getVoucherCode example

$counter = 0;
        foreach ($emails as $email) {
            $user = $this->getMailingUserByEmail($email);
            $template->assign('sUser', $user, true);
            $hash = $this->createHash((int) $user['mailaddressID'], (int) $mailing['id']);
            $template->assign('sCampaignHash', $hash, true);
            $template->assign('sRecommendations', $this->getMailingSuggest($mailing['id'], $user['userID']), true);

            /** @var array $voucher */
            $voucher = $template->getTemplateVars('sVoucher');
            if (!empty($voucher['id'])) {
                $voucher['code'] = $this->getVoucherCode($voucher['id']);
                $template->assign('sVoucher', $voucher, true);
            }

            if (empty($mailing['plaintext'])) {
                $body = $template->fetch('newsletter/index/' . $mailing['template'], $template);
            }
            $bodyText = $template->fetch('newsletter/alt/' . $mailing['template'], $template);

            if (!empty($body)) {
                $body = $this->trackFilter($body, $mailing['id']);
                $mail->setBodyHtml($body);
            }