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         private $mPageSet;
  47         private $params, $redirects, $convertTitles;
  48
  49         private $mQueryPropModules = array(
  50                 'info' => 'ApiQueryInfo',
  51                 'revisions' => 'ApiQueryRevisions',
  52                 'links' => 'ApiQueryLinks',
  53                 'iwlinks' => 'ApiQueryIWLinks',
  54                 'langlinks' => 'ApiQueryLangLinks',
  55                 'images' => 'ApiQueryImages',
  56                 'imageinfo' => 'ApiQueryImageInfo',
  57                 'stashimageinfo' => 'ApiQueryStashImageInfo',
  58                 'templates' => 'ApiQueryLinks',
  59                 'categories' => 'ApiQueryCategories',
  60                 'extlinks' => 'ApiQueryExternalLinks',
  61                 'categoryinfo' => 'ApiQueryCategoryInfo',
  62                 'duplicatefiles' => 'ApiQueryDuplicateFiles',
  63                 'pageprops' => 'ApiQueryPageProps',
  64         );
  65
  66         private $mQueryListModules = array(
  67                 'allimages' => 'ApiQueryAllimages',
  68                 'allpages' => 'ApiQueryAllpages',
  69                 'alllinks' => 'ApiQueryAllLinks',
  70                 'allcategories' => 'ApiQueryAllCategories',
  71                 'allusers' => 'ApiQueryAllUsers',
  72                 'backlinks' => 'ApiQueryBacklinks',
  73                 'blocks' => 'ApiQueryBlocks',
  74                 'categorymembers' => 'ApiQueryCategoryMembers',
  75                 'deletedrevs' => 'ApiQueryDeletedrevs',
  76                 'embeddedin' => 'ApiQueryBacklinks',
  77                 'filearchive' => 'ApiQueryFilearchive',
  78                 'imageusage' => 'ApiQueryBacklinks',
  79                 'iwbacklinks' => 'ApiQueryIWBacklinks',
  80                 'logevents' => 'ApiQueryLogEvents',
  81                 'recentchanges' => 'ApiQueryRecentChanges',
  82                 'search' => 'ApiQuerySearch',
  83                 'tags' => 'ApiQueryTags',
  84                 'usercontribs' => 'ApiQueryContributions',
  85                 'watchlist' => 'ApiQueryWatchlist',
  86                 'watchlistraw' => 'ApiQueryWatchlistRaw',
  87                 'exturlusage' => 'ApiQueryExtLinksUsage',
  88                 'users' => 'ApiQueryUsers',
  89                 'random' => 'ApiQueryRandom',
  90                 'protectedtitles' => 'ApiQueryProtectedTitles',
  91                 'querypage' => 'ApiQueryQueryPage',
  92         );
  93
  94         private $mQueryMetaModules = array(
  95                 'siteinfo' => 'ApiQuerySiteinfo',
  96                 'userinfo' => 'ApiQueryUserInfo',
  97                 'allmessages' => 'ApiQueryAllmessages',
  98         );
  99
 100         private $mSlaveDB = null;
 101         private $mNamedDB = array();
 102
 103         public function __construct( $main, $action ) {
 104                 parent::__construct( $main, $action );
 105
 106                 // Allow custom modules to be added in LocalSettings.php
 107                 global $wgAPIPropModules, $wgAPIListModules, $wgAPIMetaModules;
 108                 self::appendUserModules( $this->mQueryPropModules, $wgAPIPropModules );
 109                 self::appendUserModules( $this->mQueryListModules, $wgAPIListModules );
 110                 self::appendUserModules( $this->mQueryMetaModules, $wgAPIMetaModules );
 111
 112                 $this->mPropModuleNames = array_keys( $this->mQueryPropModules );
 113                 $this->mListModuleNames = array_keys( $this->mQueryListModules );
 114                 $this->mMetaModuleNames = array_keys( $this->mQueryMetaModules );
 115
 116                 // Allow the entire list of modules at first,
 117                 // but during module instantiation check if it can be used as a generator.
