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_from', '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(array('cl_from', '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                                 // TODO: Security issue - if the user has no right to view next title, it will still be shown
  96                                 $this->setContinueEnumParameter('continue', $this->getContinueStr($row, $lastSortKey));
  97                                 break;
  98                         }
  99
 100                         $lastSortKey = $row->cl_sortkey;        // detect duplicate sortkeys
 101
 102                         if (is_null($resultPageSet)) {
 103                                 $title = Title :: makeTitle($row->page_namespace, $row->page_title);
 104                                 if ($title->userCanRead()) {
 105                                         $vals = array();
 106                                         if ($fld_ids)
 107                                                 $vals['pageid'] = intval($row->page_id);
 108                                         if ($fld_title) {
 109                                                 $vals['ns'] = intval($title->getNamespace());
 110                                                 $vals['title'] = $title->getPrefixedText();
 111                                         }
 112                                         if ($fld_sortkey)
 113                                                 $vals['sortkey'] = $row->cl_sortkey;
 114                                         $data[] = $vals;
 115                                 }
 116                         } else {
 117                                 $resultPageSet->processDbRow($row);
 118                         }
 119                 }
 120                 $db->freeResult($res);
 121
 122                 if (is_null($resultPageSet)) {
 123                         $this->getResult()->setIndexedTagName($data, 'cm');
 124                         $this->getResult()->addValue('query', $this->getModuleName(), $data);
 125                 }
 126         }
 127
 128         private function getContinueStr($row, $lastSortKey) {
 129                 $ret = $row->cl_sortkey . '|';
 130                 if ($row->cl_sortkey == $lastSortKey)   // duplicate sort key, add cl_from
 131                         $ret .= $row->cl_from;
 132                 return $ret;
 133         }
 134
 135         /**
 136          * Add DB WHERE clause to continue previous query based on 'continue' parameter
 137          */
 138         private function setContinuation($continue) {
 139                 if (is_null($continue))
 140                         return; // This is not a continuation request
 141
 142                 $continueList = explode('|', $continue);
 143                 $hasError = count($continueList) != 2;
 144                 $from = 0;
 145                 if (!$hasError && strlen($continueList[1]) > 0) {
 146                         $from = intval($continueList[1]);
 147                         $hasError = ($from == 0);
 148                 }
 149
 150                 if ($hasError)
 151                         $this->dieUsage("Invalid continue param. You should pass the original value returned by the previous query", "badcontinue");
 152
 153                 $sortKey = $this->getDB()->addQuotes($continueList[0]);
 154
 155                 if ($from != 0) {
 156                         // Duplicate sort key continue
 157                         $this->addWhere( "cl_sortkey>$sortKey OR (cl_sortkey=$sortKey AND cl_from>=$from)" );
 158                 } else {
 159                         $this->addWhere( "cl_sortkey>=$sortKey" );
 160                 }
 161         }
 162
 163         protected function getAllowedParams() {
 164                 return array (
 165                         'category' => null,
 166                         'prop' => array (
 167                                 ApiBase :: PARAM_DFLT => 'ids|title',
 168                                 ApiBase :: PARAM_ISMULTI => true,
 169                                 ApiBase :: PARAM_TYPE => array (
 170                                         'ids',
 171                                         'title',
 172                                         'sortkey',
 173                                 )
 174                         ),
 175                         'namespace' => array (
 176                                 ApiBase :: PARAM_ISMULTI => true,
 177                                 ApiBase :: PARAM_TYPE => 'namespace',
 178                         ),
 179                         'continue' => null,
 180                         'limit' => array (
 181                                 ApiBase :: PARAM_TYPE => 'limit',
 182                                 ApiBase :: PARAM_DFLT => 10,
 183                                 ApiBase :: PARAM_MIN => 1,
 184                                 ApiBase :: PARAM_MAX => ApiBase :: LIMIT_BIG1,
 185                                 ApiBase :: PARAM_MAX2 => ApiBase :: LIMIT_BIG2
 186                         ),
 187                 );
 188         }
 189
 190         protected function getParamDescription() {
 191                 return array (
 192                         'category' => 'Which category to enumerate (required)',
 193                         'prop' => 'What pieces of information to include',
 194                         'namespace' => 'Only include pages in these namespaces',
 195                         'continue' => 'For large categories, give the value retured from previous query',
 196                         'limit' => 'The maximum number of pages to return.',
 197                 );
 198         }
 199
 200         protected function getDescription() {
 201                 return 'List all pages in a given category';
 202         }
 203
 204         protected function getExamples() {
 205                 return array (
 206                                 "Get first 10 pages in the categories [[Physics]]:",
 207                                 "  api.php?action=query&list=categorymembers&cmcategory=Physics",
 208                                 "Get page info about first 10 pages in the categories [[Physics]]:",
 209                                 "  api.php?action=query&generator=categorymembers&gcmcategory=Physics&prop=info",
 210                         );
 211         }
 212
 213         public function getVersion() {
 214                 return __CLASS__ . ': $Id$';
 215         }
 216 }
 217