wiki.inc.php

<?php
# Lifter002: TODO
# Lifter007: TODO
use Studip\Button, Studip\LinkButton;

/**
* Retrieve a WikiPage version from current seminar's WikiWikiWeb.
*
* Returns raw text data from database if requested version is
* available. If not, an
*
* @param string WikiWiki keyword to be retrieved
* @param int    Version number. If empty, latest version is returned.
*
**/
function getWikiPage($keyword, $version)
{
    $page = null;
    if ($version) {
        $page = WikiPage::find([Context::getId(), $keyword, $version]);
    }
    if ($page === null) {
        $page = WikiPage::findLatestPage(Context::getId(), $keyword);
    }

    if ($page) {
        return $page;
    }

    if ($keyword === 'WikiWikiWeb') {
        return WikiPage::getStartPage(Context::getId());
    }

    $page = new WikiPage();
    $page->range_id = Context::getId();
    $page->keyword  = $keyword;
    return $page;
}

/**
* Write a new/edited wiki page to database
*
* @param    string  keyword WikiPage name
* @param    string  version WikiPage version
* @param    string  body    WikiPage text
* @param    string  user_id Internal user id of editor
* @param    string  range_id    Internal id of seminar/einrichtung
*
**/
function submitWikiPage($keyword, $version, $body, $user_id, $range_id, $ancestor) {

    global $perm;
    releasePageLocks($keyword, $user_id); // kill lock that was set when starting to edit
    // write changes to db, show new page
    $latestVersion = getWikiPage($keyword, false);
    if ($latestVersion) {
        $date = time();
        $lastchange = $date - $latestVersion['chdate'];
    }

    StudipTransformFormat::addStudipMarkup('wiki-comments', '(\[comment\])', null, function(){return sprintf('[comment=%s]', get_fullname());});

    //TODO: Die $message Texte klingen fürchterlich. Halbsätze, Denglisch usw...
    if ($latestVersion && ($latestVersion['body'] == $body)) {
        $message = MessageBox::info(_('Keine Änderung vorgenommen.'));
        PageLayout::postMessage($message);
    } else if ($latestVersion && ($version !== null) && ($lastchange < 30*60) && ($user_id == $latestVersion['user_id'])) {
        // if same author changes again within 30 minutes, no new verison is created
        $wp = WikiPage::find([$range_id, $keyword, $version]);
        if ($wp) {
            if ($wp->isEditableBy($GLOBALS['user'])) {
                // apply replace-before-save transformations
                $wp->body = transformBeforeSave($body);
                if ($wp->isValidAncestor($ancestor)) {
                    $wp->setAncestorForAllVersions($ancestor);
                } else {
                    PageLayout::postInfo(_('Die Vorgängerseite konnte nicht gespeichert werden.'));
                }
                $wp->store();
            } else {
                PageLayout::postInfo(_('Keine Änderung vorgenommen, da zwischenzeitlich die Editier-Berechtigung entzogen wurde.'));
            }
        }
    } else {
        if ($version === null) {
            $version = 0;
        } else {
            $version = $latestVersion['version'] + 1;
        }

        // apply replace-before-save transformations
        $body = transformBeforeSave($body);
        WikiPage::create(compact('range_id', 'user_id', 'keyword', 'body', 'ancestor', 'version'));
    }
    StudipTransformFormat::removeStudipMarkup('wiki-comments');
    refreshBacklinks($keyword, $body);
}

/**
 * Retrieve latest version for a given keyword
 *
 * @param  string  keyword WikiPage name
 * @return array
 */
function getLatestVersion($keyword, $range_id) {
    $query = "SELECT *
              FROM wiki
              WHERE keyword = ? AND range_id = ?
              ORDER BY version DESC
              LIMIT 1";
    $statement = DBManager::get()->prepare($query);
    $statement->execute([$keyword, $range_id]);
    return $statement->fetch(PDO::FETCH_ASSOC);
}

/**
 * Retrieve oldest version for a given keyword
 *
 * @param    string  WikiPage name
 * @return array
 */
function getFirstVersion($keyword, $range_id) {
    $query = "SELECT *
              FROM wiki
              WHERE keyword = ? AND range_id = ?
              ORDER BY version ASC
              LIMIT 1";
    $statement = DBManager::get()->prepare($query);
    $statement->execute([$keyword, $range_id]);
    return $statement->fetch(PDO::FETCH_ASSOC);
}

