class.ilNewsItem.php

Go to the documentation of this file.

<?php
/* Copyright (c) 1998-2012 ILIAS open source, Extended GPL, see docs/LICENSE */

define("NEWS_NOTICE", 0);
define("NEWS_MESSAGE", 1);
define("NEWS_WARNING", 2);

define("NEWS_TEXT", "text");
define("NEWS_HTML", "html");
define("NEWS_AUDIO", "audio");
define("NEWS_USERS", "users");
define("NEWS_PUBLIC", "public");



class ilNewsItem
{
    protected $db;

    protected $tree;

    protected $access;

    protected $obj_data_cache;

    protected $user;

    protected $lng;

    protected $ctrl;

    protected $id;
    protected $title;
    protected $content;
    protected $content_html;
    protected $context_obj_id;
    protected $context_obj_type;
    protected $context_sub_obj_id;
    protected $context_sub_obj_type;
    protected $content_type = "text";
    protected $creation_date;
    protected $update_date;
    protected $user_id;
    protected $update_user_id;
    protected $visibility = "users";
    protected $content_long;
    protected $priority = 1;
    protected $content_is_lang_var = 0;
    protected $mob_id;
    protected $playtime;

    private static $privFeedId = false;
    private $limitation;
    
    public function __construct($a_id = 0)
    {
        global $DIC;

        $this->db = $DIC->database();
        $this->tree = $DIC->repositoryTree();
        $this->access = $DIC->access();
        $this->obj_data_cache = $DIC["ilObjDataCache"];
        $this->user = $DIC->user();
        $this->lng = $DIC->language();
        $this->ctrl = $DIC->ctrl();
        if ($a_id > 0) {
            $this->setId($a_id);
            $this->read();
        }
        $this->limitation = true;
    }

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

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

    public function setTitle($a_title)
    {
        $this->title = $a_title;
    }

    public function getTitle()
    {
        return $this->title;
    }

    public function setContent($a_content)
    {
        $this->content = $a_content;
    }

    public function getContent()
    {
        return $this->content;
    }

    public function setContextObjId($a_context_obj_id)
    {
        $this->context_obj_id = $a_context_obj_id;
    }

    public function getContextObjId()
    {
        return $this->context_obj_id;
    }

    public function setContextObjType($a_context_obj_type)
    {
        $this->context_obj_type = $a_context_obj_type;
    }

    public function getContextObjType()
    {
        return $this->context_obj_type;
    }

    public function setContextSubObjId($a_context_sub_obj_id)
    {
        $this->context_sub_obj_id = $a_context_sub_obj_id;
    }

    public function getContextSubObjId()
    {
        return $this->context_sub_obj_id;
    }

    public function setContextSubObjType($a_context_sub_obj_type)
    {
        $this->context_sub_obj_type = $a_context_sub_obj_type;
    }

    public function getContextSubObjType()
    {
        return $this->context_sub_obj_type;
    }

    public function setContentType($a_content_type = "text")
    {
        $this->content_type = $a_content_type;
    }

    public function getContentType()
    {
        return $this->content_type;
    }

    public function setCreationDate($a_creation_date)
    {
        $this->creation_date = $a_creation_date;
    }

    public function getCreationDate()
    {
        return $this->creation_date;
    }

    public function setUpdateDate($a_update_date)
    {
        $this->update_date = $a_update_date;
    }

    public function getUpdateDate()
    {
        return $this->update_date;
    }

    public function setUserId($a_user_id)
    {
        $this->user_id = $a_user_id;
    }

    public function getUserId()
    {
        return $this->user_id;
    }

    public function setUpdateUserId($a_val)
    {
        $this->update_user_id = $a_val;
    }

    public function getUpdateUserId()
    {
        return $this->update_user_id;
    }

    public function setVisibility($a_visibility = "users")
    {
        $this->visibility = $a_visibility;
    }

    public function getVisibility()
    {
        return $this->visibility;
    }

    public function setContentLong($a_content_long)
    {
        $this->content_long = $a_content_long;
    }

    public function getContentLong()
    {
        return $this->content_long;
    }

    public function setPriority($a_priority = 1)
    {
        $this->priority = $a_priority;
    }

    public function getPriority()
    {
        return $this->priority;
    }

    public function setContentIsLangVar($a_content_is_lang_var = 0)
    {
        $this->content_is_lang_var = $a_content_is_lang_var;
    }

    public function getContentIsLangVar()
    {
        return $this->content_is_lang_var;
    }

    public function setMobId($a_mob_id)
    {
        $this->mob_id = $a_mob_id;
    }

    public function getMobId()
    {
        return $this->mob_id;
    }

    public function setPlaytime($a_playtime)
    {
        $this->playtime = $a_playtime;
    }

    public function getPlaytime()
    {
        return $this->playtime;
    }


    public function setLimitation($a_limitation)
    {
        $this->limitation = $a_limitation;
    }

    public function getLimitation()
    {
        return $this->limitation;
    }

    public function setContentTextIsLangVar($a_val = 0)
    {
        $this->content_text_is_lang_var = $a_val;
    }

    public function getContentTextIsLangVar()
    {
        return $this->content_text_is_lang_var;
    }

    public function setMobPlayCounter($a_val)
    {
        $this->mob_cnt_play = $a_val;
    }
    
    public function getMobPlayCounter()
    {
        return $this->mob_cnt_play;
    }

    public function setMobDownloadCounter($a_val)
    {
        $this->mob_cnt_download = $a_val;
    }
    
    public function getMobDownloadCounter()
    {
        return $this->mob_cnt_download;
    }

    public function setContentHtml($a_val)
    {
        $this->content_html = $a_val;
    }

    public function getContentHtml()
    {
        return $this->content_html;
    }
    
    public function read()
    {
        $ilDB = $this->db;

        $query = "SELECT * FROM il_news_item WHERE id = " .
            $ilDB->quote($this->getId(), "integer");
        $set = $ilDB->query($query);
        $rec = $ilDB->fetchAssoc($set);

        $this->setTitle($rec["title"]);
        $this->setContent($rec["content"]);
        $this->setContextObjId((int) $rec["context_obj_id"]);
        $this->setContextObjType($rec["context_obj_type"]);
        $this->setContextSubObjId((int) $rec["context_sub_obj_id"]);
        $this->setContextSubObjType($rec["context_sub_obj_type"]);
        $this->setContentType($rec["content_type"]);
        $this->setCreationDate($rec["creation_date"]);
        $this->setUpdateDate($rec["update_date"]);
        $this->setUserId($rec["user_id"]);
        $this->setUpdateUserId($rec["update_user_id"]);
        $this->setVisibility($rec["visibility"]);
        $this->setContentLong($rec["content_long"]);
        $this->setPriority($rec["priority"]);
        $this->setContentIsLangVar($rec["content_is_lang_var"]);
        $this->setContentTextIsLangVar((int) $rec["content_text_is_lang_var"]);
        $this->setMobId($rec["mob_id"]);
        $this->setPlaytime($rec["playtime"]);
        $this->setMobPlayCounter($rec["mob_cnt_play"]);
        $this->setMobDownloadCounter($rec["mob_cnt_download"]);
        $this->setContentHtml($rec["content_html"]);
    }

    public function create()
    {
        $ilDB = $this->db;

