Sonata\BasketBundle\Form\BasketType::buildForm PHP Метод

    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        // always clone the basket, so the one in session is never altered
        $basket = $builder->getData();
        if (!$basket instanceof BasketInterface) {
            throw new \RunTimeException('Please provide a BasketInterface instance');
        }
        // should create a custom basket elements here
        $basketElementBuilder = $builder->create('basketElements', 'form', array('by_reference' => false));
        $basketElementBuilder->addEventSubscriber(new BasketResizeFormListener($builder->getFormFactory(), $basket));
        $builder->add($basketElementBuilder);
    }