Fixed spacing in db/debug/diff/externalstore/objectcache folder

[mediawiki.git] / includes / specials / SpecialRecentchanges.php

<?php
/**
 * Implements Special:Recentchanges
 *
 * 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
 * (at your option) 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup SpecialPage
 */

/**
 * A special page that lists last changes made to the wiki
 *
 * @ingroup SpecialPage
 */
class SpecialRecentChanges extends IncludableSpecialPage {
        var $rcOptions, $rcSubpage;
        protected $customFilters;

        public function __construct( $name = 'Recentchanges' ) {
                parent::__construct( $name );
        }

        /**
         * Get a FormOptions object containing the default options
         *
         * @return FormOptions
         */
        public function getDefaultOptions() {
                $opts = new FormOptions();

                $opts->add( 'days', $this->getUser()->getIntOption( 'rcdays' ) );
                $opts->add( 'limit', $this->getUser()->getIntOption( 'rclimit' ) );
                $opts->add( 'from', '' );

                $opts->add( 'hideminor', $this->getUser()->getBoolOption( 'hideminor' ) );
                $opts->add( 'hidebots', true  );
                $opts->add( 'hideanons', false );
                $opts->add( 'hideliu', false );
                $opts->add( 'hidepatrolled', $this->getUser()->getBoolOption( 'hidepatrolled' ) );
                $opts->add( 'hidemyself', false );

                $opts->add( 'namespace', '', FormOptions::INTNULL );
                $opts->add( 'invert', false );
                $opts->add( 'associated', false );

                $opts->add( 'categories', '' );
                $opts->add( 'categories_any', false );
                $opts->add( 'tagfilter', '' );
                return $opts;
        }

        /**
         * Create a FormOptions object with options as specified by the user
         *
         * @param array $parameters
         *
         * @return FormOptions
         */
        public function setup( $parameters ) {
                $opts = $this->getDefaultOptions();

                foreach ( $this->getCustomFilters() as $key => $params ) {
                        $opts->add( $key, $params['default'] );
                }

                $opts->fetchValuesFromRequest( $this->getRequest() );

                // Give precedence to subpage syntax
                if ( $parameters !== null ) {
                        $this->parseParameters( $parameters, $opts );
                }

                $opts->validateIntBounds( 'limit', 0, 5000 );
                return $opts;
        }

        /**
         * Get custom show/hide filters
         *
         * @return array Map of filter URL param names to properties (msg/default)
         */
        protected function getCustomFilters() {
                if ( $this->customFilters === null ) {
                        $this->customFilters = array();
                        wfRunHooks( 'SpecialRecentChangesFilters', array( $this, &$this->customFilters ) );
                }
                return $this->customFilters;
        }

        /**
         * Create a FormOptions object specific for feed requests and return it
         *
         * @return FormOptions
         */
        public function feedSetup() {
                global $wgFeedLimit;
                $opts = $this->getDefaultOptions();
                $opts->fetchValuesFromRequest( $this->getRequest() );
                $opts->validateIntBounds( 'limit', 0, $wgFeedLimit );
                return $opts;
        }

        /**
         * Get the current FormOptions for this request
         */
        public function getOptions() {
                if ( $this->rcOptions === null ) {
                        if ( $this->including() ) {
                                $isFeed = false;
                        } else {
                                $isFeed = (bool)$this->getRequest()->getVal( 'feed' );
                        }
                        $this->rcOptions = $isFeed ? $this->feedSetup() : $this->setup( $this->rcSubpage );
                }
                return $this->rcOptions;
        }

        /**
         * Main execution point
         *
         * @param string $subpage
         */
        public function execute( $subpage ) {
                $this->rcSubpage = $subpage;
                $feedFormat = $this->including() ? null : $this->getRequest()->getVal( 'feed' );

