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 if ( !defined( 'MEDIAWIKI' ) ) {
  28         // Eclipse helper - will be ignored in production
  29         require_once( "ApiQueryBase.php" );
  30 }
  31
  32 /**
  33  * A query module to list all wiki links on a given set of pages.
  34  *
  35  * @ingroup API
  36  */
  37 class ApiQueryLinks extends ApiQueryGeneratorBase {
  38
  39         const LINKS = 'links';
  40         const TEMPLATES = 'templates';
  41
  42         private $table, $prefix, $description, $helpUrl;
  43
  44         public function __construct( $query, $moduleName ) {
  45                 switch ( $moduleName ) {
  46                         case self::LINKS:
  47                                 $this->table = 'pagelinks';
  48                                 $this->prefix = 'pl';
  49                                 $this->description = 'link';
  50                                 $this->titlesParam = 'titles';
  51                                 $this->helpUrl = 'http://www.mediawiki.org/wiki/API:Properties#links_.2F_pl';
  52                                 break;
  53                         case self::TEMPLATES:
  54                                 $this->table = 'templatelinks';
  55                                 $this->prefix = 'tl';
  56                                 $this->description = 'template';
  57                                 $this->titlesParam = 'templates';
  58                                 $this->helpUrl = 'http://www.mediawiki.org/wiki/API:Properties#templates_.2F_tl';
  59                                 break;
  60                         default:
  61                                 ApiBase::dieDebug( __METHOD__, 'Unknown module name' );
  62                 }
  63
  64                 parent::__construct( $query, $moduleName, $this->prefix );
  65         }
  66
  67         public function execute() {
  68                 $this->run();
  69         }
  70
  71         public function getCacheMode( $params ) {
  72                 return 'public';
  73         }
  74
  75         public function executeGenerator( $resultPageSet ) {
  76                 $this->run( $resultPageSet );
  77         }
  78
  79         /**
  80          * @param $resultPageSet ApiPageSet
  81          * @return
  82          */
  83         private function run( $resultPageSet = null ) {
  84                 if ( $this->getPageSet()->getGoodTitleCount() == 0 ) {
  85                         return; // nothing to do
  86                 }
  87
  88                 $params = $this->extractRequestParams();
  89
  90                 $this->addFields( array(
  91                         $this->prefix . '_from AS pl_from',
  92                         $this->prefix . '_namespace AS pl_namespace',
  93                         $this->prefix . '_title AS pl_title'
  94                 ) );
  95
  96                 $this->addTables( $this->table );
  97                 $this->addWhereFld( $this->prefix . '_from', array_keys( $this->getPageSet()->getGoodTitles() ) );
  98                 $this->addWhereFld( $this->prefix . '_namespace', $params['namespace'] );
  99
 100                 if ( !is_null( $params[$this->titlesParam] ) ) {
 101                         $lb = new LinkBatch;
 102                         foreach ( $params[$this->titlesParam] as $t ) {
 103                                 $title = Title::newFromText( $t );
 104                                 if ( !$title ) {
 105                                         $this->setWarning( "``$t'' is not a valid title" );
 106                                 } else {
 107                                         $lb->addObj( $title );
 108                                 }
 109                         }
 110                         $cond = $lb->constructSet( $this->prefix, $this->getDB() );
 111                         if ( $cond ) {
 112                                 $this->addWhere( $cond );
 113                         }
 114                 }
 115
 116                 if ( !is_null( $params['continue'] ) ) {
 117                         $cont = explode( '|', $params['continue'] );
 118                         if ( count( $cont ) != 3 ) {
 119                                 $this->dieUsage( 'Invalid continue param. You should pass the ' .
 120                                         'original value returned by the previous query', '_badcontinue' );
 121                         }
 122                         $plfrom = intval( $cont[0] );
 123                         $plns = intval( $cont[1] );
 124                         $pltitle = $this->getDB()->strencode( $this->titleToKey( $cont[2] ) );
 125                         $this->addWhere(
 126                                 "{$this->prefix}_from > $plfrom OR " .
 127                                 "({$this->prefix}_from = $plfrom AND " .
 128                                 "({$this->prefix}_namespace > $plns OR " .
 129                                 "({$this->prefix}_namespace = $plns AND " .
