上一文章为大家讲解了PHP观察者模式，这里再为大家分享一个组合模式，组合模式有时候又叫做部分-整体模式，它把程序内部简单元素和复杂元素提供给客户端统一的接口，使客户端和程序的内部结构结构，内部可以随意更改扩展。
从类图上看组合模式形成一种树形结构，由枝干和叶子继承Compont显然不符合里氏代换原则。
组合模式类图：
<?php
abstract class MenuComponent
{
public $name;
public abstract function getName();
public abstract function add(MenuComponent $menu);
public abstract function remove(MenuComponent $menu);
public abstract function getChild($i);
public abstract function show();
}
class MenuItem extends MenuComponent
{
public function __construct($name)
{
$this->name = $name;
}
public function getName(){
return $this->name;
}
public function add(MenuComponent $menu){
return false;
}
public function remove(MenuComponent $menu){
return false;
}
public function getChild($i){
return null;
}
public function show(){
echo " |-".$this->getName()."\n";
}
}
class Menu extends MenuComponent
{
public $menuComponents = array();
public function __construct($name)
{
$this->name = $name;
}
public function getName()
{
return $this->name;
}
public function add(MenuComponent $menu)
{
$this->menuComponents[] = $menu;
}
public function remove(MenuComponent $menu)
{
$key = array_search($menu, $this->menuComponents);
if($key !== false) unset($this->menuComponents[$key]);
}
public function getChild($i)
{
if(isset($this->menuComponents[$i])) return $this->menuComponents[$i];
return null;
}
public function show()
{
echo ":" . $this->getName() . "\n";
foreach($this->menuComponents as $v){
$v->show();
}
}
}
class testDriver
{
public function run()
{
$menu1 = new Menu('文学');
$menuitem1 = new MenuItem('绘画');
$menuitem2 = new MenuItem('书法');
$menuitem3 = new MenuItem('小说');
$menuitem4 = new MenuItem('雕刻');
$menu1->add($menuitem1);
$menu1->add($menuitem2);
$menu1->add($menuitem3);
$menu1->add($menuitem4);
$menu1->show();
}
}
$test = new testDriver();
$test->run();本站内容如转载，需注明来源：银众网络，本文链接：http://www.yinzhong.net/article/142.html