includes/api/ApiQueryCategoryMembers.php

   1 <?php
   2
   3 /*
   4  * Created on June 14, 2007
   5  *
   6  * API for MediaWiki 1.8+
   7  *
   8  * Copyright (C) 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
  52                 $params = $this->extractRequestParams();
  53
  54                 if ( !isset( $params['title'] ) || is_null( $params['title'] ) )
  55                         $this->dieUsage( "The cmtitle parameter is required", 'notitle' );
  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                 $prop = array_flip( $params['prop'] );
  62                 $fld_ids = isset( $prop['ids'] );
  63                 $fld_title = isset( $prop['title'] );
  64                 $fld_sortkey = isset( $prop['sortkey'] );
  65                 $fld_timestamp = isset( $prop['timestamp'] );
  66
  67                 if ( is_null( $resultPageSet ) ) {
  68                         $this->addFields( array( 'cl_from', 'cl_sortkey', 'page_namespace', 'page_title' ) );
  69                         $this->addFieldsIf( 'page_id', $fld_ids );
  70                 } else {
  71                         $this->addFields( $resultPageSet->getPageTableFields() ); // will include page_ id, ns, title
  72                         $this->addFields( array( 'cl_from', 'cl_sortkey' ) );
  73                 }
  74
  75                 $this->addFieldsIf( 'cl_timestamp', $fld_timestamp || $params['sort'] == 'timestamp' );
  76                 $this->addTables( array( 'page', 'categorylinks' ) );   // must be in this order for 'USE INDEX'
  77                                                                         // Not needed after bug 10280 is applied to servers
  78                 if ( $params['sort'] == 'timestamp' )
  79                         $this->addOption( 'USE INDEX', 'cl_timestamp' );
  80                 else
  81                         $this->addOption( 'USE INDEX', 'cl_sortkey' );
  82
  83                 $this->addWhere( 'cl_from=page_id' );
  84                 $this->setContinuation( $params['continue'], $params['dir'] );
  85                 $this->addWhereFld( 'cl_to', $categoryTitle->getDBkey() );
  86                 # Scanning large datasets for rare categories sucks, and I already told
  87                 # how to have efficient subcategory access :-) ~~~~ (oh well, domas)
  88                 global $wgMiserMode;
  89                 $miser_ns = array();
  90                 if ( $wgMiserMode ) {
  91                         $miser_ns = $params['namespace'];
  92                 } else {
  93                         $this->addWhereFld( 'page_namespace', $params['namespace'] );
  94                 }
  95                 if ( $params['sort'] == 'timestamp' )
  96                         $this->addWhereRange( 'cl_timestamp', ( $params['dir'] == 'asc' ? 'newer' : 'older' ), $params['start'], $params['end'] );
  97                 else
  98                 {
  99                         $this->addWhereRange( 'cl_sortkey', ( $params['dir'] == 'asc' ? 'newer' : 'older' ), $params['startsortkey'], $params['endsortkey'] );
 100                         $this->addWhereRange( 'cl_from', ( $params['dir'] == 'asc' ? 'newer' : 'older' ), null, null );
 101                 }
 102
 103                 $limit = $params['limit'];
 104                 $this->addOption( 'LIMIT', $limit + 1 );
 105
 106                 $db = $this->getDB();
 107
 108                 $data = array ();
 109                 $count = 0;
 110                 $lastSortKey = null;
 111                 $res = $this->select( __METHOD__ );
 112                 while ( $row = $db->fetchObject( $res ) ) {
 113                         if ( ++ $count > $limit ) {
 114                                 // We've reached the one extra which shows that there are additional pages to be had. Stop here...
