includes/api/ApiQueryBacklinks.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Oct 16, 2006
   6  *
   7  * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @file
  25  */
  26
  27 /**
  28  * This is a three-in-one module to query:
  29  *   * backlinks  - links pointing to the given page,
  30  *   * embeddedin - what pages transclude the given page within themselves,
  31  *   * imageusage - what pages use the given image
  32  *
  33  * @ingroup API
  34  */
  35 class ApiQueryBacklinks extends ApiQueryGeneratorBase {
  36
  37         /**
  38          * @var Title
  39          */
  40         private $rootTitle;
  41
  42         private $params, $cont, $redirect;
  43         private $bl_ns, $bl_from, $bl_from_ns, $bl_table, $bl_code, $bl_title, $bl_fields, $hasNS;
  44
  45         /**
  46          * Maps ns and title to pageid
  47          *
  48          * @var array
  49          */
  50         private $pageMap = array();
  51         private $resultArr;
  52
  53         private $redirTitles = array();
  54         private $continueStr = null;
  55
  56         // output element name, database column field prefix, database table
  57         private $backlinksSettings = array(
  58                 'backlinks' => array(
  59                         'code' => 'bl',
  60                         'prefix' => 'pl',
  61                         'linktbl' => 'pagelinks',
  62                         'helpurl' => 'https://www.mediawiki.org/wiki/API:Backlinks',
  63                 ),
  64                 'embeddedin' => array(
  65                         'code' => 'ei',
  66                         'prefix' => 'tl',
  67                         'linktbl' => 'templatelinks',
  68                         'helpurl' => 'https://www.mediawiki.org/wiki/API:Embeddedin',
  69                 ),
  70                 'imageusage' => array(
  71                         'code' => 'iu',
  72                         'prefix' => 'il',
  73                         'linktbl' => 'imagelinks',
  74                         'helpurl' => 'https://www.mediawiki.org/wiki/API:Imageusage',
  75                 )
  76         );
  77
  78         public function __construct( ApiQuery $query, $moduleName ) {
  79                 $settings = $this->backlinksSettings[$moduleName];
  80                 $prefix = $settings['prefix'];
  81                 $code = $settings['code'];
  82                 $this->resultArr = array();
  83
  84                 parent::__construct( $query, $moduleName, $code );
  85                 $this->bl_ns = $prefix . '_namespace';
  86                 $this->bl_from = $prefix . '_from';
  87                 $this->bl_from_ns = $prefix . '_from_namespace';
  88                 $this->bl_table = $settings['linktbl'];
  89                 $this->bl_code = $code;
  90                 $this->helpUrl = $settings['helpurl'];
  91
  92                 $this->hasNS = $moduleName !== 'imageusage';
  93                 if ( $this->hasNS ) {
  94                         $this->bl_title = $prefix . '_title';
  95                         $this->bl_fields = array(
  96                                 $this->bl_ns,
  97                                 $this->bl_title
  98                         );
  99                 } else {
 100                         $this->bl_title = $prefix . '_to';
 101                         $this->bl_fields = array(
 102                                 $this->bl_title
 103                         );
 104                 }
 105         }
 106
 107         public function execute() {
 108                 $this->run();
 109         }
 110
 111         public function getCacheMode( $params ) {
 112                 return 'public';
 113         }
 114
 115         public function executeGenerator( $resultPageSet ) {
 116                 $this->run( $resultPageSet );
 117         }
 118
 119         /**
 120          * @param ApiPageSet $resultPageSet
 121          * @return void
 122          */
 123         private function runFirstQuery( $resultPageSet = null ) {
 124                 $this->addTables( array( $this->bl_table, 'page' ) );
 125                 $this->addWhere( "{$this->bl_from}=page_id" );
 126                 if ( is_null( $resultPageSet ) ) {
 127                         $this->addFields( array( 'page_id', 'page_title', 'page_namespace' ) );
 128                 } else {
 129                         $this->addFields( $resultPageSet->getPageTableFields() );
 130                 }
 131                 $this->addFields( array( 'page_is_redirect', 'from_ns' => 'page_namespace' ) );
 132
 133                 $this->addWhereFld( $this->bl_title, $this->rootTitle->getDBkey() );
 134                 if ( $this->hasNS ) {
 135                         $this->addWhereFld( $this->bl_ns, $this->rootTitle->getNamespace() );
 136                 }
 137                 $this->addWhereFld( $this->bl_from_ns, $this->params['namespace'] );
 138
 139                 if ( count( $this->cont ) >= 2 ) {
 140                         $op = $this->params['dir'] == 'descending' ? '<' : '>';
 141                         if ( count( $this->params['namespace'] ) > 1 ) {
 142                                 $this->addWhere(
 143                                         "{$this->bl_from_ns} $op {$this->cont[0]} OR " .