/**
 * Return array containing version numbes and chdates
 *
 * @param string $keyword  Wiki keyword for currently selected seminar
 * @param int    $limit    Number of links to be retrieved (default:10)
 * @param bool   $getfirst Should first (=most recent) version be retrieved too?
 * @return array
 */
function getWikiPageVersions($keyword, $limit = 10, $getfirst = false)
{
    $query = "SELECT version, chdate
              FROM wiki
              WHERE keyword = ? AND range_id = ?
              ORDER BY version DESC
              LIMIT " . (int) $limit;
    $statement = DBManager::get()->prepare($query);
    $statement->execute([$keyword, Context::getId()]);
    $versions = $statement->fetchAll(PDO::FETCH_ASSOC);

    if (!$getfirst) {
        // skip first
        $versions = array_slice($versions, 1);
    }

    return $versions;
}


/**
 * Check if given keyword exists in current WikiWikiWeb.
 *
 * @param    string  WikiPage keyword
 */
function keywordExists($str, $sem_id = null) {
    static $keywords;

    if (is_null($keywords)) {
        $query = "SELECT DISTINCT keyword, 1 FROM wiki WHERE range_id = ?";
        $statement = DBManager::get()->prepare($query);
        $statement->execute([$sem_id ?: Context::getId()]);
        $keywords = $statement->fetchGrouped(PDO::FETCH_COLUMN);
    }
    // retranscode html entities to ascii values (as stored in db)
    // (nessecary for umlauts)
    // BUG: other special chars like accented vowels don't work yet!
    //
    $trans_tbl = array_flip(get_html_translation_table(HTML_ENTITIES));
    $nonhtmlstr = strtr($str, $trans_tbl);

    return $keywords[$nonhtmlstr] ?? false;
}


/**
 * Check if keyword already exists or links to new page.
 * Returns HTML-Link-Representation.
 *
 * @param    string  WikiPage keyword
 * @param    string  current Page (for edit abort backlink)
 * @param    string  out format: "wiki"=link to wiki.php, "inline"=link on same page
 */
function isKeyword($str, $page, $format = 'wiki', $sem_id = null, $alt_str = null) {
    if (!$alt_str) {
        $alt_str = $str;
    }
    $trans_tbl = array_flip(get_html_translation_table(HTML_ENTITIES));
    $nonhtmlstr = strtr($str, $trans_tbl);
    if (!keywordExists($str, $sem_id)) {
        if ($format === 'wiki') {
            return " <a href=\"".URLHelper::getLink("?keyword=" . urlencode($nonhtmlstr) . "&view=editnew&lastpage=".urlencode($page))."\">" . $alt_str . "(?)</a>";
        } else if ($format === 'inline') {
            return $str;
        }
    } else {
        if ($format == 'wiki') {
            return " <a href=\"".URLHelper::getLink("?keyword=".urlencode($nonhtmlstr))."\">".$alt_str."</a>";
        } else if ($format == 'inline') {
            return " <a href=\"#".urlencode($nonhtmlstr)."\">".$alt_str."</a>";
        }
    }
}


/**
 * Get lock information about page
 * Returns displayable string containing lock information
 * (Template: Username1 (seit x Minuten), Username2 (seit y Minuten), ...)
 * or NULL if no locks set.
 *
 * @param    string  WikiPage keyword
 * @param    string  user_id  Internal user id
 */
function getLock($keyword, $user_id)
{
    $query = "SELECT user_id, chdate
              FROM wiki_locks
              WHERE range_id = ? AND keyword = ? AND user_id != ?
              ORDER BY chdate DESC";
    $statement = DBManager::get()->prepare($query);
    $statement->execute([Context::getId(), $keyword, $user_id]);
    $locks = $statement->fetchAll(PDO::FETCH_ASSOC);

    $lockstring = '';
    foreach ($locks as $index => $lock) {
        if ($index) {
            if ($index == count($locks) - 1) {
                $lockstring .= _(' und ');
            } else {
                $lockstring .= ', ';
            }
        }
        $duration = ceil((time() - $lock['chdate']) / 60);

        $lockstring .= get_fullname($lock['user_id'], 'full', true);
        $lockstring .= sprintf(_(' (seit %d Minuten)'), $duration);
    }

    return $lockstring;
}

/**
 * Set lock for current user and current page
 *
 * @param    DB_Seminar  db  DB_Seminar instance (no longer neccessary)
 * @param    string      user_id Internal user id
 * @param    string      range_if    Internal seminar id
 * @param    string      keyword WikiPage name
 */
function setWikiLock($db, $user_id, $range_id, $keyword) {
    $query = "REPLACE INTO wiki_locks (user_id, range_id, keyword, chdate)
              VALUES (?, ?, ?, UNIX_TIMESTAMP())";
    $statement = DBManager::get()->prepare($query);
    $statement->execute([$user_id, $range_id, $keyword]);
}


