Design-patterns/visitor.php at master · LaughingMeMe/Design-patterns · GitHub

History

94 lines (78 loc) · 2.23 KB

Raw

<?php

//访问者模式

//行为型：访问者表示一个作用于某对象结构中各元素的操作，它可以在不修改各元素类的情况下，定义作用于这些元素的新操作，即动态的添加访问者角色

interface visitor{

public function visitConcreteElementA(ConcreteElementA $concreteElementA);

public function visitConcreteElementB(ConcreteElementB $concreteElementB);

}

interface Element{

public function accept(visitor $visitor);

}

class ConcreteElementA implements Element{

public $name;

public function __construct($name){

$this->name = $name;

}

public function accept(visitor $visitor){

$visitor->visitConcreteElementA($this);

}

class ConcreteElementB implements Element{

public $name;

public function __construct($name){

$this->name = $name;

}

public function accept(visitor $visitor){

$visitor->visitConcreteElementB($this);

}

class visitorA implements visitor{

public function visitConcreteElementA(ConcreteElementA $concreteElementA){

echo '1';

}

public function visitConcreteElementB(ConcreteElementB $concreteElementB){

echo '2';

}

class visitorB implements visitor{

public function visitConcreteElementA(ConcreteElementA $concreteElementA){

echo '3';

}

public function visitConcreteElementB(ConcreteElementB $concreteElementB){

echo '4';

}

class ObjectStructure{

private $_elements = array();

public function __construct(){

}

public function attach($element){

array_push($this->_elements,$element);

}

public function detach($element){

$index = array_search($element, $this->_elements);

if(false !== $index){

unset($this->_elements[$index]);

return true;

}

return false;

}

public function accept($visitor){

foreach ($this->_elements as $key => $value) {

$value->accept($visitor);

}

$structure = new ObjectStructure();

$concreteElementA = new ConcreteElementA('A');

$concreteElementB = new ConcreteElementB('B');

$concreteElementB2 = new ConcreteElementB('B2');

$visitorA = new visitorA();

$visitorB = new visitorB();

$structure->attach($concreteElementA);

$structure->attach($concreteElementB);

$structure->attach($concreteElementB2);

$structure->detach($concreteElementB2);

$structure->accept($visitorA);

$structure->accept($visitorB);

Design-patterns/visitor.php at master · LaughingMeMe/Design-patterns · GitHub

Expand file tree

Breadcrumbs

visitor.php

Latest commit

History

Breadcrumbs

visitor.php

File metadata and controls