--- /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\EnumNode;
+
+/**
+ * Enum Node Definition.
+ *
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ */
+class EnumNodeDefinition extends ScalarNodeDefinition
+{
+ private $values;
+
+ /**
+ * @param array $values
+ *
+ * @return $this
+ */
+ public function values(array $values)
+ {
+ $values = array_unique($values);
+
+ if (empty($values)) {
+ throw new \InvalidArgumentException('->values() must be called with at least one value.');
+ }
+
+ $this->values = $values;
+
+ return $this;
+ }
+
+ /**
+ * Instantiate a Node.
+ *
+ * @return EnumNode The node
+ *
+ * @throws \RuntimeException
+ */
+ protected function instantiateNode()
+ {
+ if (null === $this->values) {
+ throw new \RuntimeException('You must call ->values() on enum nodes.');
+ }
+
+ return new EnumNode($this->name, $this->parent, $this->values);
+ }
+}