/**
 * Release all locks for wiki page that are older than 30 minutes.
 *
 * @param    string  WikiPage keyword
 */
function releaseLocks($keyword)
{
    // Prepare statement that actually releases (removes) the lock
    $query = "DELETE FROM wiki_locks WHERE range_id = ? AND keyword = ? AND chdate = ?";
    $release_statement = DBManager::get()->prepare($query);

    // Prepare and execute statement that reads all locks
    $query = "SELECT range_id, keyword, chdate
              FROM wiki_locks
              WHERE range_id = ? AND keyword = ? AND chdate < UNIX_TIMESTAMP(NOW() - INTERVAL 30 MINUTE)";
    $statement = DBManager::get()->prepare($query);
    $statement->execute([Context::getId(), $keyword]);

    while ($row = $statement->fetch(PDO::FETCH_ASSOC)) {
        $release_statement->execute([
            $row['range_id'],
            $row['keyword'],
            $row['chdate'],
        ]);
    }
}

/**
 * Release locks for current wiki page and current user
 *
 * @param    string  keyword WikiPage name
 * @param    string  user_id Internal user id
 *
 */
function releasePageLocks($keyword, $user_id)
{
    $query = "DELETE FROM wiki_locks
              WHERE range_id = ? AND keyword = ? AND user_id = ?";
    $statement = DBManager::get()->prepare($query);
    $statement->execute([Context::getId(), $keyword, $user_id]);
}


/**
* Return list of WikiWord in given page body ($str)
*
* @param    string  str
*
**/
function getWikiLinks($str) {
    $str = preg_replace('/\[nop\].*\[\/nop\]/', '', $str);
    $str = preg_replace('/\[code\].*\[\/code\]/', '', $str);
    preg_match_all(
        '/' . WikiFormat::getWikiMarkup('wiki-links')['start'] . '/',
        $str,
        $out_wikiwords,
        PREG_PATTERN_ORDER
    );
    return array_unique($out_wikiwords[1]);
}

/**
* Return list of WikiPages containing links to given page
*
* @param    string  Wiki keyword
*
**/
function getBacklinks($keyword)
{
    // don't show references from Table of contents (='toc')
    $query = "SELECT DISTINCT from_keyword
              FROM wiki_links
              WHERE range_id = ? AND to_keyword = ? AND from_keyword != 'toc'";
    $statement = DBManager::get()->prepare($query);
    $statement->execute([Context::getId(), $keyword]);
    return $statement->fetchAll(PDO::FETCH_COLUMN);
}

/**
* Refresh wiki_links table for backlinks from given page to
* other pages
*
* @param    string  keyword WikiPage-name for $str content
* @param    string  str Page content containing links
*
**/
function refreshBacklinks($keyword, $str)
{
    // insert links from page to db
    // logic: all links are added, also links to nonexistant pages
    // (these will change when submitting other pages)

    // first delete all links
    $query = "DELETE FROM wiki_links WHERE range_id = ? AND from_keyword = ?";
    $statement = DBManager::get()->prepare($query);
    $statement->execute([Context::getId(), $keyword]);

    // then reinsert those (still) existing
    $wikiLinkList = getWikiLinks($str);
    if (!empty($wikiLinkList)) {
        $query = "INSERT INTO wiki_links (range_id, from_keyword, to_keyword)
                  VALUES (?, ?, ?)";
        $statement = DBManager::get()->prepare($query);

        foreach ($wikiLinkList as $key => $value) {
            $statement->execute([Context::getId(), $keyword, $value]);
        }
    }
}

/**
 * When a page gets deleted, set the ancestor to NULL for
 * every descendant page.
 *
 * @param   string  keyword WikiPage name that was deleted.
 *
 */
function deleteAncestorRelation($keyword) {
    $query = "UPDATE wiki SET ancestor = null WHERE ancestor = ?";
    $statement = DBManager::get()->prepare($query);
    $statement->execute([$keyword]);
}

/**
* Generate Meta-Information on Wiki-Page to display in top line
*
* @param    db-query result     all information about a wikiPage
* @return   string  Displayable HTML
*
**/
function getZusatz($wikiData)
{
    if (!$wikiData || $wikiData["version"] <= 0) {
        return "";
    }

    $user = User::find($wikiData['user_id']);

