includes/api/ApiQueryCategoryMembers.php

   1 <?php
   2
   3 /**
   4  * Created on June 14, 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  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 enumerate pages that belong to a category.
  33  *
  34  * @ingroup API
  35  */
  36 class ApiQueryCategoryMembers extends ApiQueryGeneratorBase {
  37
  38         public function __construct( $query, $moduleName ) {
  39                 parent::__construct( $query, $moduleName, 'cm' );
  40         }
  41
  42         public function execute() {
  43                 $this->run();
  44         }
  45
  46         public function executeGenerator( $resultPageSet ) {
  47                 $this->run( $resultPageSet );
  48         }
  49
  50         private function run( $resultPageSet = null ) {
  51                 $params = $this->extractRequestParams();
  52
  53                 if ( !isset( $params['title'] ) || is_null( $params['title'] ) ) {
  54                         $this->dieUsage( 'The cmtitle parameter is required', 'notitle' );
  55                 }
  56                 $categoryTitle = Title::newFromText( $params['title'] );
  57
  58                 if ( is_null( $categoryTitle ) || $categoryTitle->getNamespace() != NS_CATEGORY ) {
  59                         $this->dieUsage( 'The category name you entered is not valid', 'invalidcategory' );
  60                 }
  61
  62                 $prop = array_flip( $params['prop'] );
  63                 $fld_ids = isset( $prop['ids'] );
  64                 $fld_title = isset( $prop['title'] );
  65                 $fld_sortkey = isset( $prop['sortkey'] );
  66                 $fld_timestamp = isset( $prop['timestamp'] );
  67
  68                 if ( is_null( $resultPageSet ) ) {
  69                         $this->addFields( array( 'cl_from', 'cl_sortkey', 'page_namespace', 'page_title' ) );
  70                         $this->addFieldsIf( 'page_id', $fld_ids );
  71                 } else {
  72                         $this->addFields( $resultPageSet->getPageTableFields() ); // will include page_ id, ns, title
  73                         $this->addFields( array( 'cl_from', 'cl_sortkey' ) );
  74                 }
  75
  76                 $this->addFieldsIf( 'cl_timestamp', $fld_timestamp || $params['sort'] == 'timestamp' );
  77                 $this->addTables( array( 'page', 'categorylinks' ) );   // must be in this order for 'USE INDEX'
  78                                                                         // Not needed after bug 10280 is applied to servers
  79                 if ( $params['sort'] == 'timestamp' ) {
  80                         $this->addOption( 'USE INDEX', 'cl_timestamp' );
  81                 } else {
  82                         $this->addOption( 'USE INDEX', 'cl_sortkey' );
  83                 }
  84
  85                 $this->addWhere( 'cl_from=page_id' );
  86                 $this->setContinuation( $params['continue'], $params['dir'] );
  87                 $this->addWhereFld( 'cl_to', $categoryTitle->getDBkey() );
  88                 // Scanning large datasets for rare categories sucks, and I already told
  89                 // how to have efficient subcategory access :-) ~~~~ (oh well, domas)
  90                 global $wgMiserMode;
  91                 $miser_ns = array();
  92                 if ( $wgMiserMode ) {
  93                         $miser_ns = $params['namespace'];
  94                 } else {
  95                         $this->addWhereFld( 'page_namespace', $params['namespace'] );
  96                 }
  97                 if ( $params['sort'] == 'timestamp' ) {
  98                         $this->addWhereRange( 'cl_timestamp', ( $params['dir'] == 'asc' ? 'newer' : 'older' ), $params['start'], $params['end'] );
  99                 } else {
 100                         $this->addWhereRange( 'cl_sortkey', ( $params['dir'] == 'asc' ? 'newer' : 'older' ), $params['startsortkey'], $params['endsortkey'] );
 101                         $this->addWhereRange( 'cl_from', ( $params['dir'] == 'asc' ? 'newer' : 'older' ), null, null );
 102                 }
 103
 104                 $limit = $params['limit'];
 105                 $this->addOption( 'LIMIT', $limit + 1 );
 106
 107                 $db = $this->getDB();
 108
 109                 $data = array();
 110                 $count = 0;
 111                 $lastSortKey = null;
 112                 $res = $this->select( __METHOD__ );
 113                 while ( $row = $db->fetchObject( $res ) ) {
 114                         if ( ++ $count > $limit ) {
 115                                 // We've reached the one extra which shows that there are additional pages to be had. Stop here...
