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 /**
  28  * This is the main query class. It behaves similar to ApiMain: based on the
  29  * parameters given, it will create a list of titles to work on (an ApiPageSet
  30  * object), instantiate and execute various property/list/meta modules, and
  31  * assemble all resulting data into a single ApiResult object.
  32  *
  33  * In generator mode, a generator will be executed first to populate a second
  34  * ApiPageSet object, and that object will be used for all subsequent modules.
  35  *
  36  * @ingroup API
  37  */
  38 class ApiQuery extends ApiBase {
  39
  40         private $mPropModuleNames, $mListModuleNames, $mMetaModuleNames;
  41
  42         /**
  43          * @var ApiPageSet
  44          */
  45         private $mPageSet;
  46
  47         private $params, $redirects, $convertTitles, $iwUrl;
  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                 'langbacklinks' => 'ApiQueryLangBacklinks',
  81                 'logevents' => 'ApiQueryLogEvents',
  82                 'recentchanges' => 'ApiQueryRecentChanges',
  83                 'search' => 'ApiQuerySearch',
  84                 'tags' => 'ApiQueryTags',
  85                 'usercontribs' => 'ApiQueryContributions',
  86                 'watchlist' => 'ApiQueryWatchlist',
  87                 'watchlistraw' => 'ApiQueryWatchlistRaw',
  88                 'exturlusage' => 'ApiQueryExtLinksUsage',
  89                 'users' => 'ApiQueryUsers',
  90                 'random' => 'ApiQueryRandom',
  91                 'protectedtitles' => 'ApiQueryProtectedTitles',
  92                 'querypage' => 'ApiQueryQueryPage',
  93         );
  94
  95         private $mQueryMetaModules = array(
  96                 'siteinfo' => 'ApiQuerySiteinfo',
  97                 'userinfo' => 'ApiQueryUserInfo',
  98                 'allmessages' => 'ApiQueryAllMessages',
  99         );
 100
 101         private $mSlaveDB = null;
 102         private $mNamedDB = array();
 103
 104         protected $mAllowedGenerators = array();
 105
 106         /**
 107          * @param $main ApiMain
 108          * @param $action string
 109          */
 110         public function __construct( $main, $action ) {
 111                 parent::__construct( $main, $action );
 112
 113                 // Allow custom modules to be added in LocalSettings.php
 114                 global $wgAPIPropModules, $wgAPIListModules, $wgAPIMetaModules;
 115                 self::appendUserModules( $this->mQueryPropModules, $wgAPIPropModules );
 116                 self::appendUserModules( $this->mQueryListModules, $wgAPIListModules );
 117                 self::appendUserModules( $this->mQueryMetaModules, $wgAPIMetaModules );
 118
 119                 $this->mPropModuleNames = array_keys( $this->mQueryPropModules );
 120                 $this->mListModuleNames = array_keys( $this->mQueryListModules );
 121                 $this->mMetaModuleNames = array_keys( $this->mQueryMetaModules );
 122
 123                 $this->makeGeneratorList( $this->mQueryPropModules );
 124                 $this->makeGeneratorList( $this->mQueryListModules );
 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 DatabaseBase
 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 DatabaseBase
 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 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         /**
 210          * @return ApiFormatRaw|null
 211          */
 212         public function getCustomPrinter() {
 213                 // If &exportnowrap is set, use the raw formatter
 214                 if ( $this->getParameter( 'export' ) &&
 215                                 $this->getParameter( 'exportnowrap' ) )
 216                 {
 217                         return new ApiFormatRaw( $this->getMain(),
 218                                 $this->getMain()->createPrinterByName( 'xml' ) );
 219                 } else {
 220                         return null;
 221                 }
 222         }
 223
 224         /**
 225          * Query execution happens in the following steps:
 226          * #1 Create a PageSet object with any pages requested by the user
 227          * #2 If using a generator, execute it to get a new ApiPageSet object
 228          * #3 Instantiate all requested modules.
 229          *    This way the PageSet object will know what shared data is required,
 230          *    and minimize DB calls.