                # 10 seconds server-side caching max
                $this->getOutput()->setSquidMaxage( 10 );
                # Check if the client has a cached version
                $lastmod = $this->checkLastModified( $feedFormat );
                if ( $lastmod === false ) {
                        return;
                }

                $opts = $this->getOptions();
                $this->setHeaders();
                $this->outputHeader();
                $this->addRecentChangesJS();

                // Fetch results, prepare a batch link existence check query
                $conds = $this->buildMainQueryConds( $opts );
                $rows = $this->doMainQuery( $conds, $opts );
                if ( $rows === false ) {
                        if ( !$this->including() ) {
                                $this->doHeader( $opts );
                        }
                        return;
                }

                if ( !$feedFormat ) {
                        $batch = new LinkBatch;
                        foreach ( $rows as $row ) {
                                $batch->add( NS_USER, $row->rc_user_text );
                                $batch->add( NS_USER_TALK, $row->rc_user_text );
                                $batch->add( $row->rc_namespace, $row->rc_title );
                        }
                        $batch->execute();
                }
                if ( $feedFormat ) {
                        list( $changesFeed, $formatter ) = $this->getFeedObject( $feedFormat );
                        /** @var ChangesFeed $changesFeed */
                        $changesFeed->execute( $formatter, $rows, $lastmod, $opts );
                } else {
                        $this->webOutput( $rows, $opts );
                }

                $rows->free();
        }

        /**
         * Return an array with a ChangesFeed object and ChannelFeed object
         *
         * @param string $feedFormat Feed's format (either 'rss' or 'atom')
         * @return array
         */
        public function getFeedObject( $feedFormat ) {
                $changesFeed = new ChangesFeed( $feedFormat, 'rcfeed' );
                $formatter = $changesFeed->getFeedObject(
                        $this->msg( 'recentchanges' )->inContentLanguage()->text(),
                        $this->msg( 'recentchanges-feed-description' )->inContentLanguage()->text(),
                        $this->getTitle()->getFullURL()
                );
                return array( $changesFeed, $formatter );
        }

        /**
         * Process $par and put options found if $opts
         * Mainly used when including the page
         *
         * @param string $par
         * @param FormOptions $opts
         */
        public function parseParameters( $par, FormOptions $opts ) {
                $bits = preg_split( '/\s*,\s*/', trim( $par ) );
                foreach ( $bits as $bit ) {
                        if ( 'hidebots' === $bit ) {
                                $opts['hidebots'] = true;
                        }
                        if ( 'bots' === $bit ) {
                                $opts['hidebots'] = false;
                        }
                        if ( 'hideminor' === $bit ) {
                                $opts['hideminor'] = true;
                        }
                        if ( 'minor' === $bit ) {
                                $opts['hideminor'] = false;
                        }
                        if ( 'hideliu' === $bit ) {
                                $opts['hideliu'] = true;
                        }
                        if ( 'hidepatrolled' === $bit ) {
                                $opts['hidepatrolled'] = true;
                        }
                        if ( 'hideanons' === $bit ) {
                                $opts['hideanons'] = true;
                        }
                        if ( 'hidemyself' === $bit ) {
                                $opts['hidemyself'] = true;
                        }

                        if ( is_numeric( $bit ) ) {
                                $opts['limit'] = $bit;
                        }

                        $m = array();
                        if ( preg_match( '/^limit=(\d+)$/', $bit, $m ) ) {
                                $opts['limit'] = $m[1];
                        }
                        if ( preg_match( '/^days=(\d+)$/', $bit, $m ) ) {
                                $opts['days'] = $m[1];
                        }
                        if ( preg_match( '/^namespace=(\d+)$/', $bit, $m ) ) {
                                $opts['namespace'] = $m[1];
                        }
                }
        }

