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
  66                 if (is_null($resultPageSet)) {
  67                         $this->addFields(array('cl_sortkey', 'page_namespace', 'page_title'));
  68                         $this->addFieldsIf('page_id', $fld_ids);
  69                 } else {
  70                         $this->addFields($resultPageSet->getPageTableFields()); // will include page_ id, ns, title
  71                         $this->addFields('cl_sortkey');
  72                 }
  73
  74                 $this->addTables(array('page','categorylinks'));        // must be in this order for 'USE INDEX'
  75                 $this->addOption('USE INDEX', 'cl_sortkey');            // Not needed after bug 10280 is applied to servers
  76
  77                 $this->addWhere('cl_from=page_id');
  78                 $this->setContinuation($params['continue']);
  79                 $this->addWhereFld('cl_to', $categoryTitle->getDBkey());
  80                 $this->addWhereFld('page_namespace', $params['namespace']);
  81                 $this->addOption('ORDER BY', "cl_to, cl_sortkey, cl_from");
  82
  83                 $limit = $params['limit'];
  84                 $this->addOption('LIMIT', $limit +1);
  85
  86                 $db = $this->getDB();
  87
  88                 $data = array ();
  89                 $count = 0;
  90                 $lastSortKey = null;
  91                 $res = $this->select(__METHOD__);
  92                 while ($row = $db->fetchObject($res)) {
  93                         if (++ $count > $limit) {
  94                                 // We've reached the one extra which shows that there are additional pages to be had. Stop here...
  95                                 $this->setContinueEnumParameter('continue', $this->getContinueStr($row, $lastSortKey));
  96                                 break;
  97                         }
  98
  99                         $lastSortKey = $row->cl_sortkey;        // detect duplicate sortkeys
 100
 101                         if (is_null($resultPageSet)) {
 102                                 $title = Title :: makeTitle($row->page_namespace, $row->page_title);
 103                                 if ($title->userCanRead()) {
 104                                         $vals = array();
 105                                         if ($fld_ids)
 106                                                 $vals['pageid'] = intval($row->page_id);
 107                                         if ($fld_title) {
 108                                                 $vals['ns'] = intval($title->getNamespace());
 109                                                 $vals['title'] = $title->getPrefixedText();
 110                                         }
 111                                         if ($fld_sortkey)
 112                                                 $vals['sortkey'] = $row->cl_sortkey;
 113                                         $data[] = $vals;
 114                                 }
 115                         } else {
 116                                 $resultPageSet->processDbRow($row);
 117                         }
 118                 }
 119                 $db->freeResult($res);
 120
 121                 if (is_null($resultPageSet)) {
 122                         $this->getResult()->setIndexedTagName($data, 'cm');
 123                         $this->getResult()->addValue('query', $this->getModuleName(), $data);
 124                 }
 125         }
 126
 127         private function getContinueStr($row, $lastSortKey) {
 128                 $ret = $row->cl_sortkey . '|';
 129                 if ($row->cl_sortkey == $lastSortKey)   // duplicate sort key, add cl_from
 130                         $ret .= $row->cl_from;
 131                 return $ret;
 132         }
 133
 134         /**
 135          * Add DB WHERE clause to continue previous query based on 'continue' parameter
 136          */
 137         private function setContinuation($continue) {
 138                 if (is_null($continue))
 139                         return; // This is not a continuation request
 140
 141                 $continueList = explode('|', $continue);
 142                 if (count($continueList) != 2)
 143                         $this->dieUsage("Invalid continue param. You should pass the original value returned by the previous query", "badcontinue");
 144
 145                 $sortKey = $this->getDB()->addQuotes($continueList[0]);
 146                 $from = intval($continueList[1]);
 147
 148                 if ($from != 0) {
 149                         // Duplicate sort key continue
 150                         $this->addWhere( "cl_sortkey>$sortKey OR (cl_sortkey=$sortKey AND cl_from>=$from)" );
 151                 } else {
 152                         $this->addWhere( "cl_sortkey>=$sortKey" );
 153                 }
 154         }
 155
 156         protected function getAllowedParams() {
 157                 return array (
 158                         'category' => null,
 159                         'prop' => array (
 160                                 ApiBase :: PARAM_DFLT => 'ids|title',
 161                                 ApiBase :: PARAM_ISMULTI => true,
 162                                 ApiBase :: PARAM_TYPE => array (
 163                                         'ids',
 164                                         'title',
 165                                         'sortkey',
 166                                 )
 167                         ),
 168                         'namespace' => array (
 169                                 ApiBase :: PARAM_ISMULTI => true,
 170                                 ApiBase :: PARAM_TYPE => 'namespace',
 171                         ),
 172                         'continue' => null,
 173                         'limit' => array (
 174                                 ApiBase :: PARAM_TYPE => 'limit',
 175                                 ApiBase :: PARAM_DFLT => 10,
 176                                 ApiBase :: PARAM_MIN => 1,
 177                                 ApiBase :: PARAM_MAX => ApiBase :: LIMIT_BIG1,
 178                                 ApiBase :: PARAM_MAX2 => ApiBase :: LIMIT_BIG2
 179                         ),
 180                 );
 181         }
 182
 183         protected function getParamDescription() {
 184                 return array (
 185                         'category' => 'Which category to enumerate (required)',
 186                         'prop' => 'What pieces of infromation to include',
 187                         'namespace' => 'Only include pages in these namespaces',
 188                         'continue' => 'For large categories, give the value retured from previous query',
 189                         'limit' => 'The maximum number of pages to return.',
 190                 );
 191         }
 192
 193         protected function getDescription() {
 194                 return 'List all pages in a given category';
 195         }
 196
 197         protected function getExamples() {
 198                 return array (
 199                                 "Get first 10 pages in the categories [[Physics]]:",
 200                                 "  api.php?action=query&list=categorymembers&cmcategory=Physics",
 201                                 "Get page info about first 10 pages in the categories [[Physics]]:",
 202                                 "  api.php?action=query&generator=categorymembers&gcmcategory=Physics&prop=info",
 203                         );
 204         }
 205
 206         public function getVersion() {
 207                 return __CLASS__ . ': $Id$';
 208         }
 209 }
 210