includes/api/ApiQuery.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Sep 7, 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 if ( !defined( 'MEDIAWIKI' ) ) {
  28         // Eclipse helper - will be ignored in production
  29         require_once( 'ApiBase.php' );
  30 }
  31
  32 /**
  33  * This is the main query class. It behaves similar to ApiMain: based on the
  34  * parameters given, it will create a list of titles to work on (an ApiPageSet
  35  * object), instantiate and execute various property/list/meta modules, and
  36  * assemble all resulting data into a single ApiResult object.
  37  *
  38  * In generator mode, a generator will be executed first to populate a second
  39  * ApiPageSet object, and that object will be used for all subsequent modules.
  40  *
  41  * @ingroup API
  42  */
  43 class ApiQuery extends ApiBase {
  44
  45         private $mPropModuleNames, $mListModuleNames, $mMetaModuleNames;
  46
  47         /**
  48          * @var ApiPageSet
  49          */
  50         private $mPageSet;
  51
  52         private $params, $redirects, $convertTitles, $iwUrl;
  53
  54         private $mQueryPropModules = array(
  55                 'info' => 'ApiQueryInfo',
  56                 'revisions' => 'ApiQueryRevisions',
  57                 'links' => 'ApiQueryLinks',
  58                 'iwlinks' => 'ApiQueryIWLinks',
  59                 'langlinks' => 'ApiQueryLangLinks',
  60                 'images' => 'ApiQueryImages',
  61                 'imageinfo' => 'ApiQueryImageInfo',
  62                 'stashimageinfo' => 'ApiQueryStashImageInfo',
  63                 'templates' => 'ApiQueryLinks',
  64                 'categories' => 'ApiQueryCategories',
  65                 'extlinks' => 'ApiQueryExternalLinks',
  66                 'categoryinfo' => 'ApiQueryCategoryInfo',
  67                 'duplicatefiles' => 'ApiQueryDuplicateFiles',
  68                 'pageprops' => 'ApiQueryPageProps',
  69         );
  70
  71         private $mQueryListModules = array(
  72                 'allimages' => 'ApiQueryAllimages',
  73                 'allpages' => 'ApiQueryAllpages',
  74                 'alllinks' => 'ApiQueryAllLinks',
  75                 'allcategories' => 'ApiQueryAllCategories',
  76                 'allusers' => 'ApiQueryAllUsers',
  77                 'backlinks' => 'ApiQueryBacklinks',
  78                 'blocks' => 'ApiQueryBlocks',
  79                 'categorymembers' => 'ApiQueryCategoryMembers',
  80                 'deletedrevs' => 'ApiQueryDeletedrevs',
  81                 'embeddedin' => 'ApiQueryBacklinks',
  82                 'filearchive' => 'ApiQueryFilearchive',
  83                 'imageusage' => 'ApiQueryBacklinks',
  84                 'iwbacklinks' => 'ApiQueryIWBacklinks',
  85                 'langbacklinks' => 'ApiQueryLangBacklinks',
  86                 'logevents' => 'ApiQueryLogEvents',
  87                 'recentchanges' => 'ApiQueryRecentChanges',
  88                 'search' => 'ApiQuerySearch',
  89                 'tags' => 'ApiQueryTags',
  90                 'usercontribs' => 'ApiQueryContributions',
  91                 'watchlist' => 'ApiQueryWatchlist',
  92                 'watchlistraw' => 'ApiQueryWatchlistRaw',
  93                 'exturlusage' => 'ApiQueryExtLinksUsage',
  94                 'users' => 'ApiQueryUsers',
  95                 'random' => 'ApiQueryRandom',
  96                 'protectedtitles' => 'ApiQueryProtectedTitles',
  97                 'querypage' => 'ApiQueryQueryPage',
  98         );
  99
 100         private $mQueryMetaModules = array(
 101                 'siteinfo' => 'ApiQuerySiteinfo',
 102                 'userinfo' => 'ApiQueryUserInfo',
 103                 'allmessages' => 'ApiQueryAllmessages',
 104         );
 105
 106         private $mSlaveDB = null;
 107         private $mNamedDB = array();
 108
 109         public function __construct( $main, $action ) {
 110                 parent::__construct( $main, $action );
 111
 112                 // Allow custom modules to be added in LocalSettings.php
 113                 global $wgAPIPropModules, $wgAPIListModules, $wgAPIMetaModules;
 114                 self::appendUserModules( $this->mQueryPropModules, $wgAPIPropModules );
 115                 self::appendUserModules( $this->mQueryListModules, $wgAPIListModules );
 116                 self::appendUserModules( $this->mQueryMetaModules, $wgAPIMetaModules );
 117
 118                 $this->mPropModuleNames = array_keys( $this->mQueryPropModules );
 119                 $this->mListModuleNames = array_keys( $this->mQueryListModules );
 120                 $this->mMetaModuleNames = array_keys( $this->mQueryMetaModules );
 121
 122                 // Allow the entire list of modules at first,
 123                 // but during module instantiation check if it can be used as a generator.