 144                                         "({$this->bl_from_ns} = {$this->cont[0]} AND " .
 145                                         "{$this->bl_from} $op= {$this->cont[1]})"
 146                                 );
 147                         } else {
 148                                 $this->addWhere( "{$this->bl_from} $op= {$this->cont[1]}" );
 149                         }
 150                 }
 151
 152                 if ( $this->params['filterredir'] == 'redirects' ) {
 153                         $this->addWhereFld( 'page_is_redirect', 1 );
 154                 } elseif ( $this->params['filterredir'] == 'nonredirects' && !$this->redirect ) {
 155                         // bug 22245 - Check for !redirect, as filtering nonredirects, when
 156                         // getting what links to them is contradictory
 157                         $this->addWhereFld( 'page_is_redirect', 0 );
 158                 }
 159
 160                 $this->addOption( 'LIMIT', $this->params['limit'] + 1 );
 161                 $sort = ( $this->params['dir'] == 'descending' ? ' DESC' : '' );
 162                 $orderBy = array();
 163                 if ( count( $this->params['namespace'] ) > 1 ) {
 164                         $orderBy[] = $this->bl_from_ns . $sort;
 165                 }
 166                 $orderBy[] = $this->bl_from . $sort;
 167                 $this->addOption( 'ORDER BY', $orderBy );
 168                 $this->addOption( 'STRAIGHT_JOIN' );
 169
 170                 $res = $this->select( __METHOD__ );
 171                 $count = 0;
 172                 foreach ( $res as $row ) {
 173                         if ( ++$count > $this->params['limit'] ) {
 174                                 // We've reached the one extra which shows that there are
 175                                 // additional pages to be had. Stop here...
 176                                 // Continue string may be overridden at a later step
 177                                 $this->continueStr = "{$row->from_ns}|{$row->page_id}";
 178                                 break;
 179                         }
 180
 181                         // Fill in continuation fields for later steps
 182                         if ( count( $this->cont ) < 2 ) {
 183                                 $this->cont[] = $row->from_ns;
 184                                 $this->cont[] = $row->page_id;
 185                         }
 186
 187                         $this->pageMap[$row->page_namespace][$row->page_title] = $row->page_id;
 188                         $t = Title::makeTitle( $row->page_namespace, $row->page_title );
 189                         if ( $row->page_is_redirect ) {
 190                                 $this->redirTitles[] = $t;
 191                         }
 192
 193                         if ( is_null( $resultPageSet ) ) {
 194                                 $a = array( 'pageid' => intval( $row->page_id ) );
 195                                 ApiQueryBase::addTitleInfo( $a, $t );
 196                                 if ( $row->page_is_redirect ) {
 197                                         $a['redirect'] = true;
 198                                 }
 199                                 // Put all the results in an array first
 200                                 $this->resultArr[$a['pageid']] = $a;
 201                         } else {
 202                                 $resultPageSet->processDbRow( $row );
 203                         }
 204                 }
 205         }
 206
 207         /**
 208          * @param ApiPageSet $resultPageSet
 209          * @return void
 210          */
 211         private function runSecondQuery( $resultPageSet = null ) {
 212                 $db = $this->getDB();
 213                 $this->addTables( array( 'page', $this->bl_table ) );
 214                 $this->addWhere( "{$this->bl_from}=page_id" );
 215
 216                 if ( is_null( $resultPageSet ) ) {
 217                         $this->addFields( array( 'page_id', 'page_title', 'page_namespace', 'page_is_redirect' ) );
 218                 } else {
 219                         $this->addFields( $resultPageSet->getPageTableFields() );
 220                 }
 221
 222                 $this->addFields( array( $this->bl_title, 'from_ns' => 'page_namespace' ) );
 223                 if ( $this->hasNS ) {
 224                         $this->addFields( $this->bl_ns );
 225                 }
 226
 227                 // We can't use LinkBatch here because $this->hasNS may be false
 228                 $titleWhere = array();
 229                 $allRedirNs = array();
 230                 $allRedirDBkey = array();
 231                 /** @var $t Title */
 232                 foreach ( $this->redirTitles as $t ) {
 233                         $redirNs = $t->getNamespace();
 234                         $redirDBkey = $t->getDBkey();
 235                         $titleWhere[] = "{$this->bl_title} = " . $db->addQuotes( $redirDBkey ) .