        /**
         * Get last modified date, for client caching
         * Don't use this if we are using the patrol feature, patrol changes don't
         * update the timestamp
         *
         * @param string $feedFormat
         * @return string|bool
         */
        public function checkLastModified( $feedFormat ) {
                $dbr = wfGetDB( DB_SLAVE );
                $lastmod = $dbr->selectField( 'recentchanges', 'MAX(rc_timestamp)', false, __METHOD__ );
                if ( $feedFormat || !$this->getUser()->useRCPatrol() ) {
                        if ( $lastmod && $this->getOutput()->checkLastModified( $lastmod ) ) {
                                # Client cache fresh and headers sent, nothing more to do.
                                return false;
                        }
                }
                return $lastmod;
        }

        /**
         * Return an array of conditions depending of options set in $opts
         *
         * @param FormOptions $opts
         * @return array
         */
        public function buildMainQueryConds( FormOptions $opts ) {
                $dbr = wfGetDB( DB_SLAVE );
                $conds = array();

                # It makes no sense to hide both anons and logged-in users
                # Where this occurs, force anons to be shown
                $forcebot = false;
                if ( $opts['hideanons'] && $opts['hideliu'] ) {
                        # Check if the user wants to show bots only
                        if ( $opts['hidebots'] ) {
                                $opts['hideanons'] = false;
                        } else {
                                $forcebot = true;
                                $opts['hidebots'] = false;
                        }
                }

                // Calculate cutoff
                $cutoff_unixtime = time() - ( $opts['days'] * 86400 );
                $cutoff_unixtime = $cutoff_unixtime - ($cutoff_unixtime % 86400);
                $cutoff = $dbr->timestamp( $cutoff_unixtime );

                $fromValid = preg_match( '/^[0-9]{14}$/', $opts['from'] );
                if ( $fromValid && $opts['from'] > wfTimestamp( TS_MW, $cutoff ) ) {
                        $cutoff = $dbr->timestamp( $opts['from'] );
                } else {
                        $opts->reset( 'from' );
                }

                $conds[] = 'rc_timestamp >= ' . $dbr->addQuotes( $cutoff );

                $hidePatrol = $this->getUser()->useRCPatrol() && $opts['hidepatrolled'];
                $hideLoggedInUsers = $opts['hideliu'] && !$forcebot;
                $hideAnonymousUsers = $opts['hideanons'] && !$forcebot;

                if ( $opts['hideminor'] ) {
                        $conds['rc_minor'] = 0;
                }
                if ( $opts['hidebots'] ) {
                        $conds['rc_bot'] = 0;
                }
                if ( $hidePatrol ) {
                        $conds['rc_patrolled'] = 0;
                }
                if ( $forcebot ) {
                        $conds['rc_bot'] = 1;
                }
                if ( $hideLoggedInUsers ) {
                        $conds[] = 'rc_user = 0';
                }
                if ( $hideAnonymousUsers ) {
                        $conds[] = 'rc_user != 0';
                }

                if ( $opts['hidemyself'] ) {
                        if ( $this->getUser()->getId() ) {
                                $conds[] = 'rc_user != ' . $dbr->addQuotes( $this->getUser()->getId() );
                        } else {
                                $conds[] = 'rc_user_text != ' . $dbr->addQuotes( $this->getUser()->getName() );
                        }
                }

                # Namespace filtering
                if ( $opts['namespace'] !== '' ) {
                        $selectedNS = $dbr->addQuotes( $opts['namespace'] );
                        $operator = $opts['invert'] ? '!='  : '=';
                        $boolean = $opts['invert'] ? 'AND' : 'OR';

                        # namespace association (bug 2429)
                        if ( !$opts['associated'] ) {
                                $condition = "rc_namespace $operator $selectedNS";
                        } else {
                                # Also add the associated namespace
                                $associatedNS = $dbr->addQuotes(
                                        MWNamespace::getAssociated( $opts['namespace'] )
                                );
                                $condition = "(rc_namespace $operator $selectedNS "
                                        . $boolean
                                        . " rc_namespace $operator $associatedNS)";
                        }

