Merge branch 'main' into issue-3911issue-3911

1 files changed, 696 insertions, 0 deletions

diff --git a/lib/models/StudipNews.php b/lib/models/StudipNews.php
new file mode 100644
index 0000000..ccb1828
--- /dev/null
+++ b/lib/models/StudipNews.php
@@ -0,0 +1,696 @@
+<?php
+// +---------------------------------------------------------------------------+
+// This file is part of Stud.IP
+//
+// Copyright (C) 2005 André Noack <noack@data-quest>,
+// Suchi & Berg GmbH <info@data-quest.de>
+// +---------------------------------------------------------------------------+
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or any later version.
+// +---------------------------------------------------------------------------+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+// +---------------------------------------------------------------------------+
+require_once 'lib/object.inc.php';
+
+/**
+ * StudipNews.php
+ *
+ * @author   André Noack <noack@data-quest>, Suchi & Berg GmbH <info@data-quest.de>
+ * @author   Arne Schröder <schroeder@data-quest>
+ * @access   public
+ *
+ * @property string $id alias column for news_id
+ * @property string $news_id database column
+ * @property I18NString $topic database column
+ * @property I18NString $body database column
+ * @property string $author database column
+ * @property int $date database column
+ * @property string $user_id database column
+ * @property int $expire database column
+ * @property int $allow_comments database column
+ * @property int $prio database column
+ * @property int $chdate database column
+ * @property string $chdate_uid database column
+ * @property int $mkdate database column
+ * @property SimpleORMapCollection|NewsRange[] $news_ranges has_many NewsRange
+ * @property SimpleORMapCollection|StudipComment[] $comments has_many StudipComment
+ * @property SimpleORMapCollection|NewsRoles[] $news_roles has_many NewsRoles
+ * @property User $owner belongs_to User
+ * @property int $views additional field
+ */
+class StudipNews extends SimpleORMap implements PrivacyObject
+{
+    protected static function configure($config = [])
+    {
+        $config['db_table'] = 'news';
+        $config['has_many']['news_ranges'] = [
+            'class_name'        => NewsRange::class,
+            'assoc_foreign_key' => 'news_id',
+            'on_delete'         => 'delete',
+            'on_store'          => 'store',
+        ];
+        $config['has_many']['comments'] = [
+            'class_name'        => StudipComment::class,
+            'assoc_foreign_key' => 'object_id',
+            'on_delete'         => 'delete',
+            'on_store'          => 'store',
+        ];
+        $config['belongs_to']['owner'] = [
+            'class_name'  => User::class,
+            'foreign_key' => 'user_id',
+        ];
+        $config['has_many']['news_roles'] = [
+            'class_name'        => NewsRoles::class,
+            'assoc_foreign_key' => 'news_id',
+            'on_delete'         => 'delete'
+        ];
+
+        $config['additional_fields'] = [
+            'views' => [
+                'get' => function (StudipNews $news): int {
+                    return object_return_views($news->id);
+                },
+            ],
+        ];
+
+        $config['i18n_fields'] = ['topic', 'body'];
+
+        // Strip <admin_msg> from news body
+        $config['registered_callbacks']['after_initialize'][] = function ($news) {
+            if ($news->isI18nField('body')) {
+                $news->body->setOriginal(explode('<admin_msg>', $news->body->original())[0]);
+                foreach ($news->body->toArray() as $lang => $value) {
+                    if ($value) {
+                        $news->body->setLocalized(
+                            explode('<admin_msg>', $value)[0],
+                            $lang
+                        );
+                    }
+                }
+            }
+        };
+
+        parent::configure($config);
+    }
+
+    public static function GetNewsByRange($range_id, $only_visible = false, $as_objects = false)
+    {
+        $clause = '';
+        if ($only_visible) {
+            $clause = " AND date < UNIX_TIMESTAMP() AND (date + expire) > UNIX_TIMESTAMP() ";
+        }
+        $query = "SELECT news_id AS idx, news.*
+                  FROM news_range
+                  INNER JOIN news USING (news_id)
+                  WHERE range_id = ? {$clause} ";
+        if (Config::get()->SORT_NEWS_BY_CHDATE) {
+            $query .= "ORDER BY IF(prio = 0, 6, prio) DESC, chdate DESC, date DESC, topic ASC";
+        } else {
+            $query .= "ORDER BY IF(prio = 0, 6, prio) DESC, date DESC, chdate DESC, topic ASC";
+        }
+        $statement = DBManager::get()->prepare($query);
+        $statement->execute([$range_id]);
