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         /**
  41          * List of Api Query prop modules
  42          * @var array
  43          */
  44         private static $QueryPropModules = array(
  45                 'categories' => 'ApiQueryCategories',
  46                 'categoryinfo' => 'ApiQueryCategoryInfo',
  47                 'duplicatefiles' => 'ApiQueryDuplicateFiles',
  48                 'extlinks' => 'ApiQueryExternalLinks',
  49                 'images' => 'ApiQueryImages',
  50                 'imageinfo' => 'ApiQueryImageInfo',
  51                 'info' => 'ApiQueryInfo',
  52                 'links' => 'ApiQueryLinks',
  53                 'iwlinks' => 'ApiQueryIWLinks',
  54                 'langlinks' => 'ApiQueryLangLinks',
  55                 'pageprops' => 'ApiQueryPageProps',
  56                 'revisions' => 'ApiQueryRevisions',
  57                 'stashimageinfo' => 'ApiQueryStashImageInfo',
  58                 'templates' => 'ApiQueryLinks',
  59         );
  60
  61         /**
  62          * List of Api Query list modules
  63          * @var array
  64          */
  65         private static $QueryListModules = array(
  66                 'allcategories' => 'ApiQueryAllCategories',
  67                 'allimages' => 'ApiQueryAllImages',
  68                 'alllinks' => 'ApiQueryAllLinks',
  69                 'allpages' => 'ApiQueryAllPages',
  70                 'alltransclusions' => 'ApiQueryAllLinks',
  71                 'allusers' => 'ApiQueryAllUsers',
  72                 'backlinks' => 'ApiQueryBacklinks',
  73                 'blocks' => 'ApiQueryBlocks',
  74                 'categorymembers' => 'ApiQueryCategoryMembers',
  75                 'deletedrevs' => 'ApiQueryDeletedrevs',
  76                 'embeddedin' => 'ApiQueryBacklinks',
  77                 'exturlusage' => 'ApiQueryExtLinksUsage',
  78                 'filearchive' => 'ApiQueryFilearchive',
  79                 'imageusage' => 'ApiQueryBacklinks',
  80                 'iwbacklinks' => 'ApiQueryIWBacklinks',
  81                 'langbacklinks' => 'ApiQueryLangBacklinks',
  82                 'logevents' => 'ApiQueryLogEvents',
  83                 'pageswithprop' => 'ApiQueryPagesWithProp',
  84                 'pagepropnames' => 'ApiQueryPagePropNames',
  85                 'protectedtitles' => 'ApiQueryProtectedTitles',
  86                 'querypage' => 'ApiQueryQueryPage',
  87                 'random' => 'ApiQueryRandom',
  88                 'recentchanges' => 'ApiQueryRecentChanges',
  89                 'search' => 'ApiQuerySearch',
  90                 'tags' => 'ApiQueryTags',
  91                 'usercontribs' => 'ApiQueryContributions',
  92                 'users' => 'ApiQueryUsers',
  93                 'watchlist' => 'ApiQueryWatchlist',
  94                 'watchlistraw' => 'ApiQueryWatchlistRaw',
  95         );
  96
  97         /**
  98          * List of Api Query meta modules
  99          * @var array
 100          */
 101         private static $QueryMetaModules = array(
 102                 'allmessages' => 'ApiQueryAllMessages',
 103                 'siteinfo' => 'ApiQuerySiteinfo',
 104                 'userinfo' => 'ApiQueryUserInfo',
 105         );
 106
 107         /**
 108          * @var ApiPageSet
 109          */
 110         private $mPageSet;
 111
 112         private $mParams;
 113         private $mNamedDB = array();
 114         private $mModuleMgr;
 115         private $mGeneratorContinue;
 116         private $mUseLegacyContinue;
 117
 118         /**
 119          * @param $main ApiMain
 120          * @param $action string
 121          */
 122         public function __construct( $main, $action ) {
 123                 parent::__construct( $main, $action );
 124
 125                 $this->mModuleMgr = new ApiModuleManager( $this );
 126
 127                 // Allow custom modules to be added in LocalSettings.php
 128                 global $wgAPIPropModules, $wgAPIListModules, $wgAPIMetaModules;
 129                 $this->mModuleMgr->addModules( self::$QueryPropModules, 'prop' );
 130                 $this->mModuleMgr->addModules( $wgAPIPropModules, 'prop' );
 131                 $this->mModuleMgr->addModules( self::$QueryListModules, 'list' );
 132                 $this->mModuleMgr->addModules( $wgAPIListModules, 'list' );
 133                 $this->mModuleMgr->addModules( self::$QueryMetaModules, 'meta' );
 134                 $this->mModuleMgr->addModules( $wgAPIMetaModules, 'meta' );
 135
 136                 // Create PageSet that will process titles/pageids/revids/generator
 137                 $this->mPageSet = new ApiPageSet( $this );
 138         }
 139
 140         /**
 141          * Overrides to return this instance's module manager.
