includes/api/ApiQueryLinks.php

   1 <?php
   2
   3 /**
   4  * Created on May 12, 2007
   5  *
   6  * API for MediaWiki 1.8+
   7  *
   8  * Copyright © 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
   9  *
  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.
  14  *
  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.
  19  *
  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
  24  */
  25
  26 if ( !defined( 'MEDIAWIKI' ) ) {
  27         // Eclipse helper - will be ignored in production
  28         require_once( "ApiQueryBase.php" );
  29 }
  30
  31 /**
  32  * A query module to list all wiki links on a given set of pages.
  33  *
  34  * @ingroup API
  35  */
  36 class ApiQueryLinks extends ApiQueryGeneratorBase {
  37
  38         const LINKS = 'links';
  39         const TEMPLATES = 'templates';
  40
  41         private $table, $prefix, $description;
  42
  43         public function __construct( $query, $moduleName ) {
  44                 switch ( $moduleName ) {
  45                         case self::LINKS:
  46                                 $this->table = 'pagelinks';
  47                                 $this->prefix = 'pl';
  48                                 $this->description = 'link';
  49                                 $this->titlesParam = 'titles';
  50                                 break;
  51                         case self::TEMPLATES:
  52                                 $this->table = 'templatelinks';
  53                                 $this->prefix = 'tl';
  54                                 $this->description = 'template';
  55                                 $this->titlesParam = 'templates';
  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 executeGenerator( $resultPageSet ) {
  69                 $this->run( $resultPageSet );
  70         }
  71
  72         private function run( $resultPageSet = null ) {
  73                 if ( $this->getPageSet()->getGoodTitleCount() == 0 ) {
  74                         return; // nothing to do
  75                 }
  76
  77                 $params = $this->extractRequestParams();
  78
  79                 $this->addFields( array(
  80                         $this->prefix . '_from AS pl_from',
  81                         $this->prefix . '_namespace AS pl_namespace',
  82                         $this->prefix . '_title AS pl_title'
  83                 ) );
  84
  85                 $this->addTables( $this->table );
  86                 $this->addWhereFld( $this->prefix . '_from', array_keys( $this->getPageSet()->getGoodTitles() ) );
  87                 $this->addWhereFld( $this->prefix . '_namespace', $params['namespace'] );
  88
  89                 if ( !is_null( $params[$this->titlesParam] ) ) {
  90                         $lb = new LinkBatch;
  91                         foreach ( $params[$this->titlesParam] as $t ) {
  92                                 $title = Title::newFromText( $t );
  93                                 if ( !$title ) {
  94                                         $this->setWarning( "``$t'' is not a valid title" );
  95                                 } else {
  96                                         $lb->addObj( $title );
  97                                 }
  98                         }
  99                         $cond = $lb->constructSet( $this->prefix, $this->getDB() );
 100                         if ( $cond ) {
 101                                 $this->addWhere( $cond );
 102                         }
 103                 }
 104
 105                 if ( !is_null( $params['continue'] ) ) {
 106                         $cont = explode( '|', $params['continue'] );
 107                         if ( count( $cont ) != 3 ) {
 108                                 $this->dieUsage( 'Invalid continue param. You should pass the ' .
 109                                         'original value returned by the previous query', '_badcontinue' );
 110                         }
 111                         $plfrom = intval( $cont[0] );
 112                         $plns = intval( $cont[1] );
 113                         $pltitle = $this->getDB()->strencode( $this->titleToKey( $cont[2] ) );
 114                         $this->addWhere(
 115                                 "{$this->prefix}_from > $plfrom OR " .
 116                                 "({$this->prefix}_from = $plfrom AND " .
 117                                 "({$this->prefix}_namespace > $plns OR " .
 118                                 "({$this->prefix}_namespace = $plns AND " .
 119                                 "{$this->prefix}_title >= '$pltitle')))"
 120                         );
 121                 }
 122
 123                 // Here's some MySQL craziness going on: if you use WHERE foo='bar'
 124                 // and later ORDER BY foo MySQL doesn't notice the ORDER BY is pointless
 125                 // but instead goes and filesorts, because the index for foo was used
 126                 // already. To work around this, we drop constant fields in the WHERE
 127                 // clause from the ORDER BY clause
 128                 $order = array();
 129                 if ( count( $this->getPageSet()->getGoodTitles() ) != 1 ) {
 130                         $order[] = "{$this->prefix}_from";
 131                 }
 132                 if ( count( $params['namespace'] ) != 1 ) {
 133                         $order[] = "{$this->prefix}_namespace";
 134                 }
 135
 136                 $order[] = "{$this->prefix}_title";
 137                 $this->addOption( 'ORDER BY', implode( ', ', $order ) );
 138                 $this->addOption( 'USE INDEX', "{$this->prefix}_from" );
 139                 $this->addOption( 'LIMIT', $params['limit'] + 1 );
 140
 141                 $db = $this->getDB();
 142                 $res = $this->select( __METHOD__ );
 143
 144                 if ( is_null( $resultPageSet ) ) {
 145                         $count = 0;
 146                         foreach ( $res as $row ) {
 147                                 if ( ++$count > $params['limit'] ) {
 148                                         // We've reached the one extra which shows that
 149                                         // there are additional pages to be had. Stop here...
