Decorator.php

<?php

interface Pizza
{
    public function getDescription();
    public function getPrice();
}

class PlainPizza implements Pizza
{
    public function getDescription()
    {
        return 'Massa';
    }
    
    public function getPrice()
    {
        return 15.00;
    }
}

class Topping implements Pizza
{
    protected $_pizza;
    
    public function __construct(Pizza $new_pizza)
    {
        $this->_pizza = $new_pizza;
    }
    
    public function getDescription()
    {
        return $this->_pizza->getDescription();
    }
    
    public function getPrice()
    {
        return $this->_pizza->getPrice();
    }
}

class Mozarella extends Topping
{
    public function getDescription(){
        return $this->_pizza->getDescription() . ', Mozarella';
    }
    
    public function getPrice()
    {
        return $this->_pizza->getPrice() + 5.00;
    }
}

class Ham extends Topping
{
    public function getDescription(){
        return $this->_pizza->getDescription() . ', Ham';
    }
    
    public function getPrice()
    {
        return $this->_pizza->getPrice() + 5.00;
    }
}

$my_pizza = new Mozarella(new PlainPizza);
echo $my_pizza->getDescription(), PHP_EOL;
echo $my_pizza->getPrice(), PHP_EOL;

$ham = new Ham($my_pizza);
echo $ham->getDescription(), PHP_EOL;
echo $ham->getPrice(), PHP_EOL;