includes/api/ApiQueryLinks.php

   1 <?php
   2
   3 /*
   4  * Created on May 12, 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 list all wiki links on a given set of pages.
  33  *
  34  * @ingroup API
  35  */
  36 class ApiQueryLinks extends ApiQueryGeneratorBase {
  37
  38         const LINKS = 'links';
  39         const TEMPLATES = 'templates';
  40
  41         private $table, $prefix, $description;
  42
  43         public function __construct($query, $moduleName) {
  44
  45                 switch ($moduleName) {
  46                         case self::LINKS :
  47                                 $this->table = 'pagelinks';
  48                                 $this->prefix = 'pl';
  49                                 $this->description = 'link';
  50                                 break;
  51                         case self::TEMPLATES :
  52                                 $this->table = 'templatelinks';
  53                                 $this->prefix = 'tl';
  54                                 $this->description = 'template';
  55                                 break;
  56                         default :
  57                                 ApiBase :: dieDebug(__METHOD__, 'Unknown module name');
  58                 }
  59
  60                 parent :: __construct($query, $moduleName, $this->prefix);
  61         }
  62
  63         public function execute() {
  64                 $this->run();
  65         }
  66
  67         public function executeGenerator($resultPageSet) {
  68                 $this->run($resultPageSet);
  69         }
  70
  71         private function run($resultPageSet = null) {
  72
  73                 if ($this->getPageSet()->getGoodTitleCount() == 0)
  74                         return; // nothing to do
  75
  76                 $params = $this->extractRequestParams();
  77
  78                 $this->addFields(array (
  79                         $this->prefix . '_from AS pl_from',
  80                         $this->prefix . '_namespace AS pl_namespace',
  81                         $this->prefix . '_title AS pl_title'
  82                 ));
  83
  84                 $this->addTables($this->table);
  85                 $this->addWhereFld($this->prefix . '_from', array_keys($this->getPageSet()->getGoodTitles()));
  86                 $this->addWhereFld($this->prefix . '_namespace', $params['namespace']);
  87
  88                 if(!is_null($params['continue'])) {
  89                         $cont = explode('|', $params['continue']);
  90                         if(count($cont) != 3)
  91                                 $this->dieUsage("Invalid continue param. You should pass the " .
  92                                         "original value returned by the previous query", "_badcontinue");
  93                         $plfrom = intval($cont[0]);
  94                         $plns = intval($cont[1]);
  95                         $pltitle = $this->getDB()->strencode($this->titleToKey($cont[2]));
  96                         $this->addWhere("{$this->prefix}_from > $plfrom OR ".
  97                                         "({$this->prefix}_from = $plfrom AND ".
  98                                         "({$this->prefix}_namespace > $plns OR ".
  99                                         "({$this->prefix}_namespace = $plns AND ".
 100                                         "{$this->prefix}_title >= '$pltitle')))");
 101                 }
 102
 103                 # Here's some MySQL craziness going on: if you use WHERE foo='bar'
 104                 # and later ORDER BY foo MySQL doesn't notice the ORDER BY is pointless
 105                 # but instead goes and filesorts, because the index for foo was used
 106                 # already. To work around this, we drop constant fields in the WHERE
 107                 # clause from the ORDER BY clause
 108                 $order = array();
 109                 if(count($this->getPageSet()->getGoodTitles()) != 1)
 110                         $order[] = "{$this->prefix}_from";
 111                 if(count($params['namespace']) != 1)
 112                         $order[] = "{$this->prefix}_namespace";
 113                 $order[] = "{$this->prefix}_title";
 114                 $this->addOption('ORDER BY', implode(", ", $order));
 115                 $this->addOption('USE INDEX', "{$this->prefix}_from");
 116                 $this->addOption('LIMIT', $params['limit'] + 1);
 117
 118                 $db = $this->getDB();
 119                 $res = $this->select(__METHOD__);
 120
 121                 if (is_null($resultPageSet)) {
 122                         $count = 0;
 123                         while ($row = $db->fetchObject($res)) {
 124                                 if(++$count > $params['limit']) {
 125                                         // We've reached the one extra which shows that
 126                                         // there are additional pages to be had. Stop here...
 127                                         $this->setContinueEnumParameter('continue',
 128                                                 "{$row->pl_from}|{$row->pl_namespace}|" .
 129                                                 $this->keyToTitle($row->pl_title));
 130                                         break;
 131                                 }
 132                                 $vals = array();
 133                                 ApiQueryBase :: addTitleInfo($vals, Title :: makeTitle($row->pl_namespace, $row->pl_title));
 134                                 $fit = $this->addPageSubItem($row->pl_from, $vals);
 135                                 if(!$fit)
 136                                 {
 137                                         $this->setContinueEnumParameter('continue',
 138                                                 "{$row->pl_from}|{$row->pl_namespace}|" .
 139                                                 $this->keyToTitle($row->pl_title));
 140                                         break;
 141                                 }
 142                         }
 143                 } else {
 144
 145                         $titles = array();
 146                         $count = 0;
 147                         while ($row = $db->fetchObject($res)) {
 148                                 if(++$count > $params['limit']) {
 149                                         // We've reached the one extra which shows that
 150                                         // there are additional pages to be had. Stop here...
 151                                         $this->setContinueEnumParameter('continue',
 152                                                 "{$row->pl_from}|{$row->pl_namespace}|" .
 153                                                 $this->keyToTitle($row->pl_title));
 154                                         break;
 155                                 }
 156                                 $titles[] = Title :: makeTitle($row->pl_namespace, $row->pl_title);
 157                         }
 158                         $resultPageSet->populateFromTitles($titles);
 159                 }
 160
 161                 $db->freeResult($res);
 162         }
 163
 164         public function getAllowedParams()
 165         {
 166                 return array(
 167                                 'namespace' => array(
 168                                         ApiBase :: PARAM_TYPE => 'namespace',
 169                                         ApiBase :: PARAM_ISMULTI => true
 170                                 ),
 171                                 'limit' => array(
 172                                         ApiBase :: PARAM_DFLT => 10,
 173                                         ApiBase :: PARAM_TYPE => 'limit',
 174                                         ApiBase :: PARAM_MIN => 1,
 175                                         ApiBase :: PARAM_MAX => ApiBase :: LIMIT_BIG1,
 176                                         ApiBase :: PARAM_MAX2 => ApiBase :: LIMIT_BIG2
 177                                 ),
 178                                 'continue' => null,
 179                         );
 180         }
 181
 182         public function getParamDescription()
 183         {
 184                 return array(
 185                                 'namespace' => "Show {$this->description}s in this namespace(s) only",
 186                                 'limit' => "How many {$this->description}s to return",
 187                                 'continue' => 'When more results are available, use this to continue',
 188                 );
 189         }
 190
 191         public function getDescription() {
 192                 return "Returns all {$this->description}s from the given page(s)";
 193         }
 194
 195         protected function getExamples() {
 196                 return array (
 197                                 "Get {$this->description}s from the [[Main Page]]:",
 198                                 "  api.php?action=query&prop={$this->getModuleName()}&titles=Main%20Page",
 199                                 "Get information about the {$this->description} pages in the [[Main Page]]:",
 200                                 "  api.php?action=query&generator={$this->getModuleName()}&titles=Main%20Page&prop=info",
 201                                 "Get {$this->description}s from the Main Page in the User and Template namespaces:",
 202                                 "  api.php?action=query&prop={$this->getModuleName()}&titles=Main%20Page&{$this->prefix}namespace=2|10"
 203                         );
 204         }
 205
 206         public function getVersion() {
 207                 return __CLASS__ . ': $Id$';
 208         }
 209 }