 142          * @return ApiModuleManager
 143          */
 144         public function getModuleManager() {
 145                 return $this->mModuleMgr;
 146         }
 147
 148         /**
 149          * Get the query database connection with the given name.
 150          * If no such connection has been requested before, it will be created.
 151          * Subsequent calls with the same $name will return the same connection
 152          * as the first, regardless of the values of $db and $groups
 153          * @param string $name Name to assign to the database connection
 154          * @param int $db One of the DB_* constants
 155          * @param array $groups Query groups
 156          * @return DatabaseBase
 157          */
 158         public function getNamedDB( $name, $db, $groups ) {
 159                 if ( !array_key_exists( $name, $this->mNamedDB ) ) {
 160                         $this->profileDBIn();
 161                         $this->mNamedDB[$name] = wfGetDB( $db, $groups );
 162                         $this->profileDBOut();
 163                 }
 164                 return $this->mNamedDB[$name];
 165         }
 166
 167         /**
 168          * Gets the set of pages the user has requested (or generated)
 169          * @return ApiPageSet
 170          */
 171         public function getPageSet() {
 172                 return $this->mPageSet;
 173         }
 174
 175         /**
 176          * Get the array mapping module names to class names
 177          * @deprecated since 1.21, use getModuleManager()'s methods instead
 178          * @return array array(modulename => classname)
 179          */
 180         public function getModules() {
 181                 wfDeprecated( __METHOD__, '1.21' );
 182                 return $this->getModuleManager()->getNamesWithClasses();
 183         }
 184
 185         /**
 186          * Get the generators array mapping module names to class names
 187          * @deprecated since 1.21, list of generators is maintained by ApiPageSet
 188          * @return array array(modulename => classname)
 189          */
 190         public function getGenerators() {
 191                 wfDeprecated( __METHOD__, '1.21' );
 192                 $gens = array();
 193                 foreach ( $this->mModuleMgr->getNamesWithClasses() as $name => $class ) {
 194                         if ( is_subclass_of( $class, 'ApiQueryGeneratorBase' ) ) {
 195                                 $gens[$name] = $class;
 196                         }
 197                 }
 198                 return $gens;
 199         }
 200
 201         /**
 202          * Get whether the specified module is a prop, list or a meta query module
 203          * @deprecated since 1.21, use getModuleManager()->getModuleGroup()
 204          * @param string $moduleName Name of the module to find type for
 205          * @return mixed string or null
 206          */
 207         function getModuleType( $moduleName ) {
 208                 return $this->getModuleManager()->getModuleGroup( $moduleName );
 209         }
 210
 211         /**
 212          * @return ApiFormatRaw|null
 213          */
 214         public function getCustomPrinter() {
 215                 // If &exportnowrap is set, use the raw formatter
 216                 if ( $this->getParameter( 'export' ) &&
 217                                 $this->getParameter( 'exportnowrap' ) )
 218                 {
 219                         return new ApiFormatRaw( $this->getMain(),
 220                                 $this->getMain()->createPrinterByName( 'xml' ) );
 221                 } else {
 222                         return null;
 223                 }
 224         }
 225
 226         /**
 227          * Query execution happens in the following steps:
 228          * #1 Create a PageSet object with any pages requested by the user
 229          * #2 If using a generator, execute it to get a new ApiPageSet object
 230          * #3 Instantiate all requested modules.
 231          *    This way the PageSet object will know what shared data is required,
 232          *    and minimize DB calls.
