Licson Lee says to YSITD
$data = new Sse\Data('apc'); class ChatHandler implements Sse\Event { function check(){ global $data; $hasUpdate = intval($data->get('chat_{key}_lastMessageTime')) > $lastUpdate ? true : false; return $hasUpdate; } function update(){ global $data; return $data->get('chat_{key}_message'); } }