cakephp/src/Routing/Dispatcher.php

<?php
/**
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @since         0.2.9
 * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 */
namespace Cake\Routing;

use Cake\Controller\Controller;
use Cake\Event\Event;
use Cake\Event\EventListener;
use Cake\Event\EventManagerTrait;
use Cake\Network\Request;
use Cake\Network\Response;
use Cake\Routing\Exception\MissingControllerException;
use LogicException;

/**
 * Dispatcher converts Requests into controller actions. It uses the dispatched Request
 * to locate and load the correct controller. If found, the requested action is called on
 * the controller
 *
 */
class Dispatcher {

	use EventManagerTrait;

/**
 * Connected filter objects
 *
 * @var array
 */
	protected $_filters = [];

/**
 * Dispatches and invokes given Request, handing over control to the involved controller. If the controller is set
 * to autoRender, via Controller::$autoRender, then Dispatcher will render the view.
 *
 * Actions in CakePHP can be any public method on a controller, that is not declared in Controller. If you
 * want controller methods to be public and in-accessible by URL, then prefix them with a `_`.
 * For example `public function _loadPosts() { }` would not be accessible via URL. Private and protected methods
 * are also not accessible via URL.
 *
 * If no controller of given name can be found, invoke() will throw an exception.
 * If the controller is found, and the action is not found an exception will be thrown.
 *
 * @param \Cake\Network\Request $request Request object to dispatch.
 * @param \Cake\Network\Response $response Response object to put the results of the dispatch into.
 * @return string|void if `$request['return']` is set then it returns response body, null otherwise
 * @throws \Cake\Routing\Exception\MissingControllerException When the controller is missing.
 */
	public function dispatch(Request $request, Response $response) {
		$beforeEvent = $this->dispatchEvent('Dispatcher.beforeDispatch', compact('request', 'response'));

		$request = $beforeEvent->data['request'];
		if ($beforeEvent->result instanceof Response) {
			if (isset($request->params['return'])) {
				return $beforeEvent->result->body();
			}
			$beforeEvent->result->send();
			return;
		}

		$controller = false;
		if (isset($beforeEvent->data['controller'])) {
			$controller = $beforeEvent->data['controller'];
		}

		if (!($controller instanceof Controller)) {
			throw new MissingControllerException(array(
				'class' => $request->params['controller'],
				'plugin' => empty($request->params['plugin']) ? null : $request->params['plugin'],
				'prefix' => empty($request->params['prefix']) ? null : $request->params['prefix'],
				'_ext' => empty($request->params['_ext']) ? null : $request->params['_ext']
			));
		}

		$response = $this->_invoke($controller);
		if (isset($request->params['return'])) {
			return $response->body();
		}

		$afterEvent = $this->dispatchEvent('Dispatcher.afterDispatch', compact('request', 'response'));
		$afterEvent->data['response']->send();
	}

/**
 * Initializes the components and models a controller will be using.
 * Triggers the controller action and invokes the rendering if Controller::$autoRender
 * is true. If a response object is returned by controller action that is returned
 * else controller's $response property is returned.
 *
 * @param Controller $controller Controller to invoke
 * @return \Cake\Network\Response The resulting response object
 * @throws \LogicException If data returned by controller action is not an
 *   instance of Response
 */
	protected function _invoke(Controller $controller) {
		$result = $controller->startupProcess();
		if ($result instanceof Response) {
			return $result;
		}

		$response = $controller->invokeAction();
		if ($response !== null && !($response instanceof Response)) {
			throw new LogicException('Controller action can only return an instance of Response');
		}

		if (!$response && $controller->autoRender) {
			$response = $controller->render();
		} elseif (!$response) {
			$response = $controller->response;
		}

		$result = $controller->shutdownProcess();
		if ($result instanceof Response) {
			return $result;
		}

		return $response;
	}

/**
 * Add a filter to this dispatcher.
 *
 * The added filter will be attached to the event manager used
 * by this dispatcher.
 *
 * @param \Cake\Event\EventListener $filter The filter to connect. Can be
 *   any EventListener. Typically an instance of \Cake\Routing\DispatcherFilter.
 * @return void
 */
	public function addFilter(EventListener $filter) {
		$this->_filters[] = $filter;
		$this->eventManager()->attach($filter);
	}

/**
 * Get the list of connected filters.
 *
 * @return array
 */
	public function filters() {
		return $this->_filters;
	}

}