[id1, id2] protected $objWebUserModel; public function __construct() { $this->objWebUserModel = new WebUserModel(WebUserController::getUserId()); } public function addHistory($item_type, $item_id) { $current_list = $this->getHistory($item_type); // if exist, remove it $search_key = array_search($item_id, $current_list, true); if($search_key !== false) { array_splice($current_list, $search_key, 1); } // add to front array_unshift($current_list, $item_id); $this->history[$item_type] = $current_list; // save to db $this->objWebUserModel->setValue("view-history", $this->history); } public function getHistory($item_type) { $history = $this->objWebUserModel->getValue("view-history"); return (isset($history[$item_type])) ? $history[$item_type] : []; } }