                        $conds[] = $condition;
                }
                return $conds;
        }

        /**
         * Process the query
         *
         * @param array $conds
         * @param FormOptions $opts
         * @return bool|ResultWrapper Result or false (for Recentchangeslinked only)
         */
        public function doMainQuery( $conds, $opts ) {
                $tables = array( 'recentchanges' );
                $join_conds = array();
                $query_options = array(
                        'USE INDEX' => array( 'recentchanges' => 'rc_timestamp' )
                );

                $uid = $this->getUser()->getId();
                $dbr = wfGetDB( DB_SLAVE );
                $limit = $opts['limit'];
                $namespace = $opts['namespace'];
                $invert = $opts['invert'];
                $associated = $opts['associated'];

                $fields = RecentChange::selectFields();
                // JOIN on watchlist for users
                if ( $uid ) {
                        $tables[] = 'watchlist';
                        $fields[] = 'wl_user';
                        $fields[] = 'wl_notificationtimestamp';
                        $join_conds['watchlist'] = array( 'LEFT JOIN', array(
                                'wl_user' => $uid,
                                'wl_title=rc_title',
                                'wl_namespace=rc_namespace'
                        ));
                }
                if ( $this->getUser()->isAllowed( 'rollback' ) ) {
                        $tables[] = 'page';
                        $fields[] = 'page_latest';
                        $join_conds['page'] = array( 'LEFT JOIN', 'rc_cur_id=page_id' );
                }
                // Tag stuff.
                ChangeTags::modifyDisplayQuery(
                        $tables,
                        $fields,
                        $conds,
                        $join_conds,
                        $query_options,
                        $opts['tagfilter']
                );

                if ( !wfRunHooks( 'SpecialRecentChangesQuery',
                        array( &$conds, &$tables, &$join_conds, $opts, &$query_options, &$fields ) ) )
                {
                        return false;
                }

                // Don't use the new_namespace_time timestamp index if:
                // (a) "All namespaces" selected
                // (b) We want pages in more than one namespace (inverted/associated)
                // (c) There is a tag to filter on (use tag index instead)
                // (d) UNION + sort/limit is not an option for the DBMS
                if ( $namespace === ''
                        || ( $invert || $associated )
                        || $opts['tagfilter'] != ''
                        || !$dbr->unionSupportsOrderAndLimit() )
                {
                        $res = $dbr->select( $tables, $fields, $conds, __METHOD__,
                                array( 'ORDER BY' => 'rc_timestamp DESC', 'LIMIT' => $limit ) +
                                $query_options,
                                $join_conds );
                // We have a new_namespace_time index! UNION over new=(0,1) and sort result set!
                } else {
                        // New pages
                        $sqlNew = $dbr->selectSQLText(
                                $tables,
                                $fields,
                                array( 'rc_new' => 1 ) + $conds,
                                __METHOD__,
                                array(
                                        'ORDER BY' => 'rc_timestamp DESC',
                                        'LIMIT' => $limit,
                                        'USE INDEX' => array( 'recentchanges' => 'new_name_timestamp' )
                                ),
                                $join_conds
                        );
                        // Old pages
                        $sqlOld = $dbr->selectSQLText(
                                $tables,
                                $fields,
                                array( 'rc_new' => 0 ) + $conds,
                                __METHOD__,
                                array(
                                        'ORDER BY' => 'rc_timestamp DESC',
                                        'LIMIT' => $limit,
                                        'USE INDEX' => array( 'recentchanges' => 'new_name_timestamp' )
                                ),
                                $join_conds
                        );
                        # Join the two fast queries, and sort the result set
                        $sql = $dbr->unionQueries( array( $sqlNew, $sqlOld ), false ) .
                                ' ORDER BY rc_timestamp DESC';
                        $sql = $dbr->limitResult( $sql, $limit, false );
                        $res = $dbr->query( $sql, __METHOD__ );
                }

                return $res;
        }

        /**
         * Send output to the OutputPage object, only called if not used feeds
         *
         * @param array $rows Database rows
         * @param FormOptions $opts
         */
        public function webOutput( $rows, $opts ) {
                global $wgRCShowWatchingUsers, $wgShowUpdatedMarker, $wgAllowCategorizedRecentChanges;

