code tread block

Can you tell the code at the time stepped on the block?
Example:
if we step on the object and will get a sword or effect

Please

 

I was going to type up an example, but there is one here that is much better than what I could do.

 

PHP:

const BLOCKID = Block::STONE;
public function onMove(PlayerMoveEvent $event){
    if(!$event->getFrom()->equals(($to = $event->getTo())))
        if($event->getPlayer()->getLevel()->getBlockIdAt($to->x, $to->y, $to->z) === self::BLOCKID){
            $player->getInventory()->addItem(Item::get(Item::DIAMOND_SWORD));
            //$player->addEffect(...)
        }
    }
}