 124                 $this->mAllowedGenerators = array_merge( $this->mListModuleNames, $this->mPropModuleNames );
 125         }
 126
 127         /**
 128          * Helper function to append any add-in modules to the list
 129          * @param $modules array Module array
 130          * @param $newModules array Module array to add to $modules
 131          */
 132         private static function appendUserModules( &$modules, $newModules ) {
 133                 if ( is_array( $newModules ) ) {
 134                         foreach ( $newModules as $moduleName => $moduleClass ) {
 135                                 $modules[$moduleName] = $moduleClass;
 136                         }
 137                 }
 138         }
 139
 140         /**
 141          * Gets a default slave database connection object
 142          * @return Database
 143          */
 144         public function getDB() {
 145                 if ( !isset( $this->mSlaveDB ) ) {
 146                         $this->profileDBIn();
 147                         $this->mSlaveDB = wfGetDB( DB_SLAVE, 'api' );
 148                         $this->profileDBOut();
 149                 }
 150                 return $this->mSlaveDB;
 151         }
 152
 153         /**
 154          * Get the query database connection with the given name.
 155          * If no such connection has been requested before, it will be created.
 156          * Subsequent calls with the same $name will return the same connection
 157          * as the first, regardless of the values of $db and $groups
 158          * @param $name string Name to assign to the database connection
 159          * @param $db int One of the DB_* constants
 160          * @param $groups array Query groups
 161          * @return Database
 162          */
 163         public function getNamedDB( $name, $db, $groups ) {
 164                 if ( !array_key_exists( $name, $this->mNamedDB ) ) {
 165                         $this->profileDBIn();
 166                         $this->mNamedDB[$name] = wfGetDB( $db, $groups );
 167                         $this->profileDBOut();
 168                 }
 169                 return $this->mNamedDB[$name];
 170         }
 171
 172         /**
 173          * Gets the set of pages the user has requested (or generated)
 174          * @return ApiPageSet
 175          */
 176         public function getPageSet() {
 177                 return $this->mPageSet;
 178         }
 179
 180         /**
 181          * Get the array mapping module names to class names
 182          * @return array(modulename => classname)
 183          */
 184         function getModules() {
 185                 return array_merge( $this->mQueryPropModules, $this->mQueryListModules, $this->mQueryMetaModules );
 186         }
 187
 188         /**
 189          * Get whether the specified module is a prop, list or a meta query module
 190          * @param $moduleName string Name of the module to find type for
 191          * @return mixed string or null
 192          */
 193         function getModuleType( $moduleName ) {
 194                 if ( isset( $this->mQueryPropModules[$moduleName] ) ) {
 195                         return 'prop';
 196                 }
 197
 198                 if ( isset( $this->mQueryListModules[$moduleName] ) ) {
 199                         return 'list';
 200                 }
 201
 202                 if ( isset( $this->mQueryMetaModules[$moduleName] ) ) {
 203                         return 'meta';
 204                 }
 205
 206                 return null;
 207         }
 208
 209         public function getCustomPrinter() {
 210                 // If &exportnowrap is set, use the raw formatter
 211                 if ( $this->getParameter( 'export' ) &&
 212                                 $this->getParameter( 'exportnowrap' ) )
 213                 {
 214                         return new ApiFormatRaw( $this->getMain(),
 215                                 $this->getMain()->createPrinterByName( 'xml' ) );
 216                 } else {
 217                         return null;
 218                 }
 219         }
 220
 221         /**
 222          * Query execution happens in the following steps:
 223          * #1 Create a PageSet object with any pages requested by the user
 224          * #2 If using a generator, execute it to get a new ApiPageSet object
 225          * #3 Instantiate all requested modules.
