codysnider / tt-rss

classes/api.php

<?php
class API extends Handler {

    const API_LEVEL  = 14;

    const STATUS_OK  = 0;
    const STATUS_ERR = 1;

    private $seq;

    public static function param_to_bool($p) {
        return $p && ($p !== "f" && $p !== "false");
    }

    public function before($method) {
        if (parent::before($method)) {
            header("Content-Type: text/json");

            if (!$_SESSION["uid"] && $method != "login" && $method != "isloggedin") {
                $this->wrap(self::STATUS_ERR, array("error" => 'NOT_LOGGED_IN'));
                return false;
            }

            if ($_SESSION["uid"] && $method != "logout" && !get_pref('ENABLE_API_ACCESS')) {
                $this->wrap(self::STATUS_ERR, array("error" => 'API_DISABLED'));
                return false;
            }

            $this->seq = (int) clean($_REQUEST['seq']);

            return true;
        }
        return false;
    }

    public function wrap($status, $reply) {
        print json_encode(array("seq" => $this->seq,
            "status" => $status,
            "content" => $reply));
    }

    public function getVersion() {
        $rv = array("version" => VERSION);

The constant VERSION was not found. Maybe you did not declare it correctly or list all dependencies?

        $this->wrap(self::STATUS_OK, $rv);
    }

    public function getApiLevel() {
        $rv = array("level" => self::API_LEVEL);
        $this->wrap(self::STATUS_OK, $rv);
    }

    public function login() {
        @session_destroy();

It seems like you do not handle an error condition for session_destroy(). This can introduce security issues, and is generally not recommended.

        @session_start();

It seems like you do not handle an error condition for session_start(). This can introduce security issues, and is generally not recommended.

        $login = clean($_REQUEST["user"]);
        $password = clean($_REQUEST["password"]);
        $password_base64 = base64_decode(clean($_REQUEST["password"]));

It seems like clean($_REQUEST['password']) can also be of type array; however, parameter $data of base64_decode() does only seem to accept string, maybe add an additional type check?

        if (SINGLE_USER_MODE) {

The constant SINGLE_USER_MODE was not found. Maybe you did not declare it correctly or list all dependencies?

            $login = "admin";
        }

        $sth = $this->pdo->prepare("SELECT id FROM ttrss_users WHERE login = ?");
        $sth->execute([$login]);

        if ($row = $sth->fetch()) {
            $uid = $row["id"];
        } else {
            $uid = 0;
        }

        if (!$uid) {
            $this->wrap(self::STATUS_ERR, array("error" => "LOGIN_ERROR"));
            return;
        }

        if (get_pref("ENABLE_API_ACCESS", $uid)) {
            if (authenticate_user($login, $password, false, Auth_Base::AUTH_SERVICE_API)) {               // try login with normal password
                $this->wrap(self::STATUS_OK, array("session_id" => session_id(),
                    "api_level" => self::API_LEVEL));
            } else if (authenticate_user($login, $password_base64, false, Auth_Base::AUTH_SERVICE_API)) { // else try with base64_decoded password
                $this->wrap(self::STATUS_OK, array("session_id" => session_id(),
                    "api_level" => self::API_LEVEL));
            } else {                                                         // else we are not logged in
                user_error("Failed login attempt for $login from {$_SERVER['REMOTE_ADDR']}", E_USER_WARNING);
                $this->wrap(self::STATUS_ERR, array("error" => "LOGIN_ERROR"));
            }
        } else {
            $this->wrap(self::STATUS_ERR, array("error" => "API_DISABLED"));
        }

    }

    public function logout() {
        logout_user();
        $this->wrap(self::STATUS_OK, array("status" => "OK"));
    }

    public function isLoggedIn() {
        $this->wrap(self::STATUS_OK, array("status" => $_SESSION["uid"] != ''));
    }

    public function getUnread() {
        $feed_id = clean($_REQUEST["feed_id"]);
        $is_cat = clean($_REQUEST["is_cat"]);

        if ($feed_id) {
            $this->wrap(self::STATUS_OK, array("unread" => getFeedUnread($feed_id, $is_cat)));
        } else {
            $this->wrap(self::STATUS_OK, array("unread" => Feeds::getGlobalUnread()));
        }
    }