    $s =  '<a href="' . URLHelper::getLink('?keyword=' . urlencode($wikiData['keyword'])
            . '&version='
            . $wikiData['version']). '">'
            . _('Version ')
            . $wikiData['version'] . '</a>';
    $s .= sprintf(_(', geändert von %s am %s'),
                  $user
                      ? '<a href="' . URLHelper::getLink('dispatch.php/profile?username=' . $user->username) .'">' . htmlReady($user->getFullName()) . '</a>'
                      : _('unbekannt'),
                  date('d.m.Y, H:i', $wikiData['chdate']));

    return $s;
}

function getWikiIndex($descendants, $i = 0)
{
    $i++;
    $hidden = '';
    $items = '<ul class="wiki-index">';
    if($i >= 4) {
        $hidden = ' class="hidden"';
        $items .= '<li><a href="#" class="wiki-index-more">[…]</a></li>';
    }
    foreach ($descendants as $descendant) {
        $children = $descendant->children;
        $items .= '<li'. $hidden .'><a href="' . URLHelper::getLink('wiki.php', ['keyword' => $descendant->keyword]) . '">'.htmlReady($descendant->keyword) .'</a>';
        if($children) {
            $items .= getWikiIndex($children, $i);
        }
   }
   $items .= '</ul>';
    return $items;
}

/**
* Display yes/no dialog to confirm WikiPage version deletion.
*
* @param    string  WikiPage name
* @param    string  WikiPage version (if empty: take latest)
*
* @return   string  Version number to delete
*
**/
function showDeleteDialog($keyword, $version) {
    $islatest=0; // will another version become latest version?
    $willvanish=0; // will the page be deleted entirely?
    $lv=getLatestVersion($keyword, Context::getId());
    if ($version=="latest" || $version==$lv["version"]) {
        $lv=getLatestVersion($keyword, Context::getId());
        $fv=getFirstVersion($keyword, Context::getId());
        $version=$lv["version"];
        if ($version==$fv["version"]) {
            $willvanish=1;
        }
        $islatest=1;
    }

    $msg= sprintf(_("Wollen Sie die untenstehende Version %s der Seite %s wirklich löschen?"), $version, $keyword) . "\n";
    if (!$willvanish) {
        if ($islatest) {
            $msg .= _("Diese Version ist derzeit aktuell. Nach dem Löschen wird die nächstältere Version aktuell.");
        }
    } else {
        $msg .= _("Diese Version ist die derzeit einzige. Nach dem Löschen ist die Seite komplett gelöscht.");
    }
    return $msg;
}


function showDeleteAllDialog($keyword) {
    $msg= sprintf(_("Wollen Sie die Seite %s wirklich vollständig - mit allen Versionen - löschen?"), $keyword) . "\n";
    if ($keyword === "WikiWikiWeb") {
        $msg .= _("Sie sind im Begriff die Startseite zu löschen, die dann durch einen leeren Text ersetzt wird. Damit wären auch alle anderen Seiten nicht mehr direkt erreichbar und auch das Inhaltsverzeichnis wäre leer.");
    } else {
        $numbacklinks = count(getBacklinks($keyword));
        if ($numbacklinks == 0) {
            $msg .= _("Auf diese Seite verweist keine andere Seite.");
        } else if ($numbacklinks == 1) {
            $msg .= _("Auf diese Seite verweist 1 andere Seite.");
        } else {
            $msg .= sprintf(_("Auf diese Seite verweisen %s andere Seiten."), count(getBacklinks($keyword)));
        }
    }
    return $msg;
}



/**
* Delete WikiPage version and adjust backlinks.
*
* @param    string  WikiPage name
* @param    string  WikiPage version
* @param    string  ID of seminar/einrichtung
*
* @return   string  WikiPage name to display next
*
**/
function deleteWikiPage($keyword, $version, $range_id) {
    global $perm, $dellatest;
    if (!$perm->have_studip_perm("tutor", Context::getId())) {
        throw new AccessDeniedException(_('Sie haben keine Berechtigung, Seiten zu löschen.'));
    }
    $lv=getLatestVersion($keyword, Context::getId());
    if ($lv["version"] != $version) {
        throw new InvalidArgumentException(_('Die Version, die Sie löschen wollen, ist nicht die aktuellste. Überprüfen Sie, ob inzwischen eine aktuellere Version erstellt wurde.'));
    }

    $wp = WikiPage::find([$range_id, $keyword, $version]);
    if ($wp) {
        $wp->delete();
    }

    if (!keywordExists($keyword)) { // all versions have gone
        $addmsg = '<br>' . sprintf(_("Damit ist die Seite %s mit allen Versionen gelöscht."),'<b>'.htmlReady($keyword).'</b>');
        $newkeyword = "WikiWikiWeb";
        deleteAncestorRelation($keyword);
    } else {
        $newkeyword = $keyword;
        $addmsg = "";
    }
    $message = MessageBox::info(sprintf(_('Version %s der Seite %s gelöscht.'), htmlReady($version), '<b>'.htmlReady($keyword).'</b>') . $addmsg);
    PageLayout::postMessage($message);
    if ($dellatest) {
        $lv=getLatestVersion($keyword, Context::getId());
        if ($lv) {
            $body="";
        } else {
            $body=$lv["body"];
        }
        refreshBacklinks($keyword, $body);
    }
    return $newkeyword;
}