 118                 $this->mAllowedGenerators = array_merge( $this->mListModuleNames, $this->mPropModuleNames );
 119         }
 120
 121         /**
 122          * Helper function to append any add-in modules to the list
 123          * @param $modules array Module array
 124          * @param $newModules array Module array to add to $modules
 125          */
 126         private static function appendUserModules( &$modules, $newModules ) {
 127                 if ( is_array( $newModules ) ) {
 128                         foreach ( $newModules as $moduleName => $moduleClass ) {
 129                                 $modules[$moduleName] = $moduleClass;
 130                         }
 131                 }
 132         }
 133
 134         /**
 135          * Gets a default slave database connection object
 136          * @return Database
 137          */
 138         public function getDB() {
 139                 if ( !isset( $this->mSlaveDB ) ) {
 140                         $this->profileDBIn();
 141                         $this->mSlaveDB = wfGetDB( DB_SLAVE, 'api' );
 142                         $this->profileDBOut();
 143                 }
 144                 return $this->mSlaveDB;
 145         }
 146
 147         /**
 148          * Get the query database connection with the given name.
 149          * If no such connection has been requested before, it will be created.
 150          * Subsequent calls with the same $name will return the same connection
 151          * as the first, regardless of the values of $db and $groups
 152          * @param $name string Name to assign to the database connection
 153          * @param $db int One of the DB_* constants
 154          * @param $groups array Query groups
 155          * @return Database
 156          */
 157         public function getNamedDB( $name, $db, $groups ) {
 158                 if ( !array_key_exists( $name, $this->mNamedDB ) ) {
 159                         $this->profileDBIn();
 160                         $this->mNamedDB[$name] = wfGetDB( $db, $groups );
 161                         $this->profileDBOut();
 162                 }
 163                 return $this->mNamedDB[$name];
 164         }
 165
 166         /**
 167          * Gets the set of pages the user has requested (or generated)
 168          * @return ApiPageSet
 169          */
 170         public function getPageSet() {
 171                 return $this->mPageSet;
 172         }
 173
 174         /**
 175          * Get the array mapping module names to class names
 176          * @return array(modulename => classname)
 177          */
 178         function getModules() {
 179                 return array_merge( $this->mQueryPropModules, $this->mQueryListModules, $this->mQueryMetaModules );
 180         }
 181
 182         /**
 183          * Get whether the specified module is a prop, list or a meta query module
 184          * @param $moduleName string Name of the module to find type for
 185          * @return mixed string or null
 186          */
 187         function getModuleType( $moduleName ) {
 188                 if ( array_key_exists ( $moduleName, $this->mQueryPropModules ) ) {
 189                         return 'prop';
 190                 }
 191
 192                 if ( array_key_exists ( $moduleName, $this->mQueryListModules ) ) {
 193                         return 'list';
 194                 }
 195
 196                 if ( array_key_exists ( $moduleName, $this->mQueryMetaModules ) ) {
 197                         return 'meta';
 198                 }
 199
 200                 return null;
 201         }
 202
 203         public function getCustomPrinter() {
 204                 // If &exportnowrap is set, use the raw formatter
 205                 if ( $this->getParameter( 'export' ) &&
 206                                 $this->getParameter( 'exportnowrap' ) )
 207                 {
 208                         return new ApiFormatRaw( $this->getMain(),
 209                                 $this->getMain()->createPrinterByName( 'xml' ) );
 210                 } else {
 211                         return null;
 212                 }
 213         }
 214
 215         /**
 216          * Query execution happens in the following steps:
 217          * #1 Create a PageSet object with any pages requested by the user
 218          * #2 If using a generator, execute it to get a new ApiPageSet object
 219          * #3 Instantiate all requested modules.
 220          *    This way the PageSet object will know what shared data is required,
 221          *    and minimize DB calls.