    /* Method added for ttrss-reader for Android */
    public function getCounters() {
        $this->wrap(self::STATUS_OK, Counters::getAllCounters());
    }

    public function getFeeds() {
        $cat_id = clean($_REQUEST["cat_id"]);
        $unread_only = API::param_to_bool(clean($_REQUEST["unread_only"]));
        $limit = (int) clean($_REQUEST["limit"]);
        $offset = (int) clean($_REQUEST["offset"]);
        $include_nested = API::param_to_bool(clean($_REQUEST["include_nested"]));

        $feeds = $this->api_get_feeds($cat_id, $unread_only, $limit, $offset, $include_nested);

        $this->wrap(self::STATUS_OK, $feeds);
    }

    public function getCategories() {
        $unread_only = API::param_to_bool(clean($_REQUEST["unread_only"]));
        $enable_nested = API::param_to_bool(clean($_REQUEST["enable_nested"]));
        $include_empty = API::param_to_bool(clean($_REQUEST['include_empty']));

        // TODO do not return empty categories, return Uncategorized and standard virtual cats

        if ($enable_nested) {
                    $nested_qpart = "parent_cat IS NULL";
        } else {
                    $nested_qpart = "true";
        }

        $sth = $this->pdo->prepare("SELECT
				id, title, order_id, (SELECT COUNT(id) FROM
				ttrss_feeds WHERE
				ttrss_feed_categories.id IS NOT NULL AND cat_id = ttrss_feed_categories.id) AS num_feeds,
			(SELECT COUNT(id) FROM
				ttrss_feed_categories AS c2 WHERE
				c2.parent_cat = ttrss_feed_categories.id) AS num_cats
			FROM ttrss_feed_categories
			WHERE $nested_qpart AND owner_uid = ?");
        $sth->execute([$_SESSION['uid']]);

        $cats = array();

        while ($line = $sth->fetch()) {
            if ($include_empty || $line["num_feeds"] > 0 || $line["num_cats"] > 0) {
                $unread = getFeedUnread($line["id"], true);

                if ($enable_nested) {
                                    $unread += Feeds::getCategoryChildrenUnread($line["id"]);
                }

                if ($unread || !$unread_only) {
                    array_push($cats, array("id" => $line["id"],
                        "title" => $line["title"],
                        "unread" => $unread,
                        "order_id" => (int) $line["order_id"],
                    ));
                }
            }
        }

        foreach (array(-2, -1, 0) as $cat_id) {
            if ($include_empty || !$this->isCategoryEmpty($cat_id)) {
                $unread = getFeedUnread($cat_id, true);

                if ($unread || !$unread_only) {
                    array_push($cats, array("id" => $cat_id,
                        "title" => Feeds::getCategoryTitle($cat_id),
                        "unread" => $unread));
                }
            }
        }

        $this->wrap(self::STATUS_OK, $cats);
    }

    public function getHeadlines() {
        $feed_id = clean($_REQUEST["feed_id"]);
        if ($feed_id !== "") {

            if (is_numeric($feed_id)) {
                $feed_id = (int) $feed_id;
            }

            $limit = (int) clean($_REQUEST["limit"]);