 231          * #4 Output all normalization and redirect resolution information
 232          * #5 Execute all requested modules
 233          */
 234         public function execute() {
 235                 $this->params = $this->extractRequestParams();
 236                 $this->redirects = $this->params['redirects'];
 237                 $this->convertTitles = $this->params['converttitles'];
 238                 $this->iwUrl = $this->params['iwurl'];
 239
 240                 // Create PageSet
 241                 $this->mPageSet = new ApiPageSet( $this, $this->redirects, $this->convertTitles );
 242
 243                 // Instantiate requested modules
 244                 $modules = array();
 245                 $this->instantiateModules( $modules, 'prop', $this->mQueryPropModules );
 246                 $this->instantiateModules( $modules, 'list', $this->mQueryListModules );
 247                 $this->instantiateModules( $modules, 'meta', $this->mQueryMetaModules );
 248
 249                 $cacheMode = 'public';
 250
 251                 // If given, execute generator to substitute user supplied data with generated data.
 252                 if ( isset( $this->params['generator'] ) ) {
 253                         $generator = $this->newGenerator( $this->params['generator'] );
 254                         $params = $generator->extractRequestParams();
 255                         $cacheMode = $this->mergeCacheMode( $cacheMode,
 256                                 $generator->getCacheMode( $params ) );
 257                         $this->executeGeneratorModule( $generator, $modules );
 258                 } else {
 259                         // Append custom fields and populate page/revision information
 260                         $this->addCustomFldsToPageSet( $modules, $this->mPageSet );
 261                         $this->mPageSet->execute();
 262                 }
 263
 264                 // Record page information (title, namespace, if exists, etc)
 265                 $this->outputGeneralPageInfo();
 266
 267                 // Execute all requested modules.
 268                 /**
 269                  * @var $module ApiQueryBase
 270                  */
 271                 foreach ( $modules as $module ) {
 272                         $params = $module->extractRequestParams();
 273                         $cacheMode = $this->mergeCacheMode(
 274                                 $cacheMode, $module->getCacheMode( $params ) );
 275                         $module->profileIn();
 276                         $module->execute();
 277                         wfRunHooks( 'APIQueryAfterExecute', array( &$module ) );
 278                         $module->profileOut();
 279                 }
 280
 281                 // Set the cache mode
 282                 $this->getMain()->setCacheMode( $cacheMode );
 283         }
 284
 285         /**
 286          * Update a cache mode string, applying the cache mode of a new module to it.
 287          * The cache mode may increase in the level of privacy, but public modules
 288          * added to private data do not decrease the level of privacy.
 289          *
 290          * @param $cacheMode string
 291          * @param $modCacheMode string
 292          * @return string
 293          */
 294         protected function mergeCacheMode( $cacheMode, $modCacheMode ) {
 295                 if ( $modCacheMode === 'anon-public-user-private' ) {
 296                         if ( $cacheMode !== 'private' ) {
 297                                 $cacheMode = 'anon-public-user-private';
 298                         }
 299                 } elseif ( $modCacheMode === 'public' ) {
 300                         // do nothing, if it's public already it will stay public
 301                 } else { // private
 302                         $cacheMode = 'private';
 303                 }
 304                 return $cacheMode;
 305         }
 306
 307         /**
 308          * Query modules may optimize data requests through the $this->getPageSet() object
 309          * by adding extra fields from the page table.
 310          * This function will gather all the extra request fields from the modules.
 311          * @param $modules array of module objects
 312          * @param $pageSet ApiPageSet
 313          */
 314         private function addCustomFldsToPageSet( $modules, $pageSet ) {
 315                 // Query all requested modules.
 316                 /**
 317                  * @var $module ApiQueryBase
 318                  */
 319                 foreach ( $modules as $module ) {
 320                         $module->requestExtraData( $pageSet );
 321                 }
 322         }
 323
 324         /**
 325          * Create instances of all modules requested by the client
 326          * @param $modules Array to append instantiated modules to
 327          * @param $param string Parameter name to read modules from
 328          * @param $moduleList Array array(modulename => classname)
 329          */
 330         private function instantiateModules( &$modules, $param, $moduleList ) {
 331                 if ( isset( $this->params[$param] ) ) {
 332                         foreach ( $this->params[$param] as $moduleName ) {
 333                                 $modules[] = new $moduleList[$moduleName] ( $this, $moduleName );
 334                         }
 335                 }
 336         }
 337
 338         /**
 339          * Appends an element for each page in the current pageSet with the
 340          * most general information (id, title), plus any title normalizations
 341          * and missing or invalid title/pageids/revids.
