/**
  * Check to see that the email address provided
  * is on the white list.
  *
  * @param $event
  * @return mixed
  */
 public function onUniqueEMailValidator($event)
 {
     $canRegister = \humhub\models\Setting::Get('anonymousRegistration', 'authentication_internal');
     $registerModel = new \humhub\modules\user\models\forms\AccountRegister();
     if ($canRegister) {
         if ($registerModel->load(Yii::$app->request->post())) {
             if (!EmailWhitelist::emailIsAllowed($registerModel->email)) {
                 $event->isValid = false;
                 return Yii::$app->getResponse()->redirect(Url::to(['/email_whitelist/denied/index']));
             }
         }
     }
 }
<?php

/**
 * Connected Communities Initiative
 * Copyright (C) 2016 Queensland University of Technology
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
use humhub\modules\admin\widgets\AdminMenu;
use humhub\modules\user\models\forms\AccountRegister;
//use humhub\modules\user\models\forms\Registration;
return ['id' => 'email_whitelist', 'class' => 'humhub\\modules\\email_whitelist\\Module', 'namespace' => 'humhub\\modules\\email_whitelist', 'events' => [['class' => AdminMenu::className(), 'event' => AdminMenu::EVENT_INIT, 'callback' => ['humhub\\modules\\email_whitelist\\Events', 'onAdminMenuInit']], ['class' => AccountRegister::className(), 'event' => AccountRegister::EVENT_BEFORE_VALIDATE, 'callback' => ['humhub\\modules\\email_whitelist\\Events', 'onUniqueEMailValidator']]]];