            if (!$limit || $limit >= 200) {
                $limit = 200;
            }

            $offset = (int) clean($_REQUEST["skip"]);
            $filter = clean($_REQUEST["filter"]);
            $is_cat = API::param_to_bool(clean($_REQUEST["is_cat"]));
            $show_excerpt = API::param_to_bool(clean($_REQUEST["show_excerpt"]));
            $show_content = API::param_to_bool(clean($_REQUEST["show_content"]));
            /* all_articles, unread, adaptive, marked, updated */
            $view_mode = clean($_REQUEST["view_mode"]);
            $include_attachments = API::param_to_bool(clean($_REQUEST["include_attachments"]));
            $since_id = (int) clean($_REQUEST["since_id"]);
            $include_nested = API::param_to_bool(clean($_REQUEST["include_nested"]));
            $sanitize_content = !isset($_REQUEST["sanitize"]) ||
                API::param_to_bool($_REQUEST["sanitize"]);
            $force_update = API::param_to_bool(clean($_REQUEST["force_update"]));
            $has_sandbox = API::param_to_bool(clean($_REQUEST["has_sandbox"]));
            $excerpt_length = (int) clean($_REQUEST["excerpt_length"]);
            $check_first_id = (int) clean($_REQUEST["check_first_id"]);
            $include_header = API::param_to_bool(clean($_REQUEST["include_header"]));

            $_SESSION['hasSandbox'] = $has_sandbox;

            $skip_first_id_check = false;

            $override_order = false;
            switch (clean($_REQUEST["order_by"])) {
            case "title":
                $override_order = "ttrss_entries.title, date_entered, updated";
                break;
            case "date_reverse":
                $override_order = "score DESC, date_entered, updated";
                $skip_first_id_check = true;
                break;
            case "feed_dates":
                $override_order = "updated DESC";
                break;
            }

            /* do not rely on params below */

            $search = clean($_REQUEST["search"]);

            list($headlines, $headlines_header) = $this->api_get_headlines($feed_id, $limit, $offset,
                $filter, $is_cat, $show_excerpt, $show_content, $view_mode, $override_order,
                $include_attachments, $since_id, $search,
                $include_nested, $sanitize_content, $force_update, $excerpt_length, $check_first_id, $skip_first_id_check);

            if ($include_header) {
                $this->wrap(self::STATUS_OK, array($headlines_header, $headlines));
            } else {
                $this->wrap(self::STATUS_OK, $headlines);
            }
        } else {
            $this->wrap(self::STATUS_ERR, array("error" => 'INCORRECT_USAGE'));
        }
    }

    public function updateArticle() {
        $article_ids = explode(",", clean($_REQUEST["article_ids"]));

It seems like clean($_REQUEST['article_ids']) can also be of type array; however, parameter $string of explode() does only seem to accept string, maybe add an additional type check?

        $mode = (int) clean($_REQUEST["mode"]);
        $data = clean($_REQUEST["data"]);
        $field_raw = (int) clean($_REQUEST["field"]);

        $field = "";
        $set_to = "";

        switch ($field_raw) {
        case 0:
            $field = "marked";
            $additional_fields = ",last_marked = NOW()";
            break;
        case 1:
            $field = "published";
            $additional_fields = ",last_published = NOW()";
            break;
        case 2:
            $field = "unread";
            $additional_fields = ",last_read = NOW()";
            break;
        case 3:
            $field = "note";
        };

        switch ($mode) {
        case 1:
            $set_to = "true";
            break;
        case 0:
            $set_to = "false";
            break;
        case 2:
            $set_to = "not $field";
            break;
        }

        if ($field == "note") {
            $set_to = $this->pdo->quote($data);

It seems like $data can also be of type array; however, parameter $string of PDO::quote() does only seem to accept string, maybe add an additional type check?

        }

        if ($field && $set_to && count($article_ids) > 0) {

            $article_qmarks = arr_qmarks($article_ids);

            $sth = $this->pdo->prepare("UPDATE ttrss_user_entries SET
				$field = $set_to $additional_fields

The variable $additional_fields does not seem to be defined for all execution paths leading up to this point.

				WHERE ref_id IN ($article_qmarks) AND owner_uid = ?");
            $sth->execute(array_merge($article_ids, [$_SESSION['uid']]));

            $num_updated = $sth->rowCount();

            if ($num_updated > 0 && $field == "unread") {
                $sth = $this->pdo->prepare("SELECT DISTINCT feed_id FROM ttrss_user_entries
					WHERE ref_id IN ($article_qmarks)");
                $sth->execute($article_ids);

                while ($line = $sth->fetch()) {
                    CCache::update($line["feed_id"], $_SESSION["uid"]);
                }
            }

            $this->wrap(self::STATUS_OK, array("status" => "OK",
                "updated" => $num_updated));

        } else {
            $this->wrap(self::STATUS_ERR, array("error" => 'INCORRECT_USAGE'));
        }

    }

    public function getArticle() {

        $article_ids = explode(",", clean($_REQUEST["article_id"]));

It seems like clean($_REQUEST['article_id']) can also be of type array; however, parameter $string of explode() does only seem to accept string, maybe add an additional type check?

