CIMRestService::dialogMessagesGet

static function dialogMessagesGet($arParams, $offset, CRestServer $server)
{
	$arParams = array_change_key_case($arParams, CASE_UPPER);

	if (isset($arParams['CHAT_ID']) && intval($arParams['CHAT_ID']) > 0)
	{
		$arParams['DIALOG_ID'] = 'chat'.$arParams['CHAT_ID'];
	}

	if (!BitrixImCommon::isDialogId($arParams['DIALOG_ID']))
	{
		throw new BitrixRestRestException("Dialog ID can't be empty", "DIALOG_ID_EMPTY", CRestServer::STATUS_WRONG_REQUEST);
	}

	if (!BitrixImDialog::hasAccess($arParams['DIALOG_ID']))
	{
		throw new BitrixRestRestException("You do not have access to the specified dialog", "ACCESS_ERROR", CRestServer::STATUS_FORBIDDEN);
	}

	$chatId = BitrixImDialog::getChatId($arParams['DIALOG_ID']);

	if (isset($arParams['FIRST_ID']))
	{
		if (!preg_match('/^d{1,}$/i', $arParams['FIRST_ID']))
		{
			throw new BitrixRestRestException("First ID can't be string", "FIRST_ID_STRING", CRestServer::STATUS_WRONG_REQUEST);
		}
		$options['FIRST_ID'] = intval($arParams['FIRST_ID']);
	}
	else if (isset($arParams['LAST_ID']))
	{
		if (!preg_match('/^d{1,}$/i', $arParams['LAST_ID']))
		{
			throw new BitrixRestRestException("Last ID can't be string", "LAST_ID_STRING", CRestServer::STATUS_WRONG_REQUEST);
		}
		$options['LAST_ID'] = intval($arParams['LAST_ID']) > 0? intval($arParams['LAST_ID']): 0;
	}
	$options['LIMIT'] = isset($arParams['LIMIT'])? (intval($arParams['LIMIT']) > 50? 50: intval($arParams['LIMIT'])): 20;
	$options['CONVERT_TEXT'] = isset($arParams['CONVERT_TEXT']) && $arParams['CONVERT_TEXT'] == 'Y';
	$options['JSON'] = 'Y';

	return BitrixImChat::getMessages($chatId, null, $options);
}