Support offsets in prefix searching

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

<?php
/**
 * Implements Special:Recentchangeslinked
 *
 * 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
 */

/**
 * This is to display changes made to all articles linked in an article.
 *
 * @ingroup SpecialPage
 */
class SpecialRecentChangesLinked extends SpecialRecentChanges {
        /** @var bool|Title */
        protected $rclTargetTitle;

        function __construct() {
                parent::__construct( 'Recentchangeslinked' );
        }

        public function getDefaultOptions() {
                $opts = parent::getDefaultOptions();
                $opts->add( 'target', '' );
                $opts->add( 'showlinkedto', false );

                return $opts;
        }

        public function parseParameters( $par, FormOptions $opts ) {
                $opts['target'] = $par;
        }

        public function doMainQuery( $conds, $opts ) {
                $target = $opts['target'];
                $showlinkedto = $opts['showlinkedto'];
                $limit = $opts['limit'];

                if ( $target === '' ) {
                        return false;
                }
                $outputPage = $this->getOutput();
                $title = Title::newFromURL( $target );
                if ( !$title || $title->isExternal() ) {
                        $outputPage->addHtml( '<div class="errorbox">' . $this->msg( 'allpagesbadtitle' )
                                        ->parse() . '</div>' );

                        return false;
                }

                $outputPage->setPageTitle( $this->msg( 'recentchangeslinked-title', $title->getPrefixedText() ) );

                /*
                 * Ordinary links are in the pagelinks table, while transclusions are
                 * in the templatelinks table, categorizations in categorylinks and
                 * image use in imagelinks.  We need to somehow combine all these.
                 * Special:Whatlinkshere does this by firing multiple queries and
                 * merging the results, but the code we inherit from our parent class
                 * expects only one result set so we use UNION instead.
                 */

                $dbr = wfGetDB( DB_SLAVE, 'recentchangeslinked' );
                $id = $title->getArticleID();
                $ns = $title->getNamespace();
                $dbkey = $title->getDBkey();

                $tables = array( 'recentchanges' );
                $select = RecentChange::selectFields();
                $join_conds = array();
                $query_options = array();

                // left join with watchlist table to highlight watched rows
                $uid = $this->getUser()->getId();
                if ( $uid && $this->getUser()->isAllowed( 'viewmywatchlist' ) ) {
                        $tables[] = 'watchlist';
                        $select[] = 'wl_user';
                        $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';
                        $join_conds['page'] = array( 'LEFT JOIN', 'rc_cur_id=page_id' );
                        $select[] = 'page_latest';
                }
                ChangeTags::modifyDisplayQuery(
                        $tables,
                        $select,
                        $conds,
                        $join_conds,
                        $query_options,
                        $opts['tagfilter']
                );

                if ( !$this->runMainQueryHook( $tables, $select, $conds, $query_options, $join_conds,
                        $opts )
                ) {
                        return false;
                }

                if ( $ns == NS_CATEGORY && !$showlinkedto ) {
                        // special handling for categories
                        // XXX: should try to make this less kludgy
                        $link_tables = array( 'categorylinks' );
                        $showlinkedto = true;
                } else {
                        // for now, always join on these tables; really should be configurable as in whatlinkshere
                        $link_tables = array( 'pagelinks', 'templatelinks' );
                        // imagelinks only contains links to pages in NS_FILE
                        if ( $ns == NS_FILE || !$showlinkedto ) {
                                $link_tables[] = 'imagelinks';
                        }
                }

                if ( $id == 0 && !$showlinkedto ) {
                        return false; // nonexistent pages can't link to any pages
                }

                // field name prefixes for all the various tables we might want to join with
                $prefix = array(
                        'pagelinks' => 'pl',
                        'templatelinks' => 'tl',
                        'categorylinks' => 'cl',
                        'imagelinks' => 'il'
                );

                $subsql = array(); // SELECT statements to combine with UNION

                foreach ( $link_tables as $link_table ) {
                        $pfx = $prefix[$link_table];

