public function getUnsubscribeLink($docId)
{
$user = JFactory::getUser();
$link = '';
if (!$user->get('guest'))
{
$secret = JFactory::getConfig()->get('secret');
$type = 'document';
$code = md5($user->id . $user->email . $type . $secret);
$subscriptionObject = JUDownloadFrontHelper::getSubscriptionObjectByType($user->id, $docId, $type);
$link = JRoute::_('index.php?option=com_judownload&task=subscribe.remove&sub_id=' . $subscriptionObject->id . '&code=' . $code);
}
return $link;
}