+        $ret = $statement->fetchGrouped(PDO::FETCH_ASSOC);
+        if (!(isset($GLOBALS['perm']) && $GLOBALS['perm']->have_perm('root'))) {
+            if (!(User::find($range_id) && $GLOBALS['user']->id == $range_id)) {
+                foreach ($ret as $news_id => $news) {
+                    if (!NewsRoles::checkUserAccess($news_id)) {
+                        unset($ret[$news_id]);
+                    }
+                }
+            }
+        }
+
+        return $as_objects ? static::GetNewsObjects($ret) : $ret;
+    }
+
+    public static function CountUnread($range_id = 'studip', $user_id = false)
+    {
+        $query = "SELECT nw.news_id as idx, nw.chdate > IFNULL(b.visitdate, :threshold) AS active
+                  FROM news_range a
+                  LEFT JOIN news nw ON (a.news_id = nw.news_id AND UNIX_TIMESTAMP() BETWEEN date AND date + expire)
+                  LEFT JOIN object_user_visits b ON (b.object_id = nw.news_id AND b.user_id = :user_id AND b.plugin_id = :plugin_id)
+                  WHERE a.range_id = :range_id AND nw.user_id != :user_id";
+        $statement = DBManager::get()->prepare($query);
+        $statement->bindValue(':threshold', object_get_visit_threshold());
+        $statement->bindValue(':user_id', $user_id ?: $GLOBALS['user']->id);
+        $statement->bindValue(':range_id', $range_id);
+        $plugin_id = object_type_to_id('news');
+        $statement->bindValue(':plugin_id', $plugin_id);
+        $statement->execute();
+        $ret = $statement->fetchGrouped(PDO::FETCH_ASSOC);
+        foreach ($ret as $news_id => $news) {
+            if (!NewsRoles::checkUserAccess($news_id, $user_id) && !$GLOBALS['perm']->have_perm('root') || !$news['active']) {
+                unset($ret[$news_id]);
+            }
+        }
+        return count($ret);
+    }
+
+    public static function GetNewsByAuthor($user_id, $as_objects = false)
+    {
+        $query = "SELECT news_id AS idx, news.*
+                  FROM news
+                  WHERE user_id = ? ";
+        if (Config::get()->SORT_NEWS_BY_CHDATE) {
+            $query .= "ORDER BY IF(prio = 0, 6, prio) DESC, chdate DESC, date DESC";
+        } else {
+            $query .= "ORDER BY IF(prio = 0, 6, prio) DESC, date DESC, chdate DESC";
+        }
+        $statement = DBManager::get()->prepare($query);
+        $statement->execute([$user_id]);
+        $ret = $statement->fetchGrouped(PDO::FETCH_ASSOC);
+        if (!(isset($GLOBALS['perm']) && $GLOBALS['perm']->have_perm('root'))) {
+            if ($GLOBALS['user']->id != $user_id) {
+                foreach ($ret as $news_id => $news) {
+                    if (!NewsRoles::checkUserAccess($news_id)) {
+                        unset($ret[$news_id]);
+                    }
+                }
+            }
+        }
+
+        return $as_objects ? static::GetNewsObjects($ret) : $ret;
+    }
+
+    public static function GetNewsByRSSId($rss_id, $as_objects = false)
+    {
+        if ($user_id = static::GetUserIDFromRssID($rss_id)) {
+            return static::GetNewsByRange($user_id, true, $as_objects);
+        }
+
+        return [];
+    }
+
+    public static function GetNewsObjects($news_result)
+    {
+        return array_map(
+            [static::class, 'buildExisting'],
+            (array) $news_result
+        );
+    }
+
+    /**
+     * fetches set of news items from database
+     *
+     * @param string $user_id         author id for news set
+     * @param string $area            area group for news set (global, inst, sem or user)
+     * @param string $term            search term for news topic
+     * @param int $startdate          return only news (still) visible after this date
+     * @param int $enddate            return only news (still) visible before this date
+     * @param boolean $as_objects     include StudipNews objects in result array
+     * @param int $limit              max size of returned news set
+     * @return array                  set of news items
+     */
+    public static function GetNewsRangesByFilter($user_id, $area = '', $term = '', $startdate = 0, $enddate = 0, $as_objects = false, $limit = 100)
+    {
+        $news_result    = [];
+        $query_vars     = [];
+
+        if ($limit <= 0) {
+            return $news_result;
+        }
+        $where_querypart = [];
+        if (isset($startdate)) {
+            $where_querypart[]  = '(date+expire) > ?';
+            $query_vars[]       = $startdate;
+        }
+        if (isset($enddate)) {
+            $where_querypart[]  = 'date < ?';
+            $query_vars[]       = $enddate;
+        }
+
+        if(!$GLOBALS['perm']->have_perm('root') || $area !== 'global') {
+            $where_querypart[]  = 'news.user_id = ?';
+            $query_vars[]       = $user_id;
+        }
+
+        if (isset($term)) {
