includes/api/ApiQueryLinks.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on May 12, 2007
   6  *
   7  * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @file
  25  */
  26
  27 /**
  28  * A query module to list all wiki links on a given set of pages.
  29  *
  30  * @ingroup API
  31  */
  32 class ApiQueryLinks extends ApiQueryGeneratorBase {
  33
  34         const LINKS = 'links';
  35         const TEMPLATES = 'templates';
  36
  37         private $table, $prefix, $description, $helpUrl;
  38
  39         public function __construct( $query, $moduleName ) {
  40                 switch ( $moduleName ) {
  41                         case self::LINKS:
  42                                 $this->table = 'pagelinks';
  43                                 $this->prefix = 'pl';
  44                                 $this->description = 'link';
  45                                 $this->titlesParam = 'titles';
  46                                 $this->titlesParamDescription = 'Only list links to these titles. Useful for checking whether a certain page links to a certain title.';
  47                                 $this->helpUrl = 'https://www.mediawiki.org/wiki/API:Properties#links_.2F_pl';
  48                                 break;
  49                         case self::TEMPLATES:
  50                                 $this->table = 'templatelinks';
  51                                 $this->prefix = 'tl';
  52                                 $this->description = 'template';
  53                                 $this->titlesParam = 'templates';
  54                                 $this->titlesParamDescription = 'Only list these templates. Useful for checking whether a certain page uses a certain template.';
  55                                 $this->helpUrl = 'https://www.mediawiki.org/wiki/API:Properties#templates_.2F_tl';
  56                                 break;
  57                         default:
  58                                 ApiBase::dieDebug( __METHOD__, 'Unknown module name' );
  59                 }
  60
  61                 parent::__construct( $query, $moduleName, $this->prefix );
  62         }
  63
  64         public function execute() {
  65                 $this->run();
  66         }
  67
  68         public function getCacheMode( $params ) {
  69                 return 'public';
  70         }
  71
  72         public function executeGenerator( $resultPageSet ) {
  73                 $this->run( $resultPageSet );
  74         }
  75
  76         /**
  77          * @param $resultPageSet ApiPageSet
  78          * @return
  79          */
  80         private function run( $resultPageSet = null ) {
  81                 if ( $this->getPageSet()->getGoodTitleCount() == 0 ) {
  82                         return; // nothing to do
  83                 }
  84
  85                 $params = $this->extractRequestParams();
  86
  87                 $this->addFields( array(
  88                         $this->prefix . '_from AS pl_from',
  89                         $this->prefix . '_namespace AS pl_namespace',
  90                         $this->prefix . '_title AS pl_title'
  91                 ) );
  92
  93                 $this->addTables( $this->table );
  94                 $this->addWhereFld( $this->prefix . '_from', array_keys( $this->getPageSet()->getGoodTitles() ) );
  95                 $this->addWhereFld( $this->prefix . '_namespace', $params['namespace'] );
  96
  97                 if ( !is_null( $params[$this->titlesParam] ) ) {
  98                         $lb = new LinkBatch;
  99                         foreach ( $params[$this->titlesParam] as $t ) {
 100                                 $title = Title::newFromText( $t );
 101                                 if ( !$title ) {
 102                                         $this->setWarning( "\"$t\" is not a valid title" );
 103                                 } else {
 104                                         $lb->addObj( $title );
 105                                 }
 106                         }
 107                         $cond = $lb->constructSet( $this->prefix, $this->getDB() );
 108                         if ( $cond ) {
 109                                 $this->addWhere( $cond );
 110                         }
 111                 }
 112
 113                 if ( !is_null( $params['continue'] ) ) {
 114                         $cont = explode( '|', $params['continue'] );
 115                         if ( count( $cont ) != 3 ) {
 116                                 $this->dieUsage( 'Invalid continue param. You should pass the ' .
 117                                         'original value returned by the previous query', '_badcontinue' );
 118                         }
 119                         $op = $params['dir'] == 'descending' ? '<' : '>';
 120                         $plfrom = intval( $cont[0] );
 121                         $plns = intval( $cont[1] );
 122                         $pltitle = $this->getDB()->addQuotes( $cont[2] );
 123                         $this->addWhere(
 124                                 "{$this->prefix}_from $op $plfrom OR " .
 125                                 "({$this->prefix}_from = $plfrom AND " .
 126                                 "({$this->prefix}_namespace $op $plns OR " .
 127                                 "({$this->prefix}_namespace = $plns AND " .
