学习php设计模式 php实现备忘录模式(Memento)

public function __construct() {
$this->_state = '';
}

/**

• 创建备忘录
• @return Memento 包含当前状态的备忘录对象
  */
  public function createMemento() {
  return new Memento($this->_state);
  }

/**

• 将发起人恢复到备忘录对象记录的状态上
• @param Memento $memento
  */
  public function restoreMemento(Memento $memento) {
  $this->_state = $memento->getState();
  }

public function setState($state) {
$this->_state = $state;
}

public function getState() {
return $this->_state;
}

/**

• 测试用方法，显示状态
  */
  public function showState() {
  echo "Original Status:",$this->getState(),"
  ";
  }

}

/**

• 备忘录(Memento)角色
  */
  class Memento {

private $_state;

public function __construct($state) {
$this->setState($state);
}

public function getState() {
return $this->_state;
}

public function setState($state) {
$this->_state = $state;
}

}

/**

• 负责人(Caretaker)角色
  */
  class Caretaker {

private $_memento;

public function getMemento() {
return $this->_memento;
}

public function setMemento(Memento $memento) {
$this->_memento = $memento;
}

}

/**

• 客户端
  */
  class Client {

/**

• Main program.
  */
  public static function main() {

/* 创建目标对象 */
$org = new Originator();
$org->setState('open');
$org->showState();

/* 创建备忘 */
$memento = $org->createMemento();

/* 通过Caretaker保存此备忘 */
$caretaker = new Caretaker();
$caretaker->setMemento($memento);

/* 改变目标对象的状态 */
$org->setState('close');
$org->showState();

/* 还原操作 */
$org->restoreMemento($caretaker->getMemento());
$org->showState();

}

}

Client::main();
?>