RouterListener.php

<?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\HttpKernel\EventListener;

use Symfony\Component\HttpKernel\Log\LoggerInterface;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\HttpKernel\KernelEvents;
use Symfony\Component\HttpKernel\Exception\MethodNotAllowedHttpException;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use Symfony\Component\Routing\Exception\MethodNotAllowedException;
use Symfony\Component\Routing\Exception\ResourceNotFoundException;
use Symfony\Component\Routing\Matcher\UrlMatcherInterface;
use Symfony\Component\Routing\Matcher\RequestMatcherInterface;
use Symfony\Component\Routing\RequestContext;
use Symfony\Component\Routing\RequestContextAwareInterface;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

/**
 * Initializes the context from the request and sets request attributes based on a matching route.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class RouterListener implements EventSubscriberInterface {
  private $matcher;
  private $context;
  private $logger;

  /**
   * Constructor.
   *
   * @param UrlMatcherInterface|RequestMatcherInterface $matcher The Url or Request matcher
   * @param RequestContext|null                         $context The RequestContext (can be null when $matcher implements RequestContextAwareInterface)
   * @param LoggerInterface|null                        $logger  The logger
   */
  public function __construct($matcher, RequestContext $context = null, LoggerInterface $logger = null) {
    if (!$matcher instanceof UrlMatcherInterface && !$matcher instanceof RequestMatcherInterface) {
      throw new \InvalidArgumentException('Matcher must either implement UrlMatcherInterface or RequestMatcherInterface.');
    }
    if (null === $context && !$matcher instanceof RequestContextAwareInterface) {
      throw new \InvalidArgumentException('You must either pass a RequestContext or the matcher must implement RequestContextAwareInterface.');
    }
    $this->matcher = $matcher;
    $this->context = $context ?: $matcher
      ->getContext();
    $this->logger = $logger;
  }
  public function onKernelRequest(GetResponseEvent $event) {
    $request = $event
      ->getRequest();

    // initialize the context that is also used by the generator (assuming matcher and generator share the same context instance)
    $this->context
      ->fromRequest($request);
    if ($request->attributes
      ->has('_controller')) {

      // routing is already done
      return;
    }

    // add attributes based on the request (routing)
    try {

      // matching a request is more powerful than matching a URL path + context, so try that first
      if ($this->matcher instanceof RequestMatcherInterface) {
        $parameters = $this->matcher
          ->matchRequest($request);
      }
      else {
        $parameters = $this->matcher
          ->match($request
          ->getPathInfo());
      }
      if (null !== $this->logger) {
        $this->logger
          ->info(sprintf('Matched route "%s" (parameters: %s)', $parameters['_route'], $this
          ->parametersToString($parameters)));
      }
      $request->attributes
        ->add($parameters);
      unset($parameters['_route']);
      unset($parameters['_controller']);
      $request->attributes
        ->set('_route_params', $parameters);
    } catch (ResourceNotFoundException $e) {
      $message = sprintf('No route found for "%s %s"', $request
        ->getMethod(), $request
        ->getPathInfo());
      throw new NotFoundHttpException($message, $e);
    } catch (MethodNotAllowedException $e) {
      $message = sprintf('No route found for "%s %s": Method Not Allowed (Allow: %s)', $request
        ->getMethod(), $request
        ->getPathInfo(), strtoupper(implode(', ', $e
        ->getAllowedMethods())));
      throw new MethodNotAllowedHttpException($e
        ->getAllowedMethods(), $message, $e);
    }
  }
  private function parametersToString(array $parameters) {
    $pieces = array();
    foreach ($parameters as $key => $val) {
      $pieces[] = sprintf('"%s": "%s"', $key, is_string($val) ? $val : json_encode($val));
    }
    return implode(', ', $pieces);
  }
  public static function getSubscribedEvents() {
    return array(
      KernelEvents::REQUEST => array(
        array(
          'onKernelRequest',
          32,
        ),
      ),
    );
  }

}