        $sanitize_content = !isset($_REQUEST["sanitize"]) ||
            API::param_to_bool($_REQUEST["sanitize"]);

        if ($article_ids) {

The expression $article_ids of type string[] is implicitly converted to a boolean; are you sure this is intended? If so, consider using ! empty($expr) instead to make it clear that you intend to check for an array without elements.

            $article_qmarks = arr_qmarks($article_ids);

            $sth = $this->pdo->prepare("SELECT id,guid,title,link,content,feed_id,comments,int_id,
				marked,unread,published,score,note,lang,
				".SUBSTRING_FOR_DATE."(updated,1,16) as updated,
				author,(SELECT title FROM ttrss_feeds WHERE id = feed_id) AS feed_title,
				(SELECT site_url FROM ttrss_feeds WHERE id = feed_id) AS site_url,
				(SELECT hide_images FROM ttrss_feeds WHERE id = feed_id) AS hide_images
				FROM ttrss_entries,ttrss_user_entries
				WHERE id IN ($article_qmarks) AND ref_id = id AND owner_uid = ?");

            $sth->execute(array_merge($article_ids, [$_SESSION['uid']]));

            $articles = array();

            while ($line = $sth->fetch()) {

                $attachments = Article::get_article_enclosures($line['id']);

                $article = array(
                    "id" => $line["id"],
                    "guid" => $line["guid"],
                    "title" => $line["title"],
                    "link" => $line["link"],
                    "labels" => Article::get_article_labels($line['id']),
                    "unread" => API::param_to_bool($line["unread"]),
                    "marked" => API::param_to_bool($line["marked"]),
                    "published" => API::param_to_bool($line["published"]),
                    "comments" => $line["comments"],
                    "author" => $line["author"],
                    "updated" => (int) strtotime($line["updated"]),
                    "feed_id" => $line["feed_id"],
                    "attachments" => $attachments,
                    "score" => (int) $line["score"],
                    "feed_title" => $line["feed_title"],
                    "note" => $line["note"],
                    "lang" => $line["lang"]
                );

                if ($sanitize_content) {
                    $article["content"] = sanitize(
                        $line["content"],
                        API::param_to_bool($line['hide_images']),
                        false, $line["site_url"], false, $line["id"]);
                } else {
                    $article["content"] = $line["content"];
                }

                foreach (PluginHost::getInstance()->get_hooks(PluginHost::HOOK_RENDER_ARTICLE_API) as $p) {
                    $article = $p->hook_render_article_api(array("article" => $article));
                }

                $article['content'] = DiskCache::rewriteUrls($article['content']);

                array_push($articles, $article);

            }

            $this->wrap(self::STATUS_OK, $articles);
        } else {
            $this->wrap(self::STATUS_ERR, array("error" => 'INCORRECT_USAGE'));
        }
    }

    public function getConfig() {
        $config = array(
            "icons_dir" => ICONS_DIR,

The constant ICONS_DIR was not found. Maybe you did not declare it correctly or list all dependencies?

            "icons_url" => ICONS_URL);

The constant ICONS_URL was not found. Maybe you did not declare it correctly or list all dependencies?

