class.ilPageObject.php

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<?php

define("IL_INSERT_BEFORE", 0);
define("IL_INSERT_AFTER", 1);
define("IL_INSERT_CHILD", 2);

/*

    - move dom related code to PageDom class/interface
    - move ilDB dependency to ar object
    - move internal links related code to extra class
    - make factory available through DIC, opt allow decentralized factory parts
    - PC types
    -- internal links used/implemented?
    -- styles used/implemented?
    - application classes need
    -- page object
    --- page object should return php5 domdoc (getDom() vs getDomDoc()?)
        esp. plugins should use this
    -- remove content element hook, if content is not allowed
    - PC types could move to components (e.g. blog, login)
    - How to modularize xsl?
    -- read from db?
    -- xml entries say that xslt code is used -> read file and include in
       main xslt file

*/

use ILIAS\MetaData\Services\ServicesInterface as LOMServices;

abstract class ilPageObject
{
    protected \ILIAS\COPage\Dom\DomUtil $dom_util;
    protected \ILIAS\COPage\Link\LinkManager $link;
    protected \ILIAS\COPage\PC\PCDefinition $pc_definition;
    protected int $create_user = 0;
    protected array $id_elements;
    public int $old_nr;
    protected bool $page_not_found = false;
    protected bool $show_page_act_info = false;
    protected ilObjectDefinition $obj_definition;
    public static array $exists = array();
    protected ilDBInterface $db;
    protected ilObjUser $user;
    protected ilLanguage $lng;
    protected ilTree $tree;
    protected LOMServices $lom_services;
    protected int $id;
    public ?DOMDocument $dom = null;
    public string $xml = "";
    public string $encoding = "";
    public DomNode $node;
    public string $cur_dtd = "ilias_pg_9.dtd";
    public bool $contains_int_link = false;
    public bool $needs_parsing = false;
    public string $parent_type = "";
    public int $parent_id = 0;
    public array $update_listeners = [];
    public int $update_listener_cnt = 0;
    public ?object $offline_handler = null;     // see LMPresentation handleCodeParagraph
    public bool $dom_builded = false;
    public bool $history_saved = false;
    protected string $language = "-";
    protected static array $activation_data = array();
    protected bool $import_mode = false;
    protected ilLogger $log;
    protected ?array $page_record = array();
    protected bool $active = false;
    protected ilPageConfig $page_config;
    protected string $rendermd5 = "";
    protected string $renderedcontent = "";
    protected string $renderedtime = "";
    protected string $lastchange = "";
    public int $last_change_user = 0;
    protected bool $contains_question = false;
    protected array $hier_ids = [];
    protected ?string $activationstart = null;      // IL_CAL_DATETIME format
    protected ?string $activationend = null;        // IL_CAL_DATETIME format
    protected \ILIAS\COPage\ReadingTime\ReadingTimeManager $reading_time_manager;
    protected $concrete_lang = "";
    protected \ILIAS\COPage\ID\ContentIdManager $content_id_manager;
    protected \ILIAS\COPage\Page\PageManager $page_manager;
    protected \ILIAS\COPage\Style\StyleManager $style_manager;
    protected \ILIAS\COPage\PC\DomainService $pc_service;

    final public function __construct(
        int $a_id = 0,
        int $a_old_nr = 0,
        string $a_lang = "-"
    ) {
        global $DIC;
        $this->obj_definition = $DIC["objDefinition"];
        $this->db = $DIC->database();
        $this->user = $DIC->user();
        $this->lng = $DIC->language();
        $this->tree = $DIC->repositoryTree();
        $this->log = ilLoggerFactory::getLogger('copg');
        $this->lom_services = $DIC->learningObjectMetadata();

        $this->reading_time_manager = new ILIAS\COPage\ReadingTime\ReadingTimeManager();

        $this->parent_type = $this->getParentType();
        $this->id = $a_id;
        $this->setLanguage($a_lang);

        $this->contains_int_link = false;
        $this->needs_parsing = false;
        $this->update_listeners = array();
        $this->update_listener_cnt = 0;
        $this->dom_builded = false;
        $this->page_not_found = false;
        $this->old_nr = $a_old_nr;
        $this->encoding = "UTF-8";
        $this->id_elements =
            array("PageContent",
                  "TableRow",
                  "TableData",
                  "ListItem",
                  "FileItem",
                  "Section",
                  "Tab",
                  "ContentPopup",
                  "GridCell"
            );
        $this->setActive(true);
        $this->show_page_act_info = false;

        if ($a_id != 0) {
            $this->read();
        }

        $this->initPageConfig();
        $this->afterConstructor();
        $domain = $DIC->copage()
                      ->internal()
                      ->domain();
        $this->content_id_manager = $domain
            ->contentIds($this);
        $this->page_manager = $domain->page();
        $this->pc_service = $domain->pc();
        $this->pc_definition = $domain->pc()->definition();
        $this->link = $domain->link();
        $this->style_manager = $domain->style();
        $this->dom_util = $domain->domUtil();
    }

    public function setContentIdManager(
        \ILIAS\COPage\ID\ContentIdManager $content_id_manager
    ): void {
        $this->content_id_manager = $content_id_manager;
    }

    public function afterConstructor(): void
    {
    }

    abstract public function getParentType(): string;

    public function initPageConfig(): void
    {
        $cfg = ilPageObjectFactory::getConfigInstance($this->getParentType());
        $this->setPageConfig($cfg);
    }

    public function setLanguage(string $a_val): void
    {
        $this->language = $a_val;
    }

    public function getLanguage(): string
    {
        return $this->language;
    }

    public function setPageConfig(ilPageConfig $a_val): void
    {
        $this->page_config = $a_val;
    }

    public function setConcreteLang(string $a_val)
    {
        $this->concrete_lang = $a_val;
    }

    public function getConcreteLang(): string
    {
        return $this->concrete_lang;
    }

    public function getPageConfig(): ilPageConfig
    {
        return $this->page_config;
    }

    public function setRenderMd5(string $a_rendermd5): void
    {
        $this->rendermd5 = $a_rendermd5;
    }

    public function getRenderMd5(): string
    {
        return $this->rendermd5;
    }

    public function setRenderedContent(string $a_renderedcontent): void
    {
        $this->renderedcontent = $a_renderedcontent;
    }

    public function getRenderedContent(): string
    {
        return $this->renderedcontent;
    }

    public function setRenderedTime(string $a_renderedtime): void
    {
        $this->renderedtime = $a_renderedtime;
    }

    public function getRenderedTime(): string
    {
        return $this->renderedtime;
    }

    public function setLastChange(string $a_lastchange): void
    {
        $this->lastchange = $a_lastchange;
    }

    public function getLastChange(): string
    {
        return $this->lastchange;
    }

    public function setLastChangeUser(int $a_val): void
    {
        $this->last_change_user = $a_val;
    }

    public function getLastChangeUser(): int
    {
        return $this->last_change_user;
    }

    public function setShowActivationInfo(bool $a_val): void
    {
        $this->show_page_act_info = $a_val;
    }

    public function getShowActivationInfo(): bool
    {
        return $this->show_page_act_info;
    }

    public function getCreationUserId(): int
    {
        return $this->create_user;
    }

    public function read(): void
    {
        $this->setActive(true);
        if ($this->old_nr == 0) {
            $query = "SELECT * FROM page_object" .
                " WHERE page_id = " . $this->db->quote($this->id, "integer") .
                " AND parent_type=" . $this->db->quote($this->getParentType(), "text") .
                " AND lang = " . $this->db->quote($this->getLanguage(), "text");
            $pg_set = $this->db->query($query);
            if (!$this->page_record = $this->db->fetchAssoc($pg_set)) {
                throw new ilCOPageNotFoundException("Error: Page " . $this->id . " is not in database" .
                    " (parent type " . $this->getParentType() . ", lang: " . $this->getLanguage() . ").");
            }
            $this->setActive($this->page_record["active"]);
            $this->setActivationStart($this->page_record["activation_start"]);
            $this->setActivationEnd($this->page_record["activation_end"]);
            $this->setShowActivationInfo($this->page_record["show_activation_info"]);
        } else {
            $query = "SELECT * FROM page_history" .
                " WHERE page_id = " . $this->db->quote($this->id, "integer") .
                " AND parent_type=" . $this->db->quote($this->getParentType(), "text") .
                " AND nr = " . $this->db->quote($this->old_nr, "integer") .
                " AND lang = " . $this->db->quote($this->getLanguage(), "text");
            $pg_set = $this->db->query($query);
            $this->page_record = $this->db->fetchAssoc($pg_set);
        }
        if (!$this->page_record) {
            throw new ilCOPageNotFoundException("Error: Page " . $this->id . " is not in database" .
                " (parent type " . $this->getParentType() . ", lang: " . $this->getLanguage() . ").");
        }
        $this->xml = $this->page_record["content"];
        $this->setParentId((int) $this->page_record["parent_id"]);
        $this->last_change_user = (int) ($this->page_record["last_change_user"] ?? 0);
        $this->create_user = (int) ($this->page_record["create_user"] ?? 0);
        $this->setRenderedContent((string) ($this->page_record["rendered_content"] ?? ""));
        $this->setRenderMd5((string) ($this->page_record["render_md5"] ?? ""));
        $this->setRenderedTime((string) ($this->page_record["rendered_time"] ?? ""));
        $this->setLastChange((string) ($this->page_record["last_change"] ?? ""));
    }

    public static function _exists(
        string $a_parent_type,
        int $a_id,
        string $a_lang = "",
        bool $a_no_cache = false
    ): bool {
        global $DIC;

        $db = $DIC->database();

        if (!$a_no_cache && isset(self::$exists[$a_parent_type . ":" . $a_id . ":" . $a_lang])) {
            return self::$exists[$a_parent_type . ":" . $a_id . ":" . $a_lang];
        }

        $and_lang = "";
        if ($a_lang != "") {
            $and_lang = " AND lang = " . $db->quote($a_lang, "text");
        }