 222          * #4 Output all normalization and redirect resolution information
 223          * #5 Execute all requested modules
 224          */
 225         public function execute() {
 226                 $this->params = $this->extractRequestParams();
 227                 $this->redirects = $this->params['redirects'];
 228                 $this->convertTitles = $this->params['converttitles'];
 229
 230                 // Create PageSet
 231                 $this->mPageSet = new ApiPageSet( $this, $this->redirects, $this->convertTitles );
 232
 233                 // Instantiate requested modules
 234                 $modules = array();
 235                 $this->instantiateModules( $modules, 'prop', $this->mQueryPropModules );
 236                 $this->instantiateModules( $modules, 'list', $this->mQueryListModules );
 237                 $this->instantiateModules( $modules, 'meta', $this->mQueryMetaModules );
 238
 239                 $cacheMode = 'public';
 240
 241                 // If given, execute generator to substitute user supplied data with generated data.
 242                 if ( isset( $this->params['generator'] ) ) {
 243                         $generator = $this->newGenerator( $this->params['generator'] );
 244                         $params = $generator->extractRequestParams();
 245                         $cacheMode = $this->mergeCacheMode( $cacheMode,
 246                                 $generator->getCacheMode( $params ) );
 247                         $this->executeGeneratorModule( $generator, $modules );
 248                 } else {
 249                         // Append custom fields and populate page/revision information
 250                         $this->addCustomFldsToPageSet( $modules, $this->mPageSet );
 251                         $this->mPageSet->execute();
 252                 }
 253
 254                 // Record page information (title, namespace, if exists, etc)
 255                 $this->outputGeneralPageInfo();
 256
 257                 // Execute all requested modules.
 258                 foreach ( $modules as $module ) {
 259                         $params = $module->extractRequestParams();
 260                         $cacheMode = $this->mergeCacheMode(
 261                                 $cacheMode, $module->getCacheMode( $params ) );
 262                         $module->profileIn();
 263                         $module->execute();
 264                         wfRunHooks( 'APIQueryAfterExecute', array( &$module ) );
 265                         $module->profileOut();
 266                 }
 267
 268                 // Set the cache mode
 269                 $this->getMain()->setCacheMode( $cacheMode );
 270         }
 271
 272         /**
 273          * Update a cache mode string, applying the cache mode of a new module to it.
 274          * The cache mode may increase in the level of privacy, but public modules
 275          * added to private data do not decrease the level of privacy.
 276          */
 277         protected function mergeCacheMode( $cacheMode, $modCacheMode ) {
 278                 if ( $modCacheMode === 'anon-public-user-private' ) {
 279                         if ( $cacheMode !== 'private' ) {
 280                                 $cacheMode = 'anon-public-user-private';
 281                         }
 282                 } elseif ( $modCacheMode === 'public' ) {
 283                         // do nothing, if it's public already it will stay public
 284                 } else { // private
 285                         $cacheMode = 'private';
 286                 }
 287                 return $cacheMode;
 288         }
 289
 290         /**
 291          * Query modules may optimize data requests through the $this->getPageSet() object
 292          * by adding extra fields from the page table.
 293          * This function will gather all the extra request fields from the modules.
 294          * @param $modules array of module objects
 295          * @param $pageSet ApiPageSet
 296          */
 297         private function addCustomFldsToPageSet( $modules, $pageSet ) {
 298                 // Query all requested modules.
 299                 foreach ( $modules as $module ) {
 300                         $module->requestExtraData( $pageSet );
 301                 }
 302         }
 303
 304         /**
 305          * Create instances of all modules requested by the client
 306          * @param $modules Array to append instantiated modules to
 307          * @param $param string Parameter name to read modules from
 308          * @param $moduleList Array array(modulename => classname)
 309          */
 310         private function instantiateModules( &$modules, $param, $moduleList ) {
 311                 $list = @$this->params[$param];
 312                 if ( !is_null ( $list ) ) {
 313                         foreach ( $list as $moduleName ) {
 314                                 $modules[] = new $moduleList[$moduleName] ( $this, $moduleName );
 315                         }
 316                 }
 317         }
 318
 319         /**
 320          * Appends an element for each page in the current pageSet with the
 321          * most general information (id, title), plus any title normalizations
 322          * and missing or invalid title/pageids/revids.