 342          */
 343         private function outputGeneralPageInfo() {
 344                 $pageSet = $this->getPageSet();
 345                 $result = $this->getResult();
 346
 347                 // We don't check for a full result set here because we can't be adding
 348                 // more than 380K. The maximum revision size is in the megabyte range,
 349                 // and the maximum result size must be even higher than that.
 350
 351                 // Title normalizations
 352                 $normValues = array();
 353                 foreach ( $pageSet->getNormalizedTitles() as $rawTitleStr => $titleStr ) {
 354                         $normValues[] = array(
 355                                 'from' => $rawTitleStr,
 356                                 'to' => $titleStr
 357                         );
 358                 }
 359
 360                 if ( count( $normValues ) ) {
 361                         $result->setIndexedTagName( $normValues, 'n' );
 362                         $result->addValue( 'query', 'normalized', $normValues );
 363                 }
 364
 365                 // Title conversions
 366                 $convValues = array();
 367                 foreach ( $pageSet->getConvertedTitles() as $rawTitleStr => $titleStr ) {
 368                         $convValues[] = array(
 369                                 'from' => $rawTitleStr,
 370                                 'to' => $titleStr
 371                         );
 372                 }
 373
 374                 if ( count( $convValues ) ) {
 375                         $result->setIndexedTagName( $convValues, 'c' );
 376                         $result->addValue( 'query', 'converted', $convValues );
 377                 }
 378
 379                 // Interwiki titles
 380                 $intrwValues = array();
 381                 foreach ( $pageSet->getInterwikiTitles() as $rawTitleStr => $interwikiStr ) {
 382                         $item = array(
 383                                 'title' => $rawTitleStr,
 384                                 'iw' => $interwikiStr,
 385                         );
 386                         if ( $this->iwUrl ) {
 387                                 $title = Title::newFromText( $rawTitleStr );
 388                                 $item['url'] = wfExpandUrl( $title->getFullURL(), PROTO_CURRENT );
 389                         }
 390                         $intrwValues[] = $item;
 391                 }
 392
 393                 if ( count( $intrwValues ) ) {
 394                         $result->setIndexedTagName( $intrwValues, 'i' );
 395                         $result->addValue( 'query', 'interwiki', $intrwValues );
 396                 }
 397
 398                 // Show redirect information
 399                 $redirValues = array();
 400                 /**
 401                  * @var $titleTo Title
 402                  */
 403                 foreach ( $pageSet->getRedirectTitles() as $titleStrFrom => $titleTo ) {
 404                         $r = array(
 405                                 'from' => strval( $titleStrFrom ),
 406                                 'to' => $titleTo->getPrefixedText(),
 407                         );
 408                         if ( $titleTo->getFragment() !== '' ) {
 409                                 $r['tofragment'] = $titleTo->getFragment();
 410                         }
 411                         $redirValues[] = $r;
 412                 }
 413
 414                 if ( count( $redirValues ) ) {
 415                         $result->setIndexedTagName( $redirValues, 'r' );
 416                         $result->addValue( 'query', 'redirects', $redirValues );
 417                 }
 418
 419                 // Missing revision elements
 420                 $missingRevIDs = $pageSet->getMissingRevisionIDs();
 421                 if ( count( $missingRevIDs ) ) {
 422                         $revids = array();
 423                         foreach ( $missingRevIDs as $revid ) {
 424                                 $revids[$revid] = array(
 425                                         'revid' => $revid
 426                                 );
 427                         }
 428                         $result->setIndexedTagName( $revids, 'rev' );
 429                         $result->addValue( 'query', 'badrevids', $revids );
 430                 }
 431
 432                 // Page elements
 433                 $pages = array();
 434
 435                 // Report any missing titles
 436                 foreach ( $pageSet->getMissingTitles() as $fakeId => $title ) {
 437                         $vals = array();
 438                         ApiQueryBase::addTitleInfo( $vals, $title );
 439                         $vals['missing'] = '';
 440                         $pages[$fakeId] = $vals;
 441                 }
 442                 // Report any invalid titles
 443                 foreach ( $pageSet->getInvalidTitles() as $fakeId => $title ) {
 444                         $pages[$fakeId] = array( 'title' => $title, 'invalid' => '' );
 445                 }
 446                 // Report any missing page ids
