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  * 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 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                 $count = 0;
 108                 $lastSortKey = null;
 109                 $res = $this->select( __METHOD__ );
 110                 foreach ( $res as $row ) {
 111                         if ( ++ $count > $limit ) {
 112                                 // We've reached the one extra which shows that there are additional pages to be had. Stop here...
 113                                 // TODO: Security issue - if the user has no right to view next title, it will still be shown
 114                                 if ( $params['sort'] == 'timestamp' ) {
 115                                         $this->setContinueEnumParameter( 'start', wfTimestamp( TS_ISO_8601, $row->cl_timestamp ) );
 116                                 } else {
 117                                         $this->setContinueEnumParameter( 'continue', $this->getContinueStr( $row, $lastSortKey ) );
 118                                 }
 119                                 break;
 120                         }
 121
 122                         // Since domas won't tell anyone what he told long ago, apply
 123                         // cmnamespace here. This means the query may return 0 actual
 124                         // results, but on the other hand it could save returning 5000
 125                         // useless results to the client. ~~~~
 126                         if ( count( $miser_ns ) && !in_array( $row->page_namespace, $miser_ns ) ) {
 127                                 continue;
 128                         }
 129
 130                         if ( is_null( $resultPageSet ) ) {
 131                                 $vals = array();
 132                                 if ( $fld_ids ) {
 133                                         $vals['pageid'] = intval( $row->page_id );
 134                                 }
 135                                 if ( $fld_title ) {
 136                                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 137                                         ApiQueryBase::addTitleInfo( $vals, $title );
 138                                 }
 139                                 if ( $fld_sortkey ) {
 140                                         $vals['sortkey'] = $row->cl_sortkey;
 141                                 }
 142                                 if ( $fld_timestamp ) {
 143                                         $vals['timestamp'] = wfTimestamp( TS_ISO_8601, $row->cl_timestamp );
 144                                 }
 145                                 $fit = $this->getResult()->addValue( array( 'query', $this->getModuleName() ),
 146                                                 null, $vals );
 147                                 if ( !$fit ) {
 148                                         if ( $params['sort'] == 'timestamp' ) {
 149                                                 $this->setContinueEnumParameter( 'start', wfTimestamp( TS_ISO_8601, $row->cl_timestamp ) );
 150                                         } else {
 151                                                 $this->setContinueEnumParameter( 'continue', $this->getContinueStr( $row, $lastSortKey ) );
 152                                         }
 153                                         break;
 154                                 }
 155                         } else {
 156                                 $resultPageSet->processDbRow( $row );
 157                         }
 158                         $lastSortKey = $row->cl_sortkey; // detect duplicate sortkeys
 159                 }
 160
 161                 if ( is_null( $resultPageSet ) ) {
 162                         $this->getResult()->setIndexedTagName_internal(
 163                                          array( 'query', $this->getModuleName() ), 'cm' );
 164                 }
 165         }
 166
 167         private function getContinueStr( $row, $lastSortKey ) {
 168                 $ret = $row->cl_sortkey . '|';
 169                 if ( $row->cl_sortkey == $lastSortKey ) { // duplicate sort key, add cl_from
 170                         $ret .= $row->cl_from;
 171                 }
 172                 return $ret;
 173         }
 174
 175         /**
 176          * Add DB WHERE clause to continue previous query based on 'continue' parameter
 177          */
 178         private function setContinuation( $continue, $dir ) {
 179                 if ( is_null( $continue ) ) {
 180                         return; // This is not a continuation request
 181                 }
 182
 183                 $pos = strrpos( $continue, '|' );
 184                 $sortkey = substr( $continue, 0, $pos );
 185                 $fromstr = substr( $continue, $pos + 1 );
 186                 $from = intval( $fromstr );
 187
 188                 if ( $from == 0 && strlen( $fromstr ) > 0 ) {
 189                         $this->dieUsage( 'Invalid continue param. You should pass the original value returned by the previous query', 'badcontinue' );
 190                 }
 191
 192                 $encSortKey = $this->getDB()->addQuotes( $sortkey );
 193                 $encFrom = $this->getDB()->addQuotes( $from );
 194
 195                 $op = ( $dir == 'desc' ? '<' : '>' );
 196
 197                 if ( $from != 0 ) {
 198                         // Duplicate sort key continue
 199                         $this->addWhere( "cl_sortkey$op$encSortKey OR (cl_sortkey=$encSortKey AND cl_from$op=$encFrom)" );
 200                 } else {
 201                         $this->addWhere( "cl_sortkey$op=$encSortKey" );
 202                 }
 203         }
 204
 205         public function getAllowedParams() {
 206                 return array(
 207                         'title' => null,
 208                         'prop' => array(
