當需要為現有的類增加新的功能，或則需要包裝現有類時，適合使用該模式

類圖：

java實現
抽象產品類

public abstract class Subject {

    public abstract void doSomething();
}

產品類

public class ConcreteSubject extends Subject {

    @Override
    public void doSomething() {

    }
}

抽象裝飾者

public abstract class Decoration extends Subject
 
{

    private Subject subject = null;

    public Decoration(Subject subject){
        this.subject = subject;
    }

    @Override
    public void doSomething() {
        subject.doSomething();
    }
}

裝飾者

public class ConcreteDecoration extends Decoration {


    public ConcreteDecoration(Subject subject) {
        super
 
(subject);
    }

    private void decorationMethods(){

    }

    @Override
    public void doSomething() {
        decorationMethods();
        super.doSomething();
    }
}

php實現

abstract class Subject
{
    public abstract function doSomething();    
}

class ConcreteSubject extends Subject
{
 

    public function doSomething()
    {
        echo 'doSomething';
    }
}

abstract class Decortion extends Subject
{
    private $subject;

    public function __construct(Subject $subject)
    {
        $this->subject = $subject;
    }

    public function doSomething()
    {
        $this->subject->doSomething();
    }
}

class ConcreteDecortion extends Decortion
{
    public function __construct(Subject $subject)
    {
        parent::__construct($subject);
    }

    public function decortionMethods()
    {
        echo 'decortionMethods';
    }

    public function doSomething()
    {
        $this->decortionMethods();
        parent::doSomething();
    }
}

$decortion =  new ConcreteDecortion(new ConcreteSubject());
$decortion->doSomething();