 233          * #4 Output all normalization and redirect resolution information
 234          * #5 Execute all requested modules
 235          */
 236         public function execute() {
 237                 $this->mParams = $this->extractRequestParams();
 238
 239                 // $pagesetParams is a array of parameter names used by the pageset generator
 240                 //   or null if pageset has already finished and is no longer needed
 241                 // $completeModules is a set of complete modules with the name as key
 242                 $this->initContinue( $pagesetParams, $completeModules );
 243
 244                 // Instantiate requested modules
 245                 $allModules = array();
 246                 $this->instantiateModules( $allModules, 'prop' );
 247                 $propModules = $allModules; // Keep a copy
 248                 $this->instantiateModules( $allModules, 'list' );
 249                 $this->instantiateModules( $allModules, 'meta' );
 250
 251                 // Filter modules based on continue parameter
 252                 $modules = $this->initModules( $allModules, $completeModules, $pagesetParams !== null );
 253
 254                 // Execute pageset if in legacy mode or if pageset is not done
 255                 if ( $completeModules === null || $pagesetParams !== null ) {
 256                         // Populate page/revision information
 257                         $this->mPageSet->execute();
 258                         // Record page information (title, namespace, if exists, etc)
 259                         $this->outputGeneralPageInfo();
 260                 } else {
 261                         $this->mPageSet->executeDryRun();
 262                 }
 263
 264                 $cacheMode = $this->mPageSet->getCacheMode();
 265
 266                 // Execute all unfinished modules
 267                 /** @var $module ApiQueryBase */
 268                 foreach ( $modules as $module ) {
 269                         $params = $module->extractRequestParams();
 270                         $cacheMode = $this->mergeCacheMode(
 271                                 $cacheMode, $module->getCacheMode( $params ) );
 272                         $module->profileIn();
 273                         $module->execute();
 274                         wfRunHooks( 'APIQueryAfterExecute', array( &$module ) );
 275                         $module->profileOut();
 276                 }
 277
 278                 // Set the cache mode
 279                 $this->getMain()->setCacheMode( $cacheMode );
 280
 281                 if ( $completeModules === null ) {
 282                         return; // Legacy continue, we are done
 283                 }
 284
 285                 // Reformat query-continue result section
 286                 $result = $this->getResult();
 287                 $qc = $result->getData();
 288                 if ( isset( $qc['query-continue'] ) ) {
 289                         $qc = $qc['query-continue'];
 290                         $result->unsetValue( null, 'query-continue' );
 291                 } elseif ( $this->mGeneratorContinue !== null ) {
 292                         $qc = array();
 293                 } else {
 294                         // no more "continue"s, we are done!
 295                         return;
 296                 }
 297
 298                 // we are done with all the modules that do not have result in query-continue
 299                 $completeModules = array_merge( $completeModules, array_diff_key( $modules, $qc ) );
 300                 if ( $pagesetParams !== null ) {
 301                         // The pageset is still in use, check if all props have finished
 302                         $incompleteProps = array_intersect_key( $propModules, $qc );
 303                         if ( count( $incompleteProps ) > 0 ) {
 304                                 // Properties are not done, continue with the same pageset state - copy current parameters
 305                                 $main = $this->getMain();
 306                                 $contValues = array();
 307                                 foreach ( $pagesetParams as $param ) {
 308                                         // The param name is already prefix-encoded
 309                                         $contValues[$param] = $main->getVal( $param );
 310                                 }
 311                         } elseif ( $this->mGeneratorContinue !== null ) {
 312                                 // Move to the next set of pages produced by pageset, properties need to be restarted
 313                                 $contValues = $this->mGeneratorContinue;
 314                                 $pagesetParams = array_keys( $contValues );
 315                                 $completeModules = array_diff_key( $completeModules, $propModules );
 316                         } else {
 317                                 // Done with the pageset, finish up with the the lists and meta modules
 318                                 $pagesetParams = null;
 319                         }
 320                 }
 321
 322                 $continue = '||' . implode( '|', array_keys( $completeModules ) );
 323                 if ( $pagesetParams !== null ) {
 324                         // list of all pageset parameters to use in the next request
 325                         $continue = implode( '|', $pagesetParams ) . $continue;