/**
* Delete complete WikiPage with all versions and adjust backlinks.
*
* @param    string  WikiPage name
* @param    string  ID of seminar/einrichtung
*
**/
function deleteAllWikiPage($keyword, $range_id) {
    global $perm;
    if (!$perm->have_studip_perm("tutor", Context::getId())) {
        throw new AccessDeniedException(_('Sie haben keine Berechtigung, Seiten zu löschen.'));
    }

    WikiPage::deleteBySQL("keyword = ? AND range_id = ?", [$keyword, $range_id]);
    $message = MessageBox::info(sprintf(_('Die Seite %s wurde mit allen Versionen gelöscht.'), '<b>'.htmlReady($keyword).'</b>'));
    PageLayout::postMessage($message);
    refreshBacklinks($keyword, "");
    deleteAncestorRelation($keyword);
    return "WikiWikiWeb";
}



/**
* List all topics in this seminar's wiki
*
* @param  mode  string  Either "all" or "new", affects default sorting and page title.
* @param  sortby  string  Different sortings of entries.
**/
function listPages($mode, $sortby = NULL)
{
    $lastlogindate = null;
    if ($mode === 'all') {
        $selfurl = '?view=listall';
        $sort = "ORDER by MAX(chdate) DESC"; // default sort order for "all pages"
        $nopages = _('In dieser Veranstaltung wurden noch keine WikiSeiten angelegt.');

        // help texts
        $help = _('Zeigt eine tabellarische Übersicht aller Wiki-Seiten an.');
        Helpbar::get()->ignoreDatabaseContents();
        Helpbar::get()->addPlainText('', $help);
    } else if ($mode === 'new') {
        $core_wiki = PluginManager::getInstance()->getPlugin('CoreWiki');
        $lastlogindate = object_get_visit(Context::getId(), $core_wiki->getPluginId());

        $selfurl = '?view=listnew';
        $sort = "ORDER by MAX(chdate)"; // default sort order for "new pages"
        $nopages = _('Seit Ihrem letzten Login gab es keine Änderungen.');

        // help texts
        $help = _('Zeigt eine tabellarische Übersicht neu erstellter bzw. bearbeiteter Wiki-Seiten an.');
        Helpbar::get()->ignoreDatabaseContents();
        Helpbar::get()->addPlainText('', $help);
    } else {
        throw new InvalidArgumentException(_('Fehler! Falscher Anzeigemodus:') . $mode);
    }

    $titlesortlink   = 'title';
    $versionsortlink = 'version';
    $changesortlink  = 'lastchange';

    switch ($sortby) {
        case 'title':
            // sort by keyword, prepare link for descending sorting
            $sort = "ORDER BY keyword";
            $titlesortlink = 'titledesc';
            break;
        case 'titledesc':
            // sort descending by keyword, prep link for asc. sort
            $sort = "ORDER BY keyword DESC";
            break;
        case 'version':
            $sort = "ORDER BY MAX(version) DESC, keyword ASC";
            $versionsortlink = 'versiondesc';
            break;
        case 'versiondesc':
            $sort = "ORDER BY MAX(version), keyword ASC";
            break;
        case 'lastchange':
            // sort by change date, default: newest first
            $sort = "ORDER BY MAX(chdate) DESC, keyword ASC";
            $changesortlink = 'lastchangedesc';
            break;
        case 'lastchangedesc':
            // sort by change date, oldest first
            $sort = "ORDER BY MAX(chdate), keyword ASC";
            break;
    }

    if ($mode === 'all') {
        $query = "SELECT keyword
                  FROM wiki
                  WHERE range_id = ?
                  GROUP BY keyword
                  {$sort}";
        $parameters = [Context::getId()];
    } else if ($mode === 'new') {
        $query = "SELECT keyword
                  FROM wiki
                  WHERE range_id = ? AND chdate > ?
                  GROUP BY keyword
                  {$sort}";
        $parameters = [Context::getId(), $lastlogindate];
    }

