学习php设计模式 php实现合成模式(composite)

<?php
/**
 * 抽象组件角色
 */
interface Component {
 
 /**
  * 返回自己的实例
  */
 public function getComposite();
 
 /**
  * 示例方法
  */
 public function operation();
}
 
/**
 * 树枝组件角色
 */
class Composite implements Component {
 private $_composites;
 
 public function __construct() {
  $this->_composites = array();
 }
 
 public function getComposite() {
  return $this;
 }
 
 /**
  * 示例方法，调用各个子对象的operation方法
  */
 public function operation() {
  echo 'Composite operation begin:<br />';
  foreach ($this->_composites as $composite) {
   $composite->operation();
  }
  echo 'Composite operation end:<br /><br />';
 }
 
 /**
  * 聚集管理方法 添加一个子对象
  * @param Component $component 子对象
  */
 public function add(Component $component) {
  $this->_composites[] = $component;
 }
 
 /**
  * 聚集管理方法 删除一个子对象
  * @param Component $component 子对象
  * @return boolean 删除是否成功
  */
 public function remove(Component $component) {
  foreach ($this->_composites as $key => $row) {
   if ($component == $row) {
    unset($this->_composites[$key]);
    return TRUE;
   }
  }
 
  return FALSE;
 }
 
 /**
  * 聚集管理方法 返回所有的子对象
  */
 public function getChild() {
  return $this->_composites;
 }
 
}
 
class Leaf implements Component {
 private $_name;
 
 public function __construct($name) {
  $this->_name = $name;
 }
 
 public function operation() {
  echo 'Leaf operation ', $this->_name, '<br />';
 }
 
 public function getComposite() {
  return null;
 }
}
 
 
/**
 * 客户端
 */
class Client {
 
 /**
  * Main program.
  */
 public static function main() {
  $leaf1 = new Leaf('first');
  $leaf2 = new Leaf('second');
 
  $composite = new Composite();
  $composite->add($leaf1);
  $composite->add($leaf2);
  $composite->operation();
 
  $composite->remove($leaf2);
  $composite->operation();
 }
 
}
 
Client::main();
?>