        // insert new record into db
        $this->setId($ilDB->nextId("il_news_item"));
        $ilDB->insert("il_news_item", array(
            "id" => array("integer", $this->getId()),
            "title" => array("text", $this->getTitle()),
            "content" => array("clob", $this->getContent()),
            "content_html" => array("integer", (int) $this->getContentHtml()),
            "context_obj_id" => array("integer", (int) $this->getContextObjId()),
            "context_obj_type" => array("text", $this->getContextObjType()),
            "context_sub_obj_id" => array("integer", (int) $this->getContextSubObjId()),
            "context_sub_obj_type" => array("text", $this->getContextSubObjType()),
            "content_type" => array("text", $this->getContentType()),
            "creation_date" => array("timestamp", ilUtil::now()),
            "update_date" => array("timestamp", ilUtil::now()),
            "user_id" => array("integer", $this->getUserId()),
            "update_user_id" => array("integer", (int) $this->getUpdateUserId()),
            "visibility" => array("text", $this->getVisibility()),
            "content_long" => array("clob", $this->getContentLong()),
            "priority" => array("integer", $this->getPriority()),
            "content_is_lang_var" => array("integer", $this->getContentIsLangVar()),
            "content_text_is_lang_var" => array("integer", (int) $this->getContentTextIsLangVar()),
            "mob_id" => array("integer", $this->getMobId()),
            "playtime" => array("text", $this->getPlaytime())
        ));

        
        $news_set = new ilSetting("news");
        $max_items = $news_set->get("max_items");
        if ($max_items <= 0) {
            $max_items = 50;
        }
        
        // limit number of news
        if ($this->getLimitation()) {
            // Determine how many rows should be deleted
            $query = "SELECT count(*) cnt " .
                "FROM il_news_item " .
                "WHERE " .
                    "context_obj_id = " . $ilDB->quote($this->getContextObjId(), "integer") .
                    " AND context_obj_type = " . $ilDB->quote($this->getContextObjType(), "text") .
                    " AND context_sub_obj_id = " . $ilDB->quote($this->getContextSubObjId(), "integer") .
                    " AND " . $ilDB->equals("context_sub_obj_type", $this->getContextSubObjType(), "text", true) . " ";
    
            $set = $ilDB->query($query);
            $rec = $ilDB->fetchAssoc($set);
                    
            // if we have more records than allowed, delete them
            if (($rec["cnt"] > $max_items) && $this->getContextObjId() > 0) {
                $query = "SELECT * " .
                    "FROM il_news_item " .
                    "WHERE " .
                        "context_obj_id = " . $ilDB->quote($this->getContextObjId(), "integer") .
                        " AND context_obj_type = " . $ilDB->quote($this->getContextObjType(), "text") .
                        " AND context_sub_obj_id = " . $ilDB->quote($this->getContextSubObjId(), "integer") .
                        " AND " . $ilDB->equals("context_sub_obj_type", $this->getContextSubObjType(), "text", true) .
                        " ORDER BY creation_date ASC";
    
                $ilDB->setLimit($rec["cnt"] - $max_items);
                $del_set = $ilDB->query($query);
                while ($del_item = $ilDB->fetchAssoc($del_set)) {
                    $del_news = new ilNewsItem($del_item["id"]);
                    $del_news->delete();
                }
            }
        }
    }

    public function update($a_as_new = false)
    {
        $ilDB = $this->db;

        $fields = array(
            "title" => array("text", $this->getTitle()),
            "content" => array("clob", $this->getContent()),
            "content_html" => array("integer", (int) $this->getContentHtml()),
            "context_obj_id" => array("integer", $this->getContextObjId()),
            "context_obj_type" => array("text", $this->getContextObjType()),
            "context_sub_obj_id" => array("integer", $this->getContextSubObjId()),
            "context_sub_obj_type" => array("text", $this->getContextSubObjType()),
            "content_type" => array("text", $this->getContentType()),
            "user_id" => array("integer", $this->getUserId()),
            "update_user_id" => array("integer", (int) $this->getUpdateUserId()),
            "visibility" => array("text", $this->getVisibility()),
            "content_long" => array("clob", $this->getContentLong()),
            "priority" => array("integer", $this->getPriority()),
            "content_is_lang_var" => array("integer", $this->getContentIsLangVar()),
            "content_text_is_lang_var" => array("integer", (int) $this->getContentTextIsLangVar()),
            "mob_id" => array("integer", $this->getMobId()),
            "mob_cnt_play" => array("integer", $this->getMobPlayCounter()),
            "mob_cnt_download" => array("integer", $this->getMobDownloadCounter()),
            "playtime" => array("text", $this->getPlaytime())
        );

        $now = ilUtil::now();
        if ($a_as_new) {
            $fields["creation_date"] = array("timestamp", $now);
            $fields["update_date"] = array("timestamp", $now);
        } else {
            $fields["update_date"] = array("timestamp", $now);
        }

        $ilDB->update("il_news_item", $fields, array(
            "id" => array("integer", $this->getId())
        ));
    }


    public static function _getNewsItemsOfUser(
        $a_user_id,
        $a_only_public = false,
        $a_prevent_aggregation = false,
        $a_per = 0,
        &$a_cnt = null
    ) {
        global $DIC;

        $ilAccess = $DIC->access();

        $fav_rep = new ilFavouritesDBRepository();

        $news_item = new ilNewsItem();
        $news_set = new ilSetting("news");
        
        $per = $a_per;

        include_once("./Services/News/classes/class.ilNewsSubscription.php");
        include_once("./Services/Block/classes/class.ilBlockSetting.php");
        
        // this is currently not used
        $ref_ids = ilNewsSubscription::_getSubscriptionsOfUser($a_user_id);
        
        if (ilObjUser::_lookupPref($a_user_id, "pd_items_news") != "n") {
            // get all items of the personal desktop
            $pd_items = $fav_rep->getFavouritesOfUser($a_user_id);
            foreach ($pd_items as $item) {
                if (!in_array($item["ref_id"], $ref_ids)) {
                    $ref_ids[] = $item["ref_id"];
                }
            }
            
