--- /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;
+
+use Symfony\Component\Config\Definition\Exception\InvalidConfigurationException;
+
+/**
+ * Node which only allows a finite set of values.
+ *
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ */
+class EnumNode extends ScalarNode
+{
+ private $values;
+
+ public function __construct($name, NodeInterface $parent = null, array $values = array())
+ {
+ $values = array_unique($values);
+ if (empty($values)) {
+ throw new \InvalidArgumentException('$values must contain at least one element.');
+ }
+
+ parent::__construct($name, $parent);
+ $this->values = $values;
+ }
+
+ public function getValues()
+ {
+ return $this->values;
+ }
+
+ protected function finalizeValue($value)
+ {
+ $value = parent::finalizeValue($value);
+
+ if (!in_array($value, $this->values, true)) {
+ $ex = new InvalidConfigurationException(sprintf(
+ 'The value %s is not allowed for path "%s". Permissible values: %s',
+ json_encode($value),
+ $this->getPath(),
+ implode(', ', array_map('json_encode', $this->values))));
+ $ex->setPath($this->getPath());
+
+ throw $ex;
+ }
+
+ return $value;
+ }
+}