        $query = "SELECT page_id FROM page_object WHERE page_id = " . $db->quote($a_id, "integer") . " " .
            "AND parent_type = " . $db->quote($a_parent_type, "text") . $and_lang;
        $set = $db->query($query);
        if ($row = $db->fetchAssoc($set)) {
            self::$exists[$a_parent_type . ":" . $a_id . ":" . $a_lang] = true;
            return true;
        } else {
            self::$exists[$a_parent_type . ":" . $a_id . ":" . $a_lang] = false;
            return false;
        }
    }

    public static function _existsAndNotEmpty(
        string $a_parent_type,
        int $a_id,
        string $a_lang = "-"
    ): bool {
        return ilPageUtil::_existsAndNotEmpty($a_parent_type, $a_id, $a_lang);
    }

    public function buildDom(bool $a_force = false)
    {
        if ($this->dom_builded && !$a_force) {
            return true;
        }
        $error = null;
        if ($this->getXMLContent() === "") {
            $this->setXMLContent("<PageObject></PageObject>");
        }
        $this->dom = $this->dom_util->docFromString($this->getXMLContent(true), $error);
        $path = "//PageObject";
        if (is_null($this->dom)) {
            throw new ilCOPageException("Invalid page xml (" .
                $this->getId() . "," . $this->getLanguage() . "): " . $this->getXMLContent(true));
        }
        $nodes = $this->dom_util->path($this->dom, $path);
        if (count($nodes) == 1) {
            $this->node = $nodes->item(0);
        } else {
            throw new ilCOPageException("Invalid page xml (" .
                $this->getId() . "," . $this->getLanguage() . "): " . $this->getXMLContent(true));
        }

        if (empty($error)) {
            $this->dom_builded = true;
            return true;
        } else {
            return $error;
        }
    }

    public function freeDom(): void
    {
        unset($this->dom);
    }

    public function getDomDoc(): DOMDocument
    {
        return $this->dom;
    }

    public function setId(int $a_id): void
    {
        $this->id = $a_id;
    }

    public function getId(): int
    {
        return $this->id;
    }

    public function setParentId(int $a_id): void
    {
        $this->parent_id = $a_id;
    }

    public function getParentId(): int
    {
        return $this->parent_id;
    }

    public function addUpdateListener(
        object $a_object,
        string $a_method,
        $a_parameters = ""
    ): void {
        $cnt = $this->update_listener_cnt;
        $this->update_listeners[$cnt]["object"] = $a_object;
        $this->update_listeners[$cnt]["method"] = $a_method;
        $this->update_listeners[$cnt]["parameters"] = $a_parameters;
        $this->update_listener_cnt++;
    }

    public function callUpdateListeners(): void
    {
        for ($i = 0; $i < $this->update_listener_cnt; $i++) {
            $object = $this->update_listeners[$i]["object"];
            $method = $this->update_listeners[$i]["method"];
            $parameters = $this->update_listeners[$i]["parameters"];
            $object->$method($parameters);
        }
    }

    public function setActive(bool $a_active): void
    {
        $this->active = $a_active;
    }

    public function getActive(
        bool $a_check_scheduled_activation = false
    ): bool {
        if ($a_check_scheduled_activation && !$this->active) {
            $start = new ilDateTime($this->getActivationStart(), IL_CAL_DATETIME);
            $end = new ilDateTime($this->getActivationEnd(), IL_CAL_DATETIME);
            $now = new ilDateTime(time(), IL_CAL_UNIX);
            if (!ilDateTime::_before($now, $start) && !ilDateTime::_after($now, $end)) {
                return true;
            }
        }
        return $this->active;
    }

    public static function preloadActivationDataByParentId(int $a_parent_id): void
    {
        global $DIC;

        $db = $DIC->database();
        $set = $db->query(
            "SELECT page_id, parent_type, lang, active, activation_start, activation_end, show_activation_info FROM page_object " .
            " WHERE parent_id = " . $db->quote($a_parent_id, "integer")
        );
        while ($rec = $db->fetchAssoc($set)) {
            self::$activation_data[$rec["page_id"] . ":" . $rec["parent_type"] . ":" . $rec["lang"]] = $rec;
        }
    }

    public static function _lookupActive(
        int $a_id,
        string $a_parent_type,
        bool $a_check_scheduled_activation = false,
        string $a_lang = "-"
    ): bool {
        global $DIC;

        $db = $DIC->database();

        // language must be set at least to "-"
        if ($a_lang == "") {
            $a_lang = "-";
        }

        if (isset(self::$activation_data[$a_id . ":" . $a_parent_type . ":" . $a_lang])) {
            $rec = self::$activation_data[$a_id . ":" . $a_parent_type . ":" . $a_lang];
        } else {
            $set = $db->queryF(
                "SELECT active, activation_start, activation_end FROM page_object WHERE page_id = %s" .
                " AND parent_type = %s AND lang = %s",
                array("integer", "text", "text"),
                array($a_id, $a_parent_type, $a_lang)
            );
            $rec = $db->fetchAssoc($set);
            if (!$rec) {
                return true;
            }
        }

        $rec["n"] = ilUtil::now();
        if (!$rec["active"] && $a_check_scheduled_activation) {
            if ($rec["n"] >= $rec["activation_start"] &&
                $rec["n"] <= $rec["activation_end"]) {
                return true;
            }
        }

        return (bool) $rec["active"];
    }

    public static function _isScheduledActivation(
        int $a_id,
        string $a_parent_type,
        string $a_lang = "-"
    ): bool {
        global $DIC;

        $db = $DIC->database();

        // language must be set at least to "-"
        if ($a_lang == "") {
            $a_lang = "-";
        }

        //echo "<br>";
        //var_dump(self::$activation_data); exit;
        if (isset(self::$activation_data[$a_id . ":" . $a_parent_type . ":" . $a_lang])) {
            $rec = self::$activation_data[$a_id . ":" . $a_parent_type . ":" . $a_lang];
        } else {
            $set = $db->queryF(
                "SELECT active, activation_start, activation_end FROM page_object WHERE page_id = %s" .
                " AND parent_type = %s AND lang = %s",
                array("integer", "text", "text"),
                array($a_id, $a_parent_type, $a_lang)
            );
            $rec = $db->fetchAssoc($set);
        }

        if (!$rec["active"] && $rec["activation_start"] != "") {
            return true;
        }

        return false;
    }

    public static function _writeActive(
        int $a_id,
        string $a_parent_type,
        bool $a_active
    ): void {
        global $DIC;

        $db = $DIC->database();

        // language must be set at least to "-"
        $a_lang = "-";

        $db->manipulateF(
            "UPDATE page_object SET active = %s, activation_start = %s, " .
            " activation_end = %s WHERE page_id = %s" .
            " AND parent_type = %s AND lang = %s",
            array("int", "timestamp", "timestamp", "integer", "text", "text"),
            array((int) $a_active, null, null, $a_id, $a_parent_type, $a_lang)
        );
    }

    public static function _lookupActivationData(
        int $a_id,
        string $a_parent_type,
        string $a_lang = "-"
    ): array {
        global $DIC;

        $db = $DIC->database();

        // language must be set at least to "-"
        if ($a_lang == "") {
            $a_lang = "-";
        }

        if (isset(self::$activation_data[$a_id . ":" . $a_parent_type . ":" . $a_lang])) {
            $rec = self::$activation_data[$a_id . ":" . $a_parent_type . ":" . $a_lang];
        } else {
            $set = $db->queryF(
                "SELECT active, activation_start, activation_end, show_activation_info FROM page_object WHERE page_id = %s" .
                " AND parent_type = %s AND lang = %s",
                array("integer", "text", "text"),
                array($a_id, $a_parent_type, $a_lang)
            );
            $rec = $db->fetchAssoc($set);
            if (!$rec) {
                return [
                    "active" => 1,
                    "activation_start" => null,
                    "activation_end" => null,
                    "show_activation_info" => 0
                ];
            }
        }

        return $rec;
    }

    public static function lookupParentId(int $a_id, string $a_type): int
    {
        global $DIC;

        $db = $DIC->database();

        $res = $db->query("SELECT parent_id FROM page_object WHERE page_id = " . $db->quote($a_id, "integer") . " " .
            "AND parent_type=" . $db->quote($a_type, "text"));
        $rec = $db->fetchAssoc($res);
        return (int) ($rec["parent_id"] ?? 0);
    }

    public static function _writeParentId(string $a_parent_type, int $a_pg_id, int $a_par_id): void
    {
        global $DIC;

        $db = $DIC->database();
        $db->manipulateF(
            "UPDATE page_object SET parent_id = %s WHERE page_id = %s" .
            " AND parent_type = %s",
            array("integer", "integer", "text"),
            array($a_par_id, $a_pg_id, $a_parent_type)
        );
    }

    public function setActivationStart(?string $a_activationstart): void
    {
        if ($a_activationstart == "") {
            $a_activationstart = null;
        }
        $this->activationstart = $a_activationstart;
    }

    public function getActivationStart(): ?string
    {
        return $this->activationstart;
    }

    public function setActivationEnd(?string $a_activationend): void
    {
        if ($a_activationend == "") {
            $a_activationend = null;
        }
        $this->activationend = $a_activationend;
    }

    public function getActivationEnd(): ?string
    {
        return $this->activationend;
    }

    public function getContentObject(
        string $a_hier_id,
        string $a_pc_id = ""
    ): ?ilPageContent {
        $node = $this->page_manager->content($this->getDomDoc())->getContentDomNode(
            $a_hier_id,
            $a_pc_id
        );
        $this->log->debug("getContentObject: " . " $a_hier_id, $a_pc_id, " . $node->nodeName);
        return $this->pc_service->getByNode($node, $this);
    }

    public function getContentObjectForPcId(string $pcid): ?ilPageContent
    {
        $hier_ids = $this->getHierIdsForPCIds([$pcid]);
        return $this->getContentObject($hier_ids[$pcid], $pcid);
    }

    public function getParentContentObjectForPcId(string $pcid): ?ilPageContent
    {
        $content_object = $this->getContentObjectForPcId($pcid);
        $node = $content_object->getDomNode();
        $node = $node->parentNode;
        while ($node) {
            if ($node->nodeName == "PageContent") {
                $pcid = $node->getAttribute("PCID");
                if ($pcid != "") {
                    return $this->getContentObjectForPcId($pcid);
                }
            }
            $node = $node->parentNode;
        }
        return null;
    }

