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                 $this->addTables(array('page','categorylinks'));        // must be in this order for 'USE INDEX'
  77                                                                         // Not needed after bug 10280 is applied to servers
  78                 if($params['sort'] == 'timestamp')
  79                 {
  80                         $this->addOption('USE INDEX', 'cl_timestamp');
  81                         $this->addOption('ORDER BY', 'cl_to, cl_timestamp');
  82                 }
  83                 else
  84                 {
  85                         $this->addOption('USE INDEX', 'cl_sortkey');
  86                         $this->addOption('ORDER BY', 'cl_to, cl_sortkey, cl_from');
  87                 }
  88
  89                 $this->addWhere('cl_from=page_id');
  90                 $this->setContinuation($params['continue']);
  91                 $this->addWhereFld('cl_to', $categoryTitle->getDBkey());
  92                 $this->addWhereFld('page_namespace', $params['namespace']);
  93
  94                 $limit = $params['limit'];
  95                 $this->addOption('LIMIT', $limit +1);
  96
  97                 $db = $this->getDB();
  98
  99                 $data = array ();
 100                 $count = 0;
 101                 $lastSortKey = null;
 102                 $res = $this->select(__METHOD__);
 103                 while ($row = $db->fetchObject($res)) {
 104                         if (++ $count > $limit) {
 105                                 // We've reached the one extra which shows that there are additional pages to be had. Stop here...
 106                                 // TODO: Security issue - if the user has no right to view next title, it will still be shown
 107                                 $this->setContinueEnumParameter('continue', $this->getContinueStr($row, $lastSortKey));
 108                                 break;
 109                         }
 110
 111                         $lastSortKey = $row->cl_sortkey;        // detect duplicate sortkeys
 112
 113                         if (is_null($resultPageSet)) {
 114                                 $vals = array();
 115                                 if ($fld_ids)
 116                                         $vals['pageid'] = intval($row->page_id);
 117                                 if ($fld_title) {
 118                                         $title = Title :: makeTitle($row->page_namespace, $row->page_title);
 119                                         $vals['ns'] = intval($title->getNamespace());
 120                                         $vals['title'] = $title->getPrefixedText();
 121                                 }
 122                                 if ($fld_sortkey)
 123                                         $vals['sortkey'] = $row->cl_sortkey;
 124                                 if ($fld_timestamp)
 125                                         $vals['timestamp'] = wfTimestamp(TS_ISO_8601, $row->cl_timestamp);
 126                                 $data[] = $vals;
 127                         } else {
 128                                 $resultPageSet->processDbRow($row);
 129                         }
 130                 }
 131                 $db->freeResult($res);
 132
 133                 if (is_null($resultPageSet)) {
 134                         $this->getResult()->setIndexedTagName($data, 'cm');
 135                         $this->getResult()->addValue('query', $this->getModuleName(), $data);
 136                 }
 137         }
 138
 139         private function getContinueStr($row, $lastSortKey) {
 140                 $ret = $row->cl_sortkey . '|';
 141                 if ($row->cl_sortkey == $lastSortKey)   // duplicate sort key, add cl_from
 142                         $ret .= $row->cl_from;
 143                 return $ret;
 144         }
 145
 146         /**
 147          * Add DB WHERE clause to continue previous query based on 'continue' parameter
 148          */
 149         private function setContinuation($continue) {
 150                 if (is_null($continue))
 151                         return; // This is not a continuation request
 152
 153                 $continueList = explode('|', $continue);
 154                 $hasError = count($continueList) != 2;
 155                 $from = 0;
 156                 if (!$hasError && strlen($continueList[1]) > 0) {
 157                         $from = intval($continueList[1]);
 158                         $hasError = ($from == 0);
 159                 }
 160
 161                 if ($hasError)
 162                         $this->dieUsage("Invalid continue param. You should pass the original value returned by the previous query", "badcontinue");
 163
 164                 $encSortKey = $this->getDB()->addQuotes($continueList[0]);
 165                 $encFrom = $this->getDB()->addQuotes($from);
 166
 167                 if ($from != 0) {
 168                         // Duplicate sort key continue
 169                         $this->addWhere( "cl_sortkey>$encSortKey OR (cl_sortkey=$encSortKey AND cl_from>=$encFrom)" );
 170                 } else {
 171                         $this->addWhere( "cl_sortkey>=$encSortKey" );
 172                 }
 173         }
 174
 175         protected function getAllowedParams() {
 176                 return array (
 177                         'category' => null,
 178                         'prop' => array (
 179                                 ApiBase :: PARAM_DFLT => 'ids|title',
 180                                 ApiBase :: PARAM_ISMULTI => true,
 181                                 ApiBase :: PARAM_TYPE => array (
 182                                         'ids',
 183                                         'title',
 184                                         'sortkey',
 185                                         'timestamp',
 186                                 )
 187                         ),
 188                         'namespace' => array (
 189                                 ApiBase :: PARAM_ISMULTI => true,
 190                                 ApiBase :: PARAM_TYPE => 'namespace',
 191                         ),
 192                         'continue' => null,
 193                         'limit' => array (
 194                                 ApiBase :: PARAM_TYPE => 'limit',
 195                                 ApiBase :: PARAM_DFLT => 10,
 196                                 ApiBase :: PARAM_MIN => 1,
 197                                 ApiBase :: PARAM_MAX => ApiBase :: LIMIT_BIG1,
 198                                 ApiBase :: PARAM_MAX2 => ApiBase :: LIMIT_BIG2
 199                         ),
 200                         'sort' => array(
 201                                 ApiBase :: PARAM_DFLT => 'sortkey',
 202                                 ApiBase :: PARAM_TYPE => array(
 203                                         'sortkey',
 204                                         'timestamp'
 205                                 )
 206                         )
 207                 );
 208         }
 209
 210         protected function getParamDescription() {
 211                 return array (
 212                         'category' => 'Which category to enumerate (required)',
 213                         'prop' => 'What pieces of information to include',
 214                         'namespace' => 'Only include pages in these namespaces',
 215                         'sort' => 'Property to sort by',
 216                         'continue' => 'For large categories, give the value retured from previous query',
 217                         'limit' => 'The maximum number of pages to return.',
 218                 );
 219         }
 220
 221         protected function getDescription() {
 222                 return 'List all pages in a given category';
 223         }
 224
 225         protected function getExamples() {
 226                 return array (
 227                                 "Get first 10 pages in the categories [[Physics]]:",
 228                                 "  api.php?action=query&list=categorymembers&cmcategory=Physics",
 229                                 "Get page info about first 10 pages in the categories [[Physics]]:",
 230                                 "  api.php?action=query&generator=categorymembers&gcmcategory=Physics&prop=info",
 231                         );
 232         }
 233
 234         public function getVersion() {
 235                 return __CLASS__ . ': $Id: ApiQueryCategoryMembers.php 25474 2007-09-04 14:30:31Z catrope $';
 236         }
 237 }
 238