<?php
/**
 * 發(fā)起人(Originator)角色
 */
class Originator {
 
  private $_state;
 
  public function __construct() {
    $this->_state = '';
  }
 
  /**
   * 創(chuàng)建備忘錄
   * @return Memento 包含當前狀態(tài)的備忘錄對象
   */
  public function createMemento() {
    return new Memento($this->_state);
  }
 
  /**
   * 將發(fā)起人恢復(fù)到備忘錄對象記錄的狀態(tài)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;
  }
 
  /**
   * 測試用方法，顯示狀態(tài)
   */
  public function showState() {
    echo "Original Status:", $this->getState(), "<br />";
  }
 
}
 
/**
 * 備忘錄(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;
  }
 
}
 
/**
 * 負責人(Caretaker)角色
 */
class Caretaker {
 
  private $_memento;
 
  public function getMemento() {
    return $this->_memento;
  }
 
  public function setMemento(Memento $memento) {
    $this->_memento = $memento;
  }
 
}
 
/**
 * 客戶端
 */
class Client {
 
  /**
   * Main program.
   */
  public static function main() {
 
    /* 創(chuàng)建目標對象 */
    $org = new Originator();
    $org->setState('open');
    $org->showState();
 
    /* 創(chuàng)建備忘 */
    $memento = $org->createMemento();
 
    /* 通過Caretaker保存此備忘 */
    $caretaker = new Caretaker();
    $caretaker->setMemento($memento);
 
    /* 改變目標對象的狀態(tài) */
    $org->setState('close');
    $org->showState();
 
    /* 還原操作 */
    $org->restoreMemento($caretaker->getMemento());
    $org->showState();
  }
 
}
 
Client::main();
?>