 226          *    This way the PageSet object will know what shared data is required,
 227          *    and minimize DB calls.
 228          * #4 Output all normalization and redirect resolution information
 229          * #5 Execute all requested modules
 230          */
 231         public function execute() {
 232                 $this->params = $this->extractRequestParams();
 233                 $this->redirects = $this->params['redirects'];
 234                 $this->convertTitles = $this->params['converttitles'];
 235                 $this->iwUrl = $this->params['iwurl'];
 236
 237                 // Create PageSet
 238                 $this->mPageSet = new ApiPageSet( $this, $this->redirects, $this->convertTitles );
 239
 240                 // Instantiate requested modules
 241                 $modules = array();
 242                 $this->instantiateModules( $modules, 'prop', $this->mQueryPropModules );
 243                 $this->instantiateModules( $modules, 'list', $this->mQueryListModules );
 244                 $this->instantiateModules( $modules, 'meta', $this->mQueryMetaModules );
 245
 246                 $cacheMode = 'public';
 247
 248                 // If given, execute generator to substitute user supplied data with generated data.
 249                 if ( isset( $this->params['generator'] ) ) {
 250                         $generator = $this->newGenerator( $this->params['generator'] );
 251                         $params = $generator->extractRequestParams();
 252                         $cacheMode = $this->mergeCacheMode( $cacheMode,
 253                                 $generator->getCacheMode( $params ) );
 254                         $this->executeGeneratorModule( $generator, $modules );
 255                 } else {
 256                         // Append custom fields and populate page/revision information
 257                         $this->addCustomFldsToPageSet( $modules, $this->mPageSet );
 258                         $this->mPageSet->execute();
 259                 }
 260
 261                 // Record page information (title, namespace, if exists, etc)
 262                 $this->outputGeneralPageInfo();
 263
 264                 // Execute all requested modules.
 265                 foreach ( $modules as $module ) {
 266                         $params = $module->extractRequestParams();
 267                         $cacheMode = $this->mergeCacheMode(
 268                                 $cacheMode, $module->getCacheMode( $params ) );
 269                         $module->profileIn();
 270                         $module->execute();
 271                         wfRunHooks( 'APIQueryAfterExecute', array( &$module ) );
 272                         $module->profileOut();
 273                 }
 274
 275                 // Set the cache mode
 276                 $this->getMain()->setCacheMode( $cacheMode );
 277         }
 278
 279         /**
 280          * Update a cache mode string, applying the cache mode of a new module to it.
 281          * The cache mode may increase in the level of privacy, but public modules
 282          * added to private data do not decrease the level of privacy.
 283          *
 284          * @return string
 285          */
 286         protected function mergeCacheMode( $cacheMode, $modCacheMode ) {
 287                 if ( $modCacheMode === 'anon-public-user-private' ) {
 288                         if ( $cacheMode !== 'private' ) {
 289                                 $cacheMode = 'anon-public-user-private';
 290                         }
 291                 } elseif ( $modCacheMode === 'public' ) {
 292                         // do nothing, if it's public already it will stay public
 293                 } else { // private
 294                         $cacheMode = 'private';
 295                 }
 296                 return $cacheMode;
 297         }
 298
 299         /**
 300          * Query modules may optimize data requests through the $this->getPageSet() object
 301          * by adding extra fields from the page table.
 302          * This function will gather all the extra request fields from the modules.
 303          * @param $modules array of module objects
 304          * @param $pageSet ApiPageSet
 305          */
 306         private function addCustomFldsToPageSet( $modules, $pageSet ) {
 307                 // Query all requested modules.