 236                                 ( $this->hasNS ? " AND {$this->bl_ns} = {$redirNs}" : '' );
 237                         $allRedirNs[$redirNs] = true;
 238                         $allRedirDBkey[$redirDBkey] = true;
 239                 }
 240                 $this->addWhere( $db->makeList( $titleWhere, LIST_OR ) );
 241                 $this->addWhereFld( 'page_namespace', $this->params['namespace'] );
 242
 243                 if ( count( $this->cont ) >= 6 ) {
 244                         $op = $this->params['dir'] == 'descending' ? '<' : '>';
 245
 246                         $where = "{$this->bl_from} $op= {$this->cont[5]}";
 247                         // Don't bother with namespace, title, or from_namespace if it's
 248                         // otherwise constant in the where clause.
 249                         if ( count( $this->params['namespace'] ) > 1 ) {
 250                                 $where = "{$this->bl_from_ns} $op {$this->cont[4]} OR " .
 251                                         "({$this->bl_from_ns} = {$this->cont[4]} AND ($where))";
 252                         }
 253                         if ( count( $allRedirDBkey ) > 1 ) {
 254                                 $title = $db->addQuotes( $this->cont[3] );
 255                                 $where = "{$this->bl_title} $op $title OR " .
 256                                         "({$this->bl_title} = $title AND ($where))";
 257                         }
 258                         if ( $this->hasNS && count( $allRedirNs ) > 1 ) {
 259                                 $where = "{$this->bl_ns} $op {$this->cont[2]} OR " .
 260                                         "({$this->bl_ns} = {$this->cont[2]} AND ($where))";
 261                         }
 262
 263                         $this->addWhere( $where );
 264                 }
 265                 if ( $this->params['filterredir'] == 'redirects' ) {
 266                         $this->addWhereFld( 'page_is_redirect', 1 );
 267                 } elseif ( $this->params['filterredir'] == 'nonredirects' ) {
 268                         $this->addWhereFld( 'page_is_redirect', 0 );
 269                 }
 270
 271                 $this->addOption( 'LIMIT', $this->params['limit'] + 1 );
 272                 $orderBy = array();
 273                 $sort = ( $this->params['dir'] == 'descending' ? ' DESC' : '' );
 274                 // Don't order by namespace/title/from_namespace if it's constant in the WHERE clause
 275                 if ( $this->hasNS && count( $allRedirNs ) > 1 ) {
 276                         $orderBy[] = $this->bl_ns . $sort;
 277                 }
 278                 if ( count( $allRedirDBkey ) > 1 ) {
 279                         $orderBy[] = $this->bl_title . $sort;
 280                 }
 281                 if ( count( $this->params['namespace'] ) > 1 ) {
 282                         $orderBy[] = $this->bl_from_ns . $sort;
 283                 }
 284                 $orderBy[] = $this->bl_from . $sort;
 285                 $this->addOption( 'ORDER BY', $orderBy );
 286                 $this->addOption( 'USE INDEX', array( 'page' => 'PRIMARY' ) );
 287
 288                 $res = $this->select( __METHOD__ );
 289                 $count = 0;
 290                 foreach ( $res as $row ) {
 291                         $ns = $this->hasNS ? $row->{$this->bl_ns} : NS_FILE;
 292
 293                         if ( ++$count > $this->params['limit'] ) {
 294                                 // We've reached the one extra which shows that there are
 295                                 // additional pages to be had. Stop here...