                $limit = $opts['limit'];

                if ( !$this->including() ) {
                        // Output options box
                        $this->doHeader( $opts );
                }

                // And now for the content
                $feedQuery = $this->getFeedQuery();
                if ( $feedQuery !== '' ) {
                        $this->getOutput()->setFeedAppendQuery( $feedQuery );
                } else {
                        $this->getOutput()->setFeedAppendQuery( false );
                }

                if ( $wgAllowCategorizedRecentChanges ) {
                        $this->filterByCategories( $rows, $opts );
                }

                $showWatcherCount = $wgRCShowWatchingUsers && $this->getUser()->getOption( 'shownumberswatching' );
                $watcherCache = array();

                $dbr = wfGetDB( DB_SLAVE );

                $counter = 1;
                $list = ChangesList::newFromContext( $this->getContext() );

                $s = $list->beginRecentChangesList();
                foreach ( $rows as $obj ) {
                        if ( $limit == 0 ) {
                                break;
                        }
                        $rc = RecentChange::newFromRow( $obj );
                        $rc->counter = $counter++;
                        # Check if the page has been updated since the last visit
                        if ( $wgShowUpdatedMarker && !empty( $obj->wl_notificationtimestamp ) ) {
                                $rc->notificationtimestamp = ( $obj->rc_timestamp >= $obj->wl_notificationtimestamp );
                        } else {
                                $rc->notificationtimestamp = false; // Default
                        }
                        # Check the number of users watching the page
                        $rc->numberofWatchingusers = 0; // Default
                        if ( $showWatcherCount && $obj->rc_namespace >= 0 ) {
                                if ( !isset( $watcherCache[$obj->rc_namespace][$obj->rc_title] ) ) {
                                        $watcherCache[$obj->rc_namespace][$obj->rc_title] =
                                                $dbr->selectField(
                                                        'watchlist',
                                                        'COUNT(*)',
                                                        array(
                                                                'wl_namespace' => $obj->rc_namespace,
                                                                'wl_title' => $obj->rc_title,
                                                        ),
                                                        __METHOD__ . '-watchers'
                                                );
                                }
                                $rc->numberofWatchingusers = $watcherCache[$obj->rc_namespace][$obj->rc_title];
                        }

                        $changeLine = $list->recentChangesLine( $rc, !empty( $obj->wl_user ), $counter );
                        if ( $changeLine !== false ) {
                                $s .= $changeLine;
                                --$limit;
                        }
                }
                $s .= $list->endRecentChangesList();
                $this->getOutput()->addHTML( $s );
        }

        /**
         * Get the query string to append to feed link URLs.
         *
         * @return string
         */
        public function getFeedQuery() {
                global $wgFeedLimit;

                $this->getOptions()->validateIntBounds( 'limit', 0, $wgFeedLimit );
                $options = $this->getOptions()->getChangedValues();

                // wfArrayToCgi() omits options set to null or false
                foreach ( $options as &$value ) {
                        if ( $value === false ) {
                                $value = '0';
                        }
                }
                unset( $value );

                return wfArrayToCgi( $options );
        }

        /**
         * Return the text to be displayed above the changes
         *
         * @param FormOptions $opts
         * @return string XHTML
         */
        public function doHeader( $opts ) {
                global $wgScript;

                $this->setTopText( $opts );

                $defaults = $opts->getAllValues();
                $nondefaults = $opts->getChangedValues();
                $opts->consumeValues( array(
                        'namespace', 'invert', 'associated', 'tagfilter',
                        'categories', 'categories_any'
                ) );