    public function getContentDomNode(string $a_hier_id, string $a_pc_id = ""): ?DOMNode
    {
        $cm = $this->page_manager->content($this->getDomDoc());
        return $cm->getContentDomNode($a_hier_id, $a_pc_id);
    }

    public function getDomNodeForPCId(string $pc_id): ?DOMNode
    {
        return $this->getContentDomNode("", $pc_id);
    }

    public function setXMLContent(string $a_xml, string $a_encoding = "UTF-8"): void
    {
        $this->encoding = $a_encoding;
        $this->xml = $a_xml;
    }

    public function appendXMLContent(string $a_xml): void
    {
        $this->xml .= $a_xml;
    }

    public function getXMLContent(bool $a_incl_head = false): string
    {
        // build full http path for XML DOCTYPE header.
        // Under windows a relative path doesn't work :-(
        if ($a_incl_head) {
            //echo "+".$this->encoding."+";
            $enc_str = (!empty($this->encoding))
                ? "encoding=\"" . $this->encoding . "\""
                : "";
            return "<?xml version=\"1.0\" $enc_str ?>" .
                "<!DOCTYPE PageObject SYSTEM \"" . $this->getIliasAbsolutePath() . "/components/ILIAS/Export/xml/" . $this->cur_dtd . "\">" .
                $this->xml;
        } else {
            return $this->xml;
        }
    }

    protected function getIliasAbsolutePath(): string
    {
        return ILIAS_ABSOLUTE_PATH;
    }

    public function copyXmlContent(
        bool $a_clone_mobs = false,
        int $a_new_parent_id = 0,
        int $obj_copy_id = 0,
        bool $self_ass = true
    ): string {
        $cm = $this->page_manager->contentFromXml($this->getXMLContent());
        return $cm->copyXmlContent(
            $this,
            $a_clone_mobs,
            $a_new_parent_id,
            $obj_copy_id,
            $self_ass
        );
    }

    // @todo 1: begin: generalize, remove concrete dependencies


    public function handleDeleteContent(?DOMNode $a_node = null, $move_operation = false): void
    {
        $pm = $this->page_manager->content($this->getDomDoc());
        $pm->handleDeleteContent($this, $a_node, $move_operation);
    }

    public function getXMLFromDom(
        bool $a_incl_head = false,
        bool $a_append_mobs = false,
        bool $a_append_bib = false,
        string $a_append_str = "",
        bool $a_omit_pageobject_tag = false,
        int $style_id = 0,
        bool $offline = false
    ): string {
        if ($a_incl_head) {
            //echo "\n<br>#".$this->encoding."#";
            return $this->dom_util->dump($this->node);
        } else {
            // append multimedia object elements
            if ($a_append_mobs || $a_append_bib) {
                $mobs = "";
                $bibs = "";
                if ($a_append_mobs) {
                    $mobs = $this->getMultimediaXML($offline);
                }
                if ($a_append_bib) {
                    // deprecated
                    //                                  $bibs = $this->getBibliographyXML();
                }
                $trans = $this->getLanguageVariablesXML($style_id);
                //echo htmlentities($this->dom->dump_node($this->node)); exit;
                return "<dummy>" . $this->dom_util->dump($this->node) . $mobs . $bibs . $trans . $a_append_str . "</dummy>";
            } else {
                if (is_object($this->dom)) {
                    if ($a_omit_pageobject_tag) {
                        $xml = "";
                        foreach ($this->node->childNodes as $child) {
                            $xml .= $this->dom_util->dump($child);
                        }
                    } else {
                        $xml = $this->dom_util->dump($this->node);
                        $xml = preg_replace('/<\?xml[^>]*>/i', "", $xml);
                        $xml = preg_replace('/<!DOCTYPE[^>]*>/i', "", $xml);

                        // don't use dump_node. This gives always entities.
                        //return $this->dom->dump_node($this->node);
                    }
                    return $xml;
                } else {
                    return "";
                }
            }
        }
    }

    public function getLanguageVariablesXML(int $style_id = 0): string
    {
        $xml = "<LVs>";
        $lang_vars = array(
            "ed_paste_clip",
            "ed_edit",
            "ed_edit_prop",
            "ed_delete",
            "ed_moveafter",
            "ed_movebefore",
            "ed_go",
            "ed_class",
            "ed_width",
            "ed_align_left",
            "ed_align_right",
            "ed_align_center",
            "ed_align_left_float",
            "ed_align_right_float",
            "ed_delete_item",
            "ed_new_item_before",
            "ed_new_item_after",
            "ed_copy_clip",
            "please_select",
            "ed_split_page",
            "ed_item_up",
            "ed_item_down",
            "ed_split_page_next",
            "ed_enable",
            "de_activate",
            "ed_paste",
            "ed_edit_multiple",
            "ed_cut",
            "ed_copy",
            "ed_insert_templ",
            "ed_click_to_add_pg",
            "download"
        );

        // collect lang vars from pc elements
        $defs = $this->pc_definition->getPCDefinitions();
        foreach ($defs as $def) {
            $lang_vars[] = "pc_" . $def["pc_type"];
            $lang_vars[] = "ed_insert_" . $def["pc_type"];

            $cl = $def["pc_class"];
            $lvs = call_user_func($def["pc_class"] . '::getLangVars');
            foreach ($lvs as $lv) {
                $lang_vars[] = $lv;
            }
        }

        // workaround for #30561, should go to characteristic manager
        $dummy_pc = new ilPCSectionGUI($this, null, "");
        $dummy_pc->setStyleId($style_id);
        foreach (["section", "table", "flist_li", "list_u", "list_o",
                  "table", "table_cell"] as $type) {
            $dummy_pc->getCharacteristicsOfCurrentStyle([$type]);
            foreach ($dummy_pc->getCharacteristics() as $char => $txt) {
                $xml .= "<LV name=\"char_" . $type . "_" . $char . "\" value=\"" . $txt . "\"/>";
            }
        }
        $type = "media_cont";
        $dummy_pc = new ilPCMediaObjectGUI($this, null, "");
        $dummy_pc->setStyleId($style_id);
        $dummy_pc->getCharacteristicsOfCurrentStyle([$type]);
        foreach ($dummy_pc->getCharacteristics() as $char => $txt) {
            $xml .= "<LV name=\"char_" . $type . "_" . $char . "\" value=\"" . $txt . "\"/>";
        }
        foreach (["text_block", "heading1", "heading2", "heading3"] as $type) {
            $dummy_pc = new ilPCParagraphGUI($this, null, "");
            $dummy_pc->setStyleId($style_id);
            $dummy_pc->getCharacteristicsOfCurrentStyle([$type]);
            foreach ($dummy_pc->getCharacteristics() as $char => $txt) {
                $xml .= "<LV name=\"char_" . $type . "_" . $char . "\" value=\"" . $txt . "\"/>";
            }
        }
        foreach ($lang_vars as $lang_var) {
            $xml .= $this->getLangVarXML($lang_var);
        }
        $xml .= "</LVs>";
        return $xml;
    }

    protected function getLangVarXML(string $var): string
    {
        $val = $this->lng->txt("cont_" . $var);
        $val = str_replace('"', "&quot;", $val);
        return "<LV name=\"$var\" value=\"" . $val . "\"/>";
    }

    public function getFirstParagraphText(): string
    {
        return $this->pc_service->paragraph()->getFirstParagraphText($this);
    }

    public function getParagraphForPCID(string $pcid): ?ilPCParagraph
    {
        return $this->pc_service->paragraph()->getParagraphForPCID($this, $pcid);
    }


    // @todo: can we do this better
    public function setContainsIntLink(bool $a_contains_link): void
    {
        $this->contains_int_link = $a_contains_link;
    }

    // @todo: can we do this better
    public function containsIntLink(): bool
    {
        return $this->contains_int_link;
    }

    public function setImportMode(bool $a_val): void
    {
        $this->import_mode = $a_val;
    }

    public function getImportMode(): bool
    {
        return $this->import_mode;
    }

    public function needsImportParsing(?bool $a_parse = null): bool
    {
        if ($a_parse === true) {
            $this->needs_parsing = true;
        }
        if ($a_parse === false) {
            $this->needs_parsing = false;
        }
        return $this->needs_parsing;
    }

    // @todo: can we do this better
    public function setContainsQuestion(bool $a_val): void
    {
        $this->contains_question = $a_val;
    }

    public function getContainsQuestion(): bool
    {
        return $this->contains_question;
    }


    public function collectMediaObjects(bool $a_inline_only = true): array
    {
        $mob_manager = $this->pc_service->mediaObject();
        return $mob_manager->collectMediaObjects($this->getDomDoc(), $a_inline_only);
    }

    public function getInternalLinks(): array
    {
        return $this->link->getInternalLinks($this->getDomDoc());
    }

    public function getMultimediaXML(
        bool $offline = false
    ): string
    {
        $mob_manager = $this->pc_service->mediaObject();
        return $mob_manager->getMultimediaXML($this->getDomDoc(), $offline);
    }

    public function getMediaAliasElement(int $a_mob_id, int $a_nr = 1): string
    {
        $mob_manager = $this->pc_service->mediaObject();
        return $mob_manager->getMediaAliasElement(
            $this->getDomDoc(),
            $a_mob_id,
            $a_nr
        );
    }

    public function validateDom(bool $throw = false): ?array
    {
        $this->stripHierIDs();

        // possible fix for #14820
        //libxml_disable_entity_loader(false);