            // get all memberships
            include_once 'Services/Membership/classes/class.ilParticipants.php';
            $crs_mbs = ilParticipants::_getMembershipByType($a_user_id, 'crs');
            $grp_mbs = ilParticipants::_getMembershipByType($a_user_id, 'grp');
            $items = array_merge($crs_mbs, $grp_mbs);
            foreach ($items as $i) {
                $item_references = ilObject::_getAllReferences($i);
                if (is_array($item_references) && count($item_references)) {
                    foreach ($item_references as $ref_id) {
                        if (!in_array($ref_id, $ref_ids)) {
                            $ref_ids[] = $ref_id;
                        }
                    }
                }
            }
        }
        
        $data = array();

        foreach ($ref_ids as $ref_id) {
            if (!$a_only_public) {
                // this loop should not cost too much performance
                $acc = $ilAccess->checkAccessOfUser($a_user_id, "read", "", $ref_id);
                
                if (!$acc) {
                    continue;
                }
            }
            if (ilNewsItem::getPrivateFeedId() != false) {
                global $DIC;

                $rbacsystem = $DIC->rbac()->system();
                $acc = $rbacsystem->checkAccessOfUser(ilNewsItem::getPrivateFeedId(), "read", $ref_id);
            
                if (!$acc) {
                    continue;
                }
            }

            $obj_id = ilObject::_lookupObjId($ref_id);
            $obj_type = ilObject::_lookupType($obj_id);
            $news = $news_item->getNewsForRefId(
                $ref_id,
                $a_only_public,
                false,
                $per,
                $a_prevent_aggregation,
                false,
                false,
                false,
                $a_user_id
            );
            
            // counter
            if (!is_null($a_cnt)) {
                $a_cnt[$ref_id] = count($news);
            }

            $data = ilNewsItem::mergeNews($data, $news);
        }

        $data = ilUtil::sortArray($data, "creation_date", "desc", false, true);

        return $data;
    }
    
    public function getNewsForRefId(
        $a_ref_id,
        $a_only_public = false,
        $a_stopnesting = false,
        $a_time_period = 0,
        $a_prevent_aggregation = true,
        $a_forum_group_sequences = false,
        $a_no_auto_generated = false,
        $a_ignore_date_filter = false,
        $a_user_id = null,
        $a_limit = 0,
        $a_excluded = array()
    ) {
        $obj_id = ilObject::_lookupObjId($a_ref_id);
        $obj_type = ilObject::_lookupType($obj_id);

        // get starting date
        $starting_date = "";
        if ($obj_type == "grp" || $obj_type == "crs") {
            // see #31471, #30687, and ilMembershipNotification
            if (!ilContainer::_lookupContainerSetting(
                $obj_id,
                'cont_use_news',
                true
            ) || (
                !ilContainer::_lookupContainerSetting(
                    $obj_id,
                    'cont_show_news',
                    true
                ) && !ilContainer::_lookupContainerSetting(
                    $obj_id,
                    'news_timeline'
                )
            )) {
                return [];
            }

            include_once("./Services/Block/classes/class.ilBlockSetting.php");
            $hide_news_per_date = ilBlockSetting::_lookup(
                "news",
                "hide_news_per_date",
                0,
                $obj_id
            );
            if ($hide_news_per_date && !$a_ignore_date_filter) {
                $starting_date = ilBlockSetting::_lookup(
                    "news",
                    "hide_news_date",
                    0,
                    $obj_id
                );
            }
        }

        if ($obj_type == "cat" && !$a_stopnesting) {
            $news = $this->getAggregatedChildNewsData(
                $a_ref_id,
                $a_only_public,
                $a_time_period,
                $a_prevent_aggregation,
                $starting_date,
                $a_no_auto_generated
            );
        } elseif (($obj_type == "grp" || $obj_type == "crs") &&
            !$a_stopnesting) {
            $news = $this->getAggregatedNewsData(
                $a_ref_id,
                $a_only_public,
                $a_time_period,
                $a_prevent_aggregation,
                $starting_date,
                $a_no_auto_generated,
                $a_user_id,
                $a_limit,
                $a_excluded
            );
        } else {
            $news_item = new ilNewsItem();
            $news_item->setContextObjId($obj_id);
            $news_item->setContextObjType($obj_type);
            $news = $news_item->queryNewsForContext(
                $a_only_public,
                $a_time_period,
                $starting_date,
                $a_no_auto_generated
            );
            $unset = array();
            foreach ($news as $k => $v) {
                if (!$a_only_public || $v["visibility"] == NEWS_PUBLIC ||
                    ($v["priority"] == 0 &&
                        ilBlockSetting::_lookup(
                            "news",
                            "public_notifications",
                            0,
                            $obj_id
                        ))) {
                    $news[$k]["ref_id"] = $a_ref_id;
                } else {
                    $unset[] = $k;
                }
            }
            foreach ($unset as $un) {
                unset($news[$un]);
            }
        }
        
        if (!$a_prevent_aggregation) {
            $news = $this->aggregateForums($news);
        } elseif ($a_forum_group_sequences) {
            $news = $this->aggregateForums($news, true);
        }
        
        return $news;
    }
    
    public function getAggregatedNewsData(
        $a_ref_id,
        $a_only_public = false,
        $a_time_period = 0,
        $a_prevent_aggregation = false,
        $a_starting_date = "",
        $a_no_auto_generated = false,
        $a_user_id = null,
        $a_limit = 0,
        $a_exclude = array()
    ) {
        $tree = $this->tree;
        $ilAccess = $this->access;
        $ilObjDataCache = $this->obj_data_cache;
        
        // get news of parent object
        
        $data = array();
        
        // get subtree
        $cur_node = $tree->getNodeData($a_ref_id);

        // do not check for lft (materialized path)
        if ($cur_node) {
            $nodes = (array) $tree->getSubTree($cur_node, true);
        } else {
            $nodes = array();
        }
        
        // preload object data cache
        $ref_ids = array();
        $obj_ids = array();
        foreach ($nodes as $node) {
            $ref_ids[] = $node["child"];
            $obj_ids[] = $node["obj_id"];
        }

        $ilObjDataCache->preloadReferenceCache($ref_ids);
        if (!$a_only_public) {
            include_once "Services/Object/classes/class.ilObjectActivation.php";
            ilObjectActivation::preloadData($ref_ids);
        }
        
        // no check, for which of the objects any news are available
        $news_obj_ids = ilNewsItem::filterObjIdsPerNews($obj_ids, $a_time_period, $a_starting_date);
        //$news_obj_ids = $obj_ids;
        