                        // imagelinks and categorylinks tables have no xx_namespace field,
                        // and have xx_to instead of xx_title
                        if ( $link_table == 'imagelinks' ) {
                                $link_ns = NS_FILE;
                        } elseif ( $link_table == 'categorylinks' ) {
                                $link_ns = NS_CATEGORY;
                        } else {
                                $link_ns = 0;
                        }

                        if ( $showlinkedto ) {
                                // find changes to pages linking to this page
                                if ( $link_ns ) {
                                        if ( $ns != $link_ns ) {
                                                continue;
                                        } // should never happen, but check anyway
                                        $subconds = array( "{$pfx}_to" => $dbkey );
                                } else {
                                        $subconds = array( "{$pfx}_namespace" => $ns, "{$pfx}_title" => $dbkey );
                                }
                                $subjoin = "rc_cur_id = {$pfx}_from";
                        } else {
                                // find changes to pages linked from this page
                                $subconds = array( "{$pfx}_from" => $id );
                                if ( $link_table == 'imagelinks' || $link_table == 'categorylinks' ) {
                                        $subconds["rc_namespace"] = $link_ns;
                                        $subjoin = "rc_title = {$pfx}_to";
                                } else {
                                        $subjoin = array( "rc_namespace = {$pfx}_namespace", "rc_title = {$pfx}_title" );
                                }
                        }

                        if ( $dbr->unionSupportsOrderAndLimit() ) {
                                $order = array( 'ORDER BY' => 'rc_timestamp DESC' );
                        } else {
                                $order = array();
                        }

                        $query = $dbr->selectSQLText(
                                array_merge( $tables, array( $link_table ) ),
                                $select,
                                $conds + $subconds,
                                __METHOD__,
                                $order + $query_options,
                                $join_conds + array( $link_table => array( 'INNER JOIN', $subjoin ) )
                        );

                        if ( $dbr->unionSupportsOrderAndLimit() ) {
                                $query = $dbr->limitResult( $query, $limit );
                        }

                        $subsql[] = $query;
                }

                if ( count( $subsql ) == 0 ) {
                        return false; // should never happen
                }
                if ( count( $subsql ) == 1 && $dbr->unionSupportsOrderAndLimit() ) {
                        $sql = $subsql[0];
                } else {
                        // need to resort and relimit after union
                        $sql = $dbr->unionQueries( $subsql, false ) . ' ORDER BY rc_timestamp DESC';
                        $sql = $dbr->limitResult( $sql, $limit, false );
                }

                $res = $dbr->query( $sql, __METHOD__ );

                if ( $res->numRows() == 0 ) {
                        $this->mResultEmpty = true;
                }

                return $res;
        }

        function setTopText( FormOptions $opts ) {
                $target = $this->getTargetTitle();
                if ( $target ) {
                        $this->getOutput()->addBacklinkSubtitle( $target );
                        $this->getSkin()->setRelevantTitle( $target );
                }
        }

        /**
         * Get options to be displayed in a form
         *
         * @param FormOptions $opts
         * @return array
         */
        function getExtraOptions( $opts ) {
                $extraOpts = parent::getExtraOptions( $opts );

                $opts->consumeValues( array( 'showlinkedto', 'target' ) );

                $extraOpts['target'] = array( $this->msg( 'recentchangeslinked-page' )->escaped(),
                        Xml::input( 'target', 40, str_replace( '_', ' ', $opts['target'] ) ) .
                        Xml::check( 'showlinkedto', $opts['showlinkedto'], array( 'id' => 'showlinkedto' ) ) . ' ' .
                        Xml::label( $this->msg( 'recentchangeslinked-to' )->text(), 'showlinkedto' ) );

                return $extraOpts;
        }

        /**
         * @return Title
         */
        function getTargetTitle() {
                if ( $this->rclTargetTitle === null ) {
                        $opts = $this->getOptions();
                        if ( isset( $opts['target'] ) && $opts['target'] !== '' ) {
                                $this->rclTargetTitle = Title::newFromText( $opts['target'] );
                        } else {
                                $this->rclTargetTitle = false;
                        }
                }

                return $this->rclTargetTitle;
        }
}