MediaWiki REL1_35
SpecialRandompage.php
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1<?php
26
32class RandomPage extends SpecialPage {
33 private $namespaces; // namespaces to select pages from
34 protected $isRedir = false; // should the result be a redirect?
35 protected $extra = []; // Extra SQL statements
36
37 public function __construct( $name = 'Randompage' ) {
38 $this->namespaces = MediaWikiServices::getInstance()->getNamespaceInfo()->
39 getContentNamespaces();
40 parent::__construct( $name );
41 }
42
43 public function getNamespaces() {
44 return $this->namespaces;
45 }
46
47 public function setNamespace( $ns ) {
48 if ( !$ns || $ns < NS_MAIN ) {
49 $ns = NS_MAIN;
50 }
51 $this->namespaces = [ $ns ];
52 }
53
54 // select redirects instead of normal pages?
55 public function isRedirect() {
56 return $this->isRedir;
57 }
58
59 public function execute( $par ) {
60 if ( is_string( $par ) ) {
61 // Testing for stringiness since we want to catch
62 // the empty string to mean main namespace only.
63 $this->setNamespace(
64 MediaWikiServices::getInstance()->getContentLanguage()->getNsIndex( $par ) );
65 }
66
67 $title = $this->getRandomTitle();
68
69 if ( $title === null ) {
70 $this->setHeaders();
71 // Message: randompage-nopages, randomredirect-nopages
72 $this->getOutput()->addWikiMsg( strtolower( $this->getName() ) . '-nopages',
73 $this->getNsList(), count( $this->namespaces ) );
74
75 return;
76 }
77
78 $redirectParam = $this->isRedirect() ? [ 'redirect' => 'no' ] : [];
79 $query = array_merge( $this->getRequest()->getValues(), $redirectParam );
80 unset( $query['title'] );
81 $this->getOutput()->redirect( $title->getFullURL( $query ) );
82 }
83
89 private function getNsList() {
90 $contLang = MediaWikiServices::getInstance()->getContentLanguage();
91 $nsNames = [];
92 foreach ( $this->namespaces as $n ) {
93 if ( $n === NS_MAIN ) {
94 $nsNames[] = $this->msg( 'blanknamespace' )->plain();
95 } else {
96 $nsNames[] = $contLang->getNsText( $n );
97 }
98 }
99
100 return $contLang->commaList( $nsNames );
101 }
102
107 public function getRandomTitle() {
108 $randstr = wfRandom();
109 $title = null;
110
111 if ( !$this->getHookRunner()->onSpecialRandomGetRandomTitle(
112 $randstr, $this->isRedir, $this->namespaces,
113 $this->extra, $title )
114 ) {
115 return $title;
116 }
117
118 $row = $this->selectRandomPageFromDB( $randstr, __METHOD__ );
119
120 /* If we picked a value that was higher than any in
121 * the DB, wrap around and select the page with the
122 * lowest value instead! One might think this would
123 * skew the distribution, but in fact it won't cause
124 * any more bias than what the page_random scheme
125 * causes anyway. Trust me, I'm a mathematician. :)
126 */
127 if ( !$row ) {
128 $row = $this->selectRandomPageFromDB( "0", __METHOD__ );
129 }
130
131 if ( $row ) {
132 return Title::makeTitleSafe( $row->page_namespace, $row->page_title );
133 }
134
135 return null;
136 }
137
138 protected function getQueryInfo( $randstr ) {
139 $redirect = $this->isRedirect() ? 1 : 0;
140 $tables = [ 'page' ];
141 $conds = array_merge( [
142 'page_namespace' => $this->namespaces,
143 'page_is_redirect' => $redirect,
144 'page_random >= ' . $randstr
145 ], $this->extra );
146 $joinConds = [];
147
148 // Allow extensions to modify the query
149 $this->getHookRunner()->onRandomPageQuery( $tables, $conds, $joinConds );
150
151 return [
152 'tables' => $tables,
153 'fields' => [ 'page_title', 'page_namespace' ],
154 'conds' => $conds,
155 'options' => [
156 'ORDER BY' => 'page_random',
157 'LIMIT' => 1,
158 ],
159 'join_conds' => $joinConds
160 ];
161 }
162
163 private function selectRandomPageFromDB( $randstr, $fname = __METHOD__ ) {
165
166 $query = $this->getQueryInfo( $randstr );
167 $res = $dbr->select(
168 $query['tables'],
169 $query['fields'],
170 $query['conds'],
171 $fname,
172 $query['options'],
173 $query['join_conds']
174 );
175
176 return $dbr->fetchObject( $res );
177 }
178
179 protected function getGroupName() {
180 return 'redirects';
181 }
182}
wfRandom()
Get a random decimal value in the domain of [0, 1), in a way not likely to give duplicate values for ...
wfGetDB( $db, $groups=[], $wiki=false)
Get a Database object.
MediaWikiServices is the service locator for the application scope of MediaWiki.
Special page to direct the user to a random page.
getNsList()
Get a comma-delimited list of namespaces we don't have any pages in.
getRandomTitle()
Choose a random title.
getQueryInfo( $randstr)
__construct( $name='Randompage')
selectRandomPageFromDB( $randstr, $fname=__METHOD__)
execute( $par)
Default execute method Checks user permissions.
getGroupName()
Under which header this special page is listed in Special:SpecialPages See messages 'specialpages-gro...
Parent class for all special pages.
getName()
Get the name of this Special Page.
setHeaders()
Sets headers - this should be called from the execute() method of all derived classes!...
getOutput()
Get the OutputPage being used for this instance.
msg( $key,... $params)
Wrapper around wfMessage that sets the current context.
getRequest()
Get the WebRequest being used for this instance.
const NS_MAIN
Definition Defines.php:70
const DB_REPLICA
Definition defines.php:25