includes/api/ApiQueryBacklinks.php

   1 <?php
   2
   3 /*
   4  * Created on Oct 16, 2006
   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  * This is a three-in-one module to query:
  33  *   * backlinks  - links pointing to the given page,
  34  *   * embeddedin - what pages transclude the given page within themselves,
  35  *   * imageusage - what pages use the given image
  36  *
  37  * @ingroup API
  38  */
  39 class ApiQueryBacklinks extends ApiQueryGeneratorBase {
  40
  41         private $params, $rootTitle, $contRedirs, $contLevel, $contTitle, $contID, $redirID;
  42
  43         // output element name, database column field prefix, database table
  44         private $backlinksSettings = array (
  45                 'backlinks' => array (
  46                         'code' => 'bl',
  47                         'prefix' => 'pl',
  48                         'linktbl' => 'pagelinks'
  49                 ),
  50                 'embeddedin' => array (
  51                         'code' => 'ei',
  52                         'prefix' => 'tl',
  53                         'linktbl' => 'templatelinks'
  54                 ),
  55                 'imageusage' => array (
  56                         'code' => 'iu',
  57                         'prefix' => 'il',
  58                         'linktbl' => 'imagelinks'
  59                 )
  60         );
  61
  62         public function __construct($query, $moduleName) {
  63                 $code = $prefix = $linktbl = null;
  64                 extract($this->backlinksSettings[$moduleName]);
  65
  66                 parent :: __construct($query, $moduleName, $code);
  67                 $this->bl_ns = $prefix . '_namespace';
  68                 $this->bl_from = $prefix . '_from';
  69                 $this->bl_table = $linktbl;
  70                 $this->bl_code = $code;
  71
  72                 $this->hasNS = $moduleName !== 'imageusage';
  73                 if ($this->hasNS) {
  74                         $this->bl_title = $prefix . '_title';
  75                         $this->bl_sort = "{$this->bl_ns}, {$this->bl_title}, {$this->bl_from}";
  76                         $this->bl_fields = array (
  77                                 $this->bl_ns,
  78                                 $this->bl_title
  79                         );
  80                 } else {
  81                         $this->bl_title = $prefix . '_to';
  82                         $this->bl_sort = "{$this->bl_title}, {$this->bl_from}";
  83                         $this->bl_fields = array (
  84                                 $this->bl_title
  85                         );
  86                 }
  87         }
  88
  89         public function execute() {
  90                 $this->run();
  91         }
  92
  93         public function executeGenerator($resultPageSet) {
  94                 $this->run($resultPageSet);
  95         }
  96
  97         private function prepareFirstQuery($resultPageSet = null) {
  98                 /* SELECT page_id, page_title, page_namespace, page_is_redirect
  99                  * FROM pagelinks, page WHERE pl_from=page_id
 100                  * AND pl_title='Foo' AND pl_namespace=0
 101                  * LIMIT 11 ORDER BY pl_from
 102                  */
 103                 $db = $this->getDb();
 104                 $this->addTables(array('page', $this->bl_table));
 105                 $this->addWhere("{$this->bl_from}=page_id");
 106                 if(is_null($resultPageSet))
 107                         $this->addFields(array('page_id', 'page_title', 'page_namespace'));
 108                 else
 109                         $this->addFields($resultPageSet->getPageTableFields());
 110                 $this->addFields('page_is_redirect');
 111                 $this->addWhereFld($this->bl_title, $this->rootTitle->getDbKey());
 112                 if($this->hasNS)
 113                         $this->addWhereFld($this->bl_ns, $this->rootTitle->getNamespace());
 114                 $this->addWhereFld('page_namespace', $this->params['namespace']);
 115                 if(!is_null($this->contID))
 116                         $this->addWhere("page_id>={$this->contID}");
 117                 if($this->params['filterredir'] == 'redirects')
 118                         $this->addWhereFld('page_is_redirect', 1);
 119                 if($this->params['filterredir'] == 'nonredirects')
 120                         $this->addWhereFld('page_is_redirect', 0);
 121                 $this->addOption('LIMIT', $this->params['limit'] + 1);
 122                 $this->addOption('ORDER BY', $this->bl_from);
 123         }
 124
 125         private function prepareSecondQuery($resultPageSet = null) {
 126                 /* SELECT page_id, page_title, page_namespace, page_is_redirect, pl_title, pl_namespace
 127                  * FROM pagelinks, page WHERE pl_from=page_id
 128                  * AND (pl_title='Foo' AND pl_namespace=0) OR (pl_title='Bar' AND pl_namespace=1)
 129                  * LIMIT 11 ORDER BY pl_namespace, pl_title, pl_from
 130                  */
 131                 $db = $this->getDb();
 132                 $this->addTables(array('page', $this->bl_table));
 133                 $this->addWhere("{$this->bl_from}=page_id");
 134                 if(is_null($resultPageSet))
 135                         $this->addFields(array('page_id', 'page_title', 'page_namespace', 'page_is_redirect'));
 136                 else
 137                         $this->addFields($resultPageSet->getPageTableFields());
 138                 $this->addFields($this->bl_title);
 139                 if($this->hasNS)
 140                         $this->addFields($this->bl_ns);
 141                 $titleWhere = '';
 142                 foreach($this->redirTitles as $t)
 143                         $titleWhere .= ($titleWhere != '' ? " OR " : '') .