                $panel = array();
                $panel[] = $this->optionsPanel( $defaults, $nondefaults );
                $panel[] = '<hr />';

                $extraOpts = $this->getExtraOptions( $opts );
                $extraOptsCount = count( $extraOpts );
                $count = 0;
                $submit = ' ' . Xml::submitbutton( $this->msg( 'allpagessubmit' )->text() );

                $out = Xml::openElement( 'table', array( 'class' => 'mw-recentchanges-table' ) );
                foreach ( $extraOpts as $name => $optionRow ) {
                        # Add submit button to the last row only
                        ++$count;
                        $addSubmit = ( $count === $extraOptsCount ) ? $submit : '';

                        $out .= Xml::openElement( 'tr' );
                        if ( is_array( $optionRow ) ) {
                                $out .= Xml::tags( 'td', array( 'class' => 'mw-label mw-' . $name . '-label' ), $optionRow[0] );
                                $out .= Xml::tags( 'td', array( 'class' => 'mw-input' ), $optionRow[1] . $addSubmit );
                        } else {
                                $out .= Xml::tags( 'td', array( 'class' => 'mw-input', 'colspan' => 2 ), $optionRow . $addSubmit );
                        }
                        $out .= Xml::closeElement( 'tr' );
                }
                $out .= Xml::closeElement( 'table' );

                $unconsumed = $opts->getUnconsumedValues();
                foreach ( $unconsumed as $key => $value ) {
                        $out .= Html::hidden( $key, $value );
                }

                $t = $this->getTitle();
                $out .= Html::hidden( 'title', $t->getPrefixedText() );
                $form = Xml::tags( 'form', array( 'action' => $wgScript ), $out );
                $panel[] = $form;
                $panelString = implode( "\n", $panel );

                $this->getOutput()->addHTML(
                        Xml::fieldset( $this->msg( 'recentchanges-legend' )->text(), $panelString, array( 'class' => 'rcoptions' ) )
                );

                $this->setBottomText( $opts );
        }

        /**
         * Get options to be displayed in a form
         *
         * @param FormOptions $opts
         * @return array
         */
        function getExtraOptions( $opts ) {
                $extraOpts = array();
                $extraOpts['namespace'] = $this->namespaceFilterForm( $opts );

                global $wgAllowCategorizedRecentChanges;
                if ( $wgAllowCategorizedRecentChanges ) {
                        $extraOpts['category'] = $this->categoryFilterForm( $opts );
                }

                $tagFilter = ChangeTags::buildTagFilterSelector( $opts['tagfilter'] );
                if ( count( $tagFilter ) ) {
                        $extraOpts['tagfilter'] = $tagFilter;
                }

                wfRunHooks( 'SpecialRecentChangesPanel', array( &$extraOpts, $opts ) );
                return $extraOpts;
        }

        /**
         * Send the text to be displayed above the options
         *
         * @param FormOptions $opts Unused
         */
        function setTopText( FormOptions $opts ) {
                global $wgContLang;

                $message = $this->msg( 'recentchangestext' )->inContentLanguage();
                if ( !$message->isDisabled() ) {
                        $this->getOutput()->addWikiText(
                                Html::rawElement( 'p',
                                        array( 'lang' => $wgContLang->getCode(), 'dir' => $wgContLang->getDir() ),
                                        "\n" . $message->plain() . "\n"
                                ),
                                /* $lineStart */ false,
                                /* $interface */ false
                        );
                }
        }

        /**
         * Send the text to be displayed after the options, for use in
         * Recentchangeslinked
         *
         * @param FormOptions $opts
         */
        function setBottomText( FormOptions $opts ) {}

