symfony/src/Symfony/Components/Routing/Matcher/UrlMatcher.php

<?php

namespace Symfony\Components\Routing\Matcher;

use Symfony\Components\Routing\Route;
use Symfony\Components\Routing\RouteCollection;

/*
 * This file is part of the symfony framework.
 *
 * (c) Fabien Potencier <fabien.potencier@symfony-project.com>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

/**
 * UrlMatcher matches URL based on a set of routes.
 *
 * @package    symfony
 * @subpackage routing
 * @author     Fabien Potencier <fabien.potencier@symfony-project.com>
 */
class UrlMatcher implements UrlMatcherInterface
{
  protected $routes;
  protected $defaults;
  protected $context;

  /**
   * Constructor.
   *
   * @param RouteCollection $routes   A RouteCollection instance
   * @param array           $context  The context
   * @param array           $defaults The default values
   */
  public function __construct(RouteCollection $routes, array $context = array(), array $defaults = array())
  {
    $this->routes = $routes;
    $this->context = $context;
    $this->defaults = $defaults;
  }

  /**
   * Tries to match a URL with a set of routes.
   *
   * Returns false if no route matches the URL.
   *
   * @param  string $url URL to be parsed
   *
   * @return array|false An array of parameters or false if no route matches
   */
  public function match($url)
  {
    $url = $this->normalizeUrl($url);

    foreach ($this->routes->getRoutes() as $name => $route)
    {
      $compiledRoute = $route->compile();

      // check HTTP method requirement
      if (isset($this->context['method']) && (($req = $route->getRequirement('_method')) && !in_array(strtolower($this->context['method']), array_map('strtolower', (array) $req))))
      {
        continue;
      }

      // check the static prefix of the URL first. Only use the more expensive preg_match when it matches
      if ('' !== $compiledRoute->getStaticPrefix() && 0 !== strpos($url, $compiledRoute->getStaticPrefix()))
      {
        continue;
      }

      if (!preg_match($compiledRoute->getRegex(), $url, $matches))
      {
        continue;
      }

      return array_merge($this->mergeDefaults($matches, $route->getDefaults()), array('_route' => $name));
    }

    return false;
  }

  protected function mergeDefaults($params, $defaults)
  {
    $parameters = array_merge($this->defaults, $defaults);
    foreach ($params as $key => $value)
    {
      if (!is_int($key))
      {
        $parameters[$key] = urldecode($value);
      }
    }

    return $parameters;
  }

  protected function normalizeUrl($url)
  {
    // ensure that the URL starts with a /
    if ('/' !== substr($url, 0, 1))
    {
      $url = '/'.$url;
    }

    // remove the query string
    if (false !== $pos = strpos($url, '?'))
    {
      $url = substr($url, 0, $pos);
    }

    // remove multiple /
    return preg_replace('#/+#', '/', $url);
  }
}