 144                                         "({$this->bl_title} = ".$db->addQuotes($t->getDBKey()).
 145                                         ($this->hasNS ? " AND {$this->bl_ns} = '{$t->getNamespace()}'" : "") .
 146                                         ")";
 147                 $this->addWhere($titleWhere);
 148                 $this->addWhereFld('page_namespace', $this->params['namespace']);
 149                 if(!is_null($this->redirID))
 150                         $this->addWhere("page_id>={$this->redirID}");
 151                 if($this->params['filterredir'] == 'redirects')
 152                         $this->addWhereFld('page_is_redirect', 1);
 153                 if($this->params['filterredir'] == 'nonredirects')
 154                         $this->addWhereFld('page_is_redirect', 0);
 155                 $this->addOption('LIMIT', $this->params['limit'] + 1);
 156                 $this->addOption('ORDER BY', $this->bl_sort);
 157         }
 158
 159         private function run($resultPageSet = null) {
 160                 $this->params = $this->extractRequestParams(false);
 161                 $this->redirect = isset($this->params['redirect']) && $this->params['redirect'];
 162                 $userMax = ( $this->redirect ? ApiBase::LIMIT_BIG1/2 : ApiBase::LIMIT_BIG1 );
 163                 $botMax  = ( $this->redirect ? ApiBase::LIMIT_BIG2/2 : ApiBase::LIMIT_BIG2 );
 164                 if( $this->params['limit'] == 'max' ) {
 165                         $this->params['limit'] = $this->getMain()->canApiHighLimits() ? $botMax : $userMax;
 166                         $this->getResult()->addValue( 'limits', $this->getModuleName(), $this->params['limit'] );
 167                 }
 168
 169                 $this->processContinue();
 170                 $this->prepareFirstQuery($resultPageSet);
 171
 172                 $db = $this->getDB();
 173                 $res = $this->select(__METHOD__);
 174
 175                 $count = 0;
 176                 $this->data = array ();
 177                 $this->continueStr = null;
 178                 $this->redirTitles = array();
 179                 while ($row = $db->fetchObject($res)) {
 180                         if (++ $count > $this->params['limit']) {
 181                                 // We've reached the one extra which shows that there are additional pages to be had. Stop here...
 182                                 // Continue string preserved in case the redirect query doesn't pass the limit
 183                                 $this->continueStr = $this->getContinueStr($row->page_id);
 184                                 break;
 185                         }
 186
 187                         if (is_null($resultPageSet))
 188                                 $this->extractRowInfo($row);
 189                         else
 190                         {
 191                                 if($row->page_is_redirect)
 192                                         $this->redirTitles[] = Title::makeTitle($row->page_namespace, $row->page_title);
 193                                 $resultPageSet->processDbRow($row);
 194                         }
 195                 }
 196                 $db->freeResult($res);
 197
 198                 if($this->redirect && !empty($this->redirTitles))
 199                 {
 200                         $this->resetQueryParams();
 201                         $this->prepareSecondQuery($resultPageSet);
 202                         $res = $this->select(__METHOD__);
 203                         $count = 0;
 204                         while($row = $db->fetchObject($res))
 205                         {
 206                                 if(++$count > $this->params['limit'])
 207                                 {
 208                                         // We've reached the one extra which shows that there are additional pages to be had. Stop here...