 116                                 // TODO: Security issue - if the user has no right to view next title, it will still be shown
 117                                 if ( $params['sort'] == 'timestamp' ) {
 118                                         $this->setContinueEnumParameter( 'start', wfTimestamp( TS_ISO_8601, $row->cl_timestamp ) );
 119                                 } else {
 120                                         $this->setContinueEnumParameter( 'continue', $this->getContinueStr( $row, $lastSortKey ) );
 121                                 }
 122                                 break;
 123                         }
 124
 125                         // Since domas won't tell anyone what he told long ago, apply
 126                         // cmnamespace here. This means the query may return 0 actual
 127                         // results, but on the other hand it could save returning 5000
 128                         // useless results to the client. ~~~~
 129                         if ( count( $miser_ns ) && !in_array( $row->page_namespace, $miser_ns ) ) {
 130                                 continue;
 131                         }
 132
 133                         if ( is_null( $resultPageSet ) ) {
 134                                 $vals = array();
 135                                 if ( $fld_ids ) {
 136                                         $vals['pageid'] = intval( $row->page_id );
 137                                 }
 138                                 if ( $fld_title ) {
 139                                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 140                                         ApiQueryBase::addTitleInfo( $vals, $title );
 141                                 }
 142                                 if ( $fld_sortkey ) {
 143                                         $vals['sortkey'] = $row->cl_sortkey;
 144                                 }
 145                                 if ( $fld_timestamp ) {
 146                                         $vals['timestamp'] = wfTimestamp( TS_ISO_8601, $row->cl_timestamp );
 147                                 }
 148                                 $fit = $this->getResult()->addValue( array( 'query', $this->getModuleName() ),
 149                                                 null, $vals );
 150                                 if ( !$fit ) {
 151                                         if ( $params['sort'] == 'timestamp' ) {
 152                                                 $this->setContinueEnumParameter( 'start', wfTimestamp( TS_ISO_8601, $row->cl_timestamp ) );
 153                                         } else {
 154                                                 $this->setContinueEnumParameter( 'continue', $this->getContinueStr( $row, $lastSortKey ) );
 155                                         }
 156                                         break;
 157                                 }
 158                         } else {
 159                                 $resultPageSet->processDbRow( $row );
 160                         }
 161                         $lastSortKey = $row->cl_sortkey; // detect duplicate sortkeys
 162                 }
 163                 $db->freeResult( $res );
 164
 165                 if ( is_null( $resultPageSet ) ) {
 166                         $this->getResult()->setIndexedTagName_internal(
 167                                          array( 'query', $this->getModuleName() ), 'cm' );
 168                 }
 169         }
 170
 171         private function getContinueStr( $row, $lastSortKey ) {
 172                 $ret = $row->cl_sortkey . '|';
 173                 if ( $row->cl_sortkey == $lastSortKey ) { // duplicate sort key, add cl_from
 174                         $ret .= $row->cl_from;
 175                 }
 176                 return $ret;
 177         }
 178
 179         /**
 180          * Add DB WHERE clause to continue previous query based on 'continue' parameter
 181          */
 182         private function setContinuation( $continue, $dir ) {
 183                 if ( is_null( $continue ) ) {
 184                         return; // This is not a continuation request
 185                 }
 186
 187                 $pos = strrpos( $continue, '|' );
 188                 $sortkey = substr( $continue, 0, $pos );
 189                 $fromstr = substr( $continue, $pos + 1 );
 190                 $from = intval( $fromstr );
 191
 192                 if ( $from == 0 && strlen( $fromstr ) > 0 ) {
 193                         $this->dieUsage( 'Invalid continue param. You should pass the original value returned by the previous query', 'badcontinue' );
 194                 }
 195
 196                 $encSortKey = $this->getDB()->addQuotes( $sortkey );
 197                 $encFrom = $this->getDB()->addQuotes( $from );
 198
 199                 $op = ( $dir == 'desc' ? '<' : '>' );
 200
 201                 if ( $from != 0 ) {
 202                         // Duplicate sort key continue
 203                         $this->addWhere( "cl_sortkey$op$encSortKey OR (cl_sortkey=$encSortKey AND cl_from$op=$encFrom)" );
 204                 } else {
 205                         $this->addWhere( "cl_sortkey$op=$encSortKey" );
 206                 }
 207         }
 208
 209         public function getAllowedParams() {
 210                 return array(
 211                         'title' => null,
