router.php

<?php

class Router {
  public $request_uri;
  public $routes;
  public $controller, $controller_name;
  public $action, $id;
  public $params;
  public $method;
  public $route_found = false;
  private $last_route_name;

  const default_controller = "home";
  const default_action = "index";

  public function __construct() {
    $request = $_SERVER['REQUEST_URI'];
    $pos = strpos($request, '?');
    if ($pos) $request = substr($request, 0, $pos);

    $this->request_uri = $request;
    $this->routes = array();
    $this->method = $_SERVER["REQUEST_METHOD"];
  }

  public function map($rule, $target=array(), $conditions=array()) {
    if (!array_key_exists($rule, $this->routes)) {
      $this->routes[$rule] = new Route($rule, $this->request_uri, $target, $conditions);
    }
  }

  public function nests_resources($nested_resource, $current_resource) {
    if ($_SERVER["REQUEST_METHOD"] == "GET") {
      $this->map("/$nested_resource/:id/$current_resource", array('controller' => $current_resource, 'action' => 'index'));
      $this->map("/$nested_resource/:id/$current_resource/new", array('controller' => $current_resource, 'action' => 'new'));
      $this->map("/$current_resource/:id/edit", array('controller' => $current_resource, 'action' => 'edit'));
      $this->map("/$current_resource/:id", array('controller' => $current_resource, 'action' => 'show'));
    } elseif ($_SERVER["REQUEST_METHOD"] == "POST") {
      if (array_key_exists("_method", $_REQUEST)) {
        if (strtolower($_REQUEST["_method"]) == "put") {
          $this->map("/$current_resource/:id", array('controller' => $current_resource, 'action' => 'update'));
        } elseif (strtolower($_REQUEST["_method"]) == "delete") {
          $this->map("/$current_resource/:id", array('controller' => $current_resource, 'action' => 'destroy'));
        }
      } else {
        $this->map("/$nested_resource/:id/$current_resource", array('controller' => $current_resource, 'action' => 'create'));
      }
    }
  }

  public function nests_resource($nested_resource, $current_resource) {
    if ($_SERVER["REQUEST_METHOD"] == "GET") {
      $this->map("/$nested_resource/:id/$current_resource", array('controller' => $current_resource, 'action' => 'show'));
      $this->map("/$nested_resource/:id/$current_resource/new", array('controller' => $current_resource, 'action' => 'new'));
      $this->map("/$current_resource/:id/edit", array('controller' => $current_resource, 'action' => 'edit'));
    } elseif ($_SERVER["REQUEST_METHOD"] == "POST") {
      if (array_key_exists("_method", $_REQUEST)) {
        if (strtolower($_REQUEST["_method"]) == "put") {
          $this->map("/$current_resource", array('controller' => $current_resource, 'action' => 'update'));
        } elseif (strtolower($_REQUEST["_method"]) == "delete") {
          $this->map("/$current_resource", array('controller' => $current_resource, 'action' => 'destroy'));
        }
      } else {
        $this->map("/$nested_resource/:id/$current_resource", array('controller' => $current_resource, 'action' => 'create'));
      }
    }
  }

  public function resources($name) {
    if ($_SERVER["REQUEST_METHOD"] == "GET") {
      $this->map("/$name", array('controller' => $name, 'action' => 'index'));
      $this->map("/$name/new", array('controller' => $name, 'action' => 'new'));
      $this->map("/$name/:id/edit", array('controller' => $name, 'action' => 'edit'));
      $this->map("/$name/:id", array('controller' => $name, 'action' => 'show'));
    } elseif ($_SERVER["REQUEST_METHOD"] == "POST") {
      if (array_key_exists("_method", $_REQUEST)) {
        if (strtolower($_REQUEST["_method"]) == "put") {
          $this->map("/$name/:id", array('controller' => $name, 'action' => 'update'));
        } elseif (strtolower($_REQUEST["_method"]) == "delete") {
          $this->map("/$name/:id", array('controller' => $name, 'action' => 'destroy'));
        }
      } else {
        $this->map("/$name", array('controller' => $name, 'action' => 'create'));
      }
    }
  }

  public function resource($name) {
    if ($_SERVER["REQUEST_METHOD"] == "GET") {
      $this->map("/$name", array('controller' => $name, 'action' => 'show'));
      $this->map("/$name/new", array('controller' => $name, 'action' => 'new'));
      $this->map("/$name/edit", array('controller' => $name, 'action' => 'edit'));
    } elseif ($_SERVER["REQUEST_METHOD"] == "POST") {
      if (array_key_exists("_method", $_REQUEST)) {
        if (strtolower($_REQUEST["_method"]) == "put") {
          $this->map("/$name", array('controller' => $name, 'action' => 'update'));
        } elseif (strtolower($_REQUEST["_method"]) == "delete") {
          $this->map("/$name", array('controller' => $name, 'action' => 'destroy'));
        }
      } else {
        $this->map("/$name", array('controller' => $name, 'action' => 'create'));
      }
    }
  }

  public function default_routes() {
    $this->map('/:controller');
    $this->map('/:controller/:action');
    $this->map('/:controller/:action/:id');
  }

  private function set_route($route) {
    $this->route_found = true;
    $params = $route->params;
    if (array_key_exists('controller', $params)) {
      $this->controller = $params['controller'];
    }
    if (array_key_exists('action', $params)) {
      $this->action = $params['action'];
    }
    if (array_key_exists('id', $params)) {
      $this->id = $params['id'];
    }

    $this->params = array_merge($params, $_GET);

    if (empty($this->controller)) $this->controller = default_controller;
    if (empty($this->action)) $this->action = default_action;
    if (empty($this->id)) $this->id = null;

    $w = explode('_', $this->controller);
    foreach($w as $k => $v) $w[$k] = ucfirst($v);
    $this->controller_name = implode('', $w);
  }

  public function execute() {
    foreach($this->routes as $route) {
      if ($route->is_matched) {
        $this->set_route($route);
        break;
      }
    }
  }
}

class Route {
  public $is_matched = false;
  public $params;
  public $url;
  private $conditions;

  function __construct($url, $request_uri, $target, $conditions) {
    $this->url = $url;
    $this->params = array();
    $this->conditions = $conditions;
    $p_names = array(); $p_values = array();

    preg_match_all('@:([\w]+)@', $url, $p_names, PREG_PATTERN_ORDER);
    $p_names = $p_names[0];

    $url_regex = preg_replace_callback('@:[\w]+@', array($this, 'regex_url'), $url);
    $url_regex .= '/?';

    if (preg_match('@^' . $url_regex . '$@', $request_uri, $p_values)) {
      array_shift($p_values);
      foreach($p_names as $index => $value) $this->params[substr($value,1)] = urldecode($p_values[$index]);
      foreach($target as $key => $value) $this->params[$key] = $value;
      $this->is_matched = true;
    }

    unset($p_names); unset($p_values);
  }

  function regex_url($matches) {
    $key = str_replace(':', '', $matches[0]);
    if (array_key_exists($key, $this->conditions)) {
      return '('.$this->conditions[$key].')';
    }
    else {
      return '([a-zA-Z0-9_\+\-%]+)';
    }
  }
}
?>