PHP design pattern: Decorator mode

beverage.php

<?phpnamespace DesignPattern;abstract class Beverage{    /**     * @var string     */    protected $name = ‘‘;    /**     * @return string     */    public function getName(): string    {        return $this->name;    }    /**     * @param string $name     * @return Beverage     */    public function setName(string $name): Beverage    {        $this->name = $name;        return $this;    }    /**     * @return float     */    public abstract function getCost(): float;    /**     * Beverage constructor.     */    public function __construct()    {    }}

bluemountaincoffee.php

<?phpnamespace DesignPattern;/** * 蓝山咖啡 */class BlueMountainCoffee extends Beverage{    /**     * @return float     */    public function getCost(): float    {        return 18.0;    }}

cubitacoffee.php

<?phpnamespace DesignPattern;/** * 琥爵咖啡 */class CubitaCoffee extends Beverage{    /**     * @return float     */    public function getCost(): float    {        return 24.0;    }}

coffeedecorator.php

<?phpnamespace DesignPattern;abstract class CoffeeDecorator extends Beverage{    /**     * @var CoffeeDecorator     */    protected $coffeeDecorator;    /**     * CoffeeDecorator constructor.     * @param Beverage $coffeeDecorator     */    public function __construct(Beverage $coffeeDecorator)//特别需要注意这个地方，装饰者模式必须允许对装饰后的对象再次装饰    {        parent::__construct();        $this->coffeeDecorator = $coffeeDecorator;    }}

milkdecorator.php

<?phpnamespace DesignPattern;class MilkDecorator extends CoffeeDecorator{    /**     * @return float     */    public function getCost(): float    {        return $this->coffeeDecorator->getCost() + 2.5;    }}

sugardecorator.php

<?phpnamespace DesignPattern;class SugarDecorator extends CoffeeDecorator{    /**     * @return float     */    public function getCost(): float    {        return $this->coffeeDecorator->getCost() + 1.2;    }}

Final Call:

$coffee = new \DesignPattern\BlueMountainCoffee();//生成一杯蓝山咖啡$beverage = new \DesignPattern\MilkDecorator($coffee);//给蓝山咖啡加一份牛奶$beverage = new \DesignPattern\MilkDecorator($beverage);//给蓝山咖啡再加一份牛奶$beverage = new \DesignPattern\SugarDecorator($beverage);//给蓝山咖啡加一份糖$beverage = new \DesignPattern\SugarDecorator($beverage);//给蓝山咖啡再加一份糖$beverage = new \DesignPattern\SugarDecorator($beverage);//给蓝山咖啡再加一份糖var_dump($beverage->getCost());

Program Run Result:

float(26.6)

PHP design pattern: Decorator mode