[reference][validation] Adding missing Callback constrain

weaverryan · weaverryan · commit bba67d83c788 · 2011-05-23T08:24:47.000-05:00
diff --git a/reference/constraints.rst b/reference/constraints.rst
@@ -8,6 +8,7 @@ Validation Constraints Reference
    constraints/False
    constraints/True
    constraints/Type
+   constraints/Callback
    constraints/Choice
    constraints/Collection
    constraints/Date
@@ -38,6 +39,7 @@ The following constraints are natively available in Symfony2:
 * :doc:`False <constraints/False>`
 * :doc:`True <constraints/True>`
 * :doc:`Type <constraints/Type>`
+* :doc:`Callback <constraints/Callback>`
 * :doc:`Choice <constraints/Choice>`
 * :doc:`Collection <constraints/Collection>`
 * :doc:`Date <constraints/Date>`
diff --git a/reference/constraints/Callback.rst b/reference/constraints/Callback.rst
@@ -0,0 +1,40 @@
+Callback
+========
+
+Calls methods during validation on the object. These methods can then perform
+any type of validation and assign errors where needed:
+
+.. code-block:: yaml
+
+    Acme\DemoBundle\Entity\Author:
+        constraints:
+            - Callback:
+                methods:   [isAuthorValid]
+
+Usage
+-----
+
+The callback method is passed a special ``ExecutionContext`` object::
+
+    use Symfony\Component\Validator\ExecutionContext;
+    
+    private $firstName;
+    
+    public function isAuthorValid(ExecutionContext $context)
+    {
+        // somehow you get an array of "fake names"
+        $fakeNames = array();
+        
+        // check if the name is actually a fake name
+        if (in_array($this->getFirstName(), $fakeNames)) {
+            $property_path = $context->getPropertyPath() . '.firstName';
+            $context->setPropertyPath($property_path);
+            $context->addViolation('This name sounds totally fake', array(), null);
+        }
+    }
+
+Options
+-------
+
+* ``methods``: The method names that should be executed as callbacks.
+* ``message``: The error message if the validation fails
