public function getPreKey() { static $key = array(); if (!self::$nm) { self::$nm = new NavigationMenu(); self::$angebote = self::$nm->getAngebote(); } if (!isset($key[$this->id])) { $item = self::$nm->getEntryByPageKey(array(self::$angebote), $this->key); if ($item && isset($item['url']) && isset($item['url']['preKey'])) { $key[$this->id] = $item['url']['preKey']; } else { $key[$this->id] = false; } } return $key[$this->id]; }