 150                                         $this->setContinueEnumParameter( 'continue',
 151                                                 "{$row->pl_from}|{$row->pl_namespace}|" .
 152                                                 $this->keyToTitle( $row->pl_title ) );
 153                                         break;
 154                                 }
 155                                 $vals = array();
 156                                 ApiQueryBase::addTitleInfo( $vals, Title::makeTitle( $row->pl_namespace, $row->pl_title ) );
 157                                 $fit = $this->addPageSubItem( $row->pl_from, $vals );
 158                                 if ( !$fit ) {
 159                                         $this->setContinueEnumParameter( 'continue',
 160                                                 "{$row->pl_from}|{$row->pl_namespace}|" .
 161                                                 $this->keyToTitle( $row->pl_title ) );
 162                                         break;
 163                                 }
 164                         }
 165                 } else {
 166                         $titles = array();
 167                         $count = 0;
 168                         foreach ( $res as $row ) {
 169                                 if ( ++$count > $params['limit'] ) {
 170                                         // We've reached the one extra which shows that
 171                                         // there are additional pages to be had. Stop here...
 172                                         $this->setContinueEnumParameter( 'continue',
 173                                                 "{$row->pl_from}|{$row->pl_namespace}|" .
 174                                                 $this->keyToTitle( $row->pl_title ) );
 175                                         break;
 176                                 }
 177                                 $titles[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
 178                         }
 179                         $resultPageSet->populateFromTitles( $titles );
 180                 }
 181         }
 182
 183         public function getAllowedParams() {
 184                 return array(
 185                         'namespace' => array(
 186                                 ApiBase::PARAM_TYPE => 'namespace',
 187                                 ApiBase::PARAM_ISMULTI => true
 188                         ),
 189                         'limit' => array(
 190                                 ApiBase::PARAM_DFLT => 10,
 191                                 ApiBase::PARAM_TYPE => 'limit',
 192                                 ApiBase::PARAM_MIN => 1,
 193                                 ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
 194                                 ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
 195                         ),
 196                         'continue' => null,
 197                         $this->titlesParam => array(
 198                                 ApiBase::PARAM_ISMULTI => true,
 199                         ),
 200                 );
 201         }
 202
 203         public function getParamDescription() {
 204                 $desc = $this->description;
 205                 $arr = array(
 206                         'namespace' => "Show {$desc}s in this namespace(s) only",
 207                         'limit' => "How many {$desc}s to return",
 208                         'continue' => 'When more results are available, use this to continue',
 209                 );
 210                 if ( $this->getModuleName() == self::LINKS ) {
 211                         $arr[$this->titlesParam] = 'Only list links to these titles. Useful for checking whether a certain page links to a certain title.';
 212                 } else if ( $this->getModuleName() == self::TEMPLATES ) {
 213                         $arr[$this->titlesParam] = 'Only list these templates. Useful for checking whether a certain page uses a certain template.';
 214                 }
 215                 return $arr;
 216         }
 217
 218         public function getDescription() {
 219                 return "Returns all {$this->description}s from the given page(s)";
 220         }
 221
 222         protected function getExamples() {
 223                 return array(
 224                         "Get {$this->description}s from the [[Main Page]]:",
 225                         "  api.php?action=query&prop={$this->getModuleName()}&titles=Main%20Page",
 226                         "Get information about the {$this->description} pages in the [[Main Page]]:",
 227                         "  api.php?action=query&generator={$this->getModuleName()}&titles=Main%20Page&prop=info",
 228                         "Get {$this->description}s from the Main Page in the User and Template namespaces:",
 229                         "  api.php?action=query&prop={$this->getModuleName()}&titles=Main%20Page&{$this->prefix}namespace=2|10"
 230                 );
 231         }
 232
 233         public function getVersion() {
 234                 return __CLASS__ . ': $Id$';
 235         }
 236 }