 115                                 // TODO: Security issue - if the user has no right to view next title, it will still be shown
 116                                 if ( $params['sort'] == 'timestamp' )
 117                                         $this->setContinueEnumParameter( 'start', wfTimestamp( TS_ISO_8601, $row->cl_timestamp ) );
 118                                 else
 119                                         $this->setContinueEnumParameter( 'continue', $this->getContinueStr( $row, $lastSortKey ) );
 120                                 break;
 121                         }
 122
 123                         // Since domas won't tell anyone what he told long ago, apply
 124                         // cmnamespace here. This means the query may return 0 actual
 125                         // results, but on the other hand it could save returning 5000
 126                         // useless results to the client. ~~~~
 127                         if ( count( $miser_ns ) && !in_array( $row->page_namespace, $miser_ns ) )
 128                                 continue;
 129
 130                         if ( is_null( $resultPageSet ) ) {
 131                                 $vals = array();
 132                                 if ( $fld_ids )
 133                                         $vals['pageid'] = intval( $row->page_id );
 134                                 if ( $fld_title ) {
 135                                         $title = Title :: makeTitle( $row->page_namespace, $row->page_title );
 136                                         ApiQueryBase::addTitleInfo( $vals, $title );
 137                                 }
 138                                 if ( $fld_sortkey )
 139                                         $vals['sortkey'] = $row->cl_sortkey;
 140                                 if ( $fld_timestamp )
 141                                         $vals['timestamp'] = wfTimestamp( TS_ISO_8601, $row->cl_timestamp );
 142                                 $fit = $this->getResult()->addValue( array( 'query', $this->getModuleName() ),
 143                                                 null, $vals );
 144                                 if ( !$fit )
 145                                 {
 146                                         if ( $params['sort'] == 'timestamp' )
 147                                                 $this->setContinueEnumParameter( 'start', wfTimestamp( TS_ISO_8601, $row->cl_timestamp ) );
 148                                         else
 149                                                 $this->setContinueEnumParameter( 'continue', $this->getContinueStr( $row, $lastSortKey ) );
 150                                         break;
 151                                 }
 152                         } else {
 153                                 $resultPageSet->processDbRow( $row );
 154                         }
 155                         $lastSortKey = $row->cl_sortkey;        // detect duplicate sortkeys
 156                 }
 157                 $db->freeResult( $res );
 158
 159                 if ( is_null( $resultPageSet ) ) {
 160                         $this->getResult()->setIndexedTagName_internal(
 161                                          array( 'query', $this->getModuleName() ), 'cm' );
 162                 }
 163         }
 164
 165         private function getContinueStr( $row, $lastSortKey ) {
 166                 $ret = $row->cl_sortkey . '|';
 167                 if ( $row->cl_sortkey == $lastSortKey ) // duplicate sort key, add cl_from
 168                         $ret .= $row->cl_from;
 169                 return $ret;
 170         }
 171
 172         /**
 173          * Add DB WHERE clause to continue previous query based on 'continue' parameter
 174          */
 175         private function setContinuation( $continue, $dir ) {
 176                 if ( is_null( $continue ) )
 177                         return; // This is not a continuation request
 178
 179                 $pos = strrpos( $continue, '|' );
 180                 $sortkey = substr( $continue, 0, $pos );
 181                 $fromstr = substr( $continue, $pos + 1 );
 182                 $from = intval( $fromstr );
 183
 184                 if ( $from == 0 && strlen( $fromstr ) > 0 )
 185                         $this->dieUsage( "Invalid continue param. You should pass the original value returned by the previous query", "badcontinue" );
 186
 187                 $encSortKey = $this->getDB()->addQuotes( $sortkey );
 188                 $encFrom = $this->getDB()->addQuotes( $from );
 189
 190                 $op = ( $dir == 'desc' ? '<' : '>' );
 191
 192                 if ( $from != 0 ) {
 193                         // Duplicate sort key continue
 194                         $this->addWhere( "cl_sortkey$op$encSortKey OR (cl_sortkey=$encSortKey AND cl_from$op=$encFrom)" );
 195                 } else {
 196                         $this->addWhere( "cl_sortkey$op=$encSortKey" );
 197                 }
 198         }
 199
 200         public function getAllowedParams() {
