public static function getInstance() { if (!isset(self::$instance)) { self::$instance = new Router(); } if (isset($_SESSION['educaskPreviousPage'])) { self::$previousURL = $_SESSION['educaskPreviousPage']; } else { self::$previousURL = null; } if (empty($_GET['p'])) { self::$currentURL = 'home'; return self::$instance; } $cleanURL = filter_var($_GET['p'], FILTER_SANITIZE_URL); self::$currentURL = $cleanURL; return self::$instance; }