        $config["daemon_is_running"] = file_is_locked("update_daemon.lock");

        $sth = $this->pdo->prepare("SELECT COUNT(*) AS cf FROM
			ttrss_feeds WHERE owner_uid = ?");
        $sth->execute([$_SESSION['uid']]);
        $row = $sth->fetch();

        $config["num_feeds"] = $row["cf"];

        $this->wrap(self::STATUS_OK, $config);
    }

    public function updateFeed() {
        $feed_id = (int) clean($_REQUEST["feed_id"]);

        if (!ini_get("open_basedir")) {
            RSSUtils::update_rss_feed($feed_id);
        }

        $this->wrap(self::STATUS_OK, array("status" => "OK"));
    }

    public function catchupFeed() {
        $feed_id = clean($_REQUEST["feed_id"]);
        $is_cat = clean($_REQUEST["is_cat"]);

        Feeds::catchup_feed($feed_id, $is_cat);

        $this->wrap(self::STATUS_OK, array("status" => "OK"));
    }

    public function getPref() {
        $pref_name = clean($_REQUEST["pref_name"]);

        $this->wrap(self::STATUS_OK, array("value" => get_pref($pref_name)));
    }

    public function getLabels() {
        $article_id = (int) clean($_REQUEST['article_id']);

        $rv = array();

        $sth = $this->pdo->prepare("SELECT id, caption, fg_color, bg_color
			FROM ttrss_labels2
			WHERE owner_uid = ? ORDER BY caption");
        $sth->execute([$_SESSION['uid']]);

        if ($article_id) {
                    $article_labels = Article::get_article_labels($article_id);
        } else {
                    $article_labels = array();
        }

        while ($line = $sth->fetch()) {

            $checked = false;
            foreach ($article_labels as $al) {
                if (Labels::feed_to_label_id($al[0]) == $line['id']) {
                    $checked = true;
                    break;
                }
            }

            array_push($rv, array(
                "id" => (int) Labels::label_to_feed_id($line['id']),
                "caption" => $line['caption'],
                "fg_color" => $line['fg_color'],
                "bg_color" => $line['bg_color'],
                "checked" => $checked));
        }

        $this->wrap(self::STATUS_OK, $rv);
    }

    public function setArticleLabel() {

        $article_ids = explode(",", clean($_REQUEST["article_ids"]));

It seems like clean($_REQUEST['article_ids']) can also be of type array; however, parameter $string of explode() does only seem to accept string, maybe add an additional type check?

        $label_id = (int) clean($_REQUEST['label_id']);
        $assign = API::param_to_bool(clean($_REQUEST['assign']));

        $label = Labels::find_caption(Labels::feed_to_label_id($label_id), $_SESSION["uid"]);

        $num_updated = 0;

        if ($label) {

            foreach ($article_ids as $id) {

                if ($assign) {
                                    Labels::add_article($id, $label, $_SESSION["uid"]);
                } else {
                                    Labels::remove_article($id, $label, $_SESSION["uid"]);
                }

                ++$num_updated;

            }
        }

        $this->wrap(self::STATUS_OK, array("status" => "OK",
            "updated" => $num_updated));

    }

    public function index($method) {
        $plugin = PluginHost::getInstance()->get_api_method(strtolower($method));

        if ($plugin && method_exists($plugin, $method)) {
            $reply = $plugin->$method();

            $this->wrap($reply[0], $reply[1]);

        } else {
            $this->wrap(self::STATUS_ERR, array("error" => 'UNKNOWN_METHOD', "method" => $method));
        }
    }

    public function shareToPublished() {
        $title = strip_tags(clean($_REQUEST["title"]));

It seems like clean($_REQUEST['title']) can also be of type array; however, parameter $str of strip_tags() does only seem to accept string, maybe add an additional type check?

        $url = strip_tags(clean($_REQUEST["url"]));
        $content = strip_tags(clean($_REQUEST["content"]));

        if (Article::create_published_article($title, $url, $content, "", $_SESSION["uid"])) {
            $this->wrap(self::STATUS_OK, array("status" => 'OK'));
        } else {
            $this->wrap(self::STATUS_ERR, array("error" => 'Publishing failed'));
        }
    }

    public static function api_get_feeds($cat_id, $unread_only, $limit, $offset, $include_nested = false) {

            $feeds = array();

            $pdo = Db::pdo();

            $limit = (int) $limit;
            $offset = (int) $offset;
            $cat_id = (int) $cat_id;