 323          */
 324         private function outputGeneralPageInfo() {
 325                 $pageSet = $this->getPageSet();
 326                 $result = $this->getResult();
 327
 328                 // We don't check for a full result set here because we can't be adding
 329                 // more than 380K. The maximum revision size is in the megabyte range,
 330                 // and the maximum result size must be even higher than that.
 331
 332                 // Title normalizations
 333                 $normValues = array();
 334                 foreach ( $pageSet->getNormalizedTitles() as $rawTitleStr => $titleStr ) {
 335                         $normValues[] = array(
 336                                 'from' => $rawTitleStr,
 337                                 'to' => $titleStr
 338                         );
 339                 }
 340
 341                 if ( count( $normValues ) ) {
 342                         $result->setIndexedTagName( $normValues, 'n' );
 343                         $result->addValue( 'query', 'normalized', $normValues );
 344                 }
 345
 346                 // Title conversions
 347                 $convValues = array();
 348                 foreach ( $pageSet->getConvertedTitles() as $rawTitleStr => $titleStr ) {
 349                         $convValues[] = array(
 350                                 'from' => $rawTitleStr,
 351                                 'to' => $titleStr
 352                         );
 353                 }
 354
 355                 if ( count( $convValues ) ) {
 356                         $result->setIndexedTagName( $convValues, 'c' );
 357                         $result->addValue( 'query', 'converted', $convValues );
 358                 }
 359
 360                 // Interwiki titles
 361                 $intrwValues = array();
 362                 foreach ( $pageSet->getInterwikiTitles() as $rawTitleStr => $interwikiStr ) {
 363                         $intrwValues[] = array(
 364                                 'title' => $rawTitleStr,
 365                                 'iw' => $interwikiStr
 366                         );
 367                 }
 368
 369                 if ( count( $intrwValues ) ) {
 370                         $result->setIndexedTagName( $intrwValues, 'i' );
 371                         $result->addValue( 'query', 'interwiki', $intrwValues );
 372                 }
 373
 374                 // Show redirect information
 375                 $redirValues = array();
 376                 foreach ( $pageSet->getRedirectTitles() as $titleStrFrom => $titleStrTo ) {
 377                         $redirValues[] = array(
 378                                 'from' => strval( $titleStrFrom ),
 379                                 'to' => $titleStrTo
 380                         );
 381                 }
 382
 383                 if ( count( $redirValues ) ) {
 384                         $result->setIndexedTagName( $redirValues, 'r' );
 385                         $result->addValue( 'query', 'redirects', $redirValues );
 386                 }
 387
 388                 // Missing revision elements
 389                 $missingRevIDs = $pageSet->getMissingRevisionIDs();
 390                 if ( count( $missingRevIDs ) ) {
 391                         $revids = array();
 392                         foreach ( $missingRevIDs as $revid ) {
 393                                 $revids[$revid] = array(
 394                                         'revid' => $revid
 395                                 );
 396                         }
 397                         $result->setIndexedTagName( $revids, 'rev' );
 398                         $result->addValue( 'query', 'badrevids', $revids );
 399                 }
 400
 401                 // Page elements
 402                 $pages = array();
 403
 404                 // Report any missing titles
 405                 foreach ( $pageSet->getMissingTitles() as $fakeId => $title ) {
 406                         $vals = array();
 407                         ApiQueryBase::addTitleInfo( $vals, $title );
 408                         $vals['missing'] = '';
 409                         $pages[$fakeId] = $vals;
 410                 }
 411                 // Report any invalid titles
 412                 foreach ( $pageSet->getInvalidTitles() as $fakeId => $title ) {
 413                         $pages[$fakeId] = array( 'title' => $title, 'invalid' => '' );
 414                 }
 415                 // Report any missing page ids
 416                 foreach ( $pageSet->getMissingPageIDs() as $pageid ) {
 417                         $pages[$pageid] = array(
 418                                 'pageid' => $pageid,
 419                                 'missing' => ''
 420                         );
 421                 }
 422                 // Report special pages
