BaseMessage::checkFields

static function checkFields($action, &$fields, $id, $params = null)
{
	$result = new Result();

	if ($action === 'UPDATE' && ($fields['COMPLETED'] ?? 'Y') === 'N')
	{
		$result->addError(new Error(Loc::getMessage('CRM_ACTIVITY_PROVIDER_BASEMESSAGE_CAN_NOT_UNCOMPLETE')));
	}

	return $result;
}