大话设计模式-组合模式

abstract class Component {
protected $name;

function __construct($name) {
$this->name = $name;
}

public abstract function add(Component $c);
public abstract function remove(Component $c);
public abstract function display($depth);
}

//叶节点没有子节点
class Leaf extends Component {
function __construct($name) {
parent::__construct($name);
}

//由于叶子没有再增加分枝和树叶，所以add和remove方法实现它没有意义，但这样做可以消除叶节点和枝节点对象在抽象层次的区别，他们具备完全一致的接口
public function add(Component $c) {
echo 'Cannot add to a leaf';
}

public function remove(Component $c) {
echo 'Cannot remove from a leaf';
}

public function display($depth) {
//叶节点的具体方法，此处是显示其名称和级别
echo str_pad('', $depth, '-').$this->name.'<br/>';
}
}

//枝节点
class Composite extends Component {
//一个子对象集合用来存储其下属的枝节点和叶节点
private $children;

function __construct($name) {
parent::__construct($name);
}

public function add(Component $c) {
$this->children[] = $c;
}

public function remove(Component $c) {
unset($this->children[array_search($c, $this->children)]);
}

public function display($depth) {
echo  str_pad('', $depth, '-').$this->name.'<br/>';
foreach($this->children as $component) {
$component->display($depth + 2);
}
}
}

//生成树根root，根上长出LeafA和leafB
$root = new Composite('root');
$root->add(new Leaf('Leaf A'));
$root->add(new Leaf('Leaf B'));

//根上长出分枝Composite X，分枝上也有两叶 LeafXA和LeafXB
$comp = new Composite('Composite X');
$comp->add(new Leaf("Leaf XA"));
$comp->add(new Leaf("Leaf XB"));

$root->add($comp);

//在Composite X上再长出分枝CompositeXY，分枝上也有两叶leafXYA和leafXYB
$comp2 = new Composite('Composite XY');
$comp2->add(new Leaf('Leaf XYA'));
$comp2->add(new Leaf('Leaf XYB'));

$comp->add($comp2);

$root->add(new Leaf('Leaf C'));

//根部长出两叶LeafC和LeafD，可惜LeafD没长牢，被风吹走了
$leaf = new Leaf('Leaf D');
$root->add($leaf);
$root->remove($leaf);

//显示大树的样子
$root->display(1);

//公司类
abstract class Company {
protected $name;

function __construct($name) {
$this->name = $name;
}

//增加
public abstract function add(Company $c);
//移除
public abstract function remove(Company $c);
//显示
public abstract function display($depth);
//履行职责
public abstract function lineOfDuty();
}

//具体公司类 实现接口 树枝节点
class ConcreteCompany extends Company {
private $children;

function __construct($name) {
parent::__construct($name);
}

public function add(Company $c) {
$this->children[] = $c;
}

public function remove(Company $c) {
unset($this->children[array_search($c, $this->children)]);
}

public function display($depth) {
echo  str_pad('', $depth, '-').$this->name.'<br/>';
foreach($this->children as $component) {
$component->display($depth + 2);
}
}

//履行职责
public function lineOfDuty() {
foreach($this->children as $component) {
$component->lineOfDuty();
}
}
}

//人力资源部
class HRDepartment extends Company {
function __construct($name) {
parent::__construct($name);
}

public function add(Company $c) {
}

public function remove(Company $c) {
}

public function display($depth) {
echo str_pad('', $depth, '-').$this->name.'<br/>';
}

public function lineOfDuty() {
echo $this->name.'员工招聘培训管理<br/>';
}
}

//财务部
class FinanceDepartment extends Company {
function __construct($name) {
parent::__construct($name);
}

public function add(Company $c) {
}

public function remove(Company $c) {
}

public function display($depth) {
echo str_pad('', $depth, '-').$this->name.'<br/>';
}

public function lineOfDuty() {
echo $this->name.'公司财务收支管理<br/>';
}
}

$root = new ConcreteCompany('北京总公司');
$root->add(new HRDepartment('总公司人力资源部'));
$root->add(new FinanceDepartment('总公司财务部'));

$comp = new ConcreteCompany('上海华东分公司');
$comp->add(new HRDepartment('华东分公司人力资源部'));
$comp->add(new FinanceDepartment('华东分公司财务部'));
$root->add($comp);

$comp1 = new ConcreteCompany('南京办事处');
$comp1->add(new HRDepartment('南京办事处人力资源部'));
$comp1->add(new FinanceDepartment('南京办事处财务部'));
$comp->add($comp1);

$comp2 = new ConcreteCompany('杭州办事处');
$comp2->add(new HRDepartment('杭州办事处人力资源部'));
$comp2->add(new FinanceDepartment('杭州办事处财务部'));
$comp->add($comp2);

echo '结构图：<br/>';
$root->display(1);

echo '职责：<br/>';
$root->lineOfDuty();