<?
class observable
{
   private $observers = array();
   public function register($object)
   {
      if ($object instanceof observer )
      $this->observers[] =$object;
      else
      echo "Obiekt musi implementowa interfejs Observer.\n";
   }
   public function stateChange()
   {
      foreach ($this->observers as $observer)
      {
         $observer->notify();
      }
   }
}
?>