        $error = null;
        $this->dom_util->validate($this->dom, $error, $throw);
        return $error;
    }

    public function addHierIDs(): void
    {
        $this->content_id_manager->addHierIDsToDom();
    }

    public function getHierIds(): array
    {
        return $this->content_id_manager->getHierIds();
    }

    public function stripHierIDs(): void
    {
        $this->content_id_manager->stripHierIDsFromDom();
    }

    public function stripPCIDs(): void
    {
        $this->content_id_manager->stripPCIDs();
    }

    public function getHierIdsForPCIds(array $a_pc_ids): array
    {
        return $this->content_id_manager->getHierIdsForPCIds($a_pc_ids);
    }

    public function getHierIdForPcId(string $pcid): string
    {
        return $this->content_id_manager->getHierIdForPcId($pcid);
    }

    public function getPCIdsForHierIds(array $hier_ids): array
    {
        return $this->content_id_manager->getPCIdsForHierIds($hier_ids);
    }

    public function getPCIdForHierId(string $hier_id): string
    {
        return $this->content_id_manager->getPCIdForHierId($hier_id);
    }

    public function addFileSizes(): void
    {
        $this->pc_service->fileList()->addFileSizes($this->getDomDoc());
    }

    public function resolveIntLinks(array $a_link_map = null): bool
    {
        return $this->link->resolveIntLinks($this->getDomDoc(), $a_link_map);
    }

    public function resolveMediaAliases(
        array $a_mapping,
        bool $a_reuse_existing_by_import = false
    ): bool {
        return $this->pc_service->mediaObject()->resolveMediaAliases(
            $this,
            $a_mapping,
            $a_reuse_existing_by_import
        );
    }

    public function resolveIIMMediaAliases(array $a_mapping): bool
    {
        return $this->pc_service->interactiveImage()->resolveIIMMediaAliases(
            $this->getDomDoc(),
            $a_mapping
        );
    }

    public function resolveFileItems(array $a_mapping): bool
    {
        return $this->pc_service->fileList()->resolveFileItems(
            $this->getDomDoc(),
            $a_mapping
        );
    }

    public function resolveQuestionReferences(array $a_mapping): bool
    {
        $qm = $this->pc_service->question();
        return $qm->resolveQuestionReferences(
            $this->getDomDoc(),
            $a_mapping
        );
    }


    public function moveIntLinks(array $a_from_to): bool
    {
        $this->buildDom();
        $this->addHierIDs();
        return $this->link->moveIntLinks(
            $this->getDomDoc(),
            $a_from_to
        );
    }


    public function handleRepositoryLinksOnCopy(
        array $a_mapping,
        int $a_source_ref_id
    ): void {
        $this->buildDom();

        $tree = $this->tree;
        $this->log->debug("Handle repository links...");

        $defs = $this->pc_definition->getPCDefinitions();
        foreach ($defs as $def) {
            if (method_exists($def["pc_class"], 'afterRepositoryCopy')) {
                call_user_func($def["pc_class"] . '::afterRepositoryCopy', $this, $a_mapping, $a_source_ref_id);
            }
        }

        $this->link->handleRepositoryLinksOnCopy($this->getDomDoc(), $a_mapping, $a_source_ref_id, $tree);
    }

    public function setEmptyPageXml(): void
    {
        $this->setXMLContent("<PageObject></PageObject>");
    }

    public function createFromXML(): void
    {
        $empty = false;
        if ($this->getXMLContent() === "") {
            $this->setEmptyPageXml();
            $empty = true;
        }
        $content = $this->getXMLContent();
        $this->buildDom(true);
        $dom_doc = $this->getDomDoc();

        $errors = $this->validateDom(true);

        $iel = $this->containsDeactivatedElements($content);
        $inl = $this->containsIntLinks($content);
        // create object
        $this->db->insert("page_object", array(
            "page_id" => array("integer", $this->getId()),
            "parent_id" => array("integer", $this->getParentId()),
            "lang" => array("text", $this->getLanguage()),
            "content" => array("clob", $content),
            "parent_type" => array("text", $this->getParentType()),
            "create_user" => array("integer", $this->user->getId()),
            "last_change_user" => array("integer", $this->user->getId()),
            "active" => array("integer", (int) $this->getActive()),
            "activation_start" => array("timestamp", $this->getActivationStart()),
            "activation_end" => array("timestamp", $this->getActivationEnd()),
            "show_activation_info" => array("integer", (int) $this->getShowActivationInfo()),
            "inactive_elements" => array("integer", $iel),
            "int_links" => array("integer", $inl),
            "created" => array("timestamp", ilUtil::now()),
            "last_change" => array("timestamp", ilUtil::now()),
            "is_empty" => array("integer", $empty)
        ));
        // after update event
        $this->__afterUpdate($dom_doc, $content, true, $empty);
    }

    public function updateFromXML(): bool
    {
        $this->log->debug("ilPageObject, updateFromXML(): start, id: " . $this->getId());

        $content = $this->getXMLContent();

        $this->log->debug("ilPageObject, updateFromXML(): content: " . substr($content, 0, 100));

        $this->buildDom(true);
        $dom_doc = $this->getDomDoc();

        $errors = $this->validateDom(true);

        $iel = $this->containsDeactivatedElements($content);
        $inl = $this->containsIntLinks($content);

        $this->db->update("page_object", array(
            "content" => array("clob", $content),
            "parent_id" => array("integer", $this->getParentId()),
            "last_change_user" => array("integer", $this->user->getId()),
            "last_change" => array("timestamp", ilUtil::now()),
            "active" => array("integer", $this->getActive()),
            "activation_start" => array("timestamp", $this->getActivationStart()),
            "activation_end" => array("timestamp", $this->getActivationEnd()),
            "inactive_elements" => array("integer", $iel),
            "int_links" => array("integer", $inl),
        ), array(
            "page_id" => array("integer", $this->getId()),
            "parent_type" => array("text", $this->getParentType()),
            "lang" => array("text", $this->getLanguage())
        ));

        // after update event
        $this->__afterUpdate($dom_doc, $content);

        $this->log->debug("ilPageObject, updateFromXML(): end");

        return true;
    }

    final protected function __afterUpdate(
        DOMDocument $a_domdoc,
        string $a_xml,
        bool $a_creation = false,
        bool $a_empty = false
    ): void {
        // we do not need this if we are creating an empty page
        if (!$a_creation || !$a_empty) {
            // save internal link information
            // the page object is responsible to do this, since it "offers" the
            // internal link feature pc and page classes
            $this->saveInternalLinks($a_domdoc);

            // save style usage
            $this->saveStyleUsage($a_domdoc);

            // save estimated reading time
            $this->reading_time_manager->saveTime($this);

            // pc classes hook
            $defs = $this->pc_definition->getPCDefinitions();
            foreach ($defs as $def) {
                $cl = $def["pc_class"];
                call_user_func($def["pc_class"] . '::afterPageUpdate', $this, $a_domdoc, $a_xml, $a_creation);
            }
        }

        // call page hook
        $this->afterUpdate($a_domdoc, $a_xml);

        // call update listeners
        $this->callUpdateListeners();
    }

    public function afterUpdate(DOMDocument $domdoc, string $xml): void
    {
    }

    public function update(bool $a_validate = true, bool $a_no_history = false)
    {
        $this->log->debug("start..., id: " . $this->getId());
        $lm_set = new ilSetting("lm");

        // add missing pc ids
        if (!$this->checkPCIds()) {
            $this->insertPCIds();
        }

        // test validating
        if ($a_validate) {
            $this->log->debug($this->dom_util->dump($this->getDomDoc()->documentElement));
            $errors = $this->validateDom();
        }
        //var_dump($errors); exit;
        if (empty($errors) && !$this->getEditLock()) {
            $lock = $this->getEditLockInfo();
            $errors[0] = array(0 => 0,
                               1 => $this->lng->txt("cont_not_saved_edit_lock_expired") . "<br />" .
                                   $this->lng->txt("obj_usr") . ": " .
                                   ilUserUtil::getNamePresentation($lock["edit_lock_user"]) . "<br />" .
                                   $this->lng->txt("content_until") . ": " .
                                   ilDatePresentation::formatDate(new ilDateTime($lock["edit_lock_until"], IL_CAL_UNIX))
            );
        }

        // check for duplicate pc ids
        $this->log->debug("checking duplicate ids");
        if ($this->hasDuplicatePCIds()) {
            $errors[0] = $this->lng->txt("cont_could_not_save_duplicate_pc_ids") .
                " (" . implode(", ", $this->getDuplicatePCIds()) . ")";
        }

        if (!empty($errors)) {
            $this->log->debug("ilPageObject, update(): errors: " . print_r($errors, true));
        }

        //echo "-".htmlentities($this->getXMLFromDom())."-"; exit;
        if (empty($errors)) {
            // @todo 1: is this page type or pc content type
            // related -> plugins should be able to hook in!?

            $this->log->debug("perform automatic modifications");
            $this->performAutomaticModifications();

            // get xml content
            $content = $this->getXMLFromDom();
            $dom_doc = $this->getDomDoc();

            // this needs to be locked

            // write history entry
            $old_set = $this->db->query("SELECT * FROM page_object WHERE " .
                "page_id = " . $this->db->quote($this->getId(), "integer") . " AND " .
                "parent_type = " . $this->db->quote($this->getParentType(), "text") . " AND " .
                "lang = " . $this->db->quote($this->getLanguage(), "text"));
            $last_nr_set = $this->db->query("SELECT max(nr) as mnr FROM page_history WHERE " .
                "page_id = " . $this->db->quote($this->getId(), "integer") . " AND " .
                "parent_type = " . $this->db->quote($this->getParentType(), "text") . " AND " .
                "lang = " . $this->db->quote($this->getLanguage(), "text"));
            $last_nr = $this->db->fetchAssoc($last_nr_set);
            if ($old_rec = $this->db->fetchAssoc($old_set)) {
                // only save, if something has changed
                // added user id to the check for ilias 5.0, 7.10.2014
                if (($content != $old_rec["content"] || $this->user->getId() != $old_rec["last_change_user"]) &&
                    !$a_no_history && !$this->history_saved && $lm_set->get("page_history", 1)) {
                    if ($old_rec["content"] != "<PageObject></PageObject>") {
                        $this->db->manipulateF(
                            "DELETE FROM page_history WHERE " .
                            "page_id = %s AND parent_type = %s AND hdate = %s AND lang = %s",
                            array("integer", "text", "timestamp", "text"),
                            array($old_rec["page_id"],
                                  $old_rec["parent_type"],
                                  $old_rec["last_change"],
                                  $old_rec["lang"]
                            )
                        );

                        // the following lines are a workaround for
                        // bug 6741
                        $last_c = $old_rec["last_change"];
                        if ($last_c == "") {
                            $last_c = ilUtil::now();
                        }

                        $this->db->insert("page_history", array(
                            "page_id" => array("integer", $old_rec["page_id"]),
                            "parent_type" => array("text", $old_rec["parent_type"]),
                            "lang" => array("text", $old_rec["lang"]),
                            "hdate" => array("timestamp", $last_c),
                            "parent_id" => array("integer", $old_rec["parent_id"]),
                            "content" => array("clob", $old_rec["content"]),
                            "user_id" => array("integer", $old_rec["last_change_user"]),
                            "ilias_version" => array("text", ILIAS_VERSION_NUMERIC),
                            "nr" => array("integer", (int) $last_nr["mnr"] + 1)
                        ));

