Routed URL helper for CodeIgniter

route_url_helper.php

<?php

function route_url($segments, $slash = true) {
  $CI =& get_instance();
  
  $routes = $CI->router->routes;
  
  $toReturn = false;
  
  foreach ($routes as $route => $arch) {
    $arch = str_replace('/', '\/', $arch);
    $arch = str_replace(array('$1', '$2', '$3', '$4'), '([a-zA-Z0-9\-_]+)', $arch);
    if (preg_match('/^' . $arch . '$/', $segments, $matches)) {
      $toReturn = $route;
      if (isset($matches[1])) {
        for ($i = 1; $i < count($matches); ++$i) {
          $toReturn = preg_replace('/(\(:any\))/', $matches[$i], $toReturn, 1);
        }
      }
      break;
    }
  }
  
  if ($toReturn) {
    return ($slash ? '/' : '') . $toReturn;
  }
  
  return ($slash ? '/' : '') . $segments;
}