            /* Labels */

            /* API only: -4 All feeds, including virtual feeds */
            if ($cat_id == -4 || $cat_id == -2) {
                $counters = Counters::getLabelCounters(true);

                foreach (array_values($counters) as $cv) {

                    $unread = $cv["counter"];

                    if ($unread || !$unread_only) {

                        $row = array(
                                "id" => (int) $cv["id"],
                                "title" => $cv["description"],
                                "unread" => $cv["counter"],
                                "cat_id" => -2,
                            );

                        array_push($feeds, $row);
                    }
                }
            }

            /* Virtual feeds */

            if ($cat_id == -4 || $cat_id == -1) {
                foreach (array(-1, -2, -3, -4, -6, 0) as $i) {
                    $unread = getFeedUnread($i);

                    if ($unread || !$unread_only) {
                        $title = Feeds::getFeedTitle($i);

                        $row = array(
                                "id" => $i,
                                "title" => $title,
                                "unread" => $unread,
                                "cat_id" => -1,
                            );
                        array_push($feeds, $row);
                    }

                }
            }

            /* Child cats */

            if ($include_nested && $cat_id) {
                $sth = $pdo->prepare("SELECT
					id, title, order_id FROM ttrss_feed_categories
					WHERE parent_cat = ? AND owner_uid = ? ORDER BY order_id, title");

                $sth->execute([$cat_id, $_SESSION['uid']]);

                while ($line = $sth->fetch()) {
                    $unread = getFeedUnread($line["id"], true) +
                        Feeds::getCategoryChildrenUnread($line["id"]);

                    if ($unread || !$unread_only) {
                        $row = array(
                                "id" => (int) $line["id"],
                                "title" => $line["title"],
                                "unread" => $unread,
                                "is_cat" => true,
                                "order_id" => (int) $line["order_id"]
                            );
                        array_push($feeds, $row);
                    }
                }
            }

            /* Real feeds */

            if ($limit) {
                $limit_qpart = "limit $limit OFFSET $offset";
            } else {
                $limit_qpart = "";
            }

            /* API only: -3 All feeds, excluding virtual feeds (e.g. Labels and such) */
            if ($cat_id == -4 || $cat_id == -3) {
                $sth = $pdo->prepare("SELECT
					id, feed_url, cat_id, title, order_id, ".
                        SUBSTRING_FOR_DATE."(last_updated,1,19) AS last_updated
						FROM ttrss_feeds WHERE owner_uid = ?
						ORDER BY order_id, title " . $limit_qpart);
                $sth->execute([$_SESSION['uid']]);

            } else {

                $sth = $pdo->prepare("SELECT
					id, feed_url, cat_id, title, order_id, ".
                        SUBSTRING_FOR_DATE."(last_updated,1,19) AS last_updated
						FROM ttrss_feeds WHERE
						(cat_id = :cat OR (:cat = 0 AND cat_id IS NULL))
						AND owner_uid = :uid
						ORDER BY order_id, title " . $limit_qpart);
                $sth->execute([":uid" => $_SESSION['uid'], ":cat" => $cat_id]);
            }

            while ($line = $sth->fetch()) {

                $unread = getFeedUnread($line["id"]);

                $has_icon = Feeds::feedHasIcon($line['id']);

                if ($unread || !$unread_only) {

                    $row = array(
                            "feed_url" => $line["feed_url"],
                            "title" => $line["title"],
                            "id" => (int) $line["id"],
                            "unread" => (int) $unread,
                            "has_icon" => $has_icon,
                            "cat_id" => (int) $line["cat_id"],
                            "last_updated" => (int) strtotime($line["last_updated"]),
                            "order_id" => (int) $line["order_id"],
                        );

                    array_push($feeds, $row);
                }
            }

        return $feeds;
    }

    /**
     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
     */
    public static function api_get_headlines($feed_id, $limit, $offset,
                $filter, $is_cat, $show_excerpt, $show_content, $view_mode, $order,
                $include_attachments, $since_id,
                $search = "", $include_nested = false, $sanitize_content = true,
                $force_update = false, $excerpt_length = 100, $check_first_id = false, $skip_first_id_check = false) {

