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Diffstat (limited to 'www/wiki/includes/specials/SpecialRandompage.php')
| -rw-r--r-- | www/wiki/includes/specials/SpecialRandompage.php | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/www/wiki/includes/specials/SpecialRandompage.php b/www/wiki/includes/specials/SpecialRandompage.php new file mode 100644 index 00000000..e3b567d7 --- /dev/null +++ b/www/wiki/includes/specials/SpecialRandompage.php @@ -0,0 +1,180 @@ +<?php +/** + * Implements Special:Randompage + * + * 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 + * @author Rob Church <robchur@gmail.com>, Ilmari Karonen + */ + +/** + * Special page to direct the user to a random page + * + * @ingroup SpecialPage + */ +class RandomPage extends SpecialPage { + private $namespaces; // namespaces to select pages from + protected $isRedir = false; // should the result be a redirect? + protected $extra = []; // Extra SQL statements + + public function __construct( $name = 'Randompage' ) { + $this->namespaces = MWNamespace::getContentNamespaces(); + parent::__construct( $name ); + } + + public function getNamespaces() { + return $this->namespaces; + } + + public function setNamespace( $ns ) { + if ( !$ns || $ns < NS_MAIN ) { + $ns = NS_MAIN; + } + $this->namespaces = [ $ns ]; + } + + // select redirects instead of normal pages? + public function isRedirect() { + return $this->isRedir; + } + + public function execute( $par ) { + global $wgContLang; + + if ( is_string( $par ) ) { + // Testing for stringiness since we want to catch + // the empty string to mean main namespace only. + $this->setNamespace( $wgContLang->getNsIndex( $par ) ); + } + + $title = $this->getRandomTitle(); + + if ( is_null( $title ) ) { + $this->setHeaders(); + // Message: randompage-nopages, randomredirect-nopages + $this->getOutput()->addWikiMsg( strtolower( $this->getName() ) . '-nopages', + $this->getNsList(), count( $this->namespaces ) ); + + return; + } + + $redirectParam = $this->isRedirect() ? [ 'redirect' => 'no' ] : []; + $query = array_merge( $this->getRequest()->getValues(), $redirectParam ); + unset( $query['title'] ); + $this->getOutput()->redirect( $title->getFullURL( $query ) ); + } + + /** + * Get a comma-delimited list of namespaces we don't have + * any pages in + * @return string + */ + private function getNsList() { + global $wgContLang; + $nsNames = []; + foreach ( $this->namespaces as $n ) { + if ( $n === NS_MAIN ) { + $nsNames[] = $this->msg( 'blanknamespace' )->plain(); + } else { + $nsNames[] = $wgContLang->getNsText( $n ); + } + } + + return $wgContLang->commaList( $nsNames ); + } + + /** + * Choose a random title. + * @return Title|null Title object (or null if nothing to choose from) + */ + public function getRandomTitle() { + $randstr = wfRandom(); + $title = null; + + if ( !Hooks::run( + 'SpecialRandomGetRandomTitle', + [ &$randstr, &$this->isRedir, &$this->namespaces, &$this->extra, &$title ] + ) ) { + return $title; + } + + $row = $this->selectRandomPageFromDB( $randstr ); + + /* If we picked a value that was higher than any in + * the DB, wrap around and select the page with the + * lowest value instead! One might think this would + * skew the distribution, but in fact it won't cause + * any more bias than what the page_random scheme + * causes anyway. Trust me, I'm a mathematician. :) + */ + if ( !$row ) { + $row = $this->selectRandomPageFromDB( "0" ); + } + + if ( $row ) { + return Title::makeTitleSafe( $row->page_namespace, $row->page_title ); + } + + return null; + } + + protected function getQueryInfo( $randstr ) { + $redirect = $this->isRedirect() ? 1 : 0; + $tables = [ 'page' ]; + $conds = array_merge( [ + 'page_namespace' => $this->namespaces, + 'page_is_redirect' => $redirect, + 'page_random >= ' . $randstr + ], $this->extra ); + $joinConds = []; + + // Allow extensions to modify the query + Hooks::run( 'RandomPageQuery', [ &$tables, &$conds, &$joinConds ] ); + + return [ + 'tables' => $tables, + 'fields' => [ 'page_title', 'page_namespace' ], + 'conds' => $conds, + 'options' => [ + 'ORDER BY' => 'page_random', + 'LIMIT' => 1, + ], + 'join_conds' => $joinConds + ]; + } + + private function selectRandomPageFromDB( $randstr, $fname = __METHOD__ ) { + $dbr = wfGetDB( DB_REPLICA ); + + $query = $this->getQueryInfo( $randstr ); + $res = $dbr->select( + $query['tables'], + $query['fields'], + $query['conds'], + $fname, + $query['options'], + $query['join_conds'] + ); + + return $dbr->fetchObject( $res ); + } + + protected function getGroupName() { + return 'redirects'; + } +} |