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, $moduleName) {
  63                 extract($this->backlinksSettings[$moduleName]);
  64
  65                 parent :: __construct($query, $moduleName, $code);
  66                 $this->bl_ns = $prefix . '_namespace';
  67                 $this->bl_from = $prefix . '_from';
  68                 $this->bl_table = $linktbl;
  69                 $this->bl_code = $code;
  70
  71                 $this->hasNS = $moduleName !== 'imageusage';
  72                 if ($this->hasNS) {
  73                         $this->bl_title = $prefix . '_title';
  74                         $this->bl_sort = "{$this->bl_ns}, {$this->bl_title}, {$this->bl_from}";
  75                         $this->bl_fields = array (
  76                                 $this->bl_ns,
  77                                 $this->bl_title
  78                         );
  79                 } else {
  80                         $this->bl_title = $prefix . '_to';
  81                         $this->bl_sort = "{$this->bl_title}, {$this->bl_from}";
  82                         $this->bl_fields = array (
  83                                 $this->bl_title
  84                         );
  85                 }
  86         }
  87
  88         public function execute() {
  89                 $this->run();
  90         }
  91
  92         public function executeGenerator($resultPageSet) {
  93                 $this->run($resultPageSet);
  94         }
  95
  96         private function prepareFirstQuery($resultPageSet = null) {
  97                 /* SELECT page_id, page_title, page_namespace, page_is_redirect
  98                  * FROM pagelinks, page WHERE pl_from=page_id
  99                  * AND pl_title='Foo' AND pl_namespace=0
 100                  * LIMIT 11 ORDER BY pl_from
 101                  */
 102                 $db = $this->getDB();
 103                 $this->addTables(array('page', $this->bl_table));
 104                 $this->addWhere("{$this->bl_from}=page_id");
 105                 if(is_null($resultPageSet))
 106                         $this->addFields(array('page_id', 'page_title', 'page_namespace'));
 107                 else
 108                         $this->addFields($resultPageSet->getPageTableFields());
 109                 $this->addFields('page_is_redirect');
 110                 $this->addWhereFld($this->bl_title, $this->rootTitle->getDBKey());
 111                 if($this->hasNS)
 112                         $this->addWhereFld($this->bl_ns, $this->rootTitle->getNamespace());
 113                 $this->addWhereFld('page_namespace', $this->params['namespace']);
 114                 if(!is_null($this->contID))
 115                         $this->addWhere("{$this->bl_from}>={$this->contID}");
 116                 if($this->params['filterredir'] == 'redirects')
 117                         $this->addWhereFld('page_is_redirect', 1);
 118                 if($this->params['filterredir'] == 'nonredirects')
 119                         $this->addWhereFld('page_is_redirect', 0);
 120                 $this->addOption('LIMIT', $this->params['limit'] + 1);
 121                 $this->addOption('ORDER BY', $this->bl_from);
 122         }
 123
 124         private function prepareSecondQuery($resultPageSet = null) {
 125                 /* SELECT page_id, page_title, page_namespace, page_is_redirect, pl_title, pl_namespace
 126                    FROM pagelinks, page WHERE pl_from=page_id
 127                    AND (pl_title='Foo' AND pl_namespace=0) OR (pl_title='Bar' AND pl_namespace=1)
 128                    ORDER BY pl_namespace, pl_title, pl_from LIMIT 11
 129                  */
 130                 $db = $this->getDB();
 131                 $this->addTables(array('page', $this->bl_table));
 132                 $this->addWhere("{$this->bl_from}=page_id");
 133                 if(is_null($resultPageSet))
 134                         $this->addFields(array('page_id', 'page_title', 'page_namespace', 'page_is_redirect'));
 135                 else
 136                         $this->addFields($resultPageSet->getPageTableFields());
 137                 $this->addFields($this->bl_title);
 138                 if($this->hasNS)
 139                         $this->addFields($this->bl_ns);
 140                 $titleWhere = array();
 141                 foreach($this->redirTitles as $t)
 142                         $titleWhere[] = "({$this->bl_title} = ".$db->addQuotes($t->getDBKey()).
 143                                         ($this->hasNS ? " AND {$this->bl_ns} = '{$t->getNamespace()}'" : "") .
