gift.php

См. документацию.

<?php
 
namespace Bitrix\Sale\Discount\Gift;
 
 
class Gift
{
    protected $productId;
    protected $isSku;

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

    public function getProductId()
    {
        return $this->productId;
    }
 
    public function getProduct()
    {
        //lazy load data from CCatalog
    }
}