                        $old_content = $old_rec["content"];
                        $old_domdoc = new DOMDocument();
                        $old_nr = $last_nr["mnr"] + 1;
                        $old_domdoc->loadXML('<?xml version="1.0" encoding="UTF-8"?>' . $old_content);

                        // after history entry creation event
                        $this->log->debug("calling __afterHistoryEntry");
                        $this->__afterHistoryEntry($old_domdoc, $old_content, $old_nr);

                        // only save one time
                    }
                    $this->history_saved = true;
                }
            }
            //echo htmlentities($content);
            $em = (trim($content) == "<PageObject/>")
                ? 1
                : 0;

            // @todo: pass dom instead?
            $this->log->debug("checking deactivated elements");
            $iel = $this->containsDeactivatedElements($content);
            $this->log->debug("checking internal links");
            $inl = $this->containsIntLinks($content);

            $now = ilUtil::now();
            $this->lastchange = $now;
            $this->db->update("page_object", array(
                "content" => array("clob", $content),
                "parent_id" => array("integer", $this->getParentId()),
                "last_change_user" => array("integer", $this->user->getId()),
                "last_change" => array("timestamp", $now),
                "is_empty" => array("integer", $em),
                "active" => array("integer", $this->getActive()),
                "activation_start" => array("timestamp", $this->getActivationStart()),
                "activation_end" => array("timestamp", $this->getActivationEnd()),
                "show_activation_info" => array("integer", $this->getShowActivationInfo()),
                "inactive_elements" => array("integer", $iel),
                "int_links" => array("integer", $inl),
            ), array(
                "page_id" => array("integer", $this->getId()),
                "parent_type" => array("text", $this->getParentType()),
                "lang" => array("text", $this->getLanguage())
            ));

            // after update event
            $this->log->debug("calling __afterUpdate()");
            $this->__afterUpdate($dom_doc, $content);

            $this->log->debug(
                "...ending, updated and returning true, content: " . substr(
                    $this->getXMLContent(),
                    0,
                    1000
                )
            );

            //echo "<br>PageObject::update:".htmlentities($this->getXMLContent()).":";
            return true;
        } else {
            return $errors;
        }
    }

    public function delete(): void
    {
        $copg_logger = ilLoggerFactory::getLogger('copg');
        $copg_logger->debug(
            "ilPageObject: Delete called for ID '" . $this->getId() . "'," .
            " parent type: '" . $this->getParentType() . "', " .
            " hist nr: '" . $this->old_nr . "', " .
            " lang: '" . $this->getLanguage() . "', "
        );

        $mobs = array();
        if (!$this->page_not_found) {
            $this->buildDom();
            $mobs = $this->collectMediaObjects(false);
        }
        $mobs2 = ilObjMediaObject::_getMobsOfObject(
            $this->getParentType() . ":pg",
            $this->getId(),
            false,
            $this->getLanguage()
        );

        foreach ($mobs2 as $m) {
            if (!in_array($m, $mobs)) {
                $mobs[] = $m;
            }
        }

        $copg_logger->debug("ilPageObject: ... found " . count($mobs) . " media objects.");

        $this->__beforeDelete();

        // treat plugged content
        $this->handleDeleteContent();

        // delete style usages
        $this->deleteStyleUsages(false);

        // delete internal links
        $this->deleteInternalLinks();

        // delete all mob usages
        ilObjMediaObject::_deleteAllUsages($this->getParentType() . ":pg", $this->getId());

        // delete news
        if (!$this->isTranslationPage()) {
            ilNewsItem::deleteNewsOfContext(
                $this->getParentId(),
                $this->getParentType(),
                $this->getId(),
                "pg"
            );
        }

        // delete page_object entry
        $and = $this->isTranslationPage()
            ? " AND lang = " . $this->db->quote($this->getLanguage(), "text")
            : "";
        $this->db->manipulate("DELETE FROM page_object " .
            "WHERE page_id = " . $this->db->quote($this->getId(), "integer") .
            " AND parent_type= " . $this->db->quote($this->getParentType(), "text") . $and);

        // delete media objects
        foreach ($mobs as $mob_id) {
            $copg_logger->debug("ilPageObject: ... processing mob " . $mob_id . ".");

            if (ilObject::_lookupType($mob_id) != 'mob') {
                $copg_logger->debug("ilPageObject: ... type mismatch. Ignoring mob " . $mob_id . ".");
                continue;
            }

            if (ilObject::_exists($mob_id)) {
                $copg_logger->debug("ilPageObject: ... delete mob " . $mob_id . ".");

                $mob_obj = new ilObjMediaObject($mob_id);
                $mob_obj->delete();
            } else {
                $copg_logger->debug("ilPageObject: ... missing mob " . $mob_id . ".");
            }
        }

        $this->__afterDelete();
    }

    protected function isTranslationPage(): bool
    {
        return !in_array($this->getLanguage(), ["", "-"]);
    }

    final protected function __beforeDelete(): void
    {
        // pc classes hook
        $defs = $this->pc_definition->getPCDefinitions();
        foreach ($defs as $def) {
            $cl = $def["pc_class"];
            call_user_func($def["pc_class"] . '::beforePageDelete', $this);
        }
    }

    final protected function __afterDelete(): void
    {
        $this->afterDelete();
    }

    protected function afterDelete(): void
    {
    }

    final protected function __afterHistoryEntry(
        DOMDocument $a_old_domdoc,
        string $a_old_content,
        int $a_old_nr
    ): void {
        // save style usage
        $this->saveStyleUsage($a_old_domdoc, $a_old_nr);

        // pc classes hook
        $defs = $this->pc_definition->getPCDefinitions();
        foreach ($defs as $def) {
            $cl = $def["pc_class"];
            call_user_func(
                $def["pc_class"] . '::afterPageHistoryEntry',
                $this,
                $a_old_domdoc,
                $a_old_content,
                $a_old_nr
            );
        }
    }

    public function saveStyleUsage(
        DOMDocument $a_domdoc,
        int $a_old_nr = 0
    ): void {
        $this->style_manager->saveStyleUsage(
            $this,
            $a_domdoc,
            $a_old_nr
        );
    }

    public function deleteStyleUsages(int $a_old_nr = 0): void
    {
        $this->style_manager->deleteStyleUsages($this, $a_old_nr);
    }

    public function getLastUpdateOfIncludedElements(): string
    {
        $mobs = ilObjMediaObject::_getMobsOfObject(
            $this->getParentType() . ":pg",
            $this->getId()
        );
        $files = ilObjFile::_getFilesOfObject(
            $this->getParentType() . ":pg",
            $this->getId()
        );
        $objs = array_merge($mobs, $files);
        return ilObject::_getLastUpdateOfObjects($objs);
    }

    public function deleteInternalLinks(): void
    {
        $this->link->deleteInternalLinks($this);
    }


    public function saveInternalLinks(DOMDocument $a_domdoc): void
    {
        $this->link->saveInternalLinks(
            $this,
            $a_domdoc
        );
    }

    public function create(bool $a_import = false): void
    {
        $this->createFromXML();
    }

    public function deleteContent(
        string $a_hid,
        bool $a_update = true,
        string $a_pcid = "",
        bool $move_operation = false
    ) {
        $pm = $this->page_manager->content($this->getDomDoc());
        $pm->deleteContent($this, $a_hid, $a_pcid, $move_operation);
        if ($a_update) {
            return $this->update();
        }
        return true;
    }

    public function deleteContents(
        array $a_hids,
        bool $a_update = true,
        bool $a_self_ass = false,
        bool $move_operation = false
    ) {
        $pm = $this->page_manager->content($this->getDomDoc());
        $pm->deleteContents($this, $a_hids, $a_self_ass, $move_operation);
        if ($a_update) {
            return $this->update();
        }
        return true;
    }

    public function cutContents(array $a_hids)
    {
        $this->copyContents($a_hids);
        return $this->deleteContents(
            $a_hids,
            true,
            $this->getPageConfig()->getEnableSelfAssessment(),
            true
        );
    }

    public function copyContents(array $a_hids): void
    {
        $cm = $this->page_manager->content($this->getDomDoc());
        $cm->copyContents($a_hids, $this->user);
    }

    public function pasteContents(
        string $a_hier_id,
        bool $a_self_ass = false
    ) {
        $user = $this->user;
        $cm = $this->page_manager->content($this->getDomDoc());
        $cm->pasteContents(
            $user,
            $a_hier_id,
            $this,
            $a_self_ass
        );
        return $this->update();
    }

    public function switchEnableMultiple(
        array $a_hids,
        bool $a_update = true,
        bool $a_self_ass = false
    ) {
        $cm = $this->page_manager->content($this->getDomDoc());
        $cm->switchEnableMultiple($this, $a_hids, $a_self_ass);
        if ($a_update) {
            return $this->update();
        }
        return true;
    }

    public function insertContent(
        ilPageContent $a_cont_obj,
        string $a_pos,
        int $a_mode = IL_INSERT_AFTER,
        string $a_pcid = "",
        bool $remove_placeholder = true
    ): void {
        $cm = $this->page_manager->content($this->getDomDoc());
        $cm->insertContent(
            $a_cont_obj,
            $a_pos,
            $a_mode,
            $a_pcid,
            $remove_placeholder,
            $this->getPageConfig()->getEnablePCType("PlaceHolder")
        );
    }

    public function insertContentNode(
        DOMNode $a_cont_node,
        string $a_pos,
        int $a_mode = IL_INSERT_AFTER,
        string $a_pcid = ""
    ): void {
        $cm = $this->page_manager->content($this->getDomDoc());
        $cm->insertContentNode(
            $a_cont_node,
            $a_pos,
            $a_mode,
            $a_pcid
        );
    }


    public function moveContentAfter(
        string $a_source,
        string $a_target,
        string $a_spcid = "",
        string $a_tpcid = ""
    ) {
        $cm = $this->page_manager->content($this->getDomDoc());
        $cm->moveContentAfter(
            $this,
            $a_source,
            $a_target,
            $a_spcid,
            $a_tpcid
        );
        return $this->update();
    }

