MarkingCodeGroup::renderAdminFormControl

static function renderAdminFormControl(array $field, array $product, array $config): ?string
{
	$result = parent::renderAdminFormControl($field, $product, $config);
	if ($result !== null)
	{
		if ($product['TYPE'] === CatalogProductTable::TYPE_OFFER)
		{
			$parentSelected = (int)$field['VALUE'] === self::USE_PARENT_PRODUCT_VALUE;
			$addOption = '' . htmlspecialcharsbx(Loc::getMessage('MARKING_CODE_GROUP_MESS_USE_PARENT_PRODUCT_VALUE'))
				. ''
			;
			if ($parentSelected)
			{
				$result = str_replace('selected', '', $result);
			}
			$index = strpos($result, '');
			if ($index !== false)
			{
				$index += 9; //  after first option
				$result = substr($result, 0, $index)
					. $addOption
					. substr($result, $index)
				;
			}
		}
	}

	return $result;
}