 308                 foreach ( $modules as $module ) {
 309                         $module->requestExtraData( $pageSet );
 310                 }
 311         }
 312
 313         /**
 314          * Create instances of all modules requested by the client
 315          * @param $modules Array to append instantiated modules to
 316          * @param $param string Parameter name to read modules from
 317          * @param $moduleList Array array(modulename => classname)
 318          */
 319         private function instantiateModules( &$modules, $param, $moduleList ) {
 320                 if ( isset( $this->params[$param] ) ) {
 321                         foreach ( $this->params[$param] as $moduleName ) {
 322                                 $modules[] = new $moduleList[$moduleName] ( $this, $moduleName );
 323                         }
 324                 }
 325         }
 326
 327         /**
 328          * Appends an element for each page in the current pageSet with the
 329          * most general information (id, title), plus any title normalizations
 330          * and missing or invalid title/pageids/revids.
 331          */
 332         private function outputGeneralPageInfo() {
 333                 $pageSet = $this->getPageSet();
 334                 $result = $this->getResult();
 335
 336                 // We don't check for a full result set here because we can't be adding
 337                 // more than 380K. The maximum revision size is in the megabyte range,
 338                 // and the maximum result size must be even higher than that.
 339
 340                 // Title normalizations
 341                 $normValues = array();
 342                 foreach ( $pageSet->getNormalizedTitles() as $rawTitleStr => $titleStr ) {
 343                         $normValues[] = array(
 344                                 'from' => $rawTitleStr,
 345                                 'to' => $titleStr
 346                         );
 347                 }
 348
 349                 if ( count( $normValues ) ) {
 350                         $result->setIndexedTagName( $normValues, 'n' );
 351                         $result->addValue( 'query', 'normalized', $normValues );
 352                 }
 353
 354                 // Title conversions
 355                 $convValues = array();
 356                 foreach ( $pageSet->getConvertedTitles() as $rawTitleStr => $titleStr ) {
 357                         $convValues[] = array(
 358                                 'from' => $rawTitleStr,
 359                                 'to' => $titleStr
 360                         );
 361                 }
 362
 363                 if ( count( $convValues ) ) {
 364                         $result->setIndexedTagName( $convValues, 'c' );
 365                         $result->addValue( 'query', 'converted', $convValues );
 366                 }
 367
 368                 // Interwiki titles
 369                 $intrwValues = array();
 370                 foreach ( $pageSet->getInterwikiTitles() as $rawTitleStr => $interwikiStr ) {
 371                         $item = array(
 372                                 'title' => $rawTitleStr,
 373                                 'iw' => $interwikiStr,
 374                         );
 375                         if ( $this->iwUrl ) {
 376                                 $title = Title::newFromText( $rawTitleStr );
 377                                 $item['url'] = $title->getFullURL();
 378                         }
 379                         $intrwValues[] = $item;
 380                 }
 381
 382                 if ( count( $intrwValues ) ) {
 383                         $result->setIndexedTagName( $intrwValues, 'i' );
 384                         $result->addValue( 'query', 'interwiki', $intrwValues );
 385                 }
 386
 387                 // Show redirect information
 388                 $redirValues = array();
 389                 foreach ( $pageSet->getRedirectTitles() as $titleStrFrom => $titleTo ) {
 390                         $r = array(
 391                                 'from' => strval( $titleStrFrom ),
 392                                 'to' => $titleTo->getPrefixedText(),
 393                         );
 394                         if ( $titleTo->getFragment() !== '' ) {
 395                                 $r['tofragment'] = $titleTo->getFragment();
 396                         }
 397                         $redirValues[] = $r;
 398                 }
 399
 400                 if ( count( $redirValues ) ) {
 401                         $result->setIndexedTagName( $redirValues, 'r' );
 402                         $result->addValue( 'query', 'redirects', $redirValues );
 403                 }
 404
 405                 // Missing revision elements
 406                 $missingRevIDs = $pageSet->getMissingRevisionIDs();
 407                 if ( count( $missingRevIDs ) ) {