 326                 } else {
 327                         // we are done with the pageset
 328                         $contValues = array();
 329                         $continue = '-' . $continue;
 330                 }
 331                 $contValues['continue'] = $continue;
 332                 foreach ( $qc as $qcModule ) {
 333                         foreach ( $qcModule as $qcKey => $qcValue ) {
 334                                 $contValues[$qcKey] = $qcValue;
 335                         }
 336                 }
 337                 $this->getResult()->addValue( null, 'continue', $contValues );
 338         }
 339
 340         /**
 341          * Parse 'continue' parameter into the list of complete modules and a list of generator parameters
 342          * @param array|null $pagesetParams returns list of generator params or null if pageset is done
 343          * @param array|null $completeModules returns list of finished modules (as keys), or null if legacy
 344          */
 345         private function initContinue( &$pagesetParams, &$completeModules ) {
 346                 $pagesetParams = array();
 347                 $continue = $this->mParams['continue'];
 348                 if ( $continue !== null ) {
 349                         $this->mUseLegacyContinue = false;
 350                         if ( $continue !== '' ) {
 351                                 // Format: ' pagesetParam1 | pagesetParam2 || module1 | module2 | module3 | ...
 352                                 // If pageset is done, use '-'
 353                                 $continue = explode( '||', $continue );
 354                                 $this->dieContinueUsageIf( count( $continue ) !== 2 );
 355                                 if ( $continue[0] === '-' ) {
 356                                         $pagesetParams = null; // No need to execute pageset
 357                                 } elseif ( $continue[0] !== '' ) {
 358                                         // list of pageset params that might need to be repeated
 359                                         $pagesetParams = explode( '|', $continue[0] );
 360                                 }
 361                                 $continue = $continue[1];
 362                         }
 363                         if ( $continue !== '' ) {
 364                                 $completeModules = array_flip( explode( '|', $continue ) );
 365                         } else {
 366                                 $completeModules = array();
 367                         }
 368                 } else {
 369                         $this->mUseLegacyContinue = true;
 370                         $completeModules = null;
 371                 }
 372         }
 373
 374         /**
 375          * Validate sub-modules, filter out completed ones, and do requestExtraData()
 376          * @param array $allModules An dict of name=>instance of all modules requested by the client
 377          * @param array|null $completeModules list of finished modules, or null if legacy continue
 378          * @param bool $usePageset True if pageset will be executed
 379          * @return array of modules to be processed during this execution
 380          */
 381         private function initModules( $allModules, $completeModules, $usePageset ) {
 382                 $modules = $allModules;
 383                 $tmp = $completeModules;
 384                 $wasPosted = $this->getRequest()->wasPosted();
 385                 $main = $this->getMain();
 386
 387                 /** @var $module ApiQueryBase */
 388                 foreach ( $allModules as $moduleName => $module ) {
 389                         if ( !$wasPosted && $module->mustBePosted() ) {
 390                                 $this->dieUsageMsgOrDebug( array( 'mustbeposted', $moduleName ) );
 391                         }
 392                         if ( $completeModules !== null && array_key_exists( $moduleName, $completeModules ) ) {
 393                                 // If this module is done, mark all its params as used
 394                                 $module->extractRequestParams();
 395                                 // Make sure this module is not used during execution
 396                                 unset( $modules[$moduleName] );
 397                                 unset( $tmp[$moduleName] );
 398                         } elseif ( $completeModules === null || $usePageset ) {
 399                                 // Query modules may optimize data requests through the $this->getPageSet()
 400                                 // object by adding extra fields from the page table.
 401                                 // This function will gather all the extra request fields from the modules.
 402                                 $module->requestExtraData( $this->mPageSet );
 403                         } else {
 404                                 // Error - this prop module must have finished before generator is done
 405                                 $this->dieContinueUsageIf( $this->mModuleMgr->getModuleGroup( $moduleName ) === 'prop' );
 406                         }
 407                 }
 408                 $this->dieContinueUsageIf( $completeModules !== null && count( $tmp ) !== 0 );
 409                 return $modules;
 410         }
 411
 412         /**
 413          * Update a cache mode string, applying the cache mode of a new module to it.