    $pages = DBManager::get()->fetchFirst($query, $parameters, function ($keyword) {
        return WikiPage::findLatestPage(Context::getId(), $keyword);
    });

    if (count($pages) === 0) {
        PageLayout::postInfo($nopages);
    } else {
        $template = $GLOBALS['template_factory']->open('wiki/list.php');
        $template->mode            = $mode;
        $template->url             = $selfurl;
        $template->titlesortlink   = $titlesortlink;
        $template->versionsortlink = $versionsortlink;
        $template->changesortlink  = $changesortlink;
        $template->pages           = $pages;
        $template->lastlogindate   = $lastlogindate;
        echo $template->render();
    }

    if ($mode === 'all'){
        $help_url = format_help_url('Basis.VerschiedenesFormat');

        $widget = Sidebar::get()->addWidget(new ExportWidget());
        $widget->addLink(
            _('PDF-Ausgabe aller Wiki-Seiten'),
            URLHelper::getURL('?view=exportall_pdf', ['sortby' => $sortby]),
            Icon::create('file-pdf'),
            ['target' => '_blank']
        );
        $widget->addLink(
            _('Druckansicht aller Wiki-Seiten'),
            URLHelper::getURL('?view=wikiprintall'),
            Icon::create('print'),
            ['target' => '_blank']
        );
    }

    showPageFrameEnd([]);
}

/**
* List all versions of a wiki page
*
* @param  string  WikiPage name
* @param  sortby  string  Different sortings of entries.
**/
function listPageVersions($keyword, $sortby = NULL)
{
    $selfurl = '?view=pageversions';
    $sort = "ORDER by version DESC"; // default sort order for versions"
    $nopages = _('In dieser Veranstaltung wurden noch keine WikiSeiten angelegt.');

    // help texts
    $help = _('Zeigt eine tabellarische Übersicht aller Versionen dieser Wiki-Seite an.');
    Helpbar::get()->ignoreDatabaseContents();
    Helpbar::get()->addPlainText('', $help);

    $versionsortlink = 'version';
    $changesortlink  = 'lastchange';

    switch ($sortby) {
        case 'version':
            $sort = "ORDER BY version DESC";
            $versionsortlink = 'versiondesc';
            break;
        case 'versiondesc':
            $sort = "ORDER BY version";
            break;
        case 'lastchange':
            // sort by change date, default: newest first
            $sort = "ORDER BY chdate DESC, keyword ASC";
            $changesortlink = 'lastchangedesc';
            break;
        case 'lastchangedesc':
            // sort by change date, oldest first
            $sort = "ORDER BY chdate, keyword ASC";
            break;
    }

    $pages = WikiPage::findBySQL("range_id = ? AND keyword = ? ".$sort, [Context::getId(), $keyword]);

    if (count($pages) === 0) {
        #PageLayout::postInfo($nopages);
    } else {
        $template = $GLOBALS['template_factory']->open('wiki/pageversions.php');
        $template->keyword         = $keyword;
        $template->url             = $selfurl;
        $template->titlesortlink   = $titlesortlink;
        $template->versionsortlink = $versionsortlink;
        $template->changesortlink  = $changesortlink;
        $template->pages           = $pages;
        $template->sortby          = $sortby;
        echo $template->render();
    }

    $wikiData = getWikiPage($keyword, $version);

    getShowPageInfobox($keyword, $wikiData->isLatestVersion(),TRUE);

    showPageFrameEnd([]);
}


/**
* Search Wiki
*
* @param  searchfor  string  String to search for.
* @param  searchcurrentversions  bool  it true, only consider most recent versions or pages
* @param  keyword  string  last shown page or keyword for local (one page) search
* @param keyword bool if localsearch is set, only one page (all versions) is searched
**/
function searchWiki($searchfor, $searchcurrentversions, $keyword, $localsearch)
{
    $range_id = Context::getId();
    $result   = null;
    $invalid_searchstring = false;

    // check for invalid search string
    if (mb_strlen($searchfor) < 3) {
        $invalid_searchstring = true;
    } else if ($localsearch && !$keyword) {
        $invalid_searchstring = true;
    } else {
        // make search string
        if ($localsearch) {
            $query = "SELECT *
                      FROM wiki
                      WHERE range_id = ? AND body LIKE CONCAT('%', ?, '%') AND keyword = ?
                      ORDER BY version DESC";
            $parameters = [$range_id, htmlReady($searchfor), $keyword];
        } else if (!$searchcurrentversions) {
            // search in all versions of all pages
            $query = "SELECT *
                      FROM wiki
                      WHERE range_id = ? AND body LIKE CONCAT('%', ?, '%')
                      ORDER BY keyword ASC, version DESC";
            $parameters = [$range_id, htmlReady($searchfor)];
        } else {
            // search only latest versions of all pages
            $query = "SELECT *
                      FROM wiki AS w1
                      WHERE range_id = ? AND w1.body LIKE CONCAT('%', ?, '%') AND version = (
                          SELECT MAX(version)
                          FROM wiki AS w2
                          WHERE w2.range_id = ? AND w2.keyword = w1.keyword
                      )
                      ORDER BY w1.keyword ASC";
             $parameters = [$range_id, htmlReady($searchfor), $range_id];
        }
        $pages = DBManager::get()->fetchAll($query, $parameters, function ($row) {
            return WikiPage::buildExisting($row);
        });

