Fix DictionaryField to conform to the IDataManager spec: get() should…

… raise an exception if no value can be found.

CHANGES.txt

@@ -8,6 +8,10 @@ CHANGES
 - Bugfix: applyChanges should not try to compare old and new values of the old
   value can not be accessed.
 
+- Fix DictionaryField to conform to the IDataManager spec: get() should raise
+  an exception if no value can be found.
+
+
 2.3.3 (2010-04-20)
 ------------------
 

src/z3c/form/datamanager.py

@@ -28,6 +28,7 @@
 
 from z3c.form import interfaces
 
+_marker = []
 
 class DataManager(object):
     """Data manager base class."""
@@ -117,7 +118,10 @@ def __init__(self, data, field):
 
     def get(self):
         """See z3c.form.interfaces.IDataManager"""
-        return self.data.get(self.field.__name__, self.field.missing_value)
+        value = self.data.get(self.field.__name__, _marker)
+        if value is _marker:
+            raise AttributeError
+        return value
 
     def query(self, default=interfaces.NO_VALUE):
         """See z3c.form.interfaces.IDataManager"""

src/z3c/form/datamanager.txt

@@ -283,6 +283,9 @@ The datamanager can really only deal with dictionaries and mapping types:
 Let's now access the name:
 
   >>> nameDm.get()
+  Traceback (most recent call last):
+  ...
+  AttributeError
 
   >>> nameDm.query()
   <NO_VALUE>