 414          * The cache mode may increase in the level of privacy, but public modules
 415          * added to private data do not decrease the level of privacy.
 416          *
 417          * @param $cacheMode string
 418          * @param $modCacheMode string
 419          * @return string
 420          */
 421         protected function mergeCacheMode( $cacheMode, $modCacheMode ) {
 422                 if ( $modCacheMode === 'anon-public-user-private' ) {
 423                         if ( $cacheMode !== 'private' ) {
 424                                 $cacheMode = 'anon-public-user-private';
 425                         }
 426                 } elseif ( $modCacheMode === 'public' ) {
 427                         // do nothing, if it's public already it will stay public
 428                 } else { // private
 429                         $cacheMode = 'private';
 430                 }
 431                 return $cacheMode;
 432         }
 433
 434         /**
 435          * Create instances of all modules requested by the client
 436          * @param array $modules to append instantiated modules to
 437          * @param string $param Parameter name to read modules from
 438          */
 439         private function instantiateModules( &$modules, $param ) {
 440                 if ( isset( $this->mParams[$param] ) ) {
 441                         foreach ( $this->mParams[$param] as $moduleName ) {
 442                                 $instance = $this->mModuleMgr->getModule( $moduleName, $param );
 443                                 if ( $instance === null ) {
 444                                         ApiBase::dieDebug( __METHOD__, 'Error instantiating module' );
 445                                 }
 446                                 // Ignore duplicates. TODO 2.0: die()?
 447                                 if ( !array_key_exists( $moduleName, $modules ) ) {
 448                                         $modules[$moduleName] = $instance;
 449                                 }
 450                         }
 451                 }
 452         }
 453
 454         /**
 455          * Appends an element for each page in the current pageSet with the
 456          * most general information (id, title), plus any title normalizations
 457          * and missing or invalid title/pageids/revids.
 458          */
 459         private function outputGeneralPageInfo() {
 460                 $pageSet = $this->getPageSet();
 461                 $result = $this->getResult();
 462
 463                 // We don't check for a full result set here because we can't be adding
 464                 // more than 380K. The maximum revision size is in the megabyte range,
 465                 // and the maximum result size must be even higher than that.
 466
 467                 $values = $pageSet->getNormalizedTitlesAsResult( $result );
 468                 if ( $values ) {
 469                         $result->addValue( 'query', 'normalized', $values );
 470                 }
 471                 $values = $pageSet->getConvertedTitlesAsResult( $result );
 472                 if ( $values ) {
 473                         $result->addValue( 'query', 'converted', $values );
 474                 }
 475                 $values = $pageSet->getInterwikiTitlesAsResult( $result, $this->mParams['iwurl'] );
 476                 if ( $values ) {
 477                         $result->addValue( 'query', 'interwiki', $values );
 478                 }
 479                 $values = $pageSet->getRedirectTitlesAsResult( $result );
 480                 if ( $values ) {
 481                         $result->addValue( 'query', 'redirects', $values );
 482                 }
 483                 $values = $pageSet->getMissingRevisionIDsAsResult( $result );
 484                 if ( $values ) {
 485                         $result->addValue( 'query', 'badrevids', $values );
 486                 }
 487
 488                 // Page elements
 489                 $pages = array();
 490
 491                 // Report any missing titles
 492                 foreach ( $pageSet->getMissingTitles() as $fakeId => $title ) {
 493                         $vals = array();
 494                         ApiQueryBase::addTitleInfo( $vals, $title );
 495                         $vals['missing'] = '';
 496                         $pages[$fakeId] = $vals;
 497                 }
 498                 // Report any invalid titles
 499                 foreach ( $pageSet->getInvalidTitles() as $fakeId => $title ) {
 500                         $pages[$fakeId] = array( 'title' => $title, 'invalid' => '' );
 501                 }
 502                 // Report any missing page ids
 503                 foreach ( $pageSet->getMissingPageIDs() as $pageid ) {
 504                         $pages[$pageid] = array(
 505                                 'pageid' => $pageid,
 506                                 'missing' => ''
 507                         );
 508                 }
 509                 // Report special pages