    public function insertInstIntoIDs(
        string $a_inst,
        bool $a_res_ref_to_obj_id = true
    ): void {
        $cm = $this->page_manager->content($this->getDomDoc());
        $cm->insertInstIntoIDs($a_inst, $a_res_ref_to_obj_id);
    }

    public function checkPCIds(): bool
    {
        return $this->content_id_manager->checkPCIds();
    }

    public function getAllPCIds(): array
    {
        return $this->content_id_manager->getAllPCIds();
    }

    public function hasDuplicatePCIds(): bool
    {
        return $this->content_id_manager->hasDuplicatePCIds();
    }

    public function getDuplicatePCIds(): array
    {
        return $this->content_id_manager->getDuplicatePCIds();
    }

    public function generatePCId(): string
    {
        return $this->content_id_manager->generatePCId();
    }

    public function insertPCIds(): void
    {
        $this->content_id_manager->insertPCIds();
    }

    public function sendParagraph(
        string $par_id,
        string $filename
    ): void {
        $this->pc_service->paragraph()->send(
            $this->getDomDoc(),
            $par_id,
            $filename
        );
    }

    public function registerOfflineHandler(object $handler): void
    {
        $this->offline_handler = $handler;
    }

    public function getOfflineHandler(): ?object
    {
        return $this->offline_handler;
    }

    public static function _lookupContainsDeactivatedElements(
        int $a_id,
        string $a_parent_type,
        string $a_lang = "-"
    ): bool {
        global $DIC;

        $db = $DIC->database();

        if ($a_lang == "") {
            $a_lang = "-";
        }

        $query = "SELECT * FROM page_object WHERE page_id = " .
            $db->quote($a_id, "integer") . " AND " .
            " parent_type = " . $db->quote($a_parent_type, "text") . " AND " .
            " lang = " . $db->quote($a_lang, "text") . " AND " .
            " inactive_elements = " . $db->quote(1, "integer");
        $obj_set = $db->query($query);

        if ($obj_rec = $obj_set->fetchRow(ilDBConstants::FETCHMODE_ASSOC)) {
            return true;
        }

        return false;
    }

    public function containsDeactivatedElements(string $a_content): bool
    {
        if (strpos($a_content, " Enabled=\"False\"")) {
            return true;
        }
        return false;
    }

    public function getHistoryEntries(): array
    {
        $db = $this->db;

        $h_query = "SELECT * FROM page_history " .
            " WHERE page_id = " . $db->quote($this->getId(), "integer") .
            " AND parent_type = " . $db->quote($this->getParentType(), "text") .
            " AND lang = " . $db->quote($this->getLanguage(), "text") .
            " ORDER BY hdate DESC";

        $hset = $db->query($h_query);
        $hentries = array();

        while ($hrec = $db->fetchAssoc($hset)) {
            $hrec["sortkey"] = (int) $hrec["nr"];
            $hrec["user"] = (int) $hrec["user_id"];
            $hentries[] = $hrec;
        }
        //var_dump($hentries);
        return $hentries;
    }

    public function getHistoryEntry(int $a_old_nr): ?array
    {
        $db = $this->db;

        $res = $db->queryF(
            "SELECT * FROM page_history " .
            " WHERE page_id = %s " .
            " AND parent_type = %s " .
            " AND nr = %s" .
            " AND lang = %s",
            array("integer", "text", "integer", "text"),
            array($this->getId(), $this->getParentType(), $a_old_nr, $this->getLanguage())
        );
        if ($hrec = $db->fetchAssoc($res)) {
            return $hrec;
        }

        return null;
    }

    public function getHistoryInfo(int $a_nr): array
    {
        $db = $this->db;

        // determine previous entry
        $and_nr = ($a_nr > 0)
            ? " AND nr < " . $db->quote($a_nr, "integer")
            : "";
        $res = $db->query("SELECT MAX(nr) mnr FROM page_history " .
            " WHERE page_id = " . $db->quote($this->getId(), "integer") .
            " AND parent_type = " . $db->quote($this->getParentType(), "text") .
            " AND lang = " . $db->quote($this->getLanguage(), "text") .
            $and_nr);
        $row = $db->fetchAssoc($res);
        if ($row["mnr"] > 0) {
            $res = $db->query("SELECT * FROM page_history " .
                " WHERE page_id = " . $db->quote($this->getId(), "integer") .
                " AND parent_type = " . $db->quote($this->getParentType(), "text") .
                " AND lang = " . $db->quote($this->getLanguage(), "text") .
                " AND nr = " . $db->quote((int) $row["mnr"], "integer"));
            $row = $db->fetchAssoc($res);
            $ret["previous"] = $row;
        }

        // determine next entry
        $res = $db->query("SELECT MIN(nr) mnr FROM page_history " .
            " WHERE page_id = " . $db->quote($this->getId(), "integer") .
            " AND parent_type = " . $db->quote($this->getParentType(), "text") .
            " AND lang = " . $db->quote($this->getLanguage(), "text") .
            " AND nr > " . $db->quote($a_nr, "integer"));
        $row = $db->fetchAssoc($res);
        if ($row["mnr"] > 0) {
            $res = $db->query("SELECT * FROM page_history " .
                " WHERE page_id = " . $db->quote($this->getId(), "integer") .
                " AND parent_type = " . $db->quote($this->getParentType(), "text") .
                " AND lang = " . $db->quote($this->getLanguage(), "text") .
                " AND nr = " . $db->quote((int) $row["mnr"], "integer"));
            $row = $db->fetchAssoc($res);
            $ret["next"] = $row;
        }

        // current
        if ($a_nr > 0) {
            $res = $db->query("SELECT * FROM page_history " .
                " WHERE page_id = " . $db->quote($this->getId(), "integer") .
                " AND parent_type = " . $db->quote($this->getParentType(), "text") .
                " AND lang = " . $db->quote($this->getLanguage(), "text") .
                " AND nr = " . $db->quote($a_nr, "integer"));
        } else {
            $res = $db->query("SELECT page_id, last_change hdate, parent_type, parent_id, last_change_user user_id, content, lang FROM page_object " .
                " WHERE page_id = " . $db->quote($this->getId(), "integer") .
                " AND parent_type = " . $db->quote($this->getParentType(), "text") .
                " AND lang = " . $db->quote($this->getLanguage(), "text"));
        }
        $row = $db->fetchAssoc($res);
        $ret["current"] = $row;

        return $ret;
    }

    public function preparePageForCompare(ilPageObject $page): void
    {
    }

    public function increaseViewCnt(): void
    {
        $db = $this->db;

        $db->manipulate("UPDATE page_object " .
            " SET view_cnt = view_cnt + 1 " .
            " WHERE page_id = " . $db->quote($this->getId(), "integer") .
            " AND parent_type = " . $db->quote($this->getParentType(), "text") .
            " AND lang = " . $db->quote($this->getLanguage(), "text"));
    }

    public static function getRecentChanges(
        string $a_parent_type,
        int $a_parent_id,
        int $a_period = 30,
        string $a_lang = ""
    ): array {
        global $DIC;

        $db = $DIC->database();

        $and_lang = "";
        if ($a_lang != "") {
            $and_lang = " AND lang = " . $db->quote($a_lang, "text");
        }

        $page_changes = array();
        $limit_ts = date('Y-m-d H:i:s', time() - ($a_period * 24 * 60 * 60));
        $q = "SELECT * FROM page_object " .
            " WHERE parent_id = " . $db->quote($a_parent_id, "integer") .
            " AND parent_type = " . $db->quote($a_parent_type, "text") .
            " AND last_change >= " . $db->quote($limit_ts, "timestamp") . $and_lang;
        //      " AND (TO_DAYS(now()) - TO_DAYS(last_change)) <= ".((int)$a_period);
        $set = $db->query($q);
        while ($page = $db->fetchAssoc($set)) {
            $page_changes[] = array(
                "date" => $page["last_change"],
                "id" => $page["page_id"],
                "lang" => $page["lang"],
                "type" => "page",
                "user" => $page["last_change_user"]
            );
        }

        $and_str = "";
        if ($a_period > 0) {
            $limit_ts = date('Y-m-d H:i:s', time() - ($a_period * 24 * 60 * 60));
            $and_str = " AND hdate >= " . $db->quote($limit_ts, "timestamp") . " ";
        }

        $q = "SELECT * FROM page_history " .
            " WHERE parent_id = " . $db->quote($a_parent_id, "integer") .
            " AND parent_type = " . $db->quote($a_parent_type, "text") .
            $and_str . $and_lang;
        $set = $db->query($q);
        while ($page = $db->fetchAssoc($set)) {
            $page_changes[] = array(
                "date" => $page["hdate"],
                "id" => $page["page_id"],
                "lang" => $page["lang"],
                "type" => "hist",
                "nr" => $page["nr"],
                "user" => $page["user_id"]
            );
        }

        $page_changes = ilArrayUtil::sortArray($page_changes, "date", "desc");

        return $page_changes;
    }

    public static function getAllPages(
        string $a_parent_type,
        int $a_parent_id,
        string $a_lang = "-"
    ): array {
        global $DIC;

        $db = $DIC->database();

        $and_lang = "";
        if ($a_lang != "") {
            $and_lang = " AND lang = " . $db->quote($a_lang, "text");
        }

        $q = "SELECT * FROM page_object " .
            " WHERE parent_id = " . $db->quote($a_parent_id, "integer") .
            " AND parent_type = " . $db->quote($a_parent_type, "text") . $and_lang;
        $set = $db->query($q);
        $pages = array();
        while ($page = $db->fetchAssoc($set)) {
            $key_add = ($a_lang == "")
                ? ":" . $page["lang"]
                : "";
            $pages[$page["page_id"] . $key_add] = array(
                "date" => $page["last_change"],
                "id" => $page["page_id"],
                "lang" => $page["lang"],
                "user" => $page["last_change_user"]
            );
        }

        return $pages;
    }

    public static function getNewPages(
        string $a_parent_type,
        int $a_parent_id,
        string $a_lang = "-"
    ): array {
        global $DIC;

        $db = $DIC->database();

