Ejemplo de implementación del patrón Builder

/**Ejemplo de diseño de patrón Builder*/

/**Clase Producto*/

class Pizza {
        var $masa = null;
        var $salsa = null;
        var $relleno = null;

        public function setMasa($masa){ $this->masa = $masa; }
        public function setSalsa($salsa){ $this->salsa = $salsa; }
        public function setRelleno($relleno){ $this->relleno = $relleno; }

        public function mostrarComponentes(){
                echo $this->masa." - ".$this->salsa." - ".$this->relleno."";
        }
}

/** "Abstract Builder" */

abstract class PizzaBuilder {

        var $pizza = null;

        public function getPizza() { return $this->pizza; }
        public function crearNuevaPizza() { $this->pizza = new Pizza(); }
        public abstract function buildMasa();
        public abstract function buildSalsa();
        public abstract function buildRelleno();
}

/** "ConcreteBuilder" */

class PicantePizzaBuilder extends PizzaBuilder {

        public function buildMasa(){ $this->pizza->setMasa("cocida"); }
        public function buildSalsa(){ $this->pizza->setSalsa("picante"); }
        public function buildRelleno(){
                $this->pizza->setRelleno("pimienta+salchichón");
        }
}

class HawaiPizzaBuilder extends PizzaBuilder {

        public function buildMasa(){ $this->pizza->setMasa("suave"); }
        public function buildSalsa(){ $this->pizza->setSalsa("dulce"); }
        public function buildRelleno(){ $this->pizza->setRelleno("chorizo+alcachofas"); }
}

/** "Director" */

class Cocina {

        var $pizzaBuilder;

        public function setPizzaBuilder($pb){ $this->pizzaBuilder = $pb; }
        public function getPizza(){ return $this->pizzaBuilder->getPizza(); }

        public function construirPizza() {
                $this->pizzaBuilder->crearNuevaPizza();
                $this->pizzaBuilder->buildMasa();
                $this->pizzaBuilder->buildSalsa();
                $this->pizzaBuilder->buildRelleno();
        }
}


/**Como se utilizaría*/

include('Cocina.php');
include('PicantePizzaBuilder.php');
include('HawaiPizzaBuilder.php');

$cocina = new Cocina();
$hawai_pizzabuilder = new HawaiPizzaBuilder();
$picante_pizzabuilder = new PicantePizzaBuilder();

$cocina->setPizzaBuilder($hawai_pizzabuilder );
$cocina->construirPizza();
$pizza = $cocina->getPizza();
$pizza->mostrarComponentes();

$cocina->setPizzaBuilder($picante_pizzabuilder );
$cocina->construirPizza();
$pizza = $cocina->getPizza();
$pizza->mostrarComponentes();