--- /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\DependencyInjection\Extension;
+
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+
+/**
+ * ExtensionInterface is the interface implemented by container extension classes.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+interface ExtensionInterface
+{
+ /**
+ * Loads a specific configuration.
+ *
+ * @param array $configs An array of configuration values
+ * @param ContainerBuilder $container A ContainerBuilder instance
+ *
+ * @throws \InvalidArgumentException When provided tag is not defined in this extension
+ */
+ public function load(array $configs, ContainerBuilder $container);
+
+ /**
+ * Returns the namespace to be used for this extension (XML namespace).
+ *
+ * @return string The XML namespace
+ */
+ public function getNamespace();
+
+ /**
+ * Returns the base path for the XSD files.
+ *
+ * @return string The XSD base path
+ */
+ public function getXsdValidationBasePath();
+
+ /**
+ * Returns the recommended alias to use in XML.
+ *
+ * This alias is also the mandatory prefix to use when using YAML.
+ *
+ * @return string The alias
+ */
+ public function getAlias();
+}