        /**
         * Creates the choose namespace selection
         *
         * @todo Uses radio buttons (HASHAR)
         * @param FormOptions $opts
         * @return string
         */
        protected function namespaceFilterForm( FormOptions $opts ) {
                $nsSelect = Html::namespaceSelector(
                        array( 'selected' => $opts['namespace'], 'all' => '' ),
                        array( 'name' => 'namespace', 'id' => 'namespace' )
                );
                $nsLabel = Xml::label( $this->msg( 'namespace' )->text(), 'namespace' );
                $invert = Xml::checkLabel(
                        $this->msg( 'invert' )->text(), 'invert', 'nsinvert',
                        $opts['invert'],
                        array( 'title' => $this->msg( 'tooltip-invert' )->text() )
                );
                $associated = Xml::checkLabel(
                        $this->msg( 'namespace_association' )->text(), 'associated', 'nsassociated',
                        $opts['associated'],
                        array( 'title' => $this->msg( 'tooltip-namespace_association' )->text() )
                );
                return array( $nsLabel, "$nsSelect $invert $associated" );
        }

        /**
         * Create a input to filter changes by categories
         *
         * @param FormOptions $opts
         * @return array
         */
        protected function categoryFilterForm( FormOptions $opts ) {
                list( $label, $input ) = Xml::inputLabelSep( $this->msg( 'rc_categories' )->text(),
                        'categories', 'mw-categories', false, $opts['categories'] );

                $input .= ' ' . Xml::checkLabel( $this->msg( 'rc_categories_any' )->text(),
                        'categories_any', 'mw-categories_any', $opts['categories_any'] );

                return array( $label, $input );
        }

        /**
         * Filter $rows by categories set in $opts
         *
         * @param array $rows Database rows
         * @param FormOptions $opts
         */
        function filterByCategories( &$rows, FormOptions $opts ) {
                $categories = array_map( 'trim', explode( '|', $opts['categories'] ) );

                if ( !count( $categories ) ) {
                        return;
                }

                # Filter categories
                $cats = array();
                foreach ( $categories as $cat ) {
                        $cat = trim( $cat );
                        if ( $cat == '' ) {
                                continue;
                        }
                        $cats[] = $cat;
                }

                # Filter articles
                $articles = array();
                $a2r = array();
                $rowsarr = array();
                foreach ( $rows as $k => $r ) {
                        $nt = Title::makeTitle( $r->rc_namespace, $r->rc_title );
                        $id = $nt->getArticleID();
                        if ( $id == 0 ) {
                                continue; # Page might have been deleted...
                        }
                        if ( !in_array( $id, $articles ) ) {
                                $articles[] = $id;
                        }
                        if ( !isset( $a2r[$id] ) ) {
                                $a2r[$id] = array();
                        }
                        $a2r[$id][] = $k;
                        $rowsarr[$k] = $r;
                }

                # Shortcut?
                if ( !count( $articles ) || !count( $cats ) ) {
                        return;
                }

                # Look up
                $c = new Categoryfinder;
                $c->seed( $articles, $cats, $opts['categories_any'] ? 'OR' : 'AND' );
                $match = $c->run();

                # Filter
                $newrows = array();
                foreach ( $match as $id ) {
                        foreach ( $a2r[$id] as $rev ) {
                                $k = $rev;
                                $newrows[$k] = $rowsarr[$k];
                        }
                }
                $rows = $newrows;
        }

        /**
         * Makes change an option link which carries all the other options
         *
         * @param string $title Title
         * @param array $override Options to override
         * @param array $options Current options
         * @param bool $active Whether to show the link in bold
         * @return string
         */
        function makeOptionsLink( $title, $override, $options, $active = false ) {
                $params = $override + $options;

                // Bug 36524: false values have be converted to "0" otherwise
                // wfArrayToCgi() will omit it them.
                foreach ( $params as &$value ) {
                        if ( $value === false ) {
                                $value = '0';
                        }
                }
                unset( $value );

                $text = htmlspecialchars( $title );
                if ( $active ) {
                        $text = '<strong>' . $text . '</strong>';
                }
                return Linker::linkKnown( $this->getTitle(), $text, array(), $params );
        }