        $pages = array_filter($pages, function ($page) {
            return $page->isVisibleTo($GLOBALS['user']);
        });
    }

    // quit if no pages found / search string was invalid
    if ($invalid_searchstring || count($pages) == 0) {
        if ($invalid_searchstring) {
            $message = MessageBox::error(_('Suchbegriff zu kurz. Geben Sie mindestens drei Zeichen ein.'));
        } else {
            $message = MessageBox::info(sprintf(_("Die Suche nach &raquo;%s&laquo; lieferte keine Treffer."), htmlReady($searchfor)));
        }
        PageLayout::postMessage($message);
        showWikiPage($keyword, NULL);
        return;
    }

    showPageFrameStart();

    // show hits
?>
<table class="default">
    <caption>
        <?= sprintf(_('Treffer für Suche nach %s'), '&raquo;' . htmlReady($searchfor) . '&laquo;') ?>
    <? if ($localsearch): ?>
        <?= sprintf(_('in allen Versionen der Seite %s'), '&raquo;' . htmlReady($keyword) . '&laquo;') ?>
    <? elseif ($searchcurrentversions): ?>
        <?= _('in aktuellen Versionen') ?>
    <? else: ?>
        <?= _('in allen Versionen') ?>
    <? endif; ?>
    </caption>
    <colgroup>
        <col width="10%">
        <col width="65%">
        <col width="25%">
    </colgroup>
    <thead>
        <tr>
            <th><?= _('Seite') ?></th>
            <th><?= _('Treffer') ?></th>
            <th><?= _('Version') ?></th>
        </tr>
    </thead>
    <tbody>
<?php
    $c=1;
    $last_keyword="";
    $last_keyword_count=0;
    foreach ($pages as $result) {
        if (!$localsearch) {
            // don't display more than one hit in a page's versions
            // offer link instead
            if ($result['keyword']==$last_keyword) {
                $last_keyword_count++;
                continue;
            } else if ($last_keyword_count>0) {
                print($tdheadleft."&nbsp;".$tdtail);
                if ($last_keyword_count==1) {
                    $hitstring=_("Weitere Treffer in %s älteren Version. Klicken Sie %shier%s, um diese Treffer anzuzeigen.");
                } else {
                    $hitstring=_("Weitere Treffer in %s älteren Versionen. Klicken Sie %shier%s, um diese Treffer anzuzeigen.");
                }
                print($tdheadleft."<em>".sprintf($hitstring,$last_keyword_count,"<b><a href=\"".URLHelper::getLink("?view=search&searchfor=$searchfor&keyword=".urlencode($last_keyword)."&localsearch=1")."\">","</a></b>")."</em>".$tdtail);
                print($tdheadleft."&nbsp;".$tdtail);
                print("</tr>");
            }
            $last_keyword=$result['keyword'];
            $last_keyword_count=0;
        }

        $tdheadleft="<td>";
        $tdheadcenter="<td>";
        $tdtail="</td>";

        print("<tr>");
        // Pagename
        print($tdheadleft);
        print("<a href=\"".URLHelper::getLink('?', ['keyword' => $result['keyword'], 'version' => $result['version'], 'hilight' => $searchfor, 'searchfor' => $searchfor])."\">");
        print(htmlReady($result['keyword'])."</a>");
        print($tdtail);
        // display hit previews
        $offset=0; // step through text
        $ignore_next_hits=0; // don't show hits more than once
        $first_line=1; // don't print <br> before first hit
        print($tdheadleft);
        // find all occurences
        while ($offset < mb_strlen($result['body'])) {
            $pos=mb_stripos($result['body'], $searchfor,$offset);
            if ($pos===FALSE) break;
            $offset=$pos+1;
            if (($ignore_next_hits--)>0) {
                // if more than one occurence is found
                // in a fragment to be displayed,
                // the fragment is only shown once
                continue;
            }
            // show max 80 chars
            $fragment = '';
            $split_fragment = preg_split('/('.preg_quote($searchfor,'/').')/i', mb_substr($result['body'],max(0, $pos-40), 80), -1, PREG_SPLIT_DELIM_CAPTURE);
            for ($i = 0; $i < count($split_fragment); ++$i) {
                if ($i % 2) {
                    $fragment .= '<span style="background-color:#FFFF88">';
                    $fragment .= htmlready($split_fragment[$i], false);
                    $fragment .= '</span>';
                } else {
                    $fragment .= htmlready($split_fragment[$i], false);
                }
            }
            $found_in_fragment = (count($split_fragment) - 1) / 2; // number of hits in fragment
            $ignore_next_hits = ($found_in_fragment > 1) ? $found_in_fragment - 1 : 0;
            print("...".$fragment."...");
            print "<br>";
        }
        print($tdtail);
        // version info
        print($tdheadleft);
        print(date("d.m.Y, H:i", $result['chdate'])." ("._("Version")." ".$result['version'].")");
        print($tdtail);
        print "</tr>";

