Sonata\Component\Basket\BasketInterface::countBasketElements PHP Method

    public function countBasketElements();

 /**
  * {@inheritdoc}
  */
 public function isBasketValid(BasketInterface $basket)
 {
     if ($basket->countBasketElements() == 0) {
         return false;
     }
     foreach ($basket->getBasketElements() as $element) {
         $product = $element->getProduct();
         if ($product->isRecurrentPayment() === true) {
             return false;
         }
     }
     return true;
 }