 130                                 "{$this->prefix}_title >= '$pltitle')))"
 131                         );
 132                 }
 133
 134                 // Here's some MySQL craziness going on: if you use WHERE foo='bar'
 135                 // and later ORDER BY foo MySQL doesn't notice the ORDER BY is pointless
 136                 // but instead goes and filesorts, because the index for foo was used
 137                 // already. To work around this, we drop constant fields in the WHERE
 138                 // clause from the ORDER BY clause
 139                 $order = array();
 140                 if ( count( $this->getPageSet()->getGoodTitles() ) != 1 ) {
 141                         $order[] = "{$this->prefix}_from";
 142                 }
 143                 if ( count( $params['namespace'] ) != 1 ) {
 144                         $order[] = "{$this->prefix}_namespace";
 145                 }
 146
 147                 $order[] = "{$this->prefix}_title";
 148                 $this->addOption( 'ORDER BY', implode( ', ', $order ) );
 149                 $this->addOption( 'USE INDEX', "{$this->prefix}_from" );
 150                 $this->addOption( 'LIMIT', $params['limit'] + 1 );
 151
 152                 $res = $this->select( __METHOD__ );
 153
 154                 if ( is_null( $resultPageSet ) ) {
 155                         $count = 0;
 156                         foreach ( $res as $row ) {
 157                                 if ( ++$count > $params['limit'] ) {
 158                                         // We've reached the one extra which shows that
 159                                         // there are additional pages to be had. Stop here...
 160                                         $this->setContinueEnumParameter( 'continue',
 161                                                 "{$row->pl_from}|{$row->pl_namespace}|" .
 162                                                 $this->keyToTitle( $row->pl_title ) );
 163                                         break;
 164                                 }
 165                                 $vals = array();
 166                                 ApiQueryBase::addTitleInfo( $vals, Title::makeTitle( $row->pl_namespace, $row->pl_title ) );
 167                                 $fit = $this->addPageSubItem( $row->pl_from, $vals );
 168                                 if ( !$fit ) {
 169                                         $this->setContinueEnumParameter( 'continue',
 170                                                 "{$row->pl_from}|{$row->pl_namespace}|" .
 171                                                 $this->keyToTitle( $row->pl_title ) );
 172                                         break;
 173                                 }
 174                         }
 175                 } else {
 176                         $titles = array();
 177                         $count = 0;
 178                         foreach ( $res as $row ) {
 179                                 if ( ++$count > $params['limit'] ) {
 180                                         // We've reached the one extra which shows that
 181                                         // there are additional pages to be had. Stop here...
 182                                         $this->setContinueEnumParameter( 'continue',
 183                                                 "{$row->pl_from}|{$row->pl_namespace}|" .
 184                                                 $this->keyToTitle( $row->pl_title ) );
 185                                         break;
 186                                 }
 187                                 $titles[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
 188                         }
 189                         $resultPageSet->populateFromTitles( $titles );
 190                 }
 191         }
 192
 193         public function getAllowedParams() {
 194                 return array(
 195                         'namespace' => array(
 196                                 ApiBase::PARAM_TYPE => 'namespace',
 197                                 ApiBase::PARAM_ISMULTI => true
 198                         ),
 199                         'limit' => array(
 200                                 ApiBase::PARAM_DFLT => 10,
 201                                 ApiBase::PARAM_TYPE => 'limit',
 202                                 ApiBase::PARAM_MIN => 1,
 203                                 ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
 204                                 ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
 205                         ),
 206                         'continue' => null,
 207                         $this->titlesParam => array(
 208                                 ApiBase::PARAM_ISMULTI => true,
 209                         ),
 210                 );
 211         }
 212
 213         public function getParamDescription() {
 214                 $desc = $this->description;
 215                 $arr = array(
 216                         'namespace' => "Show {$desc}s in this namespace(s) only",
 217                         'limit' => "How many {$desc}s to return",
 218                         'continue' => 'When more results are available, use this to continue',
 219                 );
 220                 if ( $this->getModuleName() == self::LINKS ) {
 221                         $arr[$this->titlesParam] = 'Only list links to these titles. Useful for checking whether a certain page links to a certain title.';
 222                 } elseif ( $this->getModuleName() == self::TEMPLATES ) {
 223                         $arr[$this->titlesParam] = 'Only list these templates. Useful for checking whether a certain page uses a certain template.';
 224                 }
 225                 return $arr;
 226         }
 227
 228         public function getDescription() {
 229                 return "Returns all {$this->description}s from the given page(s)";
 230         }
 231
 232         protected function getExamples() {
 233                 return array(
 234                         "Get {$this->description}s from the [[Main Page]]:",
 235                         "  api.php?action=query&prop={$this->getModuleName()}&titles=Main%20Page",
 236                         "Get information about the {$this->description} pages in the [[Main Page]]:",
 237                         "  api.php?action=query&generator={$this->getModuleName()}&titles=Main%20Page&prop=info",
 238                         "Get {$this->description}s from the Main Page in the User and Template namespaces:",
 239                         "  api.php?action=query&prop={$this->getModuleName()}&titles=Main%20Page&{$this->prefix}namespace=2|10"
 240                 );
 241         }
 242
 243         public function getHelpUrls() {
 244                 return $this->helpUrl;
 245         }
 246
 247         public function getVersion() {
 248                 return __CLASS__ . ': $Id$';
 249         }
 250 }