 510                 /** @var $title Title */
 511                 foreach ( $pageSet->getSpecialTitles() as $fakeId => $title ) {
 512                         $vals = array();
 513                         ApiQueryBase::addTitleInfo( $vals, $title );
 514                         $vals['special'] = '';
 515                         if ( $title->isSpecialPage() &&
 516                                         !SpecialPageFactory::exists( $title->getDbKey() ) ) {
 517                                 $vals['missing'] = '';
 518                         } elseif ( $title->getNamespace() == NS_MEDIA &&
 519                                         !wfFindFile( $title ) ) {
 520                                 $vals['missing'] = '';
 521                         }
 522                         $pages[$fakeId] = $vals;
 523                 }
 524
 525                 // Output general page information for found titles
 526                 foreach ( $pageSet->getGoodTitles() as $pageid => $title ) {
 527                         $vals = array();
 528                         $vals['pageid'] = $pageid;
 529                         ApiQueryBase::addTitleInfo( $vals, $title );
 530                         $pages[$pageid] = $vals;
 531                 }
 532
 533                 if ( count( $pages ) ) {
 534                         if ( $this->mParams['indexpageids'] ) {
 535                                 $pageIDs = array_keys( $pages );
 536                                 // json treats all map keys as strings - converting to match
 537                                 $pageIDs = array_map( 'strval', $pageIDs );
 538                                 $result->setIndexedTagName( $pageIDs, 'id' );
 539                                 $result->addValue( 'query', 'pageids', $pageIDs );
 540                         }
 541
 542                         $result->setIndexedTagName( $pages, 'page' );
 543                         $result->addValue( 'query', 'pages', $pages );
 544                 }
 545                 if ( $this->mParams['export'] ) {
 546                         $this->doExport( $pageSet, $result );
 547                 }
 548         }
 549
 550         /**
 551          * This method is called by the generator base when generator in the smart-continue
 552          * mode tries to set 'query-continue' value. ApiQuery stores those values separately
 553          * until the post-processing when it is known if the generation should continue or repeat.
 554          * @param ApiQueryGeneratorBase $module generator module
 555          * @param string $paramName
 556          * @param mixed $paramValue
 557          * @return bool true if processed, false if this is a legacy continue
 558          */
 559         public function setGeneratorContinue( $module, $paramName, $paramValue ) {
 560                 if ( $this->mUseLegacyContinue ) {
 561                         return false;
 562                 }
 563                 $paramName = $module->encodeParamName( $paramName );
 564                 if ( $this->mGeneratorContinue === null ) {
 565                         $this->mGeneratorContinue = array();
 566                 }
 567                 $this->mGeneratorContinue[$paramName] = $paramValue;
 568                 return true;
 569         }
 570
 571         /**
 572          * @param $pageSet ApiPageSet Pages to be exported
 573          * @param $result ApiResult Result to output to
 574          */
 575         private function doExport( $pageSet, $result ) {
 576                 $exportTitles = array();
 577                 $titles = $pageSet->getGoodTitles();
 578                 if ( count( $titles ) ) {
 579                         $user = $this->getUser();
 580                         /** @var $title Title */
 581                         foreach ( $titles as $title ) {
 582                                 if ( $title->userCan( 'read', $user ) ) {
 583                                         $exportTitles[] = $title;
 584                                 }
 585                         }
 586                 }
 587
 588                 $exporter = new WikiExporter( $this->getDB() );
 589                 // WikiExporter writes to stdout, so catch its
 590                 // output with an ob
 591                 ob_start();
 592                 $exporter->openStream();
 593                 foreach ( $exportTitles as $title ) {
 594                         $exporter->pageByTitle( $title );
 595                 }
 596                 $exporter->closeStream();
 597                 $exportxml = ob_get_contents();
 598                 ob_end_clean();
 599
 600                 // Don't check the size of exported stuff
 601                 // It's not continuable, so it would cause more
 602                 // problems than it'd solve
 603                 $result->disableSizeCheck();
 604                 if ( $this->mParams['exportnowrap'] ) {
 605                         $result->reset();
 606                         // Raw formatter will handle this