 144                                         ")";
 145                 $this->addWhere($db->makeList($titleWhere, LIST_OR));
 146                 $this->addWhereFld('page_namespace', $this->params['namespace']);
 147                 if(!is_null($this->redirID))
 148                 {
 149                         $first = $this->redirTitles[0];
 150                         $title = $db->strencode($first->getDBKey());
 151                         $ns = $first->getNamespace();
 152                         $from = $this->redirID;
 153                         if($this->hasNS)
 154                                 $this->addWhere("{$this->bl_ns} > $ns OR ".
 155                                                 "({$this->bl_ns} = $ns AND ".
 156                                                 "({$this->bl_title} > '$title' OR ".
 157                                                 "({$this->bl_title} = '$title' AND ".
 158                                                 "{$this->bl_from} >= $from)))");
 159                         else
 160                                 $this->addWhere("{$this->bl_title} > '$title' OR ".
 161                                                 "({$this->bl_title} = '$title' AND ".
 162                                                 "{$this->bl_from} >= $from)");
 163
 164                 }
 165                 if($this->params['filterredir'] == 'redirects')
 166                         $this->addWhereFld('page_is_redirect', 1);
 167                 if($this->params['filterredir'] == 'nonredirects')
 168                         $this->addWhereFld('page_is_redirect', 0);
 169                 $this->addOption('LIMIT', $this->params['limit'] + 1);
 170                 $this->addOption('ORDER BY', $this->bl_sort);
 171         }
 172
 173         private function run($resultPageSet = null) {
 174                 $this->params = $this->extractRequestParams(false);
 175                 $this->redirect = isset($this->params['redirect']) && $this->params['redirect'];
 176                 $userMax = ( $this->redirect ? ApiBase::LIMIT_BIG1/2 : ApiBase::LIMIT_BIG1 );
 177                 $botMax  = ( $this->redirect ? ApiBase::LIMIT_BIG2/2 : ApiBase::LIMIT_BIG2 );
 178                 if( $this->params['limit'] == 'max' ) {
 179                         $this->params['limit'] = $this->getMain()->canApiHighLimits() ? $botMax : $userMax;
 180                         $this->getResult()->addValue( 'limits', $this->getModuleName(), $this->params['limit'] );
 181                 }
 182
 183                 $this->processContinue();
 184                 $this->prepareFirstQuery($resultPageSet);
 185
 186                 $db = $this->getDB();
 187                 $res = $this->select(__METHOD__.'::firstQuery');
 188
 189                 $count = 0;
 190                 $this->data = array ();
 191                 $this->continueStr = null;
 192                 $this->redirTitles = array();
 193                 while ($row = $db->fetchObject($res)) {
 194                         if (++ $count > $this->params['limit']) {
 195                                 // We've reached the one extra which shows that there are additional pages to be had. Stop here...
 196                                 // Continue string preserved in case the redirect query doesn't pass the limit
 197                                 $this->continueStr = $this->getContinueStr($row->page_id);
 198                                 break;
 199                         }
 200
 201                         if (is_null($resultPageSet))
 202                                 $this->extractRowInfo($row);
 203                         else
 204                         {
 205                                 if($row->page_is_redirect)
 206                                         $this->redirTitles[] = Title::makeTitle($row->page_namespace, $row->page_title);
 207                                 $resultPageSet->processDbRow($row);
 208                         }
 209                 }
 210                 $db->freeResult($res);
 211
 212                 if($this->redirect && count($this->redirTitles))
 213                 {
 214                         $this->resetQueryParams();
 215                         $this->prepareSecondQuery($resultPageSet);
 216                         $res = $this->select(__METHOD__.'::secondQuery');
 217                         $count = 0;
 218                         while($row = $db->fetchObject($res))
 219                         {
 220                                 if(++$count > $this->params['limit'])
 221                                 {
 222                                         // We've reached the one extra which shows that there are additional pages to be had. Stop here...