        /**
         * Creates the options panel.
         *
         * @param array $defaults
         * @param array $nondefaults
         * @return string
         */
        function optionsPanel( $defaults, $nondefaults ) {
                global $wgRCLinkLimits, $wgRCLinkDays;

                $options = $nondefaults + $defaults;

                $note = '';
                $msg = $this->msg( 'rclegend' );
                if ( !$msg->isDisabled() ) {
                        $note .= '<div class="mw-rclegend">' . $msg->parse() . "</div>\n";
                }

                $lang = $this->getLanguage();
                $user = $this->getUser();
                if ( $options['from'] ) {
                        $note .= $this->msg( 'rcnotefrom' )->numParams( $options['limit'] )->params(
                                $lang->userTimeAndDate( $options['from'], $user ),
                                $lang->userDate( $options['from'], $user ),
                                $lang->userTime( $options['from'], $user ) )->parse() . '<br />';
                }

                # Sort data for display and make sure it's unique after we've added user data.
                $wgRCLinkLimits[] = $options['limit'];
                $wgRCLinkDays[] = $options['days'];
                sort( $wgRCLinkLimits );
                sort( $wgRCLinkDays );
                $wgRCLinkLimits = array_unique( $wgRCLinkLimits );
                $wgRCLinkDays = array_unique( $wgRCLinkDays );

                // limit links
                $cl = array();
                foreach ( $wgRCLinkLimits as $value ) {
                        $cl[] = $this->makeOptionsLink( $lang->formatNum( $value ),
                                array( 'limit' => $value ), $nondefaults, $value == $options['limit'] );
                }
                $cl = $lang->pipeList( $cl );

                // day links, reset 'from' to none
                $dl = array();
                foreach ( $wgRCLinkDays as $value ) {
                        $dl[] = $this->makeOptionsLink( $lang->formatNum( $value ),
                                array( 'days' => $value, 'from' => '' ), $nondefaults, $value == $options['days'] );
                }
                $dl = $lang->pipeList( $dl );

                // show/hide links
                $showhide = array( $this->msg( 'show' )->text(), $this->msg( 'hide' )->text() );
                $filters = array(
                        'hideminor' => 'rcshowhideminor',
                        'hidebots' => 'rcshowhidebots',
                        'hideanons' => 'rcshowhideanons',
                        'hideliu' => 'rcshowhideliu',
                        'hidepatrolled' => 'rcshowhidepatr',
                        'hidemyself' => 'rcshowhidemine'
                );
                foreach ( $this->getCustomFilters() as $key => $params ) {
                        $filters[$key] = $params['msg'];
                }
                // Disable some if needed
                if ( !$user->useRCPatrol() ) {
                        unset( $filters['hidepatrolled'] );
                }

                $links = array();
                foreach ( $filters as $key => $msg ) {
                        $link = $this->makeOptionsLink( $showhide[1 - $options[$key]],
                                array( $key => 1 - $options[$key] ), $nondefaults );
                        $links[] = $this->msg( $msg )->rawParams( $link )->escaped();
                }

                // show from this onward link
                $timestamp = wfTimestampNow();
                $now = $lang->userTimeAndDate( $timestamp, $user );
                $tl = $this->makeOptionsLink(
                        $now, array( 'from' => $timestamp ), $nondefaults
                );

                $rclinks = $this->msg( 'rclinks' )->rawParams( $cl, $dl, $lang->pipeList( $links ) )->parse();
                $rclistfrom = $this->msg( 'rclistfrom' )->rawParams( $tl )->parse();
                return "{$note}$rclinks<br />$rclistfrom";
        }

        /**
         * add javascript specific to the [[Special:RecentChanges]] page
         */
        function addRecentChangesJS() {
                $this->getOutput()->addModules( array(
                        'mediawiki.special.recentchanges',
                ) );
        }

        protected function getGroupName() {
                return 'changes';
        }
}