3 * Implements Special:Randompage
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 * http://www.gnu.org/copyleft/gpl.html
21 * @ingroup SpecialPage
22 * @author Rob Church <robchur@gmail.com>, Ilmari Karonen
26 * Special page to direct the user to a random page
28 * @ingroup SpecialPage
30 class RandomPage
extends SpecialPage
{
31 private $namespaces; // namespaces to select pages from
32 protected $isRedir = false; // should the result be a redirect?
33 protected $extra = array(); // Extra SQL statements
35 public function __construct( $name = 'Randompage' ){
36 global $wgContentNamespaces;
37 $this->namespaces
= $wgContentNamespaces;
38 parent
::__construct( $name );
41 public function getNamespaces() {
42 return $this->namespaces
;
45 public function setNamespace ( $ns ) {
46 if( !$ns ||
$ns < NS_MAIN
) {
49 $this->namespaces
= array( $ns );
52 // select redirects instead of normal pages?
53 public function isRedirect(){
54 return $this->isRedir
;
57 public function execute( $par ) {
58 global $wgOut, $wgContLang, $wgRequest;
61 $this->setNamespace( $wgContLang->getNsIndex( $par ) );
64 $title = $this->getRandomTitle();
66 if( is_null( $title ) ) {
68 $wgOut->addWikiMsg( strtolower( $this->mName
) . '-nopages',
69 $this->getNsList(), count( $this->namespaces
) );
73 $redirectParam = $this->isRedirect() ?
array( 'redirect' => 'no' ) : array();
74 $query = array_merge( $wgRequest->getValues(), $redirectParam );
75 unset( $query['title'] );
76 $wgOut->redirect( $title->getFullUrl( $query ) );
80 * Get a comma-delimited list of namespaces we don't have
84 private function getNsList() {
87 foreach( $this->namespaces
as $n ) {
88 if( $n === NS_MAIN
) {
89 $nsNames[] = wfMsgForContent( 'blanknamespace' );
91 $nsNames[] = $wgContLang->getNsText( $n );
94 return $wgContLang->commaList( $nsNames );
98 * Choose a random title.
99 * @return Title object (or null if nothing to choose from)
101 public function getRandomTitle() {
102 $randstr = wfRandom();
104 if ( !wfRunHooks( 'SpecialRandomGetRandomTitle', array( &$randstr, &$this->isRedir
, &$this->namespaces
,
105 &$this->extra
, &$title ) ) ) {
108 $row = $this->selectRandomPageFromDB( $randstr );
110 /* If we picked a value that was higher than any in
111 * the DB, wrap around and select the page with the
112 * lowest value instead! One might think this would
113 * skew the distribution, but in fact it won't cause
114 * any more bias than what the page_random scheme
115 * causes anyway. Trust me, I'm a mathematician. :)
118 $row = $this->selectRandomPageFromDB( "0" );
122 return Title
::makeTitleSafe( $row->page_namespace
, $row->page_title
);
128 protected function getQueryInfo( $randstr ) {
129 global $wgExtraRandompageSQL;
130 $redirect = $this->isRedirect() ?
1 : 0;
132 if ( $wgExtraRandompageSQL ) {
133 $this->extra
[] = $wgExtraRandompageSQL;
135 if ( $this->addExtraSQL() ) {
136 $this->extra
[] = $this->addExtraSQL();
140 'tables' => array( 'page' ),
141 'fields' => array( 'page_title', 'page_namespace' ),
142 'conds' => array_merge( array(
143 'page_namespace' => $this->namespaces
,
144 'page_is_redirect' => $redirect,
145 'page_random >= ' . $randstr
148 'ORDER BY' => 'page_random',
149 'USE INDEX' => 'page_random',
152 'join_conds' => array()
156 private function selectRandomPageFromDB( $randstr, $fname = __METHOD__
) {
157 $dbr = wfGetDB( DB_SLAVE
);
159 $query = $this->getQueryInfo( $randstr );
169 return $dbr->fetchObject( $res );
172 /* an alternative to $wgExtraRandompageSQL so subclasses
173 * can add their own SQL by overriding this function
174 * @deprecated, append to $this->extra instead
176 public function addExtraSQL() {