describe how to access form errors

Author: xabbuh

components/form/introduction.rst

@@ -617,6 +617,27 @@ and the errors will display next to the fields on error.
     For a list of all of the built-in validation constraints, see
     :doc:`/reference/constraints`.
 
+Accessing Form Errors
+~~~~~~~~~~~~~~~~~~~~~
+
+You can use the :method:`Symfony\\Component\\Form\\FormInterface::getErrors`
+method to access the list of errors. Each element is a :class:`Symfony\\Component\\Form\\FormError`
+object::
+
+    $form = ...;
+
+    // ...
+
+    // array of FormError objects
+    $errors = $form->getErrors();
+
+.. note::
+
+    Unless you enable the :ref:`error_bubbling <reference-form-option-error-bubbling>`
+    option on a particular child form, ``getErrors()`` only returns the errors
+    of the form it is accessed on. For debugging purposes, you can use the :method:`Symfony\\Component\\Form\\Form::getErrorsAsString` method which
+    returns a string representation of all errors of the whole form tree.
+
 .. _Packagist: https://packagist.org/packages/symfony/form
 .. _Twig:      http://twig.sensiolabs.org
 .. _`Twig Configuration`: http://twig.sensiolabs.org/doc/intro.html

reference/forms/types/form.rst

@@ -76,6 +76,8 @@ The actual default value of this option depends on other field options:
 .. include:: /reference/forms/types/options/empty_data.rst.inc
     :start-after: DEFAULT_PLACEHOLDER
 
+.. _reference-form-option-error-bubbling:
+
 .. include:: /reference/forms/types/options/error_bubbling.rst.inc
 
 .. include:: /reference/forms/types/options/error_mapping.rst.inc