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  * @addtogroup 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                 $category = $params['category'];
  55                 if (is_null($category))
  56                         $this->dieUsage("Category parameter is required", 'param_category');
  57                 $categoryTitle = Title::makeTitleSafe( NS_CATEGORY, $category );
  58                 if ( is_null( $categoryTitle ) )
  59                         $this->dieUsage("Category name $category is not valid", 'param_category');
  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);
  76                 $this->addTables(array('page','categorylinks'));        // must be in this order for 'USE INDEX'
  77                 $this->addOption('USE INDEX', 'cl_sortkey');            // Not needed after bug 10280 is applied to servers
  78
  79                 $this->addWhere('cl_from=page_id');
  80                 $this->setContinuation($params['continue']);
  81                 $this->addWhereFld('cl_to', $categoryTitle->getDBkey());
  82                 $this->addWhereFld('page_namespace', $params['namespace']);
  83                 $this->addOption('ORDER BY', "cl_to, cl_sortkey, cl_from");
  84
  85                 $limit = $params['limit'];
  86                 $this->addOption('LIMIT', $limit +1);
  87
  88                 $db = $this->getDB();
  89
  90                 $data = array ();
  91                 $count = 0;
  92                 $lastSortKey = null;
  93                 $res = $this->select(__METHOD__);
  94                 while ($row = $db->fetchObject($res)) {
  95                         if (++ $count > $limit) {
  96                                 // We've reached the one extra which shows that there are additional pages to be had. Stop here...
  97                                 // TODO: Security issue - if the user has no right to view next title, it will still be shown
  98                                 $this->setContinueEnumParameter('continue', $this->getContinueStr($row, $lastSortKey));
  99                                 break;
 100                         }
 101
 102                         $lastSortKey = $row->cl_sortkey;        // detect duplicate sortkeys
 103
 104                         if (is_null($resultPageSet)) {
 105                                 $vals = array();
 106                                 if ($fld_ids)
 107                                         $vals['pageid'] = intval($row->page_id);
 108                                 if ($fld_title) {
 109                                         $title = Title :: makeTitle($row->page_namespace, $row->page_title);
 110                                         $vals['ns'] = intval($title->getNamespace());
 111                                         $vals['title'] = $title->getPrefixedText();
 112                                 }
 113                                 if ($fld_sortkey)
 114                                         $vals['sortkey'] = $row->cl_sortkey;
 115                                 if ($fld_timestamp)
 116                                         $vals['timestamp'] = wfTimestamp(TS_ISO_8601, $row->cl_timestamp);
 117                                 $data[] = $vals;
 118                         } else {
 119                                 $resultPageSet->processDbRow($row);
 120                         }
 121                 }
 122                 $db->freeResult($res);
 123
 124                 if (is_null($resultPageSet)) {
 125                         $this->getResult()->setIndexedTagName($data, 'cm');
 126                         $this->getResult()->addValue('query', $this->getModuleName(), $data);
 127                 }
 128         }
 129
 130         private function getContinueStr($row, $lastSortKey) {
 131                 $ret = $row->cl_sortkey . '|';
 132                 if ($row->cl_sortkey == $lastSortKey)   // duplicate sort key, add cl_from
 133                         $ret .= $row->cl_from;
 134                 return $ret;
 135         }
 136
 137         /**
 138          * Add DB WHERE clause to continue previous query based on 'continue' parameter
 139          */
 140         private function setContinuation($continue) {
 141                 if (is_null($continue))
 142                         return; // This is not a continuation request
 143
 144                 $continueList = explode('|', $continue);
 145                 $hasError = count($continueList) != 2;
 146                 $from = 0;
 147                 if (!$hasError && strlen($continueList[1]) > 0) {
 148                         $from = intval($continueList[1]);
 149                         $hasError = ($from == 0);
 150                 }
 151
 152                 if ($hasError)
 153                         $this->dieUsage("Invalid continue param. You should pass the original value returned by the previous query", "badcontinue");
 154
 155                 $sortKey = $this->getDB()->addQuotes($continueList[0]);
 156
 157                 if ($from != 0) {
 158                         // Duplicate sort key continue
 159                         $this->addWhere( "cl_sortkey>$sortKey OR (cl_sortkey=$sortKey AND cl_from>=$from)" );
 160                 } else {
 161                         $this->addWhere( "cl_sortkey>=$sortKey" );
 162                 }
 163         }
 164
 165         protected function getAllowedParams() {
 166                 return array (
 167                         'category' => null,
 168                         'prop' => array (
 169                                 ApiBase :: PARAM_DFLT => 'ids|title',
 170                                 ApiBase :: PARAM_ISMULTI => true,
 171                                 ApiBase :: PARAM_TYPE => array (
 172                                         'ids',
 173                                         'title',
 174                                         'sortkey',
 175                                         'timestamp',
 176                                 )
 177                         ),
 178                         'namespace' => array (
 179                                 ApiBase :: PARAM_ISMULTI => true,
 180                                 ApiBase :: PARAM_TYPE => 'namespace',
 181                         ),
 182                         'continue' => null,
 183                         'limit' => array (
 184                                 ApiBase :: PARAM_TYPE => 'limit',
 185                                 ApiBase :: PARAM_DFLT => 10,
 186                                 ApiBase :: PARAM_MIN => 1,
 187                                 ApiBase :: PARAM_MAX => ApiBase :: LIMIT_BIG1,
 188                                 ApiBase :: PARAM_MAX2 => ApiBase :: LIMIT_BIG2
 189                         ),
 190                 );
 191         }
 192
 193         protected function getParamDescription() {
 194                 return array (
 195                         'category' => 'Which category to enumerate (required)',
 196                         'prop' => 'What pieces of information to include',
 197                         'namespace' => 'Only include pages in these namespaces',
 198                         'continue' => 'For large categories, give the value retured from previous query',
 199                         'limit' => 'The maximum number of pages to return.',
 200                 );
 201         }
 202
 203         protected function getDescription() {
 204                 return 'List all pages in a given category';
 205         }
 206
 207         protected function getExamples() {
 208                 return array (
 209                                 "Get first 10 pages in the categories [[Physics]]:",
 210                                 "  api.php?action=query&list=categorymembers&cmcategory=Physics",
 211                                 "Get page info about first 10 pages in the categories [[Physics]]:",
 212                                 "  api.php?action=query&generator=categorymembers&gcmcategory=Physics&prop=info",
 213                         );
 214         }
 215
 216         public function getVersion() {
 217                 return __CLASS__ . ': $Id$';
 218         }
 219 }
 220