 209                                         // We need to keep the parent page of this redir in
 210                                         if($this->hasNS)
 211                                                 $contTitle = Title::makeTitle($row->{$this->bl_ns}, $row->{$this->bl_title});
 212                                         else
 213                                                 $contTitle = Title::makeTitle(NS_IMAGE, $row->{$this->bl_title});
 214                                         $this->continueStr = $this->getContinueRedirStr($contTitle->getArticleID(), $row->page_id);
 215                                         break;
 216                                 }
 217
 218                                 if(is_null($resultPageSet))
 219                                         $this->extractRedirRowInfo($row);
 220                                 else
 221                                         $resultPageSet->processDbRow($row);
 222                         }
 223                         $db->freeResult($res);
 224                 }
 225                 if(!is_null($this->continueStr))
 226                         $this->setContinueEnumParameter('continue', $this->continueStr);
 227
 228                 if (is_null($resultPageSet)) {
 229                         $resultData = array();
 230                         foreach($this->data as $ns => $a)
 231                                 foreach($a as $title => $arr)
 232                                         $resultData[] = $arr;
 233                         $result = $this->getResult();
 234                         $result->setIndexedTagName($resultData, $this->bl_code);
 235                         $result->addValue('query', $this->getModuleName(), $resultData);
 236                 }
 237         }
 238
 239         private function extractRowInfo($row) {
 240                 if(!isset($this->data[$row->page_namespace][$row->page_title])) {
 241                         $this->data[$row->page_namespace][$row->page_title]['pageid'] = $row->page_id;
 242                         ApiQueryBase::addTitleInfo($this->data[$row->page_namespace][$row->page_title], Title::makeTitle($row->page_namespace, $row->page_title));
 243                         if($row->page_is_redirect)
 244                         {
 245                                 $this->data[$row->page_namespace][$row->page_title]['redirect'] = '';
 246                                 $this->redirTitles[] = Title::makeTitle($row->page_namespace, $row->page_title);
 247                         }
 248                 }
 249         }
 250
 251         private function extractRedirRowInfo($row)
 252         {
 253                 $a['pageid'] = $row->page_id;
 254                 ApiQueryBase::addTitleInfo($a, Title::makeTitle($row->page_namespace, $row->page_title));
 255                 if($row->page_is_redirect)
 256                         $a['redirect'] = '';
 257                 $ns = $this->hasNS ? $row->{$this->bl_ns} : NS_IMAGE;
 258                 $this->data[$ns][$row->{$this->bl_title}]['redirlinks'][] = $a;
 259                 $this->getResult()->setIndexedTagName($this->data[$ns][$row->{$this->bl_title}]['redirlinks'], $this->bl_code);
 260         }
 261
 262         protected function processContinue() {
 263                 if (!is_null($this->params['continue']))
 264                         $this->parseContinueParam();
 265                 else {
 266                         if ( $this->params['title'] !== "" ) {
 267                                 $title = Title::newFromText( $this->params['title'] );
 268                                 if ( !$title ) {
 269                                         $this->dieUsageMsg(array('invalidtitle', $this->params['title']));
 270                                 } else {
 271                                         $this->rootTitle = $title;
 272                                 }
 273                         } else {
 274                                 $this->dieUsageMsg(array('missingparam', 'title'));
 275                         }
 276                 }
 277
 278                 // only image titles are allowed for the root in imageinfo mode
 279                 if (!$this->hasNS && $this->rootTitle->getNamespace() !== NS_IMAGE)
 280                         $this->dieUsage("The title for {$this->getModuleName()} query must be an image", 'bad_image_title');
 281         }
 282
 283         protected function parseContinueParam() {
 284                 $continueList = explode('|', $this->params['continue']);
 285                 // expected format:
 286                 // ns | key | id1 [| id2]
 287                 // ns+key: root title
 288                 // id1: first-level page ID to continue from
 289                 // id2: second-level page ID to continue from
 290
 291                 // null stuff out now so we know what's set and what isn't
 292                 $this->rootTitle = $this->contID = $this->redirID = null;
 293                 $rootNs = intval($continueList[0]);
 294                 if($rootNs === 0 && $continueList[0] !== '0')
 295                         // Illegal continue parameter
 296                         $this->dieUsage("Invalid continue param. You should pass the original value returned by the previous query", "_badcontinue");
 297                 $this->rootTitle = Title::makeTitleSafe($rootNs, $continueList[1]);
 298                 if(!$this->rootTitle)
 299                         $this->dieUsage("Invalid continue param. You should pass the original value returned by the previous query", "_badcontinue");
 300                 $contID = intval($continueList[2]);
 301                 if($contID === 0 && $continueList[2] !== '0')
 302                         $this->dieUsage("Invalid continue param. You should pass the original value returned by the previous query", "_badcontinue");
 303                 $this->contID = $contID;
 304                 $redirID = intval(@$continueList[3]);
 305                 if($redirID === 0 && @$continueList[3] !== '0')
 306                         // This one isn't required
 307                         return;
 308                 $this->redirID = $redirID;
 309
 310         }
 311
 312         protected function getContinueStr($lastPageID) {
 313                 return $this->rootTitle->getNamespace() .
