--- /dev/null
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Config\Definition\Builder;
+
+use Symfony\Component\Config\Definition\BooleanNode;
+
+/**
+ * This class provides a fluent interface for defining a node.
+ *
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ */
+class BooleanNodeDefinition extends ScalarNodeDefinition
+{
+ /**
+ * {@inheritdoc}
+ */
+ public function __construct($name, NodeParentInterface $parent = null)
+ {
+ parent::__construct($name, $parent);
+
+ $this->nullEquivalent = true;
+ }
+
+ /**
+ * {@inheritdoc}
+ *
+ * @deprecated Deprecated since version 2.8, to be removed in 3.0.
+ */
+ public function cannotBeEmpty()
+ {
+ @trigger_error('The '.__METHOD__.' method is deprecated since version 2.8 and will be removed in 3.0.', E_USER_DEPRECATED);
+
+ return parent::cannotBeEmpty();
+ }
+
+ /**
+ * Instantiate a Node.
+ *
+ * @return BooleanNode The node
+ */
+ protected function instantiateNode()
+ {
+ return new BooleanNode($this->name, $this->parent);
+ }
+}