 423                 foreach ( $pageSet->getSpecialTitles() as $fakeId => $title ) {
 424                         $vals = array();
 425                         ApiQueryBase::addTitleInfo( $vals, $title );
 426                         $vals['special'] = '';
 427                         if ( $title->getNamespace() == NS_SPECIAL &&
 428                                         !SpecialPage::exists( $title->getText() ) ) {
 429                                 $vals['missing'] = '';
 430                         } elseif ( $title->getNamespace() == NS_MEDIA &&
 431                                         !wfFindFile( $title ) ) {
 432                                 $vals['missing'] = '';
 433                         }
 434                         $pages[$fakeId] = $vals;
 435                 }
 436
 437                 // Output general page information for found titles
 438                 foreach ( $pageSet->getGoodTitles() as $pageid => $title ) {
 439                         $vals = array();
 440                         $vals['pageid'] = $pageid;
 441                         ApiQueryBase::addTitleInfo( $vals, $title );
 442                         $pages[$pageid] = $vals;
 443                 }
 444
 445                 if ( count( $pages ) ) {
 446                         if ( $this->params['indexpageids'] ) {
 447                                 $pageIDs = array_keys( $pages );
 448                                 // json treats all map keys as strings - converting to match
 449                                 $pageIDs = array_map( 'strval', $pageIDs );
 450                                 $result->setIndexedTagName( $pageIDs, 'id' );
 451                                 $result->addValue( 'query', 'pageids', $pageIDs );
 452                         }
 453
 454                         $result->setIndexedTagName( $pages, 'page' );
 455                         $result->addValue( 'query', 'pages', $pages );
 456                 }
 457                 if ( $this->params['export'] ) {
 458                         $this->doExport( $pageSet, $result );
 459                 }
 460         }
 461
 462         /**
 463          * @param  $pageSet ApiPageSet Pages to be exported
 464          * @param  $result ApiResult Result to output to
 465          */
 466         private function doExport( $pageSet, $result )  {
 467                 $exportTitles = array();
 468                 $titles = $pageSet->getGoodTitles();
 469                 if( count( $titles ) ) {
 470                         foreach ( $titles as $title ) {
 471                                 if ( $title->userCanRead() ) {
 472                                         $exportTitles[] = $title;
 473                                 }
 474                         }
 475                 }
 476                 // only export when there are titles
 477                 if ( !count( $exportTitles ) ) {
 478                         return;
 479                 }
 480
 481                 $exporter = new WikiExporter( $this->getDB() );
 482                 // WikiExporter writes to stdout, so catch its
 483                 // output with an ob
 484                 ob_start();
 485                 $exporter->openStream();
 486                 foreach ( $exportTitles as $title ) {
 487                         $exporter->pageByTitle( $title );
 488                 }
 489                 $exporter->closeStream();
 490                 $exportxml = ob_get_contents();
 491                 ob_end_clean();
 492
 493                 // Don't check the size of exported stuff
 494                 // It's not continuable, so it would cause more
 495                 // problems than it'd solve
 496                 $result->disableSizeCheck();
 497                 if ( $this->params['exportnowrap'] ) {
 498                         $result->reset();
 499                         // Raw formatter will handle this
 500                         $result->addValue( null, 'text', $exportxml );
 501                         $result->addValue( null, 'mime', 'text/xml' );
 502                 } else {
 503                         $r = array();
 504                         ApiResult::setContent( $r, $exportxml );
 505                         $result->addValue( 'query', 'export', $r );
 506                 }
 507                 $result->enableSizeCheck();
 508         }
 509
 510         /**
 511          * Create a generator object of the given type and return it
 512          * @param $generatorName string Module name
 513          * @return ApiQueryGeneratorBase
 514          */
 515         public function newGenerator( $generatorName ) {
 516                 // Find class that implements requested generator
 517                 if ( isset( $this->mQueryListModules[$generatorName] ) ) {
 518                         $className = $this->mQueryListModules[$generatorName];