 223                                         // We need to keep the parent page of this redir in
 224                                         if($this->hasNS)
 225                                                 $contTitle = Title::makeTitle($row->{$this->bl_ns}, $row->{$this->bl_title});
 226                                         else
 227                                                 $contTitle = Title::makeTitle(NS_FILE, $row->{$this->bl_title});
 228                                         $this->continueStr = $this->getContinueRedirStr($contTitle->getArticleID(), $row->page_id);
 229                                         break;
 230                                 }
 231
 232                                 if(is_null($resultPageSet))
 233                                         $this->extractRedirRowInfo($row);
 234                                 else
 235                                         $resultPageSet->processDbRow($row);
 236                         }
 237                         $db->freeResult($res);
 238                 }
 239                 if(!is_null($this->continueStr))
 240                         $this->setContinueEnumParameter('continue', $this->continueStr);
 241
 242                 if (is_null($resultPageSet)) {
 243                         $resultData = array();
 244                         foreach($this->data as $ns => $a)
 245                                 foreach($a as $title => $arr)
 246                                         $resultData[] = $arr;
 247                         $result = $this->getResult();
 248                         $result->setIndexedTagName($resultData, $this->bl_code);
 249                         $result->addValue('query', $this->getModuleName(), $resultData);
 250                 }
 251         }
 252
 253         private function extractRowInfo($row) {
 254                 if(!isset($this->data[$row->page_namespace][$row->page_title])) {
 255                         $this->data[$row->page_namespace][$row->page_title]['pageid'] = $row->page_id;
 256                         ApiQueryBase::addTitleInfo($this->data[$row->page_namespace][$row->page_title], Title::makeTitle($row->page_namespace, $row->page_title));
 257                         if($row->page_is_redirect)
 258                         {
 259                                 $this->data[$row->page_namespace][$row->page_title]['redirect'] = '';
 260                                 $this->redirTitles[] = Title::makeTitle($row->page_namespace, $row->page_title);
 261                         }
 262                 }
 263         }
 264
 265         private function extractRedirRowInfo($row)
 266         {
 267                 $a['pageid'] = $row->page_id;
 268                 ApiQueryBase::addTitleInfo($a, Title::makeTitle($row->page_namespace, $row->page_title));
 269                 if($row->page_is_redirect)
 270                         $a['redirect'] = '';
 271                 $ns = $this->hasNS ? $row->{$this->bl_ns} : NS_FILE;
 272                 $this->data[$ns][$row->{$this->bl_title}]['redirlinks'][] = $a;
 273                 $this->getResult()->setIndexedTagName($this->data[$ns][$row->{$this->bl_title}]['redirlinks'], $this->bl_code);
 274         }
 275
 276         protected function processContinue() {
 277                 if (!is_null($this->params['continue']))
 278                         $this->parseContinueParam();
 279                 else {
 280                         if ( $this->params['title'] !== "" ) {
 281                                 $title = Title::newFromText( $this->params['title'] );
 282                                 if ( !$title ) {
 283                                         $this->dieUsageMsg(array('invalidtitle', $this->params['title']));
 284                                 } else {
 285                                         $this->rootTitle = $title;
 286                                 }
 287                         } else {
 288                                 $this->dieUsageMsg(array('missingparam', 'title'));
 289                         }
 290                 }
 291
 292                 // only image titles are allowed for the root in imageinfo mode
 293                 if (!$this->hasNS && $this->rootTitle->getNamespace() !== NS_FILE)
 294                         $this->dieUsage("The title for {$this->getModuleName()} query must be an image", 'bad_image_title');
 295         }
 296
 297         protected function parseContinueParam() {
 298                 $continueList = explode('|', $this->params['continue']);
 299                 // expected format:
 300                 // ns | key | id1 [| id2]
 301                 // ns+key: root title
 302                 // id1: first-level page ID to continue from
 303                 // id2: second-level page ID to continue from
 304
 305                 // null stuff out now so we know what's set and what isn't
 306                 $this->rootTitle = $this->contID = $this->redirID = null;
 307                 $rootNs = intval($continueList[0]);
 308                 if($rootNs === 0 && $continueList[0] !== '0')
 309                         // Illegal continue parameter
 310                         $this->dieUsage("Invalid continue param. You should pass the original value returned by the previous query", "_badcontinue");
 311                 $this->rootTitle = Title::makeTitleSafe($rootNs, $continueList[1]);
 312                 if(!$this->rootTitle)
 313                         $this->dieUsage("Invalid continue param. You should pass the original value returned by the previous query", "_badcontinue");
 314                 $contID = intval($continueList[2]);
 315                 if($contID === 0 && $continueList[2] !== '0')
 316                         $this->dieUsage("Invalid continue param. You should pass the original value returned by the previous query", "_badcontinue");
 317                 $this->contID = $contID;
 318                 $redirID = intval(@$continueList[3]);
 319                 if($redirID === 0 && @$continueList[3] !== '0')
 320                         // This one isn't required
 321                         return;
 322                 $this->redirID = $redirID;
 323
 324         }
 325
 326         protected function getContinueStr($lastPageID) {
 327                 return $this->rootTitle->getNamespace() .