 212                         'prop' => array(
 213                                 ApiBase::PARAM_DFLT => 'ids|title',
 214                                 ApiBase::PARAM_ISMULTI => true,
 215                                 ApiBase::PARAM_TYPE => array (
 216                                         'ids',
 217                                         'title',
 218                                         'sortkey',
 219                                         'timestamp',
 220                                 )
 221                         ),
 222                         'namespace' => array (
 223                                 ApiBase::PARAM_ISMULTI => true,
 224                                 ApiBase::PARAM_TYPE => 'namespace',
 225                         ),
 226                         'continue' => null,
 227                         'limit' => array(
 228                                 ApiBase::PARAM_TYPE => 'limit',
 229                                 ApiBase::PARAM_DFLT => 10,
 230                                 ApiBase::PARAM_MIN => 1,
 231                                 ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
 232                                 ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
 233                         ),
 234                         'sort' => array(
 235                                 ApiBase::PARAM_DFLT => 'sortkey',
 236                                 ApiBase::PARAM_TYPE => array(
 237                                         'sortkey',
 238                                         'timestamp'
 239                                 )
 240                         ),
 241                         'dir' => array(
 242                                 ApiBase::PARAM_DFLT => 'asc',
 243                                 ApiBase::PARAM_TYPE => array(
 244                                         'asc',
 245                                         'desc'
 246                                 )
 247                         ),
 248                         'start' => array(
 249                                 ApiBase::PARAM_TYPE => 'timestamp'
 250                         ),
 251                         'end' => array(
 252                                 ApiBase::PARAM_TYPE => 'timestamp'
 253                         ),
 254                         'startsortkey' => null,
 255                         'endsortkey' => null,
 256                 );
 257         }
 258
 259         public function getParamDescription() {
 260                 global $wgMiserMode;
 261                 $desc = array(
 262                         'title' => 'Which category to enumerate (required). Must include Category: prefix',
 263                         'prop' => 'What pieces of information to include',
 264                         'namespace' => 'Only include pages in these namespaces',
 265                         'sort' => 'Property to sort by',
 266                         'dir' => 'In which direction to sort',
 267                         'start' => 'Timestamp to start listing from. Can only be used with cmsort=timestamp',
 268                         'end' => 'Timestamp to end listing at. Can only be used with cmsort=timestamp',
 269                         'startsortkey' => 'Sortkey to start listing from. Can only be used with cmsort=sortkey',
 270                         'endsortkey' => 'Sortkey to end listing at. Can only be used with cmsort=sortkey',
 271                         'continue' => 'For large categories, give the value retured from previous query',
 272                         'limit' => 'The maximum number of pages to return.',
 273                 );
 274                 if ( $wgMiserMode ) {
 275                         $desc['namespace'] = array(
 276                                 $desc['namespace'],
 277                                 'NOTE: Due to $wgMiserMode, using this may result in fewer than "limit" results',
 278                                 'returned before continuing; in extreme cases, zero results may be returned.',
 279                         );
 280                 }
 281                 return $desc;
 282         }
 283
 284         public function getDescription() {
 285                 return 'List all pages in a given category';
 286         }
 287
 288         public function getPossibleErrors() {
 289                 return array_merge( parent::getPossibleErrors(), array(
 290                         array( 'code' => 'notitle', 'info' => 'The cmtitle parameter is required' ),
 291                         array( 'code' => 'invalidcategory', 'info' => 'The category name you entered is not valid' ),
 292                         array( 'code' => 'badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
 293                 ) );
 294         }
 295
 296         protected function getExamples() {
 297                 return array(
 298                         'Get first 10 pages in [[Category:Physics]]:',
 299                         '  api.php?action=query&list=categorymembers&cmtitle=Category:Physics',
 300                         'Get page info about first 10 pages in [[Category:Physics]]:',
 301                         '  api.php?action=query&generator=categorymembers&gcmtitle=Category:Physics&prop=info',
 302                 );
 303         }
 304
 305         public function getVersion() {
 306                 return __CLASS__ . ': $Id$';
 307         }
 308 }