设计模式之组合模式与PHP案例

组合模式：让客户端像修改配置文件一样简单的完成递归的动作，免除了客户端的逻辑思考。

将对象组合成树状结构以表示‘部分-整体’的层次结构。

组合模式能让客户以一致的方式处理个别对象以及组合对象。

PHP案例：

导航目录的添加与删除：

header("Content-type:text/html; charset=utf-8");

abstract class Component {

abstract function addNode(Component $obj);

abstract function removeNode(Component $obj);

abstract function show($str);

}

class Branch extends Component {

public $name='';

public $childNode = array();

public function __construct($name)

{

$this->name = $name;

}

public function addNode(Component $obj) {

// $this->childNode[] = $obj;

array_push($this->childNode,$obj);

}

public function removeNode(Component $obj) {

$key = array_search($obj, $this->childNode);

unset($this->childNode[$key]);

}

public function show($str="") {

echo $this->name."<br>";

$str.=" |- ";

foreach ($this->childNode as $val) {

echo $str;

$val->show($str);

}

}

}

class Leaf extends Component {

public $name;

public function __construct($name) {

$this->name = $name;

}

function addNode(Component $obj) {

return false;

}

function removeNode(Component $obj) {

return false;

}

function show($str="") {

echo $this->name."<br>";

}

}

$branch1 = new Branch("家电类");

$leaf11 = new Leaf("电饭煲");

$leaf12 = new Leaf("电冰箱");

$leaf13 = new Leaf("洗衣机");

$branch1->addNode($leaf11);

$branch1->addNode($leaf12);

$branch1->addNode($leaf13);

$branch2 = new Branch("电脑类");

$branch21 = new Branch("台式机");

$branch22 = new Branch("笔记本");

$leaf221 = new Leaf("华硕");

$leaf222 = new Leaf("联想");

$leaf223 = new Leaf("华为");

$leaf224 = new Leaf("华夏");

$branch22->addNode($leaf221);

$branch22->addNode($leaf222);

$branch22->addNode($leaf223);

$branch22->addNode($leaf224);

$branch2->addNode($branch21);

$branch2->addNode($branch22);

$branch1->addNode($branch2);

$branch1->show();