 447                 foreach ( $pageSet->getMissingPageIDs() as $pageid ) {
 448                         $pages[$pageid] = array(
 449                                 'pageid' => $pageid,
 450                                 'missing' => ''
 451                         );
 452                 }
 453                 // Report special pages
 454                 foreach ( $pageSet->getSpecialTitles() as $fakeId => $title ) {
 455                         $vals = array();
 456                         ApiQueryBase::addTitleInfo( $vals, $title );
 457                         $vals['special'] = '';
 458                         if ( $title->isSpecialPage() &&
 459                                         !SpecialPageFactory::exists( $title->getDbKey() ) ) {
 460                                 $vals['missing'] = '';
 461                         } elseif ( $title->getNamespace() == NS_MEDIA &&
 462                                         !wfFindFile( $title ) ) {
 463                                 $vals['missing'] = '';
 464                         }
 465                         $pages[$fakeId] = $vals;
 466                 }
 467
 468                 // Output general page information for found titles
 469                 foreach ( $pageSet->getGoodTitles() as $pageid => $title ) {
 470                         $vals = array();
 471                         $vals['pageid'] = $pageid;
 472                         ApiQueryBase::addTitleInfo( $vals, $title );
 473                         $pages[$pageid] = $vals;
 474                 }
 475
 476                 if ( count( $pages ) ) {
 477                         if ( $this->params['indexpageids'] ) {
 478                                 $pageIDs = array_keys( $pages );
 479                                 // json treats all map keys as strings - converting to match
 480                                 $pageIDs = array_map( 'strval', $pageIDs );
 481                                 $result->setIndexedTagName( $pageIDs, 'id' );
 482                                 $result->addValue( 'query', 'pageids', $pageIDs );
 483                         }
 484
 485                         $result->setIndexedTagName( $pages, 'page' );
 486                         $result->addValue( 'query', 'pages', $pages );
 487                 }
 488                 if ( $this->params['export'] ) {
 489                         $this->doExport( $pageSet, $result );
 490                 }
 491         }
 492
 493         /**
 494          * @param  $pageSet ApiPageSet Pages to be exported
 495          * @param  $result ApiResult Result to output to
 496          */
 497         private function doExport( $pageSet, $result )  {
 498                 $exportTitles = array();
 499                 $titles = $pageSet->getGoodTitles();
 500                 if ( count( $titles ) ) {
 501                         foreach ( $titles as $title ) {
 502                                 if ( $title->userCan( 'read' ) ) {
 503                                         $exportTitles[] = $title;
 504                                 }
 505                         }
 506                 }
 507
 508                 $exporter = new WikiExporter( $this->getDB() );
 509                 // WikiExporter writes to stdout, so catch its
 510                 // output with an ob
 511                 ob_start();
 512                 $exporter->openStream();
 513                 foreach ( $exportTitles as $title ) {
 514                         $exporter->pageByTitle( $title );
 515                 }
 516                 $exporter->closeStream();
 517                 $exportxml = ob_get_contents();
 518                 ob_end_clean();
 519
 520                 // Don't check the size of exported stuff
 521                 // It's not continuable, so it would cause more
 522                 // problems than it'd solve
 523                 $result->disableSizeCheck();
 524                 if ( $this->params['exportnowrap'] ) {
 525                         $result->reset();
 526                         // Raw formatter will handle this
 527                         $result->addValue( null, 'text', $exportxml );
 528                         $result->addValue( null, 'mime', 'text/xml' );
 529                 } else {
 530                         $r = array();
 531                         ApiResult::setContent( $r, $exportxml );
 532                         $result->addValue( 'query', 'export', $r );
 533                 }
 534                 $result->enableSizeCheck();
 535         }
 536
 537         /**
 538          * Create a generator object of the given type and return it
 539          * @param $generatorName string Module name
 540          * @return ApiQueryGeneratorBase
 541          */
 542         public function newGenerator( $generatorName ) {
 543                 // Find class that implements requested generator
 544                 if ( isset( $this->mQueryListModules[$generatorName] ) ) {
 545                         $className = $this->mQueryListModules[$generatorName];
 546                 } elseif ( isset( $this->mQueryPropModules[$generatorName] ) ) {
 547                         $className = $this->mQueryPropModules[$generatorName];
 548                 } else {