 209                                 ApiBase::PARAM_DFLT => 'ids|title',
 210                                 ApiBase::PARAM_ISMULTI => true,
 211                                 ApiBase::PARAM_TYPE => array (
 212                                         'ids',
 213                                         'title',
 214                                         'sortkey',
 215                                         'timestamp',
 216                                 )
 217                         ),
 218                         'namespace' => array (
 219                                 ApiBase::PARAM_ISMULTI => true,
 220                                 ApiBase::PARAM_TYPE => 'namespace',
 221                         ),
 222                         'continue' => null,
 223                         'limit' => array(
 224                                 ApiBase::PARAM_TYPE => 'limit',
 225                                 ApiBase::PARAM_DFLT => 10,
 226                                 ApiBase::PARAM_MIN => 1,
 227                                 ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
 228                                 ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
 229                         ),
 230                         'sort' => array(
 231                                 ApiBase::PARAM_DFLT => 'sortkey',
 232                                 ApiBase::PARAM_TYPE => array(
 233                                         'sortkey',
 234                                         'timestamp'
 235                                 )
 236                         ),
 237                         'dir' => array(
 238                                 ApiBase::PARAM_DFLT => 'asc',
 239                                 ApiBase::PARAM_TYPE => array(
 240                                         'asc',
 241                                         'desc'
 242                                 )
 243                         ),
 244                         'start' => array(
 245                                 ApiBase::PARAM_TYPE => 'timestamp'
 246                         ),
 247                         'end' => array(
 248                                 ApiBase::PARAM_TYPE => 'timestamp'
 249                         ),
 250                         'startsortkey' => null,
 251                         'endsortkey' => null,
 252                 );
 253         }
 254
 255         public function getParamDescription() {
 256                 global $wgMiserMode;
 257                 $p = $this->getModulePrefix();
 258                 $desc = array(
 259                         'title' => 'Which category to enumerate (required). Must include Category: prefix',
 260                         'prop' => array(
 261                                 'What pieces of information to include',
 262                                 ' ids        - Adds the page id',
 263                                 ' title      - Adds the title and namespace id of the page',
 264                                 ' sortkey    - Adds the sortkey used for the category',
 265                                 ' timestamp  - Adds the timestamp of when the page was included',
 266                         ),
 267                         'namespace' => 'Only include pages in these namespaces',
 268                         'sort' => 'Property to sort by',
 269                         'dir' => 'In which direction to sort',
 270                         'start' => "Timestamp to start listing from. Can only be used with {$p}sort=timestamp",
 271                         'end' => "Timestamp to end listing at. Can only be used with {$p}sort=timestamp",
 272                         'startsortkey' => "Sortkey to start listing from. Can only be used with {$p}sort=sortkey",
 273                         'endsortkey' => "Sortkey to end listing at. Can only be used with {$p}sort=sortkey",
 274                         'continue' => 'For large categories, give the value retured from previous query',
 275                         'limit' => 'The maximum number of pages to return.',
 276                 );
 277                 if ( $wgMiserMode ) {
 278                         $desc['namespace'] = array(
 279                                 $desc['namespace'],
 280                                 'NOTE: Due to $wgMiserMode, using this may result in fewer than "limit" results',
 281                                 'returned before continuing; in extreme cases, zero results may be returned',
 282                         );
 283                 }
 284                 return $desc;
 285         }
 286
 287         public function getDescription() {
 288                 return 'List all pages in a given category';
 289         }
 290
 291         public function getPossibleErrors() {
 292                 return array_merge( parent::getPossibleErrors(), array(
 293                         array( 'code' => 'notitle', 'info' => 'The cmtitle parameter is required' ),
 294                         array( 'code' => 'invalidcategory', 'info' => 'The category name you entered is not valid' ),
 295                         array( 'code' => 'badcontinue', 'info' => 'Invalid continue param. You should pass the original value returned by the previous query' ),
 296                 ) );
 297         }
 298
 299         protected function getExamples() {
 300                 return array(
 301                         'Get first 10 pages in [[Category:Physics]]:',
 302                         '  api.php?action=query&list=categorymembers&cmtitle=Category:Physics',
 303                         'Get page info about first 10 pages in [[Category:Physics]]:',
 304                         '  api.php?action=query&generator=categorymembers&gcmtitle=Category:Physics&prop=info',
 305                 );
 306         }
 307
 308         public function getVersion() {
 309                 return __CLASS__ . ': $Id$';
 310         }
 311 }