        // get news for all subtree nodes
        $contexts = array();
        foreach ($nodes as $node) {
            // only go on, if news are available
            if (!in_array($node["obj_id"], $news_obj_ids)) {
                continue;
            }
            
            if (!$a_only_public) {
                if (!$a_user_id) {
                    $acc = $ilAccess->checkAccess("read", "", $node["child"]);
                } else {
                    $acc = $ilAccess->checkAccessOfUser(
                        $a_user_id,
                        "read",
                        "",
                        $node["child"]
                    );
                }
                if (!$acc) {
                    continue;
                }
            }
            
            $ref_id[$node["obj_id"]] = $node["child"];
            $contexts[] = array("obj_id" => $node["obj_id"],
                "obj_type" => $node["type"]);
        }
        
        // sort and return
        $news = $this->queryNewsForMultipleContexts(
            $contexts,
            $a_only_public,
            $a_time_period,
            $a_starting_date,
            $a_no_auto_generated,
            $a_user_id,
            $a_limit,
            $a_exclude
        );
                
        $to_del = array();
        foreach ($news as $k => $v) {
            $news[$k]["ref_id"] = $ref_id[$v["context_obj_id"]];
        }
        
        $data = ilNewsItem::mergeNews($data, $news);
        $data = ilUtil::sortArray($data, "creation_date", "desc", false, true);
        
        if (!$a_prevent_aggregation) {
            $data = $this->aggregateFiles($data, $a_ref_id);
        }
                
        return $data;
    }

    protected function aggregateForums($news, $a_group_posting_sequence = false)
    {
        $to_del = array();
        $forums = array();
        
        // aggregate
        foreach ($news as $k => $v) {
            if ($a_group_posting_sequence && $last_aggregation_forum > 0 &&
                $last_aggregation_forum != $news[$k]["context_obj_id"]) {
                $forums[$last_aggregation_forum] = "";
            }

            if ($news[$k]["context_obj_type"] == "frm") {
                if ($forums[$news[$k]["context_obj_id"]] == "") {
                    // $forums[forum_id] = news_id;
                    $forums[$news[$k]["context_obj_id"]] = $k;
                    $last_aggregation_forum = $news[$k]["context_obj_id"];
                } else {
                    $to_del[] = $k;
                }
                
                $news[$k]["no_context_title"] = true;
                
                // aggregate every forum into it's "k" news
                $news[$forums[$news[$k]["context_obj_id"]]]["aggregation"][$k]
                    = $news[$k];
                $news[$k]["agg_ref_id"]
                    = $news[$k]["ref_id"];
                $news[$k]["content"] = "";
                $news[$k]["content_long"] = "";
            }
        }
        
        // delete double entries
        foreach ($to_del as $k) {
            unset($news[$k]);
        }
        //var_dump($news[14]["aggregation"]);

        
        return $news;
    }

    protected function aggregateFiles($news, $a_ref_id)
    {
        $first_file = "";
        $to_del = array();
        foreach ($news as $k => $v) {
            // aggregate file related news
            if ($news[$k]["context_obj_type"] == "file") {
                if ($first_file == "") {
                    $first_file = $k;
                } else {
                    $to_del[] = $k;
                }
                $news[$first_file]["aggregation"][$k] = $news[$k];
                $news[$first_file]["agg_ref_id"] = $a_ref_id;
                $news[$first_file]["ref_id"] = $a_ref_id;
            }
        }
        
        foreach ($to_del as $v) {
            unset($news[$v]);
        }
        
        return $news;
    }

    
    protected function getAggregatedChildNewsData(
        $a_ref_id,
        $a_only_public = false,
        $a_time_period = 0,
        $a_prevent_aggregation = false,
        $a_starting_date = "",
        $a_no_auto_generated = false
    ) {
        $tree = $this->tree;
        $ilAccess = $this->access;
        
        // get news of parent object
        $data = $this->getNewsForRefId(
            $a_ref_id,
            $a_only_public,
            true,
            $a_time_period,
            true,
            false,
            false,
            $a_no_auto_generated
        );
        foreach ($data as $k => $v) {
            $data[$k]["ref_id"] = $a_ref_id;
        }

        // get childs
        $nodes = $tree->getChilds($a_ref_id);
        
        // no check, for which of the objects any news are available
        $obj_ids = array();
        foreach ($nodes as $node) {
            $obj_ids[] = $node["obj_id"];
        }
        $news_obj_ids = ilNewsItem::filterObjIdsPerNews($obj_ids, $a_time_period, $a_starting_date);
        //$news_obj_ids = $obj_ids;

        // get news for all subtree nodes
        $contexts = array();
        foreach ($nodes as $node) {
            // only go on, if news are available
            if (!in_array($node["obj_id"], $news_obj_ids)) {
                continue;
            }

            if (!$a_only_public && !$ilAccess->checkAccess("read", "", $node["child"])) {
                continue;
            }
            $ref_id[$node["obj_id"]] = $node["child"];
            $contexts[] = array("obj_id" => $node["obj_id"],
                "obj_type" => $node["type"]);
        }
        
        $news = $this->queryNewsForMultipleContexts(
            $contexts,
            $a_only_public,
            $a_time_period,
            $a_starting_date,
            $a_no_auto_generated
        );
        foreach ($news as $k => $v) {
            $news[$k]["ref_id"] = $ref_id[$v["context_obj_id"]];
        }
        $data = ilNewsItem::mergeNews($data, $news);
        
        // sort and return
        $data = ilUtil::sortArray($data, "creation_date", "desc", false, true);
        
        if (!$a_prevent_aggregation) {
            $data = $this->aggregateFiles($data, $a_ref_id);
        }
        
        return $data;
    }

    public function setContext(int $a_obj_id, string $a_obj_type, int $a_sub_obj_id = 0, string $a_sub_obj_type = "")
    {
        $this->setContextObjId($a_obj_id);
        $this->setContextObjType($a_obj_type);
        $this->setContextSubObjId($a_sub_obj_id);
        $this->setContextSubObjType($a_sub_obj_type);
    }
    
    protected static function handleTimePeriod($a_time_period)
    {
        // time period is number of days
        if (is_numeric($a_time_period)) {
            if ($a_time_period > 0) {
                return date('Y-m-d H:i:s', time() - ($a_time_period * 24 * 60 * 60));
            }
        }
        // time period is datetime
        elseif (preg_match("/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}$/", $a_time_period)) {
            return $a_time_period;
        }
        // :TODO: what to return?
    }

    public function queryNewsForContext(
        $a_for_rss_use = false,
        $a_time_period = 0,
        $a_starting_date = "",
        $a_no_auto_generated = false,
        $a_oldest_first = false,
        $a_limit = 0
    ) {
        $ilDB = $this->db;
        $ilUser = $this->user;
        $lng = $this->lng;