 296                                 // Note we must keep the parameters for the first query constant
 297                                 // This may be overridden at a later step
 298                                 $title = $row->{$this->bl_title};
 299                                 $this->continueStr = join( '|', array_slice( $this->cont, 0, 2 ) ) .
 300                                         "|$ns|$title|{$row->from_ns}|{$row->page_id}";
 301                                 break;
 302                         }
 303
 304                         // Fill in continuation fields for later steps
 305                         if ( count( $this->cont ) < 6 ) {
 306                                 $this->cont[] = $ns;
 307                                 $this->cont[] = $row->{$this->bl_title};
 308                                 $this->cont[] = $row->from_ns;
 309                                 $this->cont[] = $row->page_id;
 310                         }
 311
 312                         if ( is_null( $resultPageSet ) ) {
 313                                 $a['pageid'] = intval( $row->page_id );
 314                                 ApiQueryBase::addTitleInfo( $a, Title::makeTitle( $row->page_namespace, $row->page_title ) );
 315                                 if ( $row->page_is_redirect ) {
 316                                         $a['redirect'] = true;
 317                                 }
 318                                 $parentID = $this->pageMap[$ns][$row->{$this->bl_title}];
 319                                 // Put all the results in an array first
 320                                 $this->resultArr[$parentID]['redirlinks'][$row->page_id] = $a;
 321                         } else {
 322                                 $resultPageSet->processDbRow( $row );
 323                         }
 324                 }
 325         }
 326
 327         /**
 328          * @param ApiPageSet $resultPageSet
 329          * @return void
 330          */
 331         private function run( $resultPageSet = null ) {
 332                 $this->params = $this->extractRequestParams( false );
 333                 $this->redirect = isset( $this->params['redirect'] ) && $this->params['redirect'];
 334                 $userMax = ( $this->redirect ? ApiBase::LIMIT_BIG1 / 2 : ApiBase::LIMIT_BIG1 );
 335                 $botMax = ( $this->redirect ? ApiBase::LIMIT_BIG2 / 2 : ApiBase::LIMIT_BIG2 );
 336
 337                 $result = $this->getResult();
 338
 339                 if ( $this->params['limit'] == 'max' ) {
 340                         $this->params['limit'] = $this->getMain()->canApiHighLimits() ? $botMax : $userMax;
 341                         $result->addParsedLimit( $this->getModuleName(), $this->params['limit'] );
 342                 } else {
 343                         $this->params['limit'] = intval( $this->params['limit'] );
 344                         $this->validateLimit( 'limit', $this->params['limit'], 1, $userMax, $botMax );
 345                 }
 346
 347                 $this->rootTitle = $this->getTitleOrPageId( $this->params )->getTitle();
 348
 349                 // only image titles are allowed for the root in imageinfo mode
 350                 if ( !$this->hasNS && $this->rootTitle->getNamespace() !== NS_FILE ) {
 351                         $this->dieUsage(
 352                                 "The title for {$this->getModuleName()} query must be a file",
 353                                 'bad_image_title'
 354                         );
 355                 }
 356
 357                 // Parse and validate continuation parameter
 358                 $this->cont = array();
 359                 if ( $this->params['continue'] !== null ) {
 360                         $db = $this->getDB();
 361                         $cont = explode( '|', $this->params['continue'] );
 362
 363                         switch ( count( $cont ) ) {
 364                                 case 8:
 365                                         // redirect page ID for result adding
 366                                         $this->cont[7] = (int)$cont[7];
 367                                         $this->dieContinueUsageIf( $cont[7] !== (string)$this->cont[7] );
 368
 369                                         /* Fall through */
 370
 371                                 case 7:
 372                                         // top-level page ID for result adding
 373                                         $this->cont[6] = (int)$cont[6];
 374                                         $this->dieContinueUsageIf( $cont[6] !== (string)$this->cont[6] );
 375
 376                                         /* Fall through */
 377
 378                                 case 6:
 379                                         // ns for 2nd query (even for imageusage)
 380                                         $this->cont[2] = (int)$cont[2];
 381                                         $this->dieContinueUsageIf( $cont[2] !== (string)$this->cont[2] );
 382
 383                                         // title for 2nd query
 384                                         $this->cont[3] = $cont[3];
 385
 386                                         // from_ns for 2nd query
 387                                         $this->cont[4] = (int)$cont[4];
 388                                         $this->dieContinueUsageIf( $cont[4] !== (string)$this->cont[4] );
 389
 390                                         // from_id for 1st query
