common\services\NotificationService::findUserActionNotify PHP Method

    public function findUserActionNotify(UserMeta $meta)
    {
        if ($meta->target_type == 'comment') {
            $condition['comment_id'] = $meta->target_id;
        } else {
            $condition['post_id'] = $meta->target_id;
        }
        return Notification::findOne(['from_user_id' => $meta->user_id, 'type' => $meta->target_type . '_' . $meta->type] + $condition);
    }