        $and = "";
        if ($a_time_period > 0) {
            $limit_ts = self::handleTimePeriod($a_time_period);
            $and = " AND creation_date >= " . $ilDB->quote($limit_ts, "timestamp") . " ";
        }
        
        if ($a_starting_date != "") {
            $and .= " AND creation_date > " . $ilDB->quote($a_starting_date, "timestamp") . " ";
        }

        if ($a_no_auto_generated) {
            $and .= " AND priority = 1 AND content_type = " . $ilDB->quote("text", "text") . " ";
        }

        // this is changed with 4.1 (news table for lm pages)
        if ($this->getContextSubObjId() > 0) {
            $and .= " AND context_sub_obj_id = " . $ilDB->quote($this->getContextSubObjId(), "integer") .
                " AND context_sub_obj_type = " . $ilDB->quote($this->getContextSubObjType(), "text");
        }

        $ordering = ($a_oldest_first)
            ? " creation_date ASC, id ASC "
            : " creation_date DESC, id DESC ";

        if ($a_for_rss_use && ilNewsItem::getPrivateFeedId() == false) {
            $query = "SELECT * " .
                "FROM il_news_item " .
                " WHERE " .
                    "context_obj_id = " . $ilDB->quote($this->getContextObjId(), "integer") .
                    " AND context_obj_type = " . $ilDB->quote($this->getContextObjType(), "text") .
                    $and .
                    " ORDER BY " . $ordering;
        } elseif (ilNewsItem::getPrivateFeedId() != false) {
            $query = "SELECT il_news_item.* " .
                ", il_news_read.user_id user_read " .
                "FROM il_news_item LEFT JOIN il_news_read " .
                "ON il_news_item.id = il_news_read.news_id AND " .
                " il_news_read.user_id = " . $ilDB->quote(ilNewsItem::getPrivateFeedId(), "integer") .
                " WHERE " .
                    "context_obj_id = " . $ilDB->quote($this->getContextObjId(), "integer") .
                    " AND context_obj_type = " . $ilDB->quote($this->getContextObjType(), "text") .
                    $and .
                    " ORDER BY " . $ordering;
        } else {
            $query = "SELECT il_news_item.* " .
                ", il_news_read.user_id as user_read " .
                "FROM il_news_item LEFT JOIN il_news_read " .
                "ON il_news_item.id = il_news_read.news_id AND " .
                " il_news_read.user_id = " . $ilDB->quote($ilUser->getId(), "integer") .
                " WHERE " .
                    "context_obj_id = " . $ilDB->quote($this->getContextObjId(), "integer") .
                    " AND context_obj_type = " . $ilDB->quote($this->getContextObjType(), "text") .
                    $and .
                    " ORDER BY " . $ordering;
        }
        //echo $query;
        $set = $ilDB->query($query);
        $result = array();
        while ($rec = $ilDB->fetchAssoc($set)) {
            if ($a_limit > 0 && count($result) >= $a_limit) {
                continue;
            }
            if (!$a_for_rss_use || (ilNewsItem::getPrivateFeedId() != false) || ($rec["visibility"] == NEWS_PUBLIC ||
                ($rec["priority"] == 0 &&
                ilBlockSetting::_lookup(
                    "news",
                    "public_notifications",
                    0,
                    $rec["context_obj_id"]
                )))) {
                $result[$rec["id"]] = $rec;
            }
        }

        // do we get data for rss and may the time limit by an issue?
        // do a second query without time limit.
        // this is not very performant, but I do not have a better
        // idea. The keep_rss_min setting is currently (Jul 2012) only set
        // by mediacasts
        if ($a_time_period != "" && $a_for_rss_use) {
            include_once("./Services/Block/classes/class.ilBlockSetting.php");
            $keep_rss_min = ilBlockSetting::_lookup(
                "news",
                "keep_rss_min",
                0,
                $this->getContextObjId()
            );
            if ($keep_rss_min > 0) {
                return $this->queryNewsForContext(
                    true,
                    0,
                    $a_starting_date,
                    $a_no_auto_generated,
                    $a_oldest_first,
                    $keep_rss_min
                );
            }
        }

        return $result;
    }

    public static function queryNewsByIds(array $a_news_ids)
    {
        global $DIC;
        $ilDB = $DIC->database();
        $news = array();
        $set = $ilDB->query("SELECT * FROM il_news_item " .
            " WHERE " . $ilDB->in("id", $a_news_ids, false, "integer"));
        while ($rec = $ilDB->fetchAssoc($set)) {
            $news[$rec["id"]] = $rec;
        }
        return $news;
    }

    public function checkNewsExistsForObjects($objects, $a_time_period = 1)
    {
        $ilDB = $this->db;
        
        $all = array();

        $limit_ts = self::handleTimePeriod($a_time_period);

        // are there any news items for relevant objects and?
        $query = $ilDB->query("SELECT id,context_obj_id,context_obj_type" .
            " FROM il_news_item" .
            " WHERE " . $ilDB->in("context_obj_id", array_keys($objects), false, "integer") .
            " AND creation_date >= " . $ilDB->quote($limit_ts, "timestamp"));
        while ($rec = $ilDB->fetchAssoc($query)) {
            if ($objects[$rec["context_obj_id"]]["type"] == $rec["context_obj_type"]) {
                $all[] = $rec["id"];
            }
        }

        return $all;
    }
    
    public function queryNewsForMultipleContexts(
        $a_contexts,
        $a_for_rss_use = false,
        $a_time_period = 0,
        $a_starting_date = "",
        $a_no_auto_generated = false,
        $a_user_id = null,
        $a_limit = 0,
        $a_exclude = array()
    ) {
        $ilDB = $this->db;
        $ilUser = $this->user;
        $lng = $this->lng;
        $ilCtrl = $this->ctrl;

        $and = "";
        if ($a_time_period > 0) {
            $limit_ts = self::handleTimePeriod($a_time_period);
            $and = " AND creation_date >= " . $ilDB->quote($limit_ts, "timestamp") . " ";
        }
            
        if ($a_starting_date != "") {
            $and .= " AND creation_date > " . $ilDB->quote($a_starting_date, "timestamp") . " ";
        }

        if ($a_no_auto_generated) {
            $and .= " AND priority = 1 AND content_type = " . $ilDB->quote("text", "text") . " ";
        }

        if ($a_limit > 0) {
            $ilDB->setLimit($a_limit, 0);
        }

        if (is_array($a_exclude) && count($a_exclude) > 0) {
            $and .= " AND " . $ilDB->in("id", $a_exclude, true, "integer") . " ";
        }