 408                         $revids = array();
 409                         foreach ( $missingRevIDs as $revid ) {
 410                                 $revids[$revid] = array(
 411                                         'revid' => $revid
 412                                 );
 413                         }
 414                         $result->setIndexedTagName( $revids, 'rev' );
 415                         $result->addValue( 'query', 'badrevids', $revids );
 416                 }
 417
 418                 // Page elements
 419                 $pages = array();
 420
 421                 // Report any missing titles
 422                 foreach ( $pageSet->getMissingTitles() as $fakeId => $title ) {
 423                         $vals = array();
 424                         ApiQueryBase::addTitleInfo( $vals, $title );
 425                         $vals['missing'] = '';
 426                         $pages[$fakeId] = $vals;
 427                 }
 428                 // Report any invalid titles
 429                 foreach ( $pageSet->getInvalidTitles() as $fakeId => $title ) {
 430                         $pages[$fakeId] = array( 'title' => $title, 'invalid' => '' );
 431                 }
 432                 // Report any missing page ids
 433                 foreach ( $pageSet->getMissingPageIDs() as $pageid ) {
 434                         $pages[$pageid] = array(
 435                                 'pageid' => $pageid,
 436                                 'missing' => ''
 437                         );
 438                 }
 439                 // Report special pages
 440                 foreach ( $pageSet->getSpecialTitles() as $fakeId => $title ) {
 441                         $vals = array();
 442                         ApiQueryBase::addTitleInfo( $vals, $title );
 443                         $vals['special'] = '';
 444                         if ( $title->getNamespace() == NS_SPECIAL &&
 445                                         !SpecialPageFactory::exists( $title->getDbKey() ) ) {
 446                                 $vals['missing'] = '';
 447                         } elseif ( $title->getNamespace() == NS_MEDIA &&
 448                                         !wfFindFile( $title ) ) {
 449                                 $vals['missing'] = '';
 450                         }
 451                         $pages[$fakeId] = $vals;
 452                 }
 453
 454                 // Output general page information for found titles
 455                 foreach ( $pageSet->getGoodTitles() as $pageid => $title ) {
 456                         $vals = array();
 457                         $vals['pageid'] = $pageid;
 458                         ApiQueryBase::addTitleInfo( $vals, $title );
 459                         $pages[$pageid] = $vals;
 460                 }
 461
 462                 if ( count( $pages ) ) {
 463                         if ( $this->params['indexpageids'] ) {
 464                                 $pageIDs = array_keys( $pages );
 465                                 // json treats all map keys as strings - converting to match
 466                                 $pageIDs = array_map( 'strval', $pageIDs );
 467                                 $result->setIndexedTagName( $pageIDs, 'id' );
 468                                 $result->addValue( 'query', 'pageids', $pageIDs );
 469                         }
 470
 471                         $result->setIndexedTagName( $pages, 'page' );
 472                         $result->addValue( 'query', 'pages', $pages );
 473                 }
 474                 if ( $this->params['export'] ) {
 475                         $this->doExport( $pageSet, $result );
 476                 }
 477         }
 478
 479         /**
 480          * @param  $pageSet ApiPageSet Pages to be exported
 481          * @param  $result ApiResult Result to output to
 482          */
 483         private function doExport( $pageSet, $result )  {
 484                 $exportTitles = array();
 485                 $titles = $pageSet->getGoodTitles();
 486                 if ( count( $titles ) ) {
 487                         foreach ( $titles as $title ) {
 488                                 if ( $title->userCanRead() ) {
 489                                         $exportTitles[] = $title;
 490                                 }
 491                         }
 492                 }
 493
 494                 $exporter = new WikiExporter( $this->getDB() );
 495                 // WikiExporter writes to stdout, so catch its
 496                 // output with an ob
 497                 ob_start();
 498                 $exporter->openStream();
 499                 foreach ( $exportTitles as $title ) {
 500                         $exporter->pageByTitle( $title );
 501                 }
 502                 $exporter->closeStream();
 503                 $exportxml = ob_get_contents();
 504                 ob_end_clean();