 201                 return array (
 202                         'title' => null,
 203                         'prop' => array (
 204                                 ApiBase :: PARAM_DFLT => 'ids|title',
 205                                 ApiBase :: PARAM_ISMULTI => true,
 206                                 ApiBase :: PARAM_TYPE => array (
 207                                         'ids',
 208                                         'title',
 209                                         'sortkey',
 210                                         'timestamp',
 211                                 )
 212                         ),
 213                         'namespace' => array (
 214                                 ApiBase :: PARAM_ISMULTI => true,
 215                                 ApiBase :: PARAM_TYPE => 'namespace',
 216                         ),
 217                         'continue' => null,
 218                         'limit' => array (
 219                                 ApiBase :: PARAM_TYPE => 'limit',
 220                                 ApiBase :: PARAM_DFLT => 10,
 221                                 ApiBase :: PARAM_MIN => 1,
 222                                 ApiBase :: PARAM_MAX => ApiBase :: LIMIT_BIG1,
 223                                 ApiBase :: PARAM_MAX2 => ApiBase :: LIMIT_BIG2
 224                         ),
 225                         'sort' => array(
 226                                 ApiBase :: PARAM_DFLT => 'sortkey',
 227                                 ApiBase :: PARAM_TYPE => array(
 228                                         'sortkey',
 229                                         'timestamp'
 230                                 )
 231                         ),
 232                         'dir' => array(
 233                                 ApiBase :: PARAM_DFLT => 'asc',
 234                                 ApiBase :: PARAM_TYPE => array(
 235                                         'asc',
 236                                         'desc'
 237                                 )
 238                         ),
 239                         'start' => array(
 240                                 ApiBase :: PARAM_TYPE => 'timestamp'
 241                         ),
 242                         'end' => array(
 243                                 ApiBase :: PARAM_TYPE => 'timestamp'
 244                         ),
 245                         'startsortkey' => null,
 246                         'endsortkey' => null,
 247                 );
 248         }
 249
 250         public function getParamDescription() {
 251                 global $wgMiserMode;
 252                 $desc = array (
 253                         'title' => 'Which category to enumerate (required). Must include Category: prefix',
 254                         'prop' => 'What pieces of information to include',
 255                         'namespace' => 'Only include pages in these namespaces',
 256                         'sort' => 'Property to sort by',
 257                         'dir' => 'In which direction to sort',
 258                         'start' => 'Timestamp to start listing from. Can only be used with cmsort=timestamp',
 259                         'end' => 'Timestamp to end listing at. Can only be used with cmsort=timestamp',
 260                         'startsortkey' => 'Sortkey to start listing from. Can only be used with cmsort=sortkey',
 261                         'endsortkey' => 'Sortkey to end listing at. Can only be used with cmsort=sortkey',
 262                         'continue' => 'For large categories, give the value retured from previous query',
 263                         'limit' => 'The maximum number of pages to return.',
 264                 );
 265                 if ( $wgMiserMode ) {
 266                         $desc['namespace'] = array(
 267                                 $desc['namespace'],
 268                                 'NOTE: Due to $wgMiserMode, using this may result in fewer than "limit" results',
 269                                 'returned before continuing; in extreme cases, zero results may be returned.',
 270                         );
 271                 }
 272                 return $desc;
 273         }
 274
 275         public function getDescription() {
 276                 return 'List all pages in a given category';
 277         }
 278
 279         protected function getExamples() {
 280                 return array (
 281                                 "Get first 10 pages in [[Category:Physics]]:",
 282                                 "  api.php?action=query&list=categorymembers&cmtitle=Category:Physics",
 283                                 "Get page info about first 10 pages in [[Category:Physics]]:",
 284                                 "  api.php?action=query&generator=categorymembers&gcmtitle=Category:Physics&prop=info",
 285                         );
 286         }
 287
 288         public function getVersion() {
 289                 return __CLASS__ . ': $Id$';
 290         }
 291 }