 519                 } elseif ( isset( $this->mQueryPropModules[$generatorName] ) ) {
 520                         $className = $this->mQueryPropModules[$generatorName];
 521                 } else {
 522                         ApiBase::dieDebug( __METHOD__, "Unknown generator=$generatorName" );
 523                 }
 524                 $generator = new $className ( $this, $generatorName );
 525                 if ( !$generator instanceof ApiQueryGeneratorBase ) {
 526                         $this->dieUsage( "Module $generatorName cannot be used as a generator", 'badgenerator' );
 527                 }
 528                 $generator->setGeneratorMode();
 529                 return $generator;
 530         }
 531
 532         /**
 533          * For generator mode, execute generator, and use its output as new
 534          * ApiPageSet
 535          * @param $generator ApiQueryGeneratorBase Generator Module
 536          * @param $modules array of module objects
 537          */
 538         protected function executeGeneratorModule( $generator, $modules ) {
 539                 // Generator results
 540                 $resultPageSet = new ApiPageSet( $this, $this->redirects, $this->convertTitles );
 541
 542                 // Add any additional fields modules may need
 543                 $generator->requestExtraData( $this->mPageSet );
 544                 $this->addCustomFldsToPageSet( $modules, $resultPageSet );
 545
 546                 // Populate page information with the original user input
 547                 $this->mPageSet->execute();
 548
 549                 // populate resultPageSet with the generator output
 550                 $generator->profileIn();
 551                 $generator->executeGenerator( $resultPageSet );
 552                 wfRunHooks( 'APIQueryGeneratorAfterExecute', array( &$generator, &$resultPageSet ) );
 553                 $resultPageSet->finishPageSetGeneration();
 554                 $generator->profileOut();
 555
 556                 // Swap the resulting pageset back in
 557                 $this->mPageSet = $resultPageSet;
 558         }
 559
 560         public function getAllowedParams() {
 561                 return array(
 562                         'prop' => array(
 563                                 ApiBase::PARAM_ISMULTI => true,
 564                                 ApiBase::PARAM_TYPE => $this->mPropModuleNames
 565                         ),
 566                         'list' => array(
 567                                 ApiBase::PARAM_ISMULTI => true,
 568                                 ApiBase::PARAM_TYPE => $this->mListModuleNames
 569                         ),
 570                         'meta' => array(
 571                                 ApiBase::PARAM_ISMULTI => true,
 572                                 ApiBase::PARAM_TYPE => $this->mMetaModuleNames
 573                         ),
 574                         'generator' => array(
 575                                 ApiBase::PARAM_TYPE => $this->mAllowedGenerators
 576                         ),
 577                         'redirects' => false,
 578                         'converttitles' => false,
 579                         'indexpageids' => false,
 580                         'export' => false,
 581                         'exportnowrap' => false,
 582                 );
 583         }
 584
 585         /**
 586          * Override the parent to generate help messages for all available query modules.
 587          * @return string
 588          */
 589         public function makeHelpMsg() {
 590                 $msg = '';
 591
 592                 // Make sure the internal object is empty
 593                 // (just in case a sub-module decides to optimize during instantiation)
 594                 $this->mPageSet = null;
 595                 $this->mAllowedGenerators = array(); // Will be repopulated
 596
 597                 $querySeparator = str_repeat( '--- ', 8 );
 598                 $moduleSeparator = str_repeat( '*** ', 10 );
 599                 $msg .= "\n$querySeparator Query: Prop  $querySeparator\n\n";
 600                 $msg .= $this->makeHelpMsgHelper( $this->mQueryPropModules, 'prop' );
 601                 $msg .= "\n$querySeparator Query: List  $querySeparator\n\n";
 602                 $msg .= $this->makeHelpMsgHelper( $this->mQueryListModules, 'list' );
 603                 $msg .= "\n$querySeparator Query: Meta  $querySeparator\n\n";
 604                 $msg .= $this->makeHelpMsgHelper( $this->mQueryMetaModules, 'meta' );
 605                 $msg .= "\n\n$moduleSeparator Modules: continuation  $moduleSeparator\n\n";
 606
 607                 // Perform the base call last because the $this->mAllowedGenerators
 608                 // will be updated inside makeHelpMsgHelper()
 609                 // Use parent to make default message for the query module
