php设计模式 Composite (组合模式)

<?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 "-- ".$this->_name." ---------<br/>";
foreach($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."<br/>";
}
}
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
// 创建menu
$subMenu1 = new Menu("sub menu1");
$subMenu2 = new Menu("sub menu2");
$subMenu3 = new Menu("sub menu3");
$item1 = new Item("163","www.163.com");
$item2 = new Item("sina","www.sina.com");
$subMenu1->add($item1);
$subMenu1->add($item2);
$item3 = new Item("baidu","www.baidu.com");
$item4 = new Item("google","www.google.com");
$subMenu2->add($item3);
$subMenu2->add($item4);
$allMenu = new Menu("All Menu");
$allMenu->add($subMenu1);
$allMenu->add($subMenu2);
$allMenu->add($subMenu3);
$objClient = new Client($allMenu);
$objClient->displayMenu();
$objClient->setMenu($subMenu2);
$objClient->displayMenu();