 505
 506                 // Don't check the size of exported stuff
 507                 // It's not continuable, so it would cause more
 508                 // problems than it'd solve
 509                 $result->disableSizeCheck();
 510                 if ( $this->params['exportnowrap'] ) {
 511                         $result->reset();
 512                         // Raw formatter will handle this
 513                         $result->addValue( null, 'text', $exportxml );
 514                         $result->addValue( null, 'mime', 'text/xml' );
 515                 } else {
 516                         $r = array();
 517                         ApiResult::setContent( $r, $exportxml );
 518                         $result->addValue( 'query', 'export', $r );
 519                 }
 520                 $result->enableSizeCheck();
 521         }
 522
 523         /**
 524          * Create a generator object of the given type and return it
 525          * @param $generatorName string Module name
 526          * @return ApiQueryGeneratorBase
 527          */
 528         public function newGenerator( $generatorName ) {
 529                 // Find class that implements requested generator
 530                 if ( isset( $this->mQueryListModules[$generatorName] ) ) {
 531                         $className = $this->mQueryListModules[$generatorName];
 532                 } elseif ( isset( $this->mQueryPropModules[$generatorName] ) ) {
 533                         $className = $this->mQueryPropModules[$generatorName];
 534                 } else {
 535                         ApiBase::dieDebug( __METHOD__, "Unknown generator=$generatorName" );
 536                 }
 537                 $generator = new $className ( $this, $generatorName );
 538                 if ( !$generator instanceof ApiQueryGeneratorBase ) {
 539                         $this->dieUsage( "Module $generatorName cannot be used as a generator", 'badgenerator' );
 540                 }
 541                 $generator->setGeneratorMode();
 542                 return $generator;
 543         }
 544
 545         /**
 546          * For generator mode, execute generator, and use its output as new
 547          * ApiPageSet
 548          * @param $generator ApiQueryGeneratorBase Generator Module
 549          * @param $modules array of module objects
 550          */
 551         protected function executeGeneratorModule( $generator, $modules ) {
 552                 // Generator results
 553                 $resultPageSet = new ApiPageSet( $this, $this->redirects, $this->convertTitles );
 554
 555                 // Add any additional fields modules may need
 556                 $generator->requestExtraData( $this->mPageSet );
 557                 $this->addCustomFldsToPageSet( $modules, $resultPageSet );
 558
 559                 // Populate page information with the original user input
 560                 $this->mPageSet->execute();
 561
 562                 // populate resultPageSet with the generator output
 563                 $generator->profileIn();
 564                 $generator->executeGenerator( $resultPageSet );
 565                 wfRunHooks( 'APIQueryGeneratorAfterExecute', array( &$generator, &$resultPageSet ) );
 566                 $resultPageSet->finishPageSetGeneration();
 567                 $generator->profileOut();
 568
 569                 // Swap the resulting pageset back in
 570                 $this->mPageSet = $resultPageSet;
 571         }
 572
 573         public function getAllowedParams() {
 574                 return array(
 575                         'prop' => array(
 576                                 ApiBase::PARAM_ISMULTI => true,
 577                                 ApiBase::PARAM_TYPE => $this->mPropModuleNames
 578                         ),
 579                         'list' => array(
 580                                 ApiBase::PARAM_ISMULTI => true,
 581                                 ApiBase::PARAM_TYPE => $this->mListModuleNames
 582                         ),
 583                         'meta' => array(
 584                                 ApiBase::PARAM_ISMULTI => true,
 585                                 ApiBase::PARAM_TYPE => $this->mMetaModuleNames
 586                         ),
 587                         'generator' => array(
 588                                 ApiBase::PARAM_TYPE => $this->mAllowedGenerators
 589                         ),
 590                         'redirects' => false,
 591                         'converttitles' => false,
 592                         'indexpageids' => false,
 593                         'export' => false,
 594                         'exportnowrap' => false,
 595                         'iwurl' => false,
 596                 );
 597         }
 598
 599         /**
 600          * Override the parent to generate help messages for all available query modules.