            $pdo = Db::pdo();

            if ($force_update && $feed_id > 0 && is_numeric($feed_id)) {
                // Update the feed if required with some basic flood control

                $sth = $pdo->prepare(
                    "SELECT cache_images,".SUBSTRING_FOR_DATE."(last_updated,1,19) AS last_updated
						FROM ttrss_feeds WHERE id = ?");
                $sth->execute([$feed_id]);

                if ($row = $sth->fetch()) {
                    $last_updated = strtotime($row["last_updated"]);
                    $cache_images = API::param_to_bool($row["cache_images"]);

                    if (!$cache_images && time() - $last_updated > 120) {
                        RSSUtils::update_rss_feed($feed_id, true);
                    } else {
                        $sth = $pdo->prepare("UPDATE ttrss_feeds SET last_updated = '1970-01-01', last_update_started = '1970-01-01'
							WHERE id = ?");
                        $sth->execute([$feed_id]);
                    }
                }
            }

            $params = array(
                "feed" => $feed_id,
                "limit" => $limit,
                "view_mode" => $view_mode,
                "cat_view" => $is_cat,
                "search" => $search,
                "override_order" => $order,
                "offset" => $offset,
                "since_id" => $since_id,
                "include_children" => $include_nested,
                "check_first_id" => $check_first_id,
                "skip_first_id_check" => $skip_first_id_check
            );

            $qfh_ret = Feeds::queryFeedHeadlines($params);

            $result = $qfh_ret[0];
            $feed_title = $qfh_ret[1];
            $first_id = $qfh_ret[6];

            $headlines = array();

            $headlines_header = array(
                'id' => $feed_id,
                'first_id' => $first_id,
                'is_cat' => $is_cat);

            if (!is_numeric($result)) {
                while ($line = $result->fetch()) {
                    $line["content_preview"] = truncate_string(strip_tags($line["content"]), $excerpt_length);
                    foreach (PluginHost::getInstance()->get_hooks(PluginHost::HOOK_QUERY_HEADLINES) as $p) {
                        $line = $p->hook_query_headlines($line, $excerpt_length, true);
                    }

                    $is_updated = ($line["last_read"] == "" &&
                        ($line["unread"] != "t" && $line["unread"] != "1"));

                    $tags = explode(",", $line["tag_cache"]);

                    $label_cache = $line["label_cache"];
                    $labels = false;

                    if ($label_cache) {
                        $label_cache = json_decode($label_cache, true);

                        if ($label_cache) {
                            if ($label_cache["no-labels"] == 1) {
                                                            $labels = array();
                            } else {
                                                            $labels = $label_cache;
                            }
                        }
                    }

                    if (!is_array($labels)) {
                        $labels = Article::get_article_labels($line["id"]);
                    }

                    $headline_row = array(
                        "id" => (int) $line["id"],
                        "guid" => $line["guid"],
                        "unread" => API::param_to_bool($line["unread"]),
                        "marked" => API::param_to_bool($line["marked"]),
                        "published" => API::param_to_bool($line["published"]),
                        "updated" => (int) strtotime($line["updated"]),
                        "is_updated" => $is_updated,
                        "title" => $line["title"],
                        "link" => $line["link"],
                        "feed_id" => $line["feed_id"] ? $line['feed_id'] : 0,
                        "tags" => $tags,
                    );

                    $enclosures = Article::get_article_enclosures($line['id']);

                    if ($include_attachments) {
                                            $headline_row['attachments'] = $enclosures;
                    }

                    if ($show_excerpt) {
                                            $headline_row["excerpt"] = $line["content_preview"];
                    }

                    if ($show_content) {

                        if ($sanitize_content) {
                            $headline_row["content"] = sanitize(
                                $line["content"],
                                API::param_to_bool($line['hide_images']),
                                false, $line["site_url"], false, $line["id"]);
                        } else {
                            $headline_row["content"] = $line["content"];
                        }
                    }