    }

    if (!$localsearch && $last_keyword_count>0) {
        print("<tr>");
        print($tdheadleft."&nbsp;".$tdtail);
        if ($last_keyword_count==1) {
            $hitstring=_("Weitere Treffer in %s älteren Version. Klicken Sie %shier%s, um diese Treffer anzuzeigen.");
        } else {
            $hitstring=_("Weitere Treffer in %s älteren Versionen. Klicken Sie %shier%s, um diese Treffer anzuzeigen.");
        }
        print($tdheadleft."<em>".sprintf($hitstring,$last_keyword_count,"<b><a href=\"".URLHelper::getLink("?view=search&searchfor=$searchfor&keyword=".urlencode($last_keyword)."&localsearch=1")."\">","</a></b>")."</em>".$tdtail);
        print($tdheadleft."&nbsp;".$tdtail);
        print("</tr>");
    }

    echo "</tbody></table><p>&nbsp;</p>";

    // search
    $widget = new SearchWidget(URLHelper::getURL('?view=search&keyword=' . urlencode($keyword)));
    $widget->addNeedle(_('Im Wiki suchen'), 'searchfor', true);
    //$widget->addFilter(_('Nur in aktuellen Versionen'), 'searchcurrentversions');
    Sidebar::get()->addWidget($widget);

    showPageFrameEnd([]);
}

/**
* Display edit form for wiki page.
*
* @param    string  keyword WikiPage name
* @param    array   wikiData    Array from DB with WikiPage data
* @param    string  user_id     Internal user id
* @param    string  backpage    Page to display if editing is aborted
*
**/
function wikiEdit($keyword, $wikiData, $user_id, $backpage=NULL, $ancestor=NULL)
{
    $parent = null;
    if (!$wikiData || $wikiData->isNew()) {
        $body     = '';
        $version  = 0;
        $lastpage = $backpage;
        $parent   = $ancestor;
    } else {
        $body     = $wikiData->body;
        $version  = $wikiData->version;
        $lastpage = null;
    }
    releaseLocks($keyword); // kill old locks
    $locks=getLock($keyword, $user_id);
    $cont='';
    if ($locks) {
        $message = MessageBox::info(sprintf(_("Die Seite wird eventuell von %s bearbeitet."), htmlReady($locks)), [_("Wenn Sie die Seite trotzdem ändern, kann ein Versionskonflikt entstehen."), _("Es werden dann beide Versionen eingetragen und müssen von Hand zusammengeführt werden."),  _("Klicken Sie auf Abbrechen, um zurückzukehren.")]);
        PageLayout::postMessage($message);
    }
    if ($keyword === 'toc') {
        $message = MessageBox::info(_("Sie bearbeiten die QuickLinks."), [_("Verwenden Sie Aufzählungszeichen (-, --, ---), um Verweise auf Seiten hinzuzufügen.")]);
        PageLayout::postMessage($message);
        if (!$body) {
            $body=_("- WikiWikiWeb\n- BeispielSeite\n-- UnterSeite1\n-- UnterSeite2");
        }
    }

    $page = WikiPage::findLatestPage(Context::getId(), Request::get('keyword', 'WikiWikiWeb'));
    // Info text for content bar (author, date etc.)
    $page_string = '';
    if ($page) {
        $user = User::find($page->user_id);
        if ($user) {
            $editor = sprintf('<a href="%s">%s</a>',
                URLHelper::getLink('dispatch.php/profile?username=' . $user->username),
                htmlReady($user->getFullName()));
        } else {
            $editor = _('unbekannt');
        }
        $page_string = sprintf(_('<a %s> Version %s</a>, geändert von %s'),
            ' href="' . URLHelper::getLink('', ['keyword' => $page->keyword, 'version' => $page->version]) . '"',
            $page->version, $editor);
        $page_string .= '<br>';
        $page_string .= strftime(_('am %x, %X'), $page->chdate);
        if ($page->keyword === 'WikiWikiWeb' || $page->isDescendantOf('WikiWikiWeb')) {