+            $where_querypart[]  = "topic LIKE CONCAT('%', ?, '%')";
+            $query_vars[]       = $term;
+        }
+        switch ($area) {
+            case 'global':
+                $select_querypart   = 'CONCAT(news_id, "_studip") AS idx, range_id, news.* ';
+                $from_querypart     = 'news_range INNER JOIN news USING(news_id)';
+                $where_querypart[]  = 'range_id = ?';
+                if (Config::get()->SORT_NEWS_BY_CHDATE) {
+                    $order_querypart = 'news.chdate DESC, news.date DESC';
+                } else {
+                    $order_querypart = 'news.date DESC, news.chdate DESC';
+                }
+                $query_vars[]       = 'studip';
+                break;
+            case 'sem':
+                $select_querypart   = 'CONCAT(news_id, "_", range_id) AS idx, range_id, seminare.Name AS title, '
+                    .'seminare.start_time AS start, news.*, seminare.start_time, sd1.name AS startsem, '
+                    .'IFNULL((SELECT semester_data.name FROM semester_data INNER JOIN semester_courses USING (semester_id) WHERE semester_courses.course_id = seminare.Seminar_id ORDER BY semester_data.beginn DESC LIMIT 1), "'._("unbegrenzt").'") AS endsem ';
+                $from_querypart     = 'news INNER JOIN news_range USING(news_id) INNER JOIN seminare ON Seminar_id = range_id '
+                    .'LEFT JOIN semester_data sd1 ON (start_time BETWEEN sd1.beginn AND sd1.ende) ';
+                if (Config::get()->SORT_NEWS_BY_CHDATE) {
+                    $order_querypart = 'seminare.Name, news.chdate DESC, news.date DESC';
+                } else {
+                    $order_querypart = 'seminare.Name, news.date DESC, news.chdate DESC';
+                }
+                break;
+            case 'inst':
+                $select_querypart   = 'CONCAT(news_id, "_", range_id) AS idx, range_id, Institute.Name AS title, news.* ';
+                $from_querypart     = 'Institute INNER JOIN news_range ON Institut_id = range_id INNER JOIN news USING(news_id)';
+                if (Config::get()->SORT_NEWS_BY_CHDATE) {
+                    $order_querypart = 'Institute.Name, news.chdate DESC, news.date DESC';
+                } else {
+                    $order_querypart = 'Institute.Name, news.date DESC, news.chdate DESC';
+                }
+                break;
+            case 'user':
+                $select_querypart   = 'CONCAT(news_id, "_", auth_user_md5.user_id) AS idx, range_id, auth_user_md5.user_id AS userid, news.* ';
+                $from_querypart     = 'auth_user_md5 INNER JOIN news_range ON auth_user_md5.user_id = range_id INNER JOIN news USING(news_id)';
+                if (Config::get()->SORT_NEWS_BY_CHDATE) {
+                    $order_querypart = 'auth_user_md5.Nachname, news.chdate DESC, news.date DESC';
+                } else {
+                    $order_querypart = 'auth_user_md5.Nachname, news.date DESC, news.chdate DESC';
+                }
+                break;
+            default:
+                foreach (['global', 'inst', 'sem', 'user'] as $type) {
+                    $add_news = static::GetNewsRangesByFilter($user_id, $type, $term, $startdate, $enddate, $as_objects, $limit);
+                    if (is_array($add_news) && isset($add_news[$type])) {
+                        $limit          = $limit - count($add_news[$type]);
+                        $news_result    = array_merge($news_result, $add_news);
+                    }
+                }
+                return $news_result;
+        }
+        $query = "SELECT " . $select_querypart . "
+                  FROM " . $from_querypart . "
+                  WHERE " . implode(' AND ', $where_querypart) . "
+                  ORDER BY " . $order_querypart . " LIMIT 0, ?";
+
+        $query_vars[]   = $limit;
+        $statement      = DBManager::get()->prepare($query);
+        $statement->execute($query_vars);
+        $news_result    = $statement->fetchGrouped();
+
+        $objects = [$area => []];
+        foreach ($news_result as $id => $result) {
+            $objects[$area][$id] = [
+                'range_id' => $result['range_id'],
+                'title'    => $result['title'] ?? '',
+            ];
+            if ($area === 'sem') {
+                if (!isset($objects[$area][$id]['semester'])) {
+                    $objects[$area][$id]['semester'] = '';
+                }
+                $objects[$area][$id]['semester'] .= sprintf('(%s%s)',
+                    $result['startsem'],
+                    $result['startsem'] != $result['endsem'] ? ' - ' . $result['endsem'] : '');
+            } elseif ($area === 'user') {
+                if ($GLOBALS['user']->id === $result['userid']) {
+                    $objects[$area][$id]['title'] = _('Ankündigungen auf Ihrer Profilseite');