 128                                 "{$this->prefix}_title $op= $pltitle)))"
 129                         );
 130                 }
 131
 132                 $sort = ( $params['dir'] == 'descending' ? ' DESC' : '' );
 133                 // Here's some MySQL craziness going on: if you use WHERE foo='bar'
 134                 // and later ORDER BY foo MySQL doesn't notice the ORDER BY is pointless
 135                 // but instead goes and filesorts, because the index for foo was used
 136                 // already. To work around this, we drop constant fields in the WHERE
 137                 // clause from the ORDER BY clause
 138                 $order = array();
 139                 if ( count( $this->getPageSet()->getGoodTitles() ) != 1 ) {
 140                         $order[] = $this->prefix . '_from' . $sort;
 141                 }
 142                 if ( count( $params['namespace'] ) != 1 ) {
 143                         $order[] = $this->prefix . '_namespace' . $sort;
 144                 }
 145
 146                 $order[] = $this->prefix . '_title' . $sort;
 147                 $this->addOption( 'ORDER BY', $order );
 148                 $this->addOption( 'USE INDEX', $this->prefix . '_from' );
 149                 $this->addOption( 'LIMIT', $params['limit'] + 1 );
 150
 151                 $res = $this->select( __METHOD__ );
 152
 153                 if ( is_null( $resultPageSet ) ) {
 154                         $count = 0;
 155                         foreach ( $res as $row ) {
 156                                 if ( ++$count > $params['limit'] ) {
 157                                         // We've reached the one extra which shows that
 158                                         // there are additional pages to be had. Stop here...
 159                                         $this->setContinueEnumParameter( 'continue',
 160                                                 "{$row->pl_from}|{$row->pl_namespace}|{$row->pl_title}" );
 161                                         break;
 162                                 }
 163                                 $vals = array();
 164                                 ApiQueryBase::addTitleInfo( $vals, Title::makeTitle( $row->pl_namespace, $row->pl_title ) );
 165                                 $fit = $this->addPageSubItem( $row->pl_from, $vals );
 166                                 if ( !$fit ) {
 167                                         $this->setContinueEnumParameter( 'continue',
 168                                                 "{$row->pl_from}|{$row->pl_namespace}|{$row->pl_title}" );
 169                                         break;
 170                                 }
 171                         }
 172                 } else {
 173                         $titles = array();
 174                         $count = 0;
 175                         foreach ( $res as $row ) {
 176                                 if ( ++$count > $params['limit'] ) {
 177                                         // We've reached the one extra which shows that
 178                                         // there are additional pages to be had. Stop here...
 179                                         $this->setContinueEnumParameter( 'continue',
 180                                                 "{$row->pl_from}|{$row->pl_namespace}|{$row->pl_title}" );
 181                                         break;
 182                                 }
 183                                 $titles[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
 184                         }
 185                         $resultPageSet->populateFromTitles( $titles );
 186                 }
 187         }
 188
 189         public function getAllowedParams() {
 190                 return array(
 191                         'namespace' => array(
 192                                 ApiBase::PARAM_TYPE => 'namespace',
 193                                 ApiBase::PARAM_ISMULTI => true
 194                         ),
 195                         'limit' => array(
 196                                 ApiBase::PARAM_DFLT => 10,
 197                                 ApiBase::PARAM_TYPE => 'limit',
 198                                 ApiBase::PARAM_MIN => 1,
 199                                 ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
 200                                 ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
 201                         ),
 202                         'continue' => null,
 203                         $this->titlesParam => array(
 204                                 ApiBase::PARAM_ISMULTI => true,
 205                         ),
 206                         'dir' => array(
 207                                 ApiBase::PARAM_DFLT => 'ascending',
 208                                 ApiBase::PARAM_TYPE => array(
 209                                         'ascending',
 210                                         'descending'
 211                                 )
 212                         ),
 213                 );
 214         }
 215
 216         public function getParamDescription() {
 217                 $desc = $this->description;
 218                 return array(
 219                         'namespace' => "Show {$desc}s in this namespace(s) only",
 220                         'limit' => "How many {$desc}s to return",
 221                         'continue' => 'When more results are available, use this to continue',
 222                         $this->titlesParam => $this->titlesParamDescription,
 223                         'dir' => 'The direction in which to list',
 224                 );
 225         }
 226
 227         public function getResultProperties() {
 228                 return array(
 229                         '' => array(
 230                                 'ns' => 'namespace',
 231                                 'title' => 'string'
 232                         )
 233                 );
 234         }
 235
 236         public function getDescription() {
 237                 return "Returns all {$this->description}s from the given page(s)";
 238         }
 239
 240         public function getExamples() {
 241                 $desc = $this->description;
 242                 $name = $this->getModuleName();
 243                 return array(
 244                         "api.php?action=query&prop={$name}&titles=Main%20Page" => "Get {$desc}s from the [[Main Page]]:",
 245                         "api.php?action=query&generator={$name}&titles=Main%20Page&prop=info" => "Get information about the {$desc} pages in the [[Main Page]]:",
 246                         "api.php?action=query&prop={$name}&titles=Main%20Page&{$this->prefix}namespace=2|10" => "Get {$desc}s from the Main Page in the User and Template namespaces:",
 247                 );
 248         }
 249
 250         public function getHelpUrls() {
 251                 return $this->helpUrl;
 252         }
 253
 254         public function getVersion() {
 255                 return __CLASS__ . ': $Id$';
 256         }
 257 }