Phosphorum\Controllers\DiscussionsController::subscribeAction PHP Method

    public function subscribeAction($id)
    {
        if (!$this->checkTokenGet('post-' . $id)) {
            return $this->response->redirect();
        }
        $usersId = $this->session->get('identity');
        if (!$usersId) {
            $this->flashSession->error('You must be logged first');
            return $this->response->redirect();
        }
        $post = Posts::findFirstById($id);
        if (!$post) {
            $this->flashSession->error('The discussion does not exist');
            return $this->response->redirect();
        }
        $subscription = PostsSubscribers::findFirst(['posts_id = ?0 AND users_id = ?1', 'bind' => [$post->id, $usersId]]);
        if (!$subscription) {
            $subscription = new PostsSubscribers();
            $subscription->posts_id = $post->id;
            $subscription->users_id = $usersId;
            $subscription->created_at = time();
            if ($subscription->save()) {
                $this->flashSession->notice('You are now subscribed to this post');
            }
        }
        return $this->response->redirect('discussion/' . $post->id . '/' . $post->slug);
    }