 328                 '|' . $this->rootTitle->getDBkey() .
 329                 '|' . $lastPageID;
 330         }
 331
 332         protected function getContinueRedirStr($lastPageID, $lastRedirID) {
 333                 return $this->getContinueStr($lastPageID) . '|' . $lastRedirID;
 334         }
 335
 336         public function getAllowedParams() {
 337                 $retval =  array (
 338                         'title' => null,
 339                         'continue' => null,
 340                         'namespace' => array (
 341                                 ApiBase :: PARAM_ISMULTI => true,
 342                                 ApiBase :: PARAM_TYPE => 'namespace'
 343                         ),
 344                         'filterredir' => array(
 345                                 ApiBase :: PARAM_DFLT => 'all',
 346                                 ApiBase :: PARAM_TYPE => array(
 347                                         'all',
 348                                         'redirects',
 349                                         'nonredirects'
 350                                 )
 351                         ),
 352                         'limit' => array (
 353                                 ApiBase :: PARAM_DFLT => 10,
 354                                 ApiBase :: PARAM_TYPE => 'limit',
 355                                 ApiBase :: PARAM_MIN => 1,
 356                                 ApiBase :: PARAM_MAX => ApiBase :: LIMIT_BIG1,
 357                                 ApiBase :: PARAM_MAX2 => ApiBase :: LIMIT_BIG2
 358                         )
 359                 );
 360                 if($this->getModuleName() == 'embeddedin')
 361                         return $retval;
 362                 $retval['redirect'] = false;
 363                 return $retval;
 364         }
 365
 366         public function getParamDescription() {
 367                 $retval = array (
 368                         'title' => 'Title to search. If null, titles= parameter will be used instead, but will be obsolete soon.',
 369                         'continue' => 'When more results are available, use this to continue.',
 370                         'namespace' => 'The namespace to enumerate.',
 371                         'filterredir' => 'How to filter for redirects'
 372                 );
 373                 if($this->getModuleName() != 'embeddedin')
 374                         return array_merge($retval, array(
 375                                 'redirect' => 'If linking page is a redirect, find all pages that link to that redirect as well. Maximum limit is halved.',
 376                                 'limit' => "How many total pages to return. If {$this->bl_code}redirect is enabled, limit applies to each level separately."
 377                         ));
 378                 return array_merge($retval, array(
 379                         'limit' => "How many total pages to return."
 380                 ));
 381         }
 382
 383         public function getDescription() {
 384                 switch ($this->getModuleName()) {
 385                         case 'backlinks' :
 386                                 return 'Find all pages that link to the given page';
 387                         case 'embeddedin' :
 388                                 return 'Find all pages that embed (transclude) the given title';
 389                         case 'imageusage' :
 390                                 return 'Find all pages that use the given image title.';
 391                         default :
 392                                 ApiBase :: dieDebug(__METHOD__, 'Unknown module name');
 393                 }
 394         }
 395
 396         protected function getExamples() {
 397                 static $examples = array (
 398                         'backlinks' => array (
 399                                 "api.php?action=query&list=backlinks&bltitle=Main%20Page",
 400                                 "api.php?action=query&generator=backlinks&gbltitle=Main%20Page&prop=info"
 401                         ),
 402                         'embeddedin' => array (
 403                                 "api.php?action=query&list=embeddedin&eititle=Template:Stub",
 404                                 "api.php?action=query&generator=embeddedin&geititle=Template:Stub&prop=info"
 405                         ),
 406                         'imageusage' => array (
 407                                 "api.php?action=query&list=imageusage&iutitle=Image:Albert%20Einstein%20Head.jpg",
 408                                 "api.php?action=query&generator=imageusage&giutitle=Image:Albert%20Einstein%20Head.jpg&prop=info"
 409                         )
 410                 );
 411
 412                 return $examples[$this->getModuleName()];
 413         }
 414
 415         public function getVersion() {
 416                 return __CLASS__ . ': $Id: ApiQueryBacklinks.php 46135 2009-01-24 13:03:40Z catrope $';
 417         }
 418 }