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