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         private function run( $resultPageSet = null ) {
  78                 if ( $this->getPageSet()->getGoodTitleCount() == 0 ) {
  79                         return; // nothing to do
  80                 }
  81
  82                 $params = $this->extractRequestParams();
  83
  84                 $this->addFields( array(
  85                         $this->prefix . '_from AS pl_from',
  86                         $this->prefix . '_namespace AS pl_namespace',
  87                         $this->prefix . '_title AS pl_title'
  88                 ) );
  89
  90                 $this->addTables( $this->table );
  91                 $this->addWhereFld( $this->prefix . '_from', array_keys( $this->getPageSet()->getGoodTitles() ) );
  92                 $this->addWhereFld( $this->prefix . '_namespace', $params['namespace'] );
  93
  94                 if ( !is_null( $params[$this->titlesParam] ) ) {
  95                         $lb = new LinkBatch;
  96                         foreach ( $params[$this->titlesParam] as $t ) {
  97                                 $title = Title::newFromText( $t );
  98                                 if ( !$title ) {
  99                                         $this->setWarning( "``$t'' is not a valid title" );
 100                                 } else {
 101                                         $lb->addObj( $title );
 102                                 }
 103                         }
 104                         $cond = $lb->constructSet( $this->prefix, $this->getDB() );
 105                         if ( $cond ) {
 106                                 $this->addWhere( $cond );
 107                         }
 108                 }
 109
 110                 if ( !is_null( $params['continue'] ) ) {
 111                         $cont = explode( '|', $params['continue'] );
 112                         if ( count( $cont ) != 3 ) {
 113                                 $this->dieUsage( 'Invalid continue param. You should pass the ' .
 114                                         'original value returned by the previous query', '_badcontinue' );
 115                         }
 116                         $plfrom = intval( $cont[0] );
 117                         $plns = intval( $cont[1] );
 118                         $pltitle = $this->getDB()->strencode( $this->titleToKey( $cont[2] ) );
 119                         $this->addWhere(
 120                                 "{$this->prefix}_from > $plfrom OR " .
 121                                 "({$this->prefix}_from = $plfrom AND " .
 122                                 "({$this->prefix}_namespace > $plns OR " .
 123                                 "({$this->prefix}_namespace = $plns AND " .
 124                                 "{$this->prefix}_title >= '$pltitle')))"
 125                         );
 126                 }
 127
 128                 // Here's some MySQL craziness going on: if you use WHERE foo='bar'
 129                 // and later ORDER BY foo MySQL doesn't notice the ORDER BY is pointless
 130                 // but instead goes and filesorts, because the index for foo was used
 131                 // already. To work around this, we drop constant fields in the WHERE
 132                 // clause from the ORDER BY clause
 133                 $order = array();
 134                 if ( count( $this->getPageSet()->getGoodTitles() ) != 1 ) {
 135                         $order[] = "{$this->prefix}_from";
 136                 }
 137                 if ( count( $params['namespace'] ) != 1 ) {
 138                         $order[] = "{$this->prefix}_namespace";
 139                 }
 140
 141                 $order[] = "{$this->prefix}_title";
 142                 $this->addOption( 'ORDER BY', implode( ', ', $order ) );
 143                 $this->addOption( 'USE INDEX', "{$this->prefix}_from" );
 144                 $this->addOption( 'LIMIT', $params['limit'] + 1 );
 145
 146                 $res = $this->select( __METHOD__ );
 147
 148                 if ( is_null( $resultPageSet ) ) {
 149                         $count = 0;
 150                         foreach ( $res as $row ) {
 151                                 if ( ++$count > $params['limit'] ) {
 152                                         // We've reached the one extra which shows that
 153                                         // there are additional pages to be had. Stop here...
 154                                         $this->setContinueEnumParameter( 'continue',
 155                                                 "{$row->pl_from}|{$row->pl_namespace}|" .
 156                                                 $this->keyToTitle( $row->pl_title ) );
 157                                         break;
 158                                 }
 159                                 $vals = array();
 160                                 ApiQueryBase::addTitleInfo( $vals, Title::makeTitle( $row->pl_namespace, $row->pl_title ) );
 161                                 $fit = $this->addPageSubItem( $row->pl_from, $vals );
 162                                 if ( !$fit ) {
 163                                         $this->setContinueEnumParameter( 'continue',
 164                                                 "{$row->pl_from}|{$row->pl_namespace}|" .
 165                                                 $this->keyToTitle( $row->pl_title ) );
 166                                         break;
 167                                 }
 168                         }
 169                 } else {
 170                         $titles = array();
 171                         $count = 0;
 172                         foreach ( $res as $row ) {
 173                                 if ( ++$count > $params['limit'] ) {
 174                                         // We've reached the one extra which shows that
 175                                         // there are additional pages to be had. Stop here...
 176                                         $this->setContinueEnumParameter( 'continue',
 177                                                 "{$row->pl_from}|{$row->pl_namespace}|" .
 178                                                 $this->keyToTitle( $row->pl_title ) );
 179                                         break;
 180                                 }
 181                                 $titles[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
 182                         }
 183                         $resultPageSet->populateFromTitles( $titles );
 184                 }
 185         }
 186
 187         public function getAllowedParams() {
 188                 return array(
 189                         'namespace' => array(
 190                                 ApiBase::PARAM_TYPE => 'namespace',
 191                                 ApiBase::PARAM_ISMULTI => true
 192                         ),
 193                         'limit' => array(
 194                                 ApiBase::PARAM_DFLT => 10,
 195                                 ApiBase::PARAM_TYPE => 'limit',
 196                                 ApiBase::PARAM_MIN => 1,
 197                                 ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
 198                                 ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
 199                         ),
 200                         'continue' => null,
 201                         $this->titlesParam => array(
 202                                 ApiBase::PARAM_ISMULTI => true,
 203                         ),
 204                 );
 205         }
 206
 207         public function getParamDescription() {
 208                 $desc = $this->description;
 209                 $arr = array(
 210                         'namespace' => "Show {$desc}s in this namespace(s) only",
 211                         'limit' => "How many {$desc}s to return",
 212                         'continue' => 'When more results are available, use this to continue',
 213                 );
 214                 if ( $this->getModuleName() == self::LINKS ) {
 215                         $arr[$this->titlesParam] = 'Only list links to these titles. Useful for checking whether a certain page links to a certain title.';
 216                 } else if ( $this->getModuleName() == self::TEMPLATES ) {
 217                         $arr[$this->titlesParam] = 'Only list these templates. Useful for checking whether a certain page uses a certain template.';
 218                 }
 219                 return $arr;
 220         }
 221
 222         public function getDescription() {
 223                 return "Returns all {$this->description}s from the given page(s)";
 224         }
 225
 226         protected function getExamples() {
 227                 return array(
 228                         "Get {$this->description}s from the [[Main Page]]:",
 229                         "  api.php?action=query&prop={$this->getModuleName()}&titles=Main%20Page",
 230                         "Get information about the {$this->description} pages in the [[Main Page]]:",
 231                         "  api.php?action=query&generator={$this->getModuleName()}&titles=Main%20Page&prop=info",
 232                         "Get {$this->description}s from the Main Page in the User and Template namespaces:",
 233                         "  api.php?action=query&prop={$this->getModuleName()}&titles=Main%20Page&{$this->prefix}namespace=2|10"
 234                 );
 235         }
 236
 237         public function getVersion() {
 238                 return __CLASS__ . ': $Id$';
 239         }
 240 }