6 * Created on Monday, January 28, 2008
8 * Copyright © 2008 Brent Garber
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write to the Free Software Foundation, Inc.,
22 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
23 * http://www.gnu.org/copyleft/gpl.html
28 if ( !defined( 'MEDIAWIKI' ) ) {
29 // Eclipse helper - will be ignored in production
30 require_once( 'ApiQueryBase.php' );
34 * Query module to get list of random pages
39 class ApiQueryRandom
extends ApiQueryGeneratorBase
{
41 public function __construct( $query, $moduleName ) {
42 parent
::__construct( $query, $moduleName, 'rn' );
45 public function execute() {
49 public function executeGenerator( $resultPageSet ) {
50 $this->run( $resultPageSet );
57 * @param $resultPageSet ApiPageSet
61 protected function prepareQuery( $randstr, $limit, $namespace, &$resultPageSet, $redirect ) {
62 $this->resetQueryParams();
63 $this->addTables( 'page' );
64 $this->addOption( 'LIMIT', $limit );
65 $this->addWhereFld( 'page_namespace', $namespace );
66 $this->addWhereRange( 'page_random', 'newer', $randstr, null );
67 $this->addWhereFld( 'page_is_redirect', $redirect );
68 $this->addOption( 'USE INDEX', 'page_random' );
69 if ( is_null( $resultPageSet ) ) {
70 $this->addFields( array( 'page_id', 'page_title', 'page_namespace' ) );
72 $this->addFields( $resultPageSet->getPageTableFields() );
76 protected function runQuery( &$resultPageSet ) {
77 $res = $this->select( __METHOD__
);
79 foreach ( $res as $row ) {
81 if ( is_null( $resultPageSet ) ) {
83 if ( !in_array( $row->page_id
, $this->pageIDs
) ) {
84 $fit = $this->getResult()->addValue(
85 array( 'query', $this->getModuleName() ),
86 null, $this->extractRowInfo( $row ) );
88 // We can't really query-continue a random list.
89 // Return an insanely high value so
90 // $count < $limit is false
93 $this->pageIDs
[] = $row->page_id
;
96 $resultPageSet->processDbRow( $row );
103 public function run( $resultPageSet = null ) {
104 $params = $this->extractRequestParams();
105 $result = $this->getResult();
106 $this->pageIDs
= array();
108 $this->prepareQuery( wfRandom(), $params['limit'], $params['namespace'], $resultPageSet, $params['redirect'] );
109 $count = $this->runQuery( $resultPageSet );
110 if ( $count < $params['limit'] ) {
111 /* We got too few pages, we probably picked a high value
112 * for page_random. We'll just take the lowest ones, see
113 * also the comment in Title::getRandomTitle()
115 $this->prepareQuery( 0, $params['limit'] - $count, $params['namespace'], $resultPageSet, $params['redirect'] );
116 $this->runQuery( $resultPageSet );
119 if ( is_null( $resultPageSet ) ) {
120 $result->setIndexedTagName_internal( array( 'query', $this->getModuleName() ), 'page' );
124 private function extractRowInfo( $row ) {
125 $title = Title
::makeTitle( $row->page_namespace
, $row->page_title
);
127 $vals['id'] = intval( $row->page_id
);
128 ApiQueryBase
::addTitleInfo( $vals, $title );
132 public function getCacheMode( $params ) {
136 public function getAllowedParams() {
138 'namespace' => array(
139 ApiBase
::PARAM_TYPE
=> 'namespace',
140 ApiBase
::PARAM_ISMULTI
=> true
143 ApiBase
::PARAM_TYPE
=> 'limit',
144 ApiBase
::PARAM_DFLT
=> 1,
145 ApiBase
::PARAM_MIN
=> 1,
146 ApiBase
::PARAM_MAX
=> 10,
147 ApiBase
::PARAM_MAX2
=> 20
153 public function getParamDescription() {
155 'namespace' => 'Return pages in these namespaces only',
156 'limit' => 'Limit how many random pages will be returned',
157 'redirect' => 'Load a random redirect instead of a random page'
161 public function getDescription() {
163 'Get a set of random pages',
164 'NOTE: Pages are listed in a fixed sequence, only the starting point is random. This means that if, for example, "Main Page" is the first ',
165 ' random page on your list, "List of fictional monkeys" will *always* be second, "List of people on stamps of Vanuatu" third, etc',
166 'NOTE: If the number of pages in the namespace is lower than rnlimit, you will get fewer pages. You will not get the same page twice'
170 protected function getExamples() {
171 return 'api.php?action=query&list=random&rnnamespace=0&rnlimit=2';
174 public function getVersion() {
175 return __CLASS__
. ': $Id: ApiQueryRandom.php overlordq$';