 549                         ApiBase::dieDebug( __METHOD__, "Unknown generator=$generatorName" );
 550                 }
 551                 $generator = new $className ( $this, $generatorName );
 552                 if ( !$generator instanceof ApiQueryGeneratorBase ) {
 553                         $this->dieUsage( "Module $generatorName cannot be used as a generator", 'badgenerator' );
 554                 }
 555                 $generator->setGeneratorMode();
 556                 return $generator;
 557         }
 558
 559         /**
 560          * For generator mode, execute generator, and use its output as new
 561          * ApiPageSet
 562          * @param $generator ApiQueryGeneratorBase Generator Module
 563          * @param $modules array of module objects
 564          */
 565         protected function executeGeneratorModule( $generator, $modules ) {
 566                 // Generator results
 567                 $resultPageSet = new ApiPageSet( $this, $this->redirects, $this->convertTitles );
 568
 569                 // Add any additional fields modules may need
 570                 $generator->requestExtraData( $this->mPageSet );
 571                 $this->addCustomFldsToPageSet( $modules, $resultPageSet );
 572
 573                 // Populate page information with the original user input
 574                 $this->mPageSet->execute();
 575
 576                 // populate resultPageSet with the generator output
 577                 $generator->profileIn();
 578                 $generator->executeGenerator( $resultPageSet );
 579                 wfRunHooks( 'APIQueryGeneratorAfterExecute', array( &$generator, &$resultPageSet ) );
 580                 $resultPageSet->finishPageSetGeneration();
 581                 $generator->profileOut();
 582
 583                 // Swap the resulting pageset back in
 584                 $this->mPageSet = $resultPageSet;
 585         }
 586
 587         public function getAllowedParams() {
 588                 return array(
 589                         'prop' => array(
 590                                 ApiBase::PARAM_ISMULTI => true,
 591                                 ApiBase::PARAM_TYPE => $this->mPropModuleNames
 592                         ),
 593                         'list' => array(
 594                                 ApiBase::PARAM_ISMULTI => true,
 595                                 ApiBase::PARAM_TYPE => $this->mListModuleNames
 596                         ),
 597                         'meta' => array(
 598                                 ApiBase::PARAM_ISMULTI => true,
 599                                 ApiBase::PARAM_TYPE => $this->mMetaModuleNames
 600                         ),
 601                         'generator' => array(
 602                                 ApiBase::PARAM_TYPE => $this->mAllowedGenerators
 603                         ),
 604                         'redirects' => false,
 605                         'converttitles' => false,
 606                         'indexpageids' => false,
 607                         'export' => false,
 608                         'exportnowrap' => false,
 609                         'iwurl' => false,
 610                 );
 611         }
 612
 613         /**
 614          * Override the parent to generate help messages for all available query modules.
 615          * @return string
 616          */
 617         public function makeHelpMsg() {
 618                 // Make sure the internal object is empty
 619                 // (just in case a sub-module decides to optimize during instantiation)
 620                 $this->mPageSet = null;
 621
 622                 $querySeparator = str_repeat( '--- ', 12 );
 623                 $moduleSeparator = str_repeat( '*** ', 14 );
 624                 $msg = "\n$querySeparator Query: Prop  $querySeparator\n\n";
 625                 $msg .= $this->makeHelpMsgHelper( $this->mQueryPropModules, 'prop' );
 626                 $msg .= "\n$querySeparator Query: List  $querySeparator\n\n";
 627                 $msg .= $this->makeHelpMsgHelper( $this->mQueryListModules, 'list' );
 628                 $msg .= "\n$querySeparator Query: Meta  $querySeparator\n\n";
 629                 $msg .= $this->makeHelpMsgHelper( $this->mQueryMetaModules, 'meta' );
 630                 $msg .= "\n\n$moduleSeparator Modules: continuation  $moduleSeparator\n\n";
 631
 632                 // Use parent to make default message for the query module
 633                 $msg = parent::makeHelpMsg() . $msg;
 634
 635                 return $msg;
 636         }
 637
 638         /**
 639          * For all modules in $moduleList, generate help messages and join them together
 640          * @param $moduleList Array array(modulename => classname)
 641          * @param $paramName string Parameter name
 642          * @return string
 643          */
 644         private function makeHelpMsgHelper( $moduleList, $paramName ) {
 645                 $moduleDescriptions = array();
 646
 647                 foreach ( $moduleList as $moduleName => $moduleClass ) {
 648                         /**
 649                          * @var $module ApiQueryBase
 650                          */