 391                                         $this->cont[5] = (int)$cont[5];
 392                                         $this->dieContinueUsageIf( $cont[5] !== (string)$this->cont[5] );
 393
 394                                         /* Fall through */
 395
 396                                 case 2:
 397                                         // from_ns for 1st query
 398                                         $this->cont[0] = (int)$cont[0];
 399                                         $this->dieContinueUsageIf( $cont[0] !== (string)$this->cont[0] );
 400
 401                                         // from_id for 1st query
 402                                         $this->cont[1] = (int)$cont[1];
 403                                         $this->dieContinueUsageIf( $cont[1] !== (string)$this->cont[1] );
 404
 405                                         break;
 406
 407                                 default:
 408                                         $this->dieContinueUsageIf( true );
 409                         }
 410
 411                         ksort( $this->cont );
 412                 }
 413
 414                 $this->runFirstQuery( $resultPageSet );
 415                 if ( $this->redirect && count( $this->redirTitles ) ) {
 416                         $this->resetQueryParams();
 417                         $this->runSecondQuery( $resultPageSet );
 418                 }
 419
 420                 // Fill in any missing fields in case it's needed below
 421                 $this->cont += array( 0, 0, 0, '', 0, 0, 0 );
 422
 423                 if ( is_null( $resultPageSet ) ) {
 424                         // Try to add the result data in one go and pray that it fits
 425                         $code = $this->bl_code;
 426                         $data = array_map( function ( $arr ) use ( $result, $code ) {
 427                                 if ( isset( $arr['redirlinks'] ) ) {
 428                                         $arr['redirlinks'] = array_values( $arr['redirlinks'] );
 429                                         ApiResult::setIndexedTagName( $arr['redirlinks'], $code );
 430                                 }
 431                                 return $arr;
 432                         }, array_values( $this->resultArr ) );
 433                         $fit = $result->addValue( 'query', $this->getModuleName(), $data );
 434                         if ( !$fit ) {
 435                                 // It didn't fit. Add elements one by one until the
 436                                 // result is full.
 437                                 ksort( $this->resultArr );
 438                                 if ( count( $this->cont ) >= 7 ) {
 439                                         $startAt = $this->cont[6];
 440                                 } else {
 441                                         reset( $this->resultArr );
 442                                         $startAt = key( $this->resultArr );
 443                                 }
 444                                 $idx = 0;
 445                                 foreach ( $this->resultArr as $pageID => $arr ) {
 446                                         if ( $pageID < $startAt ) {
 447                                                 continue;
 448                                         }
 449
 450                                         // Add the basic entry without redirlinks first
 451                                         $fit = $result->addValue(
 452                                                 array( 'query', $this->getModuleName() ),
 453                                                 $idx, array_diff_key( $arr, array( 'redirlinks' => '' ) ) );
 454                                         if ( !$fit ) {
 455                                                 $this->continueStr = join( '|', array_slice( $this->cont, 0, 6 ) ) .
 456                                                         "|$pageID";
 457                                                 break;
 458                                         }
 459
 460                                         $hasRedirs = false;
 461                                         $redirLinks = isset( $arr['redirlinks'] ) ? (array)$arr['redirlinks'] : array();
 462                                         ksort( $redirLinks );
 463                                         if ( count( $this->cont ) >= 8 && $pageID == $startAt ) {
 464                                                 $redirStartAt = $this->cont[7];
 465                                         } else {
 466                                                 reset( $redirLinks );
 467                                                 $redirStartAt = key( $redirLinks );
 468                                         }
 469                                         foreach ( $redirLinks as $key => $redir ) {
 470                                                 if ( $key < $redirStartAt ) {
 471                                                         continue;
 472                                                 }
 473
 474                                                 $fit = $result->addValue(
 475                                                         array( 'query', $this->getModuleName(), $idx, 'redirlinks' ),
 476                                                         null, $redir );
 477                                                 if ( !$fit ) {
 478                                                         $this->continueStr = join( '|', array_slice( $this->cont, 0, 6 ) ) .