        $ids = array();
        $type = array();

        foreach ($a_contexts as $cont) {
            $ids[] = $cont["obj_id"];
            $type[$cont["obj_id"]] = $cont["obj_type"];
        }
        
        if ($a_for_rss_use && ilNewsItem::getPrivateFeedId() == false) {
            $query = "SELECT * " .
                "FROM il_news_item " .
                " WHERE " .
                    $ilDB->in("context_obj_id", $ids, false, "integer") . " " .
                    $and .
                    " ORDER BY creation_date DESC ";
        } elseif (ilNewsItem::getPrivateFeedId() != false) {
            $query = "SELECT il_news_item.* " .
                ", il_news_read.user_id as user_read " .
                "FROM il_news_item LEFT JOIN il_news_read " .
                "ON il_news_item.id = il_news_read.news_id AND " .
                " il_news_read.user_id = " . $ilDB->quote(ilNewsItem::getPrivateFeedId(), "integer") .
                " WHERE " .
                    $ilDB->in("context_obj_id", $ids, false, "integer") . " " .
                    $and .
                    " ORDER BY creation_date DESC ";
        } else {
            if ($a_user_id) {
                $user_id = $a_user_id;
            } else {
                $user_id = $ilUser->getId();
            }
            $query = "SELECT il_news_item.* " .
                ", il_news_read.user_id as user_read " .
                "FROM il_news_item LEFT JOIN il_news_read " .
                "ON il_news_item.id = il_news_read.news_id AND " .
                " il_news_read.user_id = " . $ilDB->quote($user_id, "integer") .
                " WHERE " .
                    $ilDB->in("context_obj_id", $ids, false, "integer") . " " .
                    $and .
                    " ORDER BY creation_date DESC ";
        }

        $set = $ilDB->query($query);
        $result = array();
        while ($rec = $ilDB->fetchAssoc($set)) {
            if ($type[$rec["context_obj_id"]] == $rec["context_obj_type"]) {
                if (!$a_for_rss_use || ilNewsItem::getPrivateFeedId() != false || ($rec["visibility"] == NEWS_PUBLIC ||
                    ($rec["priority"] == 0 &&
                    ilBlockSetting::_lookup(
                        "news",
                        "public_notifications",
                        0,
                        $rec["context_obj_id"]
                    )))) {
                    $result[$rec["id"]] = $rec;
                }
            }
        }

        return $result;
    }


    public static function _setRead($a_user_id, $a_news_id)
    {
        global $DIC;

        $ilDB = $DIC->database();
        $ilAppEventHandler = $DIC["ilAppEventHandler"];
        
        $ilDB->replace(
            "il_news_read",
            array(
                "user_id" => array("integer", $a_user_id),
                "news_id" => array("integer", $a_news_id)
                ),
            array()
        );
        
        /*
        $ilDB->manipulate("DELETE FROM il_news_read WHERE ".
            "user_id = ".$ilDB->quote($a_user_id, "integer").
            " AND news_id = ".$ilDB->quote($a_news_id, "integer"));
        $ilDB->manipulate("INSERT INTO il_news_read (user_id, news_id) VALUES (".
            $ilDB->quote($a_user_id, "integer").",".
            $ilDB->quote($a_news_id, "integer").")");*/

        $ilAppEventHandler->raise(
            "Services/News",
            "readNews",
            array("user_id" => $a_user_id, "news_ids" => array($a_news_id))
        );
    }
    
    public static function _setUnread($a_user_id, $a_news_id)
    {
        global $DIC;

        $ilDB = $DIC->database();
        $ilAppEventHandler = $DIC["ilAppEventHandler"];
        
        $ilDB->manipulate("DELETE FROM il_news_read (user_id, news_id) VALUES (" .
            " WHERE user_id = " . $ilDB->quote($a_user_id, "integer") .
            " AND news_id = " . $ilDB->quote($a_news_id, "integer"));

        $ilAppEventHandler->raise(
            "Services/News",
            "unreadNews",
            array("user_id" => $a_user_id, "news_ids" => array($a_news_id))
        );
    }
    
    public static function mergeNews($n1, $n2)
    {
        foreach ($n2 as $id => $news) {
            $n1[$id] = $news;
        }
        
        return $n1;
    }
    
    public static function _getDefaultVisibilityForRefId($a_ref_id)
    {
        global $DIC;

        $tree = $DIC->repositoryTree();
        $ilSetting = $DIC->settings();

        include_once("./Services/Block/classes/class.ilBlockSetting.php");

        $news_set = new ilSetting("news");
        $default_visibility = ($news_set->get("default_visibility") != "")
                ? $news_set->get("default_visibility")
                : "users";

        if ($tree->isInTree($a_ref_id)) {
            $path = $tree->getPathFull($a_ref_id);
            
            foreach ($path as $key => $row) {
                if (!in_array($row["type"], array("root", "cat","crs", "fold", "grp"))) {
                    continue;
                }

                $visibility = ilBlockSetting::_lookup(
                    "news",
                    "default_visibility",
                    0,
                    $row["obj_id"]
                );
                    
                if ($visibility != "") {
                    $default_visibility = $visibility;
                }
            }
        }
        
        return $default_visibility;
    }
    
    
    public function delete()
    {
        $ilDB = $this->db;
        
        // delete il_news_read entries
        $ilDB->manipulate("DELETE FROM il_news_read " .
            " WHERE news_id = " . $ilDB->quote($this->getId(), "integer"));
        
        // delete multimedia object
        $mob = $this->getMobId();
        
        // delete
        $query = "DELETE FROM il_news_item" .
            " WHERE id = " . $ilDB->quote($this->getId(), "integer");
        $ilDB->manipulate($query);
        
        // delete mob after news, to have a "mob usage" of 0
        if ($mob > 0 and ilObject::_exists($mob)) {
            include_once("./Services/MediaObjects/classes/class.ilObjMediaObject.php");
            $mob = new ilObjMediaObject($mob);
            $mob->delete();
        }
    }
    
    public static function getNewsOfContext(
        $a_context_obj_id,
        $a_context_obj_type,
        $a_context_sub_obj_id = 0,
        $a_context_sub_obj_type = ""
    ) {
        global $DIC;

        $ilDB = $DIC->database();
        
        if ($a_context_obj_id == 0 || $a_context_obj_type == "") {
            return [];
        }

        if ($a_context_sub_obj_id > 0) {
            $and = " AND context_sub_obj_id = " . $ilDB->quote($a_context_sub_obj_id, "integer") .
                " AND context_sub_obj_type = " . $ilDB->quote($a_context_sub_obj_type, "text");
        }
        
        // get news records
        $query = "SELECT * FROM il_news_item" .
            " WHERE context_obj_id = " . $ilDB->quote($a_context_obj_id, "integer") .
            " AND context_obj_type = " . $ilDB->quote($a_context_obj_type, "text") .
            $and;