+                } else {
+                    $objects[$area][$id]['title'] = sprintf(_('Ankündigungen auf der Profilseite von %s'), get_fullname($result['userid']));
+                }
+            } elseif ($area === 'global') {
+                $objects[$area][$id]['title'] = _('Ankündigungen auf der Stud.IP Startseite');
+            }
+            if ($as_objects) {
+                $objects[$area][$id]['object'] = self::build($result, false);
+            }
+        }
+
+        return $objects;
+    }
+
+    public static function GetUserIdFromRssID($rss_id)
+    {
+        $ret = static::GetRangeIdFromRssID($rss_id);
+        return $ret['range_id'];
+    }
+
+    public static function GetRssIdFromUserId($user_id)
+    {
+        return static::GetRssIdFromRangeId($user_id);
+    }
+
+    public static function GetRangeFromRssID($rss_id)
+    {
+        if ($rss_id){
+            $query = "SELECT range_id ,range_type
+                      FROM news_rss_range
+                      WHERE rss_id = ?";
+            $statement = DBManager::get()->prepare($query);
+            $statement->execute([$rss_id]);
+            $ret = $statement->fetch(PDO::FETCH_ASSOC);
+
+            if (count($ret)) {
+                return $ret;
+            }
+        }
+        return false;
+    }
+
+    public static function GetRangeIdFromRssID($rss_id)
+    {
+        $ret = static::GetRangeFromRssID($rss_id);
+        return $ret['range_id'];
+    }
+
+    public static function GetRssIdFromRangeId($range_id)
+    {
+        $query = "SELECT rss_id FROM news_rss_range WHERE range_id = ?";
+        $statement = DBManager::get()->prepare($query);
+        $statement->execute([$range_id]);
+        return $statement->fetchColumn();
+    }
+
+    public static function SetRssId($range_id, $type = false)
+    {
+        if (!$type){
+            $type = get_object_type($range_id);
+            if ($type === 'fak') {
+                $type = 'inst';
+            }
+        }
+        $rss_id = md5('StudipRss' . $range_id);
+
+        $query = "REPLACE INTO news_rss_range (range_id,rss_id,range_type)
+                  VALUES (?, ?, ?)";
+        $statement = DBManager::get()->prepare($query);
+        $statement->execute([
+            $range_id,
+            $rss_id,
+            $type
+        ]);
+        return $statement->rowCount();
+    }
+
+    public static function UnsetRssId($range_id)
+    {
+        $query = "DELETE FROM news_rss_range WHERE range_id = ?";
+        $statement = DBManager::get()->prepare($query);
+        $statement->execute([$range_id]);
+        return $statement->rowCount();
+    }
+
+    public static function GetAdminMsg($user_id, $date)
+    {
+        return sprintf(
+            _('Zuletzt aktualisiert von %s (%s) am %s'),
+            get_fullname($user_id),
+            get_username($user_id),
+            date('d.m.y', $date)
+        );
+    }
+
+    public static function DoGarbageCollect($news_deletion_days = false)
+    {
+        $db = DBManager::get();
+        $queries = [];
+        $parameters = [];
+
+        if ($news_deletion_days !== false) {
+            $queries[] = "SELECT news.news_id
+                          FROM news
+                          WHERE date + expire + ? < UNIX_TIMESTAMP()";
+            $parameters[] = (int) $news_deletion_days;
+        }
+
+        $queries[] = "SELECT news_range.news_id
+                      FROM news_range
+                      LEFT JOIN news USING (news_id)
+                      WHERE news.news_id IS NULL";
+        $queries[] = "SELECT news.news_id
+                      FROM news
+                      LEFT JOIN news_range USING (news_id)
+                      WHERE range_id IS NULL";
+
+        $query = implode(' UNION DISTINCT ', $queries);
+        $stm = $db->prepare($query);
+        $stm->execute($parameters);
+        $result = $stm->fetchAll(PDO::FETCH_COLUMN);
+        $killed = 0;
+        if (count($result) > 0) {
+            $query = "DELETE FROM news WHERE news_id IN (?)";
+            $statement = $db->prepare($query);
+            $statement->execute([$result]);
+            $killed = $statement->rowCount();
+
+            $query = "DELETE FROM news_range WHERE news_id IN (?)";
+            $statement = $db->prepare($query);
+            $statement->execute([$result]);
+
+            object_kill_visits(null, $result);
+            object_kill_views($result);
+            StudipComment::DeleteCommentsByObject($result);
+        }
+        return $killed;
+    }
+
+    public static function DeleteNewsRanges($range_id)
+    {
+        $query = "DELETE FROM news_range WHERE range_id = :id";
+        $statement = DBManager::get()->prepare($query);
+        $statement->bindValue(':id', $range_id);
+        $result = $statement->execute();
