1 files changed, 37 insertions, 1 deletions
diff --git a/django/core/exceptions.py b/django/core/exceptions.py
index 1c21031739..fee7db4778 100644
--- a/django/core/exceptions.py
+++ b/django/core/exceptions.py
@@ -32,6 +32,42 @@ class FieldError(Exception):
     """Some kind of problem with a model field."""
     pass
 
-class ValidationError(Exception):
+NON_FIELD_ERRORS = '__all__'
+class BaseValidationError(Exception):
     """An error while validating data."""
+    def __init__(self, message, code=None, params=None):
+        import operator
+        from django.utils.encoding import force_unicode
+        """
+        ValidationError can be passed any object that can be printed (usually
+        a string), a list of objects or a dictionary.
+        """
+        if isinstance(message, dict):
+            self.message_dict = message
+            # Reduce each list of messages into a single list.
+            message = reduce(operator.add, message.values())
+
+        if isinstance(message, list):
+            self.messages = [force_unicode(msg) for msg in message]
+        else:
+            self.code = code
+            self.params = params
+            message = force_unicode(message)
+            self.messages = [message]
+
+    def __str__(self):
+        # This is needed because, without a __str__(), printing an exception
+        # instance would result in this:
+        # AttributeError: ValidationError instance has no attribute 'args'
+        # See http://www.python.org/doc/current/tut/node10.html#handling
+        if hasattr(self, 'message_dict'):
+            return repr(self.message_dict)
+        return repr(self.messages)
+
+class ValidationError(BaseValidationError):
     pass
+
+class UnresolvableValidationError(BaseValidationError):
+    """Validation error that cannot be resolved by the user."""
+    pass
+