4 * Copyright © 2008 Brent Garber
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
19 * http://www.gnu.org/copyleft/gpl.html
25 * Query module to get list of random pages
29 class ApiQueryRandom
extends ApiQueryGeneratorBase
{
30 public function __construct( ApiQuery
$query, $moduleName ) {
31 parent
::__construct( $query, $moduleName, 'rn' );
34 public function execute() {
38 public function executeGenerator( $resultPageSet ) {
39 $this->run( $resultPageSet );
43 * Actually perform the query and add pages to the result.
44 * @param ApiPageSet|null $resultPageSet
45 * @param int $limit Number of pages to fetch
46 * @param string|null $start Starting page_random
47 * @param int $startId Starting page_id
48 * @param string|null $end Ending page_random
49 * @return array (int, string|null) Number of pages left to query and continuation string
51 protected function runQuery( $resultPageSet, $limit, $start, $startId, $end ) {
52 $params = $this->extractRequestParams();
54 $this->resetQueryParams();
55 $this->addTables( 'page' );
56 $this->addFields( [ 'page_id', 'page_random' ] );
57 if ( is_null( $resultPageSet ) ) {
58 $this->addFields( [ 'page_title', 'page_namespace' ] );
60 $this->addFields( $resultPageSet->getPageTableFields() );
62 $this->addWhereFld( 'page_namespace', $params['namespace'] );
63 if ( $params['redirect'] ||
$params['filterredir'] === 'redirects' ) {
64 $this->addWhereFld( 'page_is_redirect', 1 );
65 } elseif ( $params['filterredir'] === 'nonredirects' ) {
66 $this->addWhereFld( 'page_is_redirect', 0 );
67 } elseif ( is_null( $resultPageSet ) ) {
68 $this->addFields( [ 'page_is_redirect' ] );
70 $this->addOption( 'LIMIT', $limit +
1 );
72 if ( $start !== null ) {
73 $start = $this->getDB()->addQuotes( $start );
75 $startId = (int)$startId; // safety
76 $this->addWhere( "page_random = $start AND page_id >= $startId OR page_random > $start" );
78 $this->addWhere( "page_random >= $start" );
81 if ( $end !== null ) {
82 $this->addWhere( 'page_random < ' . $this->getDB()->addQuotes( $end ) );
84 $this->addOption( 'ORDER BY', [ 'page_random', 'page_id' ] );
86 $result = $this->getResult();
87 $path = [ 'query', $this->getModuleName() ];
89 $res = $this->select( __METHOD__
);
91 foreach ( $res as $row ) {
92 if ( $count++
>= $limit ) {
93 return [ 0, "{$row->page_random}|{$row->page_id}" ];
95 if ( is_null( $resultPageSet ) ) {
96 $title = Title
::makeTitle( $row->page_namespace
, $row->page_title
);
98 'id' => (int)$row->page_id
,
100 ApiQueryBase
::addTitleInfo( $page, $title );
101 if ( isset( $row->page_is_redirect
) ) {
102 $page['redirect'] = (bool)$row->page_is_redirect
;
104 $fit = $result->addValue( $path, null, $page );
106 return [ 0, "{$row->page_random}|{$row->page_id}" ];
109 $resultPageSet->processDbRow( $row );
113 return [ $limit - $count, null ];
117 * @param ApiPageSet|null $resultPageSet
119 public function run( $resultPageSet = null ) {
120 $params = $this->extractRequestParams();
122 // Since 'filterredir" will always be set in $params, we have to dig
123 // into the WebRequest to see if it was actually passed.
124 $request = $this->getMain()->getRequest();
125 if ( $request->getCheck( $this->encodeParamName( 'filterredir' ) ) ) {
126 $this->requireMaxOneParameter( $params, 'filterredir', 'redirect' );
129 if ( isset( $params['continue'] ) ) {
130 $cont = explode( '|', $params['continue'] );
131 $this->dieContinueUsageIf( count( $cont ) != 4 );
134 $startId = (int)$cont[2];
135 $end = $cont[3] ?
$rand : null;
136 $this->dieContinueUsageIf( !preg_match( '/^0\.\d+$/', $rand ) );
137 $this->dieContinueUsageIf( !preg_match( '/^0\.\d+$/', $start ) );
138 $this->dieContinueUsageIf( $cont[2] !== (string)$startId );
139 $this->dieContinueUsageIf( $cont[3] !== '0' && $cont[3] !== '1' );
147 // Set the non-continue if this is being used as a generator
148 // (as a list it doesn't matter because lists never non-continue)
149 if ( $resultPageSet !== null ) {
150 $endFlag = $end === null ?
0 : 1;
151 $this->getContinuationManager()->addGeneratorNonContinueParam(
152 $this, 'continue', "$rand|$start|$startId|$endFlag"
156 list( $left, $continue ) =
157 $this->runQuery( $resultPageSet, $params['limit'], $start, $startId, $end );
158 if ( $end === null && $continue === null ) {
159 // Wrap around. We do this even if $left === 0 for continuation
160 // (saving a DB query in this rare case probably isn't worth the
161 // added code complexity it would require).
163 list( $left, $continue ) = $this->runQuery( $resultPageSet, $left, null, null, $end );
166 if ( $continue !== null ) {
167 $endFlag = $end === null ?
0 : 1;
168 $this->setContinueEnumParameter( 'continue', "$rand|$continue|$endFlag" );
171 if ( is_null( $resultPageSet ) ) {
172 $this->getResult()->addIndexedTagName( [ 'query', $this->getModuleName() ], 'page' );
176 public function getCacheMode( $params ) {
180 public function getAllowedParams() {
183 ApiBase
::PARAM_TYPE
=> 'namespace',
184 ApiBase
::PARAM_ISMULTI
=> true
187 ApiBase
::PARAM_TYPE
=> [ 'all', 'redirects', 'nonredirects' ],
188 ApiBase
::PARAM_DFLT
=> 'nonredirects', // for BC
191 ApiBase
::PARAM_DEPRECATED
=> true,
192 ApiBase
::PARAM_DFLT
=> false,
195 ApiBase
::PARAM_TYPE
=> 'limit',
196 ApiBase
::PARAM_DFLT
=> 1,
197 ApiBase
::PARAM_MIN
=> 1,
198 ApiBase
::PARAM_MAX
=> ApiBase
::LIMIT_BIG1
,
199 ApiBase
::PARAM_MAX2
=> ApiBase
::LIMIT_BIG2
202 ApiBase
::PARAM_HELP_MSG
=> 'api-help-param-continue'
207 protected function getExamplesMessages() {
209 'action=query&list=random&rnnamespace=0&rnlimit=2'
210 => 'apihelp-query+random-example-simple',
211 'action=query&generator=random&grnnamespace=0&grnlimit=2&prop=info'
212 => 'apihelp-query+random-example-generator',
216 public function getHelpUrls() {
217 return 'https://www.mediawiki.org/wiki/Special:MyLanguage/API:Random';