 601          * @return string
 602          */
 603         public function makeHelpMsg() {
 604                 // Make sure the internal object is empty
 605                 // (just in case a sub-module decides to optimize during instantiation)
 606                 $this->mPageSet = null;
 607                 $this->mAllowedGenerators = array(); // Will be repopulated
 608
 609                 $querySeparator = str_repeat( '--- ', 12 );
 610                 $moduleSeparator = str_repeat( '*** ', 14 );
 611                 $msg = "\n$querySeparator Query: Prop  $querySeparator\n\n";
 612                 $msg .= $this->makeHelpMsgHelper( $this->mQueryPropModules, 'prop' );
 613                 $msg .= "\n$querySeparator Query: List  $querySeparator\n\n";
 614                 $msg .= $this->makeHelpMsgHelper( $this->mQueryListModules, 'list' );
 615                 $msg .= "\n$querySeparator Query: Meta  $querySeparator\n\n";
 616                 $msg .= $this->makeHelpMsgHelper( $this->mQueryMetaModules, 'meta' );
 617                 $msg .= "\n\n$moduleSeparator Modules: continuation  $moduleSeparator\n\n";
 618
 619                 // Perform the base call last because the $this->mAllowedGenerators
 620                 // will be updated inside makeHelpMsgHelper()
 621                 // Use parent to make default message for the query module
 622                 $msg = parent::makeHelpMsg() . $msg;
 623
 624                 return $msg;
 625         }
 626
 627         /**
 628          * For all modules in $moduleList, generate help messages and join them together
 629          * @param $moduleList Array array(modulename => classname)
 630          * @param $paramName string Parameter name
 631          * @return string
 632          */
 633         private function makeHelpMsgHelper( $moduleList, $paramName ) {
 634                 $moduleDescriptions = array();
 635
 636                 foreach ( $moduleList as $moduleName => $moduleClass ) {
 637                         $module = new $moduleClass( $this, $moduleName, null );
 638
 639                         $msg = ApiMain::makeHelpMsgHeader( $module, $paramName );
 640                         $msg2 = $module->makeHelpMsg();
 641                         if ( $msg2 !== false ) {
 642                                 $msg .= $msg2;
 643                         }
 644                         if ( $module instanceof ApiQueryGeneratorBase ) {
 645                                 $this->mAllowedGenerators[] = $moduleName;
 646                                 $msg .= "Generator:\n  This module may be used as a generator\n";
 647                         }
 648                         $moduleDescriptions[] = $msg;
 649                 }
 650
 651                 return implode( "\n", $moduleDescriptions );
 652         }
 653
 654         /**
 655          * Override to add extra parameters from PageSet
 656          * @return string
 657          */
 658         public function makeHelpMsgParameters() {
 659                 $psModule = new ApiPageSet( $this );
 660                 return $psModule->makeHelpMsgParameters() . parent::makeHelpMsgParameters();
 661         }
 662
 663         public function shouldCheckMaxlag() {
 664                 return true;
 665         }
 666
 667         public function getParamDescription() {
 668                 return array(
 669                         'prop' => 'Which properties to get for the titles/revisions/pageids. Module help is available below',
 670                         'list' => 'Which lists to get. Module help is available below',
 671                         'meta' => 'Which metadata to get about the site. Module help is available below',
 672                         'generator' => array( 'Use the output of a list as the input for other prop/list/meta items',
 673                                         'NOTE: generator parameter names must be prefixed with a \'g\', see examples' ),
 674                         'redirects' => 'Automatically resolve redirects',
 675                         'converttitles' => array( "Convert titles to other variants if necessary. Only works if the wiki's content language supports variant conversion.",
 676                                         'Languages that support variant conversion include kk, ku, gan, tg, sr, zh' ),
 677                         'indexpageids' => 'Include an additional pageids section listing all returned page IDs',
 678                         'export' => 'Export the current revisions of all given or generated pages',
 679                         'exportnowrap' => 'Return the export XML without wrapping it in an XML result (same format as Special:Export). Can only be used with export',
 680                         'iwurl' => 'Whether to get the full URL if the title is an interwiki link',
 681                 );
 682         }
 683
 684         public function getDescription() {
 685                 return array(
 686                         'Query API module allows applications to get needed pieces of data from the MediaWiki databases,',
 687                         'and is loosely based on the old query.php interface.',
 688                         'All data modifications will first have to use query to acquire a token to prevent abuse from malicious sites'
 689                 );
 690         }
 691
 692         public function getPossibleErrors() {
 693                 return array_merge( parent::getPossibleErrors(), array(
 694                         array( 'code' => 'badgenerator', 'info' => 'Module $generatorName cannot be used as a generator' ),
 695                 ) );
 696         }
 697
 698         protected function getExamples() {
 699                 return array(
 700                         'api.php?action=query&prop=revisions&meta=siteinfo&titles=Main%20Page&rvprop=user|comment',
 701                         'api.php?action=query&generator=allpages&gapprefix=API/&prop=revisions',
 702                 );
 703         }
 704
 705         public function getVersion() {
 706                 $psModule = new ApiPageSet( $this );
 707                 $vers = array();
 708                 $vers[] = __CLASS__ . ': $Id$';
 709                 $vers[] = $psModule->getVersion();
 710                 return $vers;
 711         }
 712 }