PHP设计模式之组合模式定义与应用示例

<?php
/**
 * 组合模式
 *
 * 将对象组合成树形结构以表示"部分-整体"的层次结构,使得客户对单个对象和复合对象的使用具有一致性
 */
abstract class menucomponent
{
  public function add($component)
  {
  }
  public function remove($component)
  {
  }
  public function getname()
  {
  }
  public function geturl()
  {
  }
  public function display()
  {
  }
}
class menu extends menucomponent
{
  private $_items = array();
  private $_name = null;
  public function __construct($name)
  {
    $this->_name = $name;
  }
  public function add($component)
  {
    $this->_items[] = $component;
  }
  public function remove($component)
  {
    $key = array_search($component, $this->_items);
    if ($key !== false) unset($this->_items[$key]);
  }
  public function display()
  {
    echo "-- " . $this->_name . " --------- \r\n ";
    foreach ($this->_items as $item) {
      $item->display();
    }
  }
}
class item extends menucomponent
{
  private $_name = null;
  private $_url = null;
  public function __construct($name, $url)
  {
    $this->_name = $name;
    $this->_url = $url;
  }
  public function display()
  {
    echo $this->_name . "#" . $this->_url . " \r\n ";
  }
}
class client
{
  private $_menu = null;
  public function __construct($menu)
  {
    $this->_menu = $menu;
  }
  public function setmenu($menu)
  {
    $this->_menu = $menu;
  }
  public function displaymenu()
  {
    $this->_menu->display();
  }
}
// 实例一下
// 人
$item3 = new item("baidu", "www.baidu.com");
$item4 = new item("google", "www.google.com");
$item1 = new item("163", "www.163.com");
$item2 = new item("sina", "www.sina.com");
// 班级
$submenu1 = new menu("sub menu1");
$submenu1->add($item1);
$submenu1->add($item2);
$submenu2 = new menu("sub menu2");
$submenu2->add($item3);
$submenu2->add($item4);
$submenu3 = new menu("sub menu3");
$submenu3->add($item3);
$submenu3->add($item4);
// 所有班级
$allmenu = new menu("all menu");
$allmenu->add($submenu1);
$allmenu->add($submenu2);
$allmenu->add($submenu3);
// 打印所有班级
$objclient = new client($allmenu);
$objclient->displaymenu();
// 打印第2 班级
$objclient->setmenu($submenu2);
$objclient->displaymenu();
?>