hedera-web/rest/dms/invoice.php

<?php

use Vn\Web\Security;
use Vn\Web\Util;
use Vn\Lib;

class Invoice extends Vn\Web\RestRequest {
	const PARAMS = ['invoice'];
	const SECURITY = Security::INVOKER;

	function run($db) {
		$pdfPath = $db->getValueFromFile(__DIR__ .'/invoice',
			['invoice' =>(int) $_GET['invoice']]);

		if (!$pdfPath)
			throw new Lib\UserException(s('Invoice id not found'));

		Util::printFile($pdfPath);
	}
}