 651                         $module = new $moduleClass( $this, $moduleName, null );
 652
 653                         $msg = ApiMain::makeHelpMsgHeader( $module, $paramName );
 654                         $msg2 = $module->makeHelpMsg();
 655                         if ( $msg2 !== false ) {
 656                                 $msg .= $msg2;
 657                         }
 658                         if ( $module instanceof ApiQueryGeneratorBase ) {
 659                                 $msg .= "Generator:\n  This module may be used as a generator\n";
 660                         }
 661                         $moduleDescriptions[] = $msg;
 662                 }
 663
 664                 return implode( "\n", $moduleDescriptions );
 665         }
 666
 667         /**
 668          * Adds any classes that are a subclass of ApiQueryGeneratorBase
 669          * to the allowed generator list
 670          * @param $moduleList array()
 671          */
 672         private function makeGeneratorList( $moduleList ) {
 673                 foreach( $moduleList as  $moduleName => $moduleClass ) {
 674                         if ( is_subclass_of( $moduleClass, 'ApiQueryGeneratorBase'  ) ) {
 675                                 $this->mAllowedGenerators[] = $moduleName;
 676                         }
 677                 }
 678         }
 679
 680         /**
 681          * Override to add extra parameters from PageSet
 682          * @return string
 683          */
 684         public function makeHelpMsgParameters() {
 685                 $psModule = new ApiPageSet( $this );
 686                 return $psModule->makeHelpMsgParameters() . parent::makeHelpMsgParameters();
 687         }
 688
 689         public function shouldCheckMaxlag() {
 690                 return true;
 691         }
 692
 693         public function getParamDescription() {
 694                 return array(
 695                         'prop' => 'Which properties to get for the titles/revisions/pageids. Module help is available below',
 696                         'list' => 'Which lists to get. Module help is available below',
 697                         'meta' => 'Which metadata to get about the site. Module help is available below',
 698                         'generator' => array( 'Use the output of a list as the input for other prop/list/meta items',
 699                                         'NOTE: generator parameter names must be prefixed with a \'g\', see examples' ),
 700                         'redirects' => 'Automatically resolve redirects',
 701                         'converttitles' => array( "Convert titles to other variants if necessary. Only works if the wiki's content language supports variant conversion.",
 702                                         'Languages that support variant conversion include ' . implode( ', ', LanguageConverter::$languagesWithVariants ) ),
 703                         'indexpageids' => 'Include an additional pageids section listing all returned page IDs',
 704                         'export' => 'Export the current revisions of all given or generated pages',
 705                         'exportnowrap' => 'Return the export XML without wrapping it in an XML result (same format as Special:Export). Can only be used with export',
 706                         'iwurl' => 'Whether to get the full URL if the title is an interwiki link',
 707                 );
 708         }
 709
 710         public function getDescription() {
 711                 return array(
 712                         'Query API module allows applications to get needed pieces of data from the MediaWiki databases,',
 713                         'and is loosely based on the old query.php interface.',
 714                         'All data modifications will first have to use query to acquire a token to prevent abuse from malicious sites'
 715                 );
 716         }
 717
 718         public function getPossibleErrors() {
 719                 return array_merge( parent::getPossibleErrors(), array(
 720                         array( 'code' => 'badgenerator', 'info' => 'Module $generatorName cannot be used as a generator' ),
 721                 ) );
 722         }
 723
 724         public function getExamples() {
 725                 return array(
 726                         'api.php?action=query&prop=revisions&meta=siteinfo&titles=Main%20Page&rvprop=user|comment',
 727                         'api.php?action=query&generator=allpages&gapprefix=API/&prop=revisions',
 728                 );
 729         }
 730
 731         public function getHelpUrls() {
 732                 return array(
 733                         'https://www.mediawiki.org/wiki/API:Meta',
 734                         'https://www.mediawiki.org/wiki/API:Properties',
 735                         'https://www.mediawiki.org/wiki/API:Lists',
 736                 );
 737         }
 738
 739         public function getVersion() {
 740                 $psModule = new ApiPageSet( $this );
 741                 $vers = array();
 742                 $vers[] = __CLASS__ . ': $Id$';
 743                 $vers[] = $psModule->getVersion();
 744                 return $vers;
 745         }
 746 }