public function subscribe($subscribe = true)
{
// To subscribe or not to subscribe, that ...
if (!Config::enabled('o_topic_subscriptions') || !Auth::check()) {
return false;
}
if ($subscribe && !$this->isUserSubscribed()) {
$this->subscription()->insert(array('user_id' => User::current()->id));
} elseif (!$subscribe && $this->isUserSubscribed()) {
$this->subscription()->delete();
}
}