        $and_lang = "";
        if ($a_lang != "") {
            $and_lang = " AND lang = " . $db->quote($a_lang, "text");
        }

        $pages = array();

        $q = "SELECT * FROM page_object " .
            " WHERE parent_id = " . $db->quote($a_parent_id, "integer") .
            " AND parent_type = " . $db->quote($a_parent_type, "text") . $and_lang .
            " ORDER BY created DESC";
        $set = $db->query($q);
        while ($page = $db->fetchAssoc($set)) {
            if ($page["created"] != "") {
                $pages[] = array(
                    "created" => $page["created"],
                    "id" => $page["page_id"],
                    "lang" => $page["lang"],
                    "user" => $page["create_user"],
                );
            }
        }

        return $pages;
    }

    public static function getParentObjectContributors(
        string $a_parent_type,
        int $a_parent_id,
        string $a_lang = "-"
    ): array {
        global $DIC;

        $db = $DIC->database();

        $and_lang = "";
        if ($a_lang != "") {
            $and_lang = " AND lang = " . $db->quote($a_lang, "text");
        }

        $contributors = array();
        $set = $db->queryF(
            "SELECT last_change_user, lang, page_id FROM page_object " .
            " WHERE parent_id = %s AND parent_type = %s " .
            " AND last_change_user != %s" . $and_lang,
            array("integer", "text", "integer"),
            array($a_parent_id, $a_parent_type, 0)
        );

        while ($page = $db->fetchAssoc($set)) {
            if ($a_lang == "") {
                $contributors[$page["last_change_user"]][$page["page_id"]][$page["lang"]] = 1;
            } else {
                $contributors[$page["last_change_user"]][$page["page_id"]] = 1;
            }
        }

        $set = $db->queryF(
            "SELECT count(*) as cnt, lang, page_id, user_id FROM page_history " .
            " WHERE parent_id = %s AND parent_type = %s AND user_id != %s " . $and_lang .
            " GROUP BY page_id, user_id, lang ",
            array("integer", "text", "integer"),
            array($a_parent_id, $a_parent_type, 0)
        );
        while ($hpage = $db->fetchAssoc($set)) {
            if ($a_lang == "") {
                $contributors[$hpage["user_id"]][$hpage["page_id"]][$hpage["lang"]] =
                    ($contributors[$hpage["user_id"]][$hpage["page_id"]][$hpage["lang"]] ?? 0) + $hpage["cnt"];
            } else {
                $contributors[$hpage["user_id"]][$hpage["page_id"]] =
                    ($contributors[$hpage["user_id"]][$hpage["page_id"]] ?? 0) + $hpage["cnt"];
            }
        }

        $c = array();
        foreach ($contributors as $k => $co) {
            if (ilObject::_lookupType($k) == "usr") {
                $name = ilObjUser::_lookupName($k);
                $c[] = array("user_id" => $k,
                             "pages" => $co,
                             "lastname" => $name["lastname"],
                             "firstname" => $name["firstname"]
                );
            }
        }

        return $c;
    }

    public static function getPageContributors(
        string $a_parent_type,
        int $a_page_id,
        string $a_lang = "-"
    ): array {
        global $DIC;

        $db = $DIC->database();

        $and_lang = "";
        if ($a_lang != "") {
            $and_lang = " AND lang = " . $db->quote($a_lang, "text");
        }

        $contributors = array();
        $set = $db->queryF(
            "SELECT last_change_user, lang FROM page_object " .
            " WHERE page_id = %s AND parent_type = %s " .
            " AND last_change_user != %s" . $and_lang,
            array("integer", "text", "integer"),
            array($a_page_id, $a_parent_type, 0)
        );

        while ($page = $db->fetchAssoc($set)) {
            if ($a_lang == "") {
                $contributors[$page["last_change_user"]][$page["lang"]] = 1;
            } else {
                $contributors[$page["last_change_user"]] = 1;
            }
        }

        $set = $db->queryF(
            "SELECT count(*) as cnt, lang, page_id, user_id FROM page_history " .
            " WHERE page_id = %s AND parent_type = %s AND user_id != %s " . $and_lang .
            " GROUP BY user_id, page_id, lang ",
            array("integer", "text", "integer"),
            array($a_page_id, $a_parent_type, 0)
        );
        while ($hpage = $db->fetchAssoc($set)) {
            if ($a_lang === "") {
                $contributors[$hpage["user_id"]][$page["lang"]] =
                    ($contributors[$hpage["user_id"]][$page["lang"]] ?? 0) + $hpage["cnt"];
            } else {
                $contributors[$hpage["user_id"]] =
                    ($contributors[$hpage["user_id"]] ?? 0) + $hpage["cnt"];
            }
        }

        $c = array();
        foreach ($contributors as $k => $co) {
            $name = ilObjUser::_lookupName($k);
            $c[] = array("user_id" => $k,
                         "pages" => $co,
                         "lastname" => $name["lastname"],
                         "firstname" => $name["firstname"]
            );
        }

        return $c;
    }

    public function writeRenderedContent(
        string $a_content,
        string $a_md5
    ): void {
        global $DIC;

        $db = $DIC->database();

        $db->update("page_object", array(
            "rendered_content" => array("clob", $a_content),
            "render_md5" => array("text", $a_md5),
            "rendered_time" => array("timestamp", ilUtil::now())
        ), array(
            "page_id" => array("integer", $this->getId()),
            "lang" => array("text", $this->getLanguage()),
            "parent_type" => array("text", $this->getParentType())
        ));
    }

    public static function getPagesWithLinks(
        string $a_parent_type,
        int $a_parent_id,
        string $a_lang = "-"
    ): array {
        global $DIC;

        $db = $DIC->database();

        $and_lang = "";
        if ($a_lang != "") {
            $and_lang = " AND lang = " . $db->quote($a_lang, "text");
        }

        $q = "SELECT * FROM page_object " .
            " WHERE parent_id = " . $db->quote($a_parent_id, "integer") .
            " AND parent_type = " . $db->quote($a_parent_type, "text") .
            " AND int_links = " . $db->quote(1, "integer") . $and_lang;
        $set = $db->query($q);
        $pages = array();
        while ($page = $db->fetchAssoc($set)) {
            $key_add = ($a_lang == "")
                ? ":" . $page["lang"]
                : "";
            $pages[$page["page_id"] . $key_add] = array(
                "date" => $page["last_change"],
                "id" => $page["page_id"],
                "lang" => $page["lang"],
                "user" => $page["last_change_user"]
            );
        }

        return $pages;
    }

    public function containsIntLinks(string $a_content): bool
    {
        if (strpos($a_content, "IntLink")) {
            return true;
        }
        return false;
    }

    public function performAutomaticModifications(): void
    {
    }

    protected function getContentManager(): \ILIAS\COPage\Page\PageContentManager
    {
        $this->buildDom();
        return $this->page_manager->content($this->getDomDoc());
    }

    public function saveInitialOpenedContent(
        string $a_type,
        int $a_id,
        string $a_target
    ): void {
        $cm = $this->getContentManager();
        $cm->setInitialOpenedContent($a_type, $a_id, $a_target);
        $this->update();
    }

    public function getInitialOpenedContent(): array
    {
        $cm = $this->getContentManager();
        return $cm->getInitialOpenedContent();
    }

    public function beforePageContentUpdate(ilPageContent $a_page_content): void
    {
    }

    public function copy(
        int $a_id,
        string $a_parent_type = "",
        int $a_new_parent_id = 0,
        bool $a_clone_mobs = false,
        int $obj_copy_id = 0,
        bool $overwrite_existing = true
    ): void {
        if ($a_parent_type == "") {
            $a_parent_type = $this->getParentType();
            if ($a_new_parent_id == 0) {
                $a_new_parent_id = $this->getParentId();
            }
        }

        foreach (self::lookupTranslations($this->getParentType(), $this->getId()) as $l) {
            $existed = false;
            $orig_page = ilPageObjectFactory::getInstance($this->getParentType(), $this->getId(), 0, $l);
            if (ilPageObject::_exists($a_parent_type, $a_id, $l)) {
                if (!$overwrite_existing) {
                    continue;
                }
                $new_page_object = ilPageObjectFactory::getInstance($a_parent_type, $a_id, 0, $l);
                $existed = true;
            } else {
                $new_page_object = ilPageObjectFactory::getInstance($a_parent_type, 0, 0, $l);
                $new_page_object->setParentId($a_new_parent_id);
                $new_page_object->setId($a_id);
            }
            $new_page_object->setXMLContent($orig_page->copyXMLContent($a_clone_mobs, $a_new_parent_id, $obj_copy_id));
            $new_page_object->setActive($orig_page->getActive());
            $new_page_object->setActivationStart($orig_page->getActivationStart());
            $new_page_object->setActivationEnd($orig_page->getActivationEnd());
            $this->setCopyProperties($new_page_object);
            if ($existed) {
                $new_page_object->buildDom();
                $new_page_object->update();
            } else {
                $new_page_object->create(false);
            }
        }
    }

    protected function setCopyProperties(ilPageObject $new_page): void
    {
    }


    public static function lookupTranslations(
        string $a_parent_type,
        int $a_id
    ): array {
        global $DIC;

        $db = $DIC->database();

        $set = $db->query(
            "SELECT lang FROM page_object " .
            " WHERE page_id = " . $db->quote($a_id, "integer") .
            " AND parent_type = " . $db->quote($a_parent_type, "text")
        );
        $langs = array();
        while ($rec = $db->fetchAssoc($set)) {
            $langs[] = $rec["lang"];
        }
        return $langs;
    }

    public function copyPageToTranslation(
        string $a_target_lang
    ): void {
        $transl_page = ilPageObjectFactory::getInstance(
            $this->getParentType(),
            0,
            0,
            $a_target_lang
        );
        $this->setTranslationProperties($transl_page);
        $transl_page->create(false);
    }

    protected function setTranslationProperties(self $transl_page): void
    {
        $transl_page->setId($this->getId());
        $transl_page->setParentId($this->getParentId());
        $transl_page->setXMLContent($this->copyXmlContent());
        $transl_page->setActive($this->getActive());
        $transl_page->setActivationStart($this->getActivationStart());
        $transl_page->setActivationEnd($this->getActivationEnd());
    }



    public function getEditLock(): bool
    {
        $db = $this->db;
        $user = $this->user;

