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();