Add validator which succeeds if at least one of its subvalidators succeeded.

CHANGES.txt

@@ -7,6 +7,12 @@ Bug Fixes
 - Un-break wrapping of callable instances as ``colander.deferred``.
   See https://github.com/Pylons/colander/issues/141.
 
+Features
+~~~~~~~~
+
+- Add `Any` validator which succeeds if at least one of its subvalidators
+  succeeded.
+
 1.0b1 (2013-09-01)
 ------------------
 

colander/__init__.py

@@ -205,6 +205,18 @@ class All(object):
                 exc.children.extend(e.children)
             raise exc
 
+class Any(All):
+    """ Composite validator which succeeds if at least one of its
+    subvalidators does not raise an :class:`colander.Invalid` exception."""
+    def __call__(self, node, value):
+        try:
+            return super(Any, self).__call__(node, value)
+        except Invalid as e:
+            if len(e.msg) < len(self.validators):
+                # At least one validator did not fail:
+                return
+            raise
+
 class Function(object):
     """ Validator which accepts a function and an optional message;
     the function is called with the ``value`` during validation.

colander/tests/test_colander.py

@@ -219,6 +219,35 @@ class TestAll(unittest.TestCase):
         exc = invalid_exc(validator, node, None)
         self.assertEqual(exc.children, [exc1, exc2])
 
+class TestAny(unittest.TestCase):
+    def _makeOne(self, validators):
+        from colander import Any
+        return Any(*validators)
+
+    def test_success(self):
+        validator1 = DummyValidator('msg1')
+        validator2 = DummyValidator()
+        validator = self._makeOne([validator1, validator2])
+        self.assertEqual(validator(None, None), None)
+
+    def test_failure(self):
+        validator1 = DummyValidator('msg1')
+        validator2 = DummyValidator('msg2')
+        validator = self._makeOne([validator1, validator2])
+        e = invalid_exc(validator, None, None)
+        self.assertEqual(e.msg, ['msg1', 'msg2'])
+
+    def test_Invalid_children(self):
+        from colander import Invalid
+        node1 = DummySchemaNode(None, 'node1')
+        node = DummySchemaNode(None, 'node')
+        node.children = [node1]
+        exc1 = Invalid(node1, 'exc1')
+        validator1 = DummyValidator('validator1', [exc1])
+        validator2 = DummyValidator()
+        validator = self._makeOne([validator1, validator2])
+        self.assertEqual(validator(None, None), None)
+
 class TestFunction(unittest.TestCase):
     def _makeOne(self, *arg, **kw):
         from colander import Function

docs/api.rst

@@ -53,6 +53,8 @@ Validators
 
   .. autoclass:: All
 
+  .. autoclass:: Any
+
   .. autoclass:: Range
 
   .. autoclass:: Length