 610                 $msg = parent::makeHelpMsg() . $msg;
 611
 612                 return $msg;
 613         }
 614
 615         /**
 616          * For all modules in $moduleList, generate help messages and join them together
 617          * @param $moduleList Array array(modulename => classname)
 618          * @param $paramName string Parameter name
 619          * @return string
 620          */
 621         private function makeHelpMsgHelper( $moduleList, $paramName ) {
 622                 $moduleDescriptions = array();
 623
 624                 foreach ( $moduleList as $moduleName => $moduleClass ) {
 625                         $module = new $moduleClass ( $this, $moduleName, null );
 626
 627                         $msg = ApiMain::makeHelpMsgHeader( $module, $paramName );
 628                         $msg2 = $module->makeHelpMsg();
 629                         if ( $msg2 !== false ) {
 630                                 $msg .= $msg2;
 631                         }
 632                         if ( $module instanceof ApiQueryGeneratorBase ) {
 633                                 $this->mAllowedGenerators[] = $moduleName;
 634                                 $msg .= "Generator:\n  This module may be used as a generator\n";
 635                         }
 636                         $moduleDescriptions[] = $msg;
 637                 }
 638
 639                 return implode( "\n", $moduleDescriptions );
 640         }
 641
 642         /**
 643          * Override to add extra parameters from PageSet
 644          * @return string
 645          */
 646         public function makeHelpMsgParameters() {
 647                 $psModule = new ApiPageSet( $this );
 648                 return $psModule->makeHelpMsgParameters() . parent::makeHelpMsgParameters();
 649         }
 650
 651         public function shouldCheckMaxlag() {
 652                 return true;
 653         }
 654
 655         public function getParamDescription() {
 656                 return array(
 657                         'prop' => 'Which properties to get for the titles/revisions/pageids. Module help is available below',
 658                         'list' => 'Which lists to get. Module help is available below',
 659                         'meta' => 'Which metadata to get about the site. Module help is available below',
 660                         'generator' => array( 'Use the output of a list as the input for other prop/list/meta items',
 661                                         'NOTE: generator parameter names must be prefixed with a \'g\', see examples' ),
 662                         'redirects' => 'Automatically resolve redirects',
 663                         'converttitles' => array( "Convert titles to other variants if necessary. Only works if the wiki's content language supports variant conversion.",
 664                                         'Languages that support variant conversion include kk, ku, gan, tg, sr, zh' ),
 665                         'indexpageids' => 'Include an additional pageids section listing all returned page IDs',
 666                         'export' => 'Export the current revisions of all given or generated pages',
 667                         'exportnowrap' => 'Return the export XML without wrapping it in an XML result (same format as Special:Export). Can only be used with export',
 668                 );
 669         }
 670
 671         public function getDescription() {
 672                 return array(
 673                         'Query API module allows applications to get needed pieces of data from the MediaWiki databases,',
 674                         'and is loosely based on the old query.php interface.',
 675                         'All data modifications will first have to use query to acquire a token to prevent abuse from malicious sites'
 676                 );
 677         }
 678
 679         public function getPossibleErrors() {
 680                 return array_merge( parent::getPossibleErrors(), array(
 681                         array( 'code' => 'badgenerator', 'info' => 'Module $generatorName cannot be used as a generator' ),
 682                 ) );
 683         }
 684
 685         protected function getExamples() {
 686                 return array(
 687                         'api.php?action=query&prop=revisions&meta=siteinfo&titles=Main%20Page&rvprop=user|comment',
 688                         'api.php?action=query&generator=allpages&gapprefix=API/&prop=revisions',
 689                 );
 690         }
 691
 692         public function getVersion() {
 693                 $psModule = new ApiPageSet( $this );
 694                 $vers = array();
 695                 $vers[] = __CLASS__ . ': $Id$';
 696                 $vers[] = $psModule->getVersion();
 697                 return $vers;
 698         }
 699 }