Allow functions for typecast for properties

2 files changed, 7 insertions, 1 deletions

diff --git a/active_document/metadata.py b/active_document/metadata.py
index e5fa565..1dfab1f 100644
--- a/active_document/metadata.py
+++ b/active_document/metadata.py
@@ -14,6 +14,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
+import types
 from os.path import join, exists, abspath, dirname
 from gettext import gettext as _
 
@@ -299,7 +300,9 @@ def _convert(typecast, value):
         first = iter(typecast).next()
         return type(first) is not type and type(first) not in _LIST_TYPES
 
-    if typecast in [None, str]:
+    if type(typecast) is types.FunctionType:
+        value = typecast(value)
+    elif typecast in [None, str]:
         if isinstance(value, unicode):
             value = value.encode('utf-8')
         else:
diff --git a/tests/units/metadata.py b/tests/units/metadata.py
index a31787e..e70e2b7 100755
--- a/tests/units/metadata.py
+++ b/tests/units/metadata.py
@@ -88,6 +88,9 @@ class MetadataTest(tests.Test):
         prop = metadata.Property('prop', typecast=[frozenset(['A', 'B', 'C'])])
         self.assertEqual(('A', 'B', 'C'), prop.convert(['A', 'B', 'C']))
 
+        prop = metadata.Property('prop', typecast=lambda x: x + 1)
+        self.assertEqual(1, prop.convert(0))
+
     def test_Property_reprcast(self):
         prop = metadata.Property('prop', typecast=int)
         self.assertEqual(['0'], prop.reprcast(0))