+
+        static::DoGarbageCollect();
+
+        return $result;
+    }
+
+    public static function DeleteNewsByAuthor($user_id)
+    {
+        $deleted = 0;
+        foreach (static::GetNewsByAuthor($user_id, true) as $news) {
+            $deleted += $news->delete();
+        }
+        return $deleted;
+    }
+
+    public static function haveRangePermission($operation, $range_id, $user_id = '')
+    {
+        static $news_range_perm_cache;
+        if (isset($news_range_perm_cache[$user_id.$range_id.$operation])) {
+            return $news_range_perm_cache[$user_id.$range_id.$operation];
+        }
+        if (!$user_id) {
+            $user_id = $GLOBALS['user']->id;
+        }
+        if ($GLOBALS['perm']->have_perm('root', $user_id)) {
+            return $news_range_perm_cache[$user_id.$range_id.$operation] = true;
+        }
+
+        $type = get_object_type($range_id, ['global', 'sem', 'inst', 'fak', 'user']);
+        switch($type) {
+            case 'global':
+                if ($operation === 'view')
+                    return $news_range_perm_cache[$user_id.$range_id.$operation] = true;
+                break;
+            case 'fak':
+            case 'inst':
+            case 'sem':
+                if ($operation === 'view'
+                    && ($type !== 'sem'
+                        || $GLOBALS['perm']->have_studip_perm('user', $range_id)
+                        || (Config::get()->ENABLE_FREE_ACCESS && Seminar::getInstance($range_id)->read_level == 0)
+                        )) {
+                        return $news_range_perm_cache[$user_id.$range_id.$operation] = true;
+                    }
+                if ($operation === 'edit' || $operation === 'copy') {
+                    if ($GLOBALS['perm']->have_studip_perm('tutor', $range_id))
+                        return $news_range_perm_cache[$user_id.$range_id.$operation] = true;
+                }
+                break;
+            case 'user':
+                if ($operation === 'view') {
+                    if ($range_id === $user_id || get_visibility_by_id($range_id)) {
+                        return $news_range_perm_cache[$user_id.$range_id.$operation] = true;
+                    }
+                } elseif ($operation === 'edit' || $operation == 'copy') {
+                    if ($GLOBALS['perm']->have_profile_perm('user', $range_id))
+                        return $news_range_perm_cache[$user_id.$range_id.$operation] = true;
+                }
+                break;
+        }
+        return $news_range_perm_cache[$user_id.$range_id.$operation] = false;
+    }
+
+    public function restoreRanges()
+    {
+        $this->resetRelation('news_ranges');
+        return count($this->news_ranges);
+    }
+
+    public function getRanges()
+    {
+        return $this->news_ranges->pluck('range_id');
+    }
+
+    public function issetRange($range_id)
+    {
+        return array_search($range_id, $this->getRanges()) !== false;
+    }
+
+    public function addRange($range_id)
+    {
+        if (!$this->issetRange($range_id)) {
+            $range = new NewsRange([$this->getId(), $range_id]);
+            if ($range->isNew()) {
+                $range->range_id = $range_id;
+                $range->news_id = $this->getId();
+            }
+            $this->news_ranges[] = $range;
+            return true;
+        }
+
+        return false;
+    }
+
+    public function deleteRange($range_id)
+    {
+        if ($this->issetRange($range_id)) {
+            return $this->news_ranges->unsetBy('range_id', $range_id);
+        }
+
+        return false;
+    }
+
+    public function storeRanges()
+    {
+        $this->storeRelations();
+    }
+
+    public function delete()
+    {
+        object_kill_visits(null, $this->getId());
+        object_kill_views($this->getId());
+        return parent::delete();
+    }
+
+    /**
+     * checks, if user has permission to perform given operation on news object
+     *
+     * @param string $operation       delete, unassign, edit, copy, or view
+     * @param string $check_range_id  specified range-id, used only for unassign-operation
+     * @param string $user_id         optional; check permission for
+     *                                given user ID; otherwise for the
+     *                                global $user's ID
+     * @return boolean true or false
+     */
+    public function havePermission($operation, $check_range_id = '', $user_id = null)
+    {
+        if (!$user_id) {
+            $user_id = $GLOBALS['user']->id;
+        }
+        if (!in_array($operation, ['delete', 'unassign', 'edit', 'copy', 'view'])) {
+            return false;
+        }
+
+        // in order to unassign, there must be more than one range assigned; $check_range_id must be specified.
