--- a/__init__.py	Tue Sep 11 22:32:01 2012 +0200
+++ b/__init__.py	Mon Sep 17 17:48:55 2012 +0200
@@ -199,3 +199,26 @@
         CW_EVENT_MANAGER.bind(event, func, *args, **kwargs)
         return func
     return _decorator
+
+
+from yams.schema import role_name as rname
+
+def validation_error(entity, errors, substitutions=None, i18nvalues=None):
+    """easy way to retrieve a :class:`cubicweb.ValidationError` for an entity or eid.
+
+    You may also have 2-tuple as error keys, :func:`yams.role_name` will be
+    called automatically for them.
+
+    Messages in errors **should not be translated yet**, though marked for
+    internationalization. You may give an additional substition dictionary that
+    will be used for interpolation after the translation.
+    """
+    if substitutions is None:
+        # set empty dict else translation won't be done for backward
+        # compatibility reason (see ValidationError.tr method)
+        substitutions = {}
+    for key in errors.keys():
+        if isinstance(key, tuple):
+            errors[rname(*key)] = errors.pop(key)
+    return ValidationError(getattr(entity, 'eid', entity), errors,
+                           substitutions, i18nvalues)