        $news_set = $ilDB->query($query);

        $news_arr = [];
        while ($news = $ilDB->fetchAssoc($news_set)) {
            $news_arr[] = new ilNewsItem($news["id"]);
        }
        return $news_arr;
    }

    public static function deleteNewsOfContext(
        $a_context_obj_id,
        $a_context_obj_type,
        $a_context_sub_obj_id = 0,
        $a_context_sub_obj_type = ""
    ) {
        foreach (self::getNewsOfContext(
            $a_context_obj_id,
            $a_context_obj_type,
            $a_context_sub_obj_id,
            $a_context_sub_obj_type
        ) as $n) {
            $n->delete();
        }
    }

    public static function _lookupTitle($a_news_id)
    {
        global $DIC;

        $ilDB = $DIC->database();
        
        $query = "SELECT title FROM il_news_item WHERE id = " .
            $ilDB->quote($a_news_id, "integer");
        $set = $ilDB->query($query);
        $rec = $ilDB->fetchAssoc($set);
        return $rec["title"];
    }

    public static function _lookupVisibility($a_news_id)
    {
        global $DIC;

        $ilDB = $DIC->database();
        
        $query = "SELECT visibility FROM il_news_item WHERE id = " .
            $ilDB->quote($a_news_id, "integer");
        $set = $ilDB->query($query);
        $rec = $ilDB->fetchAssoc($set);

        return $rec["visibility"];
    }

    public static function _lookupMobId($a_news_id)
    {
        global $DIC;

        $ilDB = $DIC->database();

        $query = "SELECT mob_id FROM il_news_item WHERE id = " .
            $ilDB->quote($a_news_id, "integer");
        $set = $ilDB->query($query);
        $rec = $ilDB->fetchAssoc($set);
        return $rec["mob_id"];
    }

    public static function filterObjIdsPerNews($a_obj_ids, $a_time_period = 0, $a_starting_date = "", $a_ending_date = '', $ignore_period = false)
    {
        global $DIC;

        $ilDB = $DIC->database();

        $and = "";
        if ($a_time_period > 0) {
            $limit_ts = self::handleTimePeriod($a_time_period);
            $and = " AND creation_date >= " . $ilDB->quote($limit_ts, "timestamp") . " ";
        }

        if ($a_starting_date != "") {
            $and .= " AND creation_date >= " . $ilDB->quote($a_starting_date, "timestamp");
        }

        $query = "SELECT DISTINCT(context_obj_id) AS obj_id FROM il_news_item" .
            " WHERE " . $ilDB->in("context_obj_id", $a_obj_ids, false, "integer") . " " . $and;
        //" WHERE context_obj_id IN (".implode(ilUtil::quoteArray($a_obj_ids),",").")".$and;

        $set = $ilDB->query($query);
        $objs = array();
        while ($rec = $ilDB->fetchAssoc($set)) {
            $objs[] = $rec["obj_id"];
        }

        return $objs;
    }

    public static function determineNewsTitleByNewsId($a_news_id, $a_agg_ref_id = 0, $a_aggregation = "")
    {
        global $DIC;

        $ilDB = $DIC->database();

        $query = "SELECT context_obj_type, content_is_lang_var, title FROM il_news_item WHERE id = " .
            $ilDB->quote($a_news_id, "integer");
        $set = $ilDB->query($query);
        $rec = $ilDB->fetchAssoc($set);

        return self::determineNewsTitle(
            $rec["context_obj_type"],
            $rec["title"],
            $rec["content_is_lang_var"],
            $a_agg_ref_id,
            $a_aggregation
        );
    }

    public static function determineNewsTitle(
        $a_context_obj_type,
        $a_title,
        $a_content_is_lang_var,
        $a_agg_ref_id = 0,
        $a_aggregation = ""
    ) {
        global $DIC;

        $lng = $DIC->language();
        $obj_definition = $DIC["objDefinition"];

        if ($a_agg_ref_id > 0) {
            $cnt = count($a_aggregation);
            
            // forums
            if ($a_context_obj_type == "frm") {
                if ($cnt > 1) {
                    return sprintf($lng->txt("news_x_postings"), $cnt);
                } else {
                    return $lng->txt("news_1_postings");
                }
            } else {    // files
                $up_cnt = $cr_cnt = 0;
                foreach ($a_aggregation as $item) {
                    if ($item["title"] == "file_updated") {
                        $up_cnt++;
                    } else {
                        $cr_cnt++;
                    }
                }
                $sep = "";
                if ($cr_cnt == 1) {
                    $tit = $lng->txt("news_1_file_created");
                    $sep = "<br />";
                } elseif ($cr_cnt > 1) {
                    $tit = sprintf($lng->txt("news_x_files_created"), $cr_cnt);
                    $sep = "<br />";
                }
                if ($up_cnt == 1) {
                    $tit .= $sep . $lng->txt("news_1_file_updated");
                } elseif ($up_cnt > 1) {
                    $tit .= $sep . sprintf($lng->txt("news_x_files_updated"), $up_cnt);
                }
                return $tit;
            }
        } else {
            if ($a_content_is_lang_var) {
                if ($obj_definition->isPlugin($a_context_obj_type)) {
                    return ilObjectPlugin::lookupTxtById($a_context_obj_type, $a_title);
                }
                return $lng->txt($a_title);
            } else {
                return $a_title;
            }
        }
        
        return "";
    }

    public static function determineNewsContent($a_context_obj_type, $a_content, $a_is_lang_var)
    {
        global $DIC;

        $lng = $DIC->language();
        $obj_definition = $DIC["objDefinition"];

        if ($a_is_lang_var) {
            if ($obj_definition->isPlugin($a_context_obj_type)) {
                return ilObjectPlugin::lookupTxtById($a_context_obj_type, $a_content);
            }
            $lng->loadLanguageModule($a_context_obj_type);
            return $lng->txt($a_content);
        } else {
            return $a_content;
        }
    }

    
    
    public static function getFirstNewsIdForContext(
        $a_context_obj_id,
        $a_context_obj_type,
        $a_context_sub_obj_id = "",
        $a_context_sub_obj_type = ""
    ) {
        global $DIC;

        $ilDB = $DIC->database();
        
        // Determine how many rows should be deleted
        $query = "SELECT * " .
            "FROM il_news_item " .
            "WHERE " .
                "context_obj_id = " . $ilDB->quote($a_context_obj_id, "integer") .
                " AND context_obj_type = " . $ilDB->quote($a_context_obj_type, "text") .
                " AND context_sub_obj_id = " . $ilDB->quote($a_context_sub_obj_id, "integer") .
                " AND " . $ilDB->equals("context_sub_obj_type", $a_context_sub_obj_type, "text", true);
                
