self.assertEqual(sweden['name'], 'Finland')
+
+    def test_changes(self):
+        Country = warlock.model_factory(fixture)
+        sweden = Country(name='Sweden', population=9379116)
+        self.assertEqual(sweden.changes, {})
+        sweden['name'] = 'Finland'
+        self.assertEqual(sweden.changes, {'name': 'Finland'})
+        sweden['name'] = 'Norway'
+        self.assertEqual(sweden.changes, {'name': 'Norway'})
diff --git a/warlock/core.py b/warlock/core.py
index c8359b7..eacd7ab 100644
--- a/warlock/core.py
+++ b/warlock/core.py
@@ -38,6 +38,8 @@ def model_factory(schema):
             else:
                 self.__dict__['raw'] = kwargs
 
+            self.__dict__['changes'] = {}
+
         def __getattr__(self, key):
             try:
                 return self.__getitem__(key)
@@ -55,6 +57,7 @@ def model_factory(schema):
             except ValidationError:
                 raise InvalidOperation()
             self.__dict__['raw'] = mutation
+            self.__dict__['changes'][key] = value
 
         def __setattr__(self, key, value):
             self.__setitem__(key, value)
@@ -65,5 +68,9 @@ def model_factory(schema):
         def items(self):
             return copy.deepcopy(self.__dict__['raw']).items()
 
+        @property
+        def changes(self):
+            return copy.deepcopy(self.__dict__['changes'])
+
     Model.__name__ = str(schema['name'])
     return Model