+        if ($operation === 'unassign' && count($this->getRanges()) < 2) {
+            return false;
+        }
+        // root, owner, and owner's deputy have full permission
+        if ($GLOBALS['perm']->have_perm('root', $user_id)
+            || ($user_id === $this->user_id && $GLOBALS['perm']->have_perm('autor'))
+            || (Deputy::isEditActivated() && Deputy::isDeputy($user_id, $this->user_id, true)))
+        {
+            return true;
+        }
+
+        // check news' ranges for edit, copy or view permission
+        if ($operation === 'unassign' || $operation === 'delete') {
+            $range_operation = 'edit';
+        } else {
+            $range_operation = $operation;
+        }
+        $permission_ranges = 0;
+        foreach ($this->getRanges() as $range_id) {
+            if (static::haveRangePermission($range_operation, $range_id, $user_id)) {
+                if ($operation === 'view' || $operation === 'edit' || $operation === 'copy') {
+                    // in order to view, edit, copy, or unassign, access to one of the ranges is sufficient
+                    return true;
+                } elseif ($operation === 'unassign' && $range_id === $check_range_id) {
+                    // in order to unassign, access to the specified range is needed
+                    return true;
+                }
+                // in order to delete, access to all ranges is necessary
+                $permission_ranges += 1;
+            } elseif ($operation === 'delete') {
+                return false;
+            }
+        }
+        if ($operation === 'delete' && count($this->getRanges()) == $permission_ranges) {
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * checks, if basic news data is complete
+     *
+     * @return boolean true or false
+     */
+    public function validate()
+    {
+        if (!$this->user_id && $this->isNew()) {
+            $this->user_id = $GLOBALS['user']->id;
+            $this->author = get_fullname(false, 'full', false);
+        }
+        if (!$this->user_id OR !$this->author) {
+            PageLayout::postError(_('Fehler: Personenangabe unvollständig.'));
+            return false;
+        }
+        if (!$this->topic) {
+            PageLayout::postError(_('Bitte geben Sie einen Titel für die Ankündigung ein.'));
+            return false;
+        }
+        if (!$this->body) {
+            PageLayout::postError(_('Bitte geben Sie einen Inhalt für die Ankündigung ein.'));
+            return false;
+        }
+        if (!count($this->getRanges())) {
+            PageLayout::postError(_('Die Ankündigung muss mindestens einem Bereich zugeordnet sein.'));
+            return false;
+        }
+        if ((int)$this->date < 1) {
+            PageLayout::postError(_('Ungültiges Einstelldatum.'));
+            return false;
+        }
+        if ((int)$this->expire < 1) {
+            PageLayout::postError(_('Ungültiges Ablaufdatum.'));
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Export available data of a given user into a storage object
+     * (an instance of the StoredUserData class) for that user.
+     *
+     * @param StoredUserData $storage object to store data into
+     */
+    public static function exportUserData(StoredUserData $storage)
+    {
+        $sorm = self::findBySQL("user_id = ?", [$storage->user_id]);
+        if ($sorm) {
+            $field_data = [];
+            foreach ($sorm as $row) {
+                $field_data[] = $row->toRawArray();
+            }
+            if ($field_data) {
+                $storage->addTabularData(_('Ankündigungen'), 'news', $field_data);
+            }
+        }
+    }
+}