 314                 '|' . $this->rootTitle->getDBkey() .
 315                 '|' . $lastPageID;
 316         }
 317
 318         protected function getContinueRedirStr($lastPageID, $lastRedirID) {
 319                 return $this->getContinueStr($lastPageID) . '|' . $lastRedirID;
 320         }
 321
 322         public function getAllowedParams() {
 323                 $retval =  array (
 324                         'title' => null,
 325                         'continue' => null,
 326                         'namespace' => array (
 327                                 ApiBase :: PARAM_ISMULTI => true,
 328                                 ApiBase :: PARAM_TYPE => 'namespace'
 329                         ),
 330                         'filterredir' => array(
 331                                 ApiBase :: PARAM_DFLT => 'all',
 332                                 ApiBase :: PARAM_TYPE => array(
 333                                         'all',
 334                                         'redirects',
 335                                         'nonredirects'
 336                                 )
 337                         ),
 338                         'limit' => array (
 339                                 ApiBase :: PARAM_DFLT => 10,
 340                                 ApiBase :: PARAM_TYPE => 'limit',
 341                                 ApiBase :: PARAM_MIN => 1,
 342                                 ApiBase :: PARAM_MAX => ApiBase :: LIMIT_BIG1,
 343                                 ApiBase :: PARAM_MAX2 => ApiBase :: LIMIT_BIG2
 344                         )
 345                 );
 346                 if($this->getModuleName() == 'embeddedin')
 347                         return $retval;
 348                 $retval['redirect'] = false;
 349                 return $retval;
 350         }
 351
 352         public function getParamDescription() {
 353                 $retval = array (
 354                         'title' => 'Title to search. If null, titles= parameter will be used instead, but will be obsolete soon.',
 355                         'continue' => 'When more results are available, use this to continue.',
 356                         'namespace' => 'The namespace to enumerate.',
 357                         'filterredir' => 'How to filter for redirects'
 358                 );
 359                 if($this->getModuleName() != 'embeddedin')
 360                         return array_merge($retval, array(
 361                                 'redirect' => 'If linking page is a redirect, find all pages that link to that redirect as well. Maximum limit is halved.',
 362                                 'limit' => "How many total pages to return. If {$this->bl_code}redirect is enabled, limit applies to each level separately."
 363                         ));
 364                 return array_merge($retval, array(
 365                         'limit' => "How many total pages to return."
 366                 ));
 367         }
 368
 369         public function getDescription() {
 370                 switch ($this->getModuleName()) {
 371                         case 'backlinks' :
 372                                 return 'Find all pages that link to the given page';
 373                         case 'embeddedin' :
 374                                 return 'Find all pages that embed (transclude) the given title';
 375                         case 'imageusage' :
 376                                 return 'Find all pages that use the given image title.';
 377                         default :
 378                                 ApiBase :: dieDebug(__METHOD__, 'Unknown module name');
 379                 }
 380         }
 381
 382         protected function getExamples() {
 383                 static $examples = array (
 384                         'backlinks' => array (
 385                                 "api.php?action=query&list=backlinks&bltitle=Main%20Page",
 386                                 "api.php?action=query&generator=backlinks&gbltitle=Main%20Page&prop=info"
 387                         ),
 388                         'embeddedin' => array (
 389                                 "api.php?action=query&list=embeddedin&eititle=Template:Stub",
 390                                 "api.php?action=query&generator=embeddedin&geititle=Template:Stub&prop=info"
 391                         ),
 392                         'imageusage' => array (
 393                                 "api.php?action=query&list=imageusage&iutitle=Image:Albert%20Einstein%20Head.jpg",
 394                                 "api.php?action=query&generator=imageusage&giutitle=Image:Albert%20Einstein%20Head.jpg&prop=info"
 395                         )
 396                 );
 397
 398                 return $examples[$this->getModuleName()];
 399         }
 400
 401         public function getVersion() {
 402                 return __CLASS__ . ': $Id$';
 403         }
 404 }