VatTable::onBeforeAdd

static function onBeforeAdd(ORMEvent $event): ORMEventResult
{
	$result = new ORMEventResult;
	$fields = $event->getParameter('fields');

	if (isset($fields['EXCLUDE_VAT']) && $fields['EXCLUDE_VAT'] === 'Y')
	{
		if (static::isExistsExcludeVat())
		{
			$result->addError(
				new ORMEntityError(Loc::getMessage('VAT_ENTITY_ERR_EXCLUDE_VAT_ALREADY_EXISTS'))
			);

			return $result;
		}

		$result->modifyFields([
			'RATE' => null,
		]);
	}

	return $result;
}