extranet.php

<?php
namespace Bitrix\Landing\Controller\ActionFilter;
 
use Bitrix\Main\Error;
use Bitrix\Main\Event;
use Bitrix\Main\EventResult;
 
final class Extranet extends \Bitrix\Main\Engine\ActionFilter\Base
{
    public function onBeforeAction(Event $event): ?EventResult
    {
        $user = \CUser::getList(
            'ID', 'ASC',
            ['ID_EQUAL_EXACT' => \Bitrix\Landing\Manager::getUserId()],
            ['FIELDS' => 'ID', 'SELECT' => ['UF_DEPARTMENT']]
        )->fetch();
 
        $isIntranet = ($user['UF_DEPARTMENT'][0] ?? 0) > 0;
        if (!$isIntranet)
        {
            $this->addError(new Error('Extranet site is not allowed.', 'EXTRANET_IS_NOT_ALLOWED'));
            return new EventResult(EventResult::ERROR, null, null, $this);
        }
 
        return null;
    }
}