        $min = $this->getEffectiveEditLockTime();
        if ($min > 0) {
            // try to set the lock for the user
            $ts = time();
            $db->manipulate(
                "UPDATE page_object SET " .
                " edit_lock_user = " . $db->quote($user->getId(), "integer") . "," .
                " edit_lock_ts = " . $db->quote($ts, "integer") .
                " WHERE (edit_lock_user = " . $db->quote($user->getId(), "integer") . " OR " .
                " edit_lock_ts < " . $db->quote(time() - ($min * 60), "integer") . ") " .
                " AND page_id = " . $db->quote($this->getId(), "integer") .
                " AND parent_type = " . $db->quote($this->getParentType(), "text")
            );

            $set = $db->query(
                "SELECT edit_lock_user FROM page_object " .
                " WHERE page_id = " . $db->quote($this->getId(), "integer") .
                " AND parent_type = " . $db->quote($this->getParentType(), "text")
            );
            $rec = $db->fetchAssoc($set);
            if ($rec["edit_lock_user"] != $user->getId()) {
                return false;
            }
        }

        return true;
    }

    public function releasePageLock(): bool
    {
        $db = $this->db;
        $user = $this->user;
        $aset = new ilSetting("adve");

        $min = (int) $aset->get("block_mode_minutes");
        if ($min > 0) {
            // try to set the lock for the user
            $ts = time();
            $db->manipulate(
                "UPDATE page_object SET " .
                " edit_lock_user = " . $db->quote($user->getId(), "integer") . "," .
                " edit_lock_ts = 0" .
                " WHERE edit_lock_user = " . $db->quote($user->getId(), "integer") .
                " AND page_id = " . $db->quote($this->getId(), "integer") .
                " AND parent_type = " . $db->quote($this->getParentType(), "text")
            );

            $set = $db->query(
                "SELECT edit_lock_user FROM page_object " .
                " WHERE page_id = " . $db->quote($this->getId(), "integer") .
                " AND parent_type = " . $db->quote($this->getParentType(), "text")
            );
            $rec = $db->fetchAssoc($set);
            if ($rec["edit_lock_user"] != $user->getId()) {
                return false;
            }
        }

        return true;
    }

    public function getEditLockInfo(): array
    {
        $db = $this->db;

        $aset = new ilSetting("adve");
        $min = (int) $aset->get("block_mode_minutes");

        $set = $db->query(
            "SELECT edit_lock_user, edit_lock_ts FROM page_object " .
            " WHERE page_id = " . $db->quote($this->getId(), "integer") .
            " AND parent_type = " . $db->quote($this->getParentType(), "text")
        );
        $rec = $db->fetchAssoc($set);
        $rec["edit_lock_until"] = $rec["edit_lock_ts"] + $min * 60;

        return $rec;
    }

    public static function truncateHTML(
        string $a_text,
        int $a_length = 100,
        string $a_ending = '...',
        bool $a_exact = false,
        bool $a_consider_html = true
    ): string {
        $open_tags = [];
        if ($a_consider_html) {
            // if the plain text is shorter than the maximum length, return the whole text
            if (strlen(preg_replace('/<.*?>/', '', $a_text)) <= $a_length) {
                return $a_text;
            }

            // splits all html-tags to scanable lines
            $total_length = strlen($a_ending);
            $open_tags = array();
            $truncate = '';
            preg_match_all('/(<.+?>)?([^<>]*)/s', $a_text, $lines, PREG_SET_ORDER);
            foreach ($lines as $line_matchings) {
                // if there is any html-tag in this line, handle it and add it (uncounted) to the output
                if (!empty($line_matchings[1])) {
                    // if it's an "empty element" with or without xhtml-conform closing slash
                    if (preg_match(
                        '/^<(\s*.+?\/\s*|\s*(img|br|input|hr|area|base|basefont|col|frame|isindex|link|meta|param)(\s.+?)?)>$/is',
                        $line_matchings[1]
                    )) {
                        // do nothing
                    } // if tag is a closing tag
                    elseif (preg_match('/^<\s*\/([^\s]+?)\s*>$/s', $line_matchings[1], $tag_matchings)) {
                        // delete tag from $open_tags list
                        $pos = array_search($tag_matchings[1], $open_tags);
                        if ($pos !== false) {
                            unset($open_tags[$pos]);
                        }
                    } // if tag is an opening tag
                    elseif (preg_match('/^<\s*([^\s>!]+).*?>$/s', $line_matchings[1], $tag_matchings)) {
                        // add tag to the beginning of $open_tags list
                        array_unshift($open_tags, strtolower($tag_matchings[1]));
                    }
                    // add html-tag to $truncate'd text
                    $truncate .= $line_matchings[1];
                }

                // calculate the length of the plain text part of the line; handle entities as one character
                $content_length = strlen(preg_replace(
                    '/&[0-9a-z]{2,8};|&#[0-9]{1,7};|[0-9a-f]{1,6};/i',
                    ' ',
                    $line_matchings[2]
                ));
                if ($total_length + $content_length > $a_length) {
                    // the number of characters which are left
                    $left = $a_length - $total_length;
                    $entities_length = 0;
                    // search for html entities
                    if (preg_match_all(
                        '/&[0-9a-z]{2,8};|&#[0-9]{1,7};|[0-9a-f]{1,6};/i',
                        $line_matchings[2],
                        $entities,
                        PREG_OFFSET_CAPTURE
                    )) {
                        // calculate the real length of all entities in the legal range
                        foreach ($entities[0] as $entity) {
                            if ($entity[1] + 1 - $entities_length <= $left) {
                                $left--;
                                $entities_length += strlen($entity[0]);
                            } else {
                                // no more characters left
                                break;
                            }
                        }
                    }

                    // $truncate .= substr($line_matchings[2], 0, $left+$entities_length);
                    $truncate .= ilStr::shortenText($line_matchings[2], 0, $left + $entities_length);

                    // maximum lenght is reached, so get off the loop
                    break;
                } else {
                    $truncate .= $line_matchings[2];
                    $total_length += $content_length;
                }

                // if the maximum length is reached, get off the loop
                if ($total_length >= $a_length) {
                    break;
                }
            }
        } else {
            if (strlen($a_text) <= $a_length) {
                return $a_text;
            } else {
                // $truncate = substr($a_text, 0, $a_length - strlen($a_ending));
                $truncate = ilStr::shortenText($a_text, 0, $a_length - strlen($a_ending));
            }
        }

        // THIS IS BUGGY AS IT MIGHT BREAK AN OPEN TAG AT THE END
        if (!count($open_tags)) {
            // if the words shouldn't be cut in the middle...
            if (!$a_exact) {
                // ...search the last occurance of a space...
                $spacepos = strrpos($truncate, ' ');
                if ($spacepos !== false) {
                    // ...and cut the text in this position
                    // $truncate = substr($truncate, 0, $spacepos);
                    $truncate = ilStr::shortenText($truncate, 0, $spacepos);
                }
            }
        }

        // add the defined ending to the text
        $truncate .= $a_ending;

        if ($a_consider_html) {
            // close all unclosed html-tags
            foreach ($open_tags as $tag) {
                $truncate .= '</' . $tag . '>';
            }
        }

        return $truncate;
    }

    public function getContentTemplates(): array
    {
        return array();
    }

    public static function getLastChangeByParent(
        string $a_parent_type,
        int $a_parent_id,
        string $a_lang = ""
    ): string {
        global $DIC;

        $db = $DIC->database();

        $and_lang = "";
        if ($a_lang != "") {
            $and_lang = " AND lang = " . $db->quote($a_lang, "text");
        }

        $db->setLimit(1, 0);
        $q = "SELECT last_change FROM page_object " .
            " WHERE parent_id = " . $db->quote($a_parent_id, "integer") .
            " AND parent_type = " . $db->quote($a_parent_type, "text") . $and_lang .
            " ORDER BY last_change DESC";

        $set = $db->query($q);
        $rec = $db->fetchAssoc($set);

        return $rec["last_change"];
    }

    public function getEffectiveEditLockTime(): int
    {
        if ($this->getPageConfig()->getEditLockSupport() == false) {
            return 0;
        }

        $aset = new ilSetting("adve");
        $min = (int) $aset->get("block_mode_minutes");

        return $min;
    }

    public function resolveResources(array $ref_mapping): bool
    {
        return ilPCResources::resolveResources($this, $ref_mapping);
    }

    public function getRepoObjId(): ?int
    {
        return $this->getParentId();
    }

    public function getPCModel(): array
    {
        $model = [];
        /*
        $this->log->debug("--- Get page model start");
        $model = [];
        foreach ($this->getAllPCIds() as $pc_id) {
            $co = $this->getContentObjectForPcId($pc_id);
            if ($co !== null) {
                $co_model = $co->getModel();
                if ($co_model !== null) {
                    $model[$pc_id] = $co_model;
                }
            }
        }
        $this->log->debug("--- Get page model end");
        */

        $config = $this->getPageConfig();
        foreach ($this->pc_definition->getPCDefinitions() as $def) {
            $model_provider = $this->pc_definition->getPCModelProviderByName($def["name"]);
            if ($config->getEnablePCType($def["name"]) || $def["name"] === "PlaceHolder") {
                if (!is_null($model_provider)) {
                    foreach ($model_provider->getModels(
                        $this->dom_util,
                        $this
                    ) as $pc_id => $co_model) {
                        $model[$pc_id] = $co_model;
                    }
                }
            }
        }
        return $model;
    }

    public function assignCharacteristic(
        array $targets,
        string $char_par,
        string $char_sec,
        string $char_med
    ) {
        if (is_array($targets)) {
            foreach ($targets as $t) {
                $tarr = explode(":", $t);
                $cont_obj = $this->getContentObject($tarr[0], $tarr[1]);
                if (is_object($cont_obj) && $cont_obj->getType() == "par") {
                    $cont_obj->setCharacteristic($char_par);
                }
                if (is_object($cont_obj) && $cont_obj->getType() == "sec") {
                    $cont_obj->setCharacteristic($char_sec);
                }
                if (is_object($cont_obj) && $cont_obj->getType() == "media") {
                    $cont_obj->setClass($char_med);
                }
            }
            return $this->update();
        }
        return true;
    }
}