        $set = $ilDB->query($query);
        $rec = $ilDB->fetchAssoc($set);
        
        return $rec["id"];
    }

    public static function getLastNewsIdForContext(
        $a_context_obj_id,
        $a_context_obj_type,
        $a_context_sub_obj_id = "",
        $a_context_sub_obj_type = "",
        $a_only_today = false
    ) {
        global $DIC;

        $ilDB = $DIC->database();

        // Determine how many rows should be deleted
        $query = "SELECT id, update_date " .
            "FROM il_news_item " .
            "WHERE " .
                "context_obj_id = " . $ilDB->quote($a_context_obj_id, "integer") .
                " AND context_obj_type = " . $ilDB->quote($a_context_obj_type, "text") .
                " AND context_sub_obj_id = " . $ilDB->quote($a_context_sub_obj_id, "integer") .
                " AND " . $ilDB->equals("context_sub_obj_type", $a_context_sub_obj_type, "text", true) .
            " ORDER BY update_date DESC";

        $ilDB->setLimit(1);
        $set = $ilDB->query($query);
        $rec = $ilDB->fetchAssoc($set);

        $id = (int) $rec["id"];
        if ($a_only_today) {
            $now = ilUtil::now();
            if (substr($now, 0, 10) != substr($rec["update_date"], 0, 10)) {
                $id = 0;
            }
        }

        return $id;
    }


    public static function _lookupMediaObjectUsages($a_mob_id)
    {
        global $DIC;

        $ilDB = $DIC->database();
        
        $query = "SELECT * " .
            "FROM il_news_item " .
            "WHERE " .
                " mob_id = " . $ilDB->quote($a_mob_id, "integer");
                
        $usages = array();
        $set = $ilDB->query($query);
        while ($rec = $ilDB->fetchAssoc($set)) {
            $usages[$rec["id"]] = array("type" => "news", "id" => $rec["id"]);
        }
        
        return $usages;
    }

    public static function _lookupContextObjId($a_news_id)
    {
        global $DIC;

        $ilDB = $DIC->database();
        
        $query = "SELECT * " .
            "FROM il_news_item " .
            "WHERE " .
                " id = " . $ilDB->quote($a_news_id, "integer");
        $set = $ilDB->query($query);
        $rec = $ilDB->fetchAssoc($set);
        
        return $rec["context_obj_id"];
    }

    public static function _lookupDefaultPDPeriod()
    {
        $news_set = new ilSetting("news");
        $per = $news_set->get("pd_period");
        if ($per == 0) {
            $per = 30;
        }
        
        return $per;
    }

    public static function _lookupUserPDPeriod($a_user_id)
    {
        $news_set = new ilSetting("news");
        $allow_shorter_periods = $news_set->get("allow_shorter_periods");
        $allow_longer_periods = $news_set->get("allow_longer_periods");
        $default_per = ilNewsItem::_lookupDefaultPDPeriod();
        
        include_once("./Services/Block/classes/class.ilBlockSetting.php");
        $per = ilBlockSetting::_lookup(
            "pdnews",
            "news_pd_period",
            $a_user_id,
            0
        );

        // news period information
        if ($per <= 0 ||
            (!$allow_shorter_periods && ($per < $default_per)) ||
            (!$allow_longer_periods && ($per > $default_per))
            ) {
            $per = $default_per;
        }
        
        return $per;
    }

    public static function _lookupRSSPeriod()
    {
        $news_set = new ilSetting("news");
        $rss_period = $news_set->get("rss_period");
        if ($rss_period == 0) {         // default to two weeks
            $rss_period = 14;
        }
        return $rss_period;
    }

    public static function setPrivateFeedId($a_userId)
    {
        ilNewsItem::$privFeedId = $a_userId;
    }

    public static function getPrivateFeedId()
    {
        return ilNewsItem::$privFeedId;
    }
    
    public function deliverMobFile($a_purpose = "Standard", $a_increase_download_cnt = false)
    {
        $mob = $this->getMobId();
        include_once("./Services/MediaObjects/classes/class.ilObjMediaObject.php");
        $mob = new ilObjMediaObject($mob);
        $mob_dir = ilObjMediaObject::_getDirectory($mob->getId());
        
        // check purpose
        if (!$mob->hasPurposeItem($a_purpose)) {
            return false;
        }
        
        $m_item = $mob->getMediaItem($a_purpose);
        if ($m_item->getLocationType() != "Reference") {
            $file = $mob_dir . "/" . $m_item->getLocation();
            if (file_exists($file) && is_file($file)) {
                if ($a_increase_download_cnt) {
                    $this->increaseDownloadCounter();
                }
                ilUtil::deliverFile($file, $m_item->getLocation(), "", false, false, false);
                return true;
            } else {
                ilUtil::sendFailure("File not found!", true);
                return false;
            }
        } else {
            if ($a_increase_download_cnt) {
                $this->increaseDownloadCounter();
            }
            ilUtil::redirect($m_item->getLocation());
        }
    }
    
    public function increaseDownloadCounter()
    {
        $ilDB = $this->db;

        $cnt = $this->getMobDownloadCounter();
        $cnt++;
        $this->setMobDownloadCounter($cnt);
        $ilDB->manipulate(
            "UPDATE il_news_item SET " .
            " mob_cnt_download = " . $ilDB->quote($cnt, "integer") .
            " WHERE id = " . $ilDB->quote($this->getId(), "integer")
        );
    }
    
    public function increasePlayCounter()
    {
        $ilDB = $this->db;

        $cnt = $this->getMobPlayCounter();
        $cnt++;
        $this->setMobPlayCounter($cnt);
        $ilDB->manipulate(
            "UPDATE il_news_item SET " .
            " mob_cnt_play = " . $ilDB->quote($cnt, "integer") .
            " WHERE id = " . $ilDB->quote($this->getId(), "integer")
        );
    }

    public static function prepareNewsDataFromCache($a_cres)
    {
        global $DIC;

        $ilDB = $DIC->database();

        $data = $a_cres;
        $news_ids = array_keys($data);
        $set = $ilDB->query("SELECT id FROM il_news_item " .
            " WHERE " . $ilDB->in("id", $news_ids, false, "integer"));
        $existing_ids = array();
        while ($rec = $ilDB->fetchAssoc($set)) {
            $existing_ids[] = $rec["id"];
        }
        //var_dump($existing_ids);
        $existing_news = array();
        foreach ($data as $k => $v) {
            if (in_array($k, $existing_ids)) {
                $existing_news[$k] = $v;
            }
        }

        //var_dump($data);
        //var_dump($existing_news);

        return $existing_news;
    }
}