                    // unify label output to ease parsing
                    if ($labels["no-labels"] == 1) {
                        $labels = array();
                    }

                    $headline_row["labels"] = $labels;

                    $headline_row["feed_title"] = $line["feed_title"] ? $line["feed_title"] : $feed_title;

                    $headline_row["comments_count"] = (int) $line["num_comments"];
                    $headline_row["comments_link"] = $line["comments"];

                    $headline_row["always_display_attachments"] = API::param_to_bool($line["always_display_enclosures"]);

                    $headline_row["author"] = $line["author"];

                    $headline_row["score"] = (int) $line["score"];
                    $headline_row["note"] = $line["note"];
                    $headline_row["lang"] = $line["lang"];

                    foreach (PluginHost::getInstance()->get_hooks(PluginHost::HOOK_RENDER_ARTICLE_API) as $p) {
                        $headline_row = $p->hook_render_article_api(array("headline" => $headline_row));
                    }

                    $headline_row["content"] = DiskCache::rewriteUrls($headline_row['content']);

                    list ($flavor_image, $flavor_stream) = Article::get_article_image($enclosures, $line["content"], $line["site_url"]);

                    $headline_row["flavor_image"] = $flavor_image;
                    $headline_row["flavor_stream"] = $flavor_stream;

                    array_push($headlines, $headline_row);
                }
            } else if (is_numeric($result) && $result == -1) {
                $headlines_header['first_id_changed'] = true;
            }

            return array($headlines, $headlines_header);
    }

    public function unsubscribeFeed() {
        $feed_id = (int) clean($_REQUEST["feed_id"]);

        $sth = $this->pdo->prepare("SELECT id FROM ttrss_feeds WHERE
			id = ? AND owner_uid = ?");
        $sth->execute([$feed_id, $_SESSION['uid']]);

        if ($sth->fetch()) {
            Pref_Feeds::remove_feed($feed_id, $_SESSION["uid"]);
            $this->wrap(self::STATUS_OK, array("status" => "OK"));
        } else {
            $this->wrap(self::STATUS_ERR, array("error" => "FEED_NOT_FOUND"));
        }
    }

    public function subscribeToFeed() {
        $feed_url = clean($_REQUEST["feed_url"]);
        $category_id = (int) clean($_REQUEST["category_id"]);
        $login = clean($_REQUEST["login"]);
        $password = clean($_REQUEST["password"]);

        if ($feed_url) {
            $rc = Feeds::subscribe_to_feed($feed_url, $category_id, $login, $password);

            $this->wrap(self::STATUS_OK, array("status" => $rc));
        } else {
            $this->wrap(self::STATUS_ERR, array("error" => 'INCORRECT_USAGE'));
        }
    }

    public function getFeedTree() {
        $include_empty = API::param_to_bool(clean($_REQUEST['include_empty']));

        $pf = new Pref_Feeds($_REQUEST);

        $_REQUEST['mode'] = 2;
        $_REQUEST['force_show_empty'] = $include_empty;

        if ($pf) {

$pf is of type Pref_Feeds, thus it always evaluated to true.

            $data = $pf->makefeedtree();
            $this->wrap(self::STATUS_OK, array("categories" => $data));
        } else {
            $this->wrap(self::STATUS_ERR, array("error" =>
                'UNABLE_TO_INSTANTIATE_OBJECT'));
        }

    }

    // only works for labels or uncategorized for the time being
    private function isCategoryEmpty($id) {

        if ($id == -2) {
            $sth = $this->pdo->prepare("SELECT COUNT(id) AS count FROM ttrss_labels2
				WHERE owner_uid = ?");
            $sth->execute([$_SESSION['uid']]);
            $row = $sth->fetch();

            return $row["count"] == 0;

        } else if ($id == 0) {
            $sth = $this->pdo->prepare("SELECT COUNT(id) AS count FROM ttrss_feeds
				WHERE cat_id IS NULL AND owner_uid = ?");
            $sth->execute([$_SESSION['uid']]);
            $row = $sth->fetch();

            return $row["count"] == 0;

        }

        return false;
    }


}