 479                                                                 "|$pageID|$key";
 480                                                         break;
 481                                                 }
 482                                                 $hasRedirs = true;
 483                                         }
 484                                         if ( $hasRedirs ) {
 485                                                 $result->addIndexedTagName(
 486                                                         array( 'query', $this->getModuleName(), $idx, 'redirlinks' ),
 487                                                         $this->bl_code );
 488                                         }
 489                                         if ( !$fit ) {
 490                                                 break;
 491                                         }
 492
 493                                         $idx++;
 494                                 }
 495                         }
 496
 497                         $result->addIndexedTagName(
 498                                 array( 'query', $this->getModuleName() ),
 499                                 $this->bl_code
 500                         );
 501                 }
 502                 if ( !is_null( $this->continueStr ) ) {
 503                         $this->setContinueEnumParameter( 'continue', $this->continueStr );
 504                 }
 505         }
 506
 507         public function getAllowedParams() {
 508                 $retval = array(
 509                         'title' => array(
 510                                 ApiBase::PARAM_TYPE => 'string',
 511                         ),
 512                         'pageid' => array(
 513                                 ApiBase::PARAM_TYPE => 'integer',
 514                         ),
 515                         'continue' => array(
 516                                 ApiBase::PARAM_HELP_MSG => 'api-help-param-continue',
 517                         ),
 518                         'namespace' => array(
 519                                 ApiBase::PARAM_ISMULTI => true,
 520                                 ApiBase::PARAM_TYPE => 'namespace'
 521                         ),
 522                         'dir' => array(
 523                                 ApiBase::PARAM_DFLT => 'ascending',
 524                                 ApiBase::PARAM_TYPE => array(
 525                                         'ascending',
 526                                         'descending'
 527                                 )
 528                         ),
 529                         'filterredir' => array(
 530                                 ApiBase::PARAM_DFLT => 'all',
 531                                 ApiBase::PARAM_TYPE => array(
 532                                         'all',
 533                                         'redirects',
 534                                         'nonredirects'
 535                                 )
 536                         ),
 537                         'limit' => array(
 538                                 ApiBase::PARAM_DFLT => 10,
 539                                 ApiBase::PARAM_TYPE => 'limit',
 540                                 ApiBase::PARAM_MIN => 1,
 541                                 ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
 542                                 ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
 543                         )
 544                 );
 545                 if ( $this->getModuleName() == 'embeddedin' ) {
 546                         return $retval;
 547                 }
 548                 $retval['redirect'] = false;
 549
 550                 return $retval;
 551         }
 552
 553         protected function getExamplesMessages() {
 554                 static $examples = array(
 555                         'backlinks' => array(
 556                                 'action=query&list=backlinks&bltitle=Main%20Page'
 557                                         => 'apihelp-query+backlinks-example-simple',
 558                                 'action=query&generator=backlinks&gbltitle=Main%20Page&prop=info'
 559                                         => 'apihelp-query+backlinks-example-generator',
 560                         ),
 561                         'embeddedin' => array(
 562                                 'action=query&list=embeddedin&eititle=Template:Stub'
 563                                         => 'apihelp-query+embeddedin-example-simple',
 564                                 'action=query&generator=embeddedin&geititle=Template:Stub&prop=info'
 565                                         => 'apihelp-query+embeddedin-example-generator',
 566                         ),
 567                         'imageusage' => array(
 568                                 'action=query&list=imageusage&iutitle=File:Albert%20Einstein%20Head.jpg'
 569                                         => 'apihelp-query+imageusage-example-simple',
 570                                 'action=query&generator=imageusage&giutitle=File:Albert%20Einstein%20Head.jpg&prop=info'
 571                                         => 'apihelp-query+imageusage-example-generator',
 572                         )
 573                 );
 574
 575                 return $examples[$this->getModuleName()];
 576         }
 577
 578         public function getHelpUrls() {
 579                 return $this->helpUrl;
 580         }
 581 }