adding interface for middleware

lib/public/appframework/imiddleware.php

+<?php
+
+/**
+ * ownCloud - App Framework
+ *
+ * @author Bernhard Posselt
+ * @copyright 2012 Bernhard Posselt nukeawhale@gmail.com
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+
+namespace OCP\AppFramework;
+use OCP\AppFramework\Http\Response;
+
+
+/**
+ * Middleware is used to provide hooks before or after controller methods and
+ * deal with possible exceptions raised in the controller methods.
+ * They're modeled after Django's middleware system:
+ * https://docs.djangoproject.com/en/dev/topics/http/middleware/
+ */
+interface MiddleWare {
+
+
+	/**
+	 * This is being run in normal order before the controller is being
+	 * called which allows several modifications and checks
+	 *
+	 * @param Controller $controller the controller that is being called
+	 * @param string $methodName the name of the method that will be called on
+	 *                           the controller
+	 */
+	function beforeController($controller, $methodName);
+
+
+	/**
+	 * This is being run when either the beforeController method or the
+	 * controller method itself is throwing an exception. The middleware is
+	 * asked in reverse order to handle the exception and to return a response.
+	 * If the response is null, it is assumed that the exception could not be
+	 * handled and the error will be thrown again
+	 *
+	 * @param Controller $controller the controller that is being called
+	 * @param string $methodName the name of the method that will be called on
+	 *                           the controller
+	 * @param \Exception $exception the thrown exception
+	 * @throws \Exception the passed in exception if it cant handle it
+	 * @return Response a Response object in case that the exception was handled
+	 */
+	function afterException($controller, $methodName, \Exception $exception);
+
+	/**
+	 * This is being run after a successful controller method call and allows
+	 * the manipulation of a Response object. The middleware is run in reverse order
+	 *
+	 * @param Controller $controller the controller that is being called
+	 * @param string $methodName the name of the method that will be called on
+	 *                           the controller
+	 * @param Response $response the generated response from the controller
+	 * @return Response a Response object
+	 */
+	function afterController($controller, $methodName, Response $response);
+
+	/**
+	 * This is being run after the response object has been rendered and
+	 * allows the manipulation of the output. The middleware is run in reverse order
+	 *
+	 * @param Controller $controller the controller that is being called
+	 * @param string $methodName the name of the method that will be called on
+	 *                           the controller
+	 * @param string $output the generated output from a response
+	 * @return string the output that should be printed
+	 */
+	function beforeOutput($controller, $methodName, $output);
+}