 607                         $result->addValue( null, 'text', $exportxml );
 608                         $result->addValue( null, 'mime', 'text/xml' );
 609                 } else {
 610                         $r = array();
 611                         ApiResult::setContent( $r, $exportxml );
 612                         $result->addValue( 'query', 'export', $r );
 613                 }
 614                 $result->enableSizeCheck();
 615         }
 616
 617         public function getAllowedParams( $flags = 0 ) {
 618                 $result = array(
 619                         'prop' => array(
 620                                 ApiBase::PARAM_ISMULTI => true,
 621                                 ApiBase::PARAM_TYPE => $this->mModuleMgr->getNames( 'prop' )
 622                         ),
 623                         'list' => array(
 624                                 ApiBase::PARAM_ISMULTI => true,
 625                                 ApiBase::PARAM_TYPE => $this->mModuleMgr->getNames( 'list' )
 626                         ),
 627                         'meta' => array(
 628                                 ApiBase::PARAM_ISMULTI => true,
 629                                 ApiBase::PARAM_TYPE => $this->mModuleMgr->getNames( 'meta' )
 630                         ),
 631                         'indexpageids' => false,
 632                         'export' => false,
 633                         'exportnowrap' => false,
 634                         'iwurl' => false,
 635                         'continue' => null,
 636                 );
 637                 if ( $flags ) {
 638                         $result += $this->getPageSet()->getFinalParams( $flags );
 639                 }
 640                 return $result;
 641         }
 642
 643         /**
 644          * Override the parent to generate help messages for all available query modules.
 645          * @return string
 646          */
 647         public function makeHelpMsg() {
 648
 649                 // Use parent to make default message for the query module
 650                 $msg = parent::makeHelpMsg();
 651
 652                 $querySeparator = str_repeat( '--- ', 12 );
 653                 $moduleSeparator = str_repeat( '*** ', 14 );
 654                 $msg .= "\n$querySeparator Query: Prop  $querySeparator\n\n";
 655                 $msg .= $this->makeHelpMsgHelper( 'prop' );
 656                 $msg .= "\n$querySeparator Query: List  $querySeparator\n\n";
 657                 $msg .= $this->makeHelpMsgHelper( 'list' );
 658                 $msg .= "\n$querySeparator Query: Meta  $querySeparator\n\n";
 659                 $msg .= $this->makeHelpMsgHelper( 'meta' );
 660                 $msg .= "\n\n$moduleSeparator Modules: continuation  $moduleSeparator\n\n";
 661
 662                 return $msg;
 663         }
 664
 665         /**
 666          * For all modules of a given group, generate help messages and join them together
 667          * @param string $group Module group
 668          * @return string
 669          */
 670         private function makeHelpMsgHelper( $group ) {
 671                 $moduleDescriptions = array();
 672
 673                 $moduleNames = $this->mModuleMgr->getNames( $group );
 674                 sort( $moduleNames );
 675                 foreach ( $moduleNames as $name ) {
 676                         /**
 677                          * @var $module ApiQueryBase
 678                          */
 679                         $module = $this->mModuleMgr->getModule( $name );
 680
 681                         $msg = ApiMain::makeHelpMsgHeader( $module, $group );
 682                         $msg2 = $module->makeHelpMsg();
 683                         if ( $msg2 !== false ) {
 684                                 $msg .= $msg2;
 685                         }
 686                         if ( $module instanceof ApiQueryGeneratorBase ) {
 687                                 $msg .= "Generator:\n  This module may be used as a generator\n";
 688                         }
 689                         $moduleDescriptions[] = $msg;
 690                 }
 691
 692                 return implode( "\n", $moduleDescriptions );
 693         }
 694
 695         public function shouldCheckMaxlag() {
 696                 return true;
 697         }
 698
 699         public function getParamDescription() {
 700                 return $this->getPageSet()->getParamDescription() + array(
 701                         'prop' => 'Which properties to get for the titles/revisions/pageids. Module help is available below',
 702                         'list' => 'Which lists to get. Module help is available below',
 703                         'meta' => 'Which metadata to get about the site. Module help is available below',
 704                         'indexpageids' => 'Include an additional pageids section listing all returned page IDs',
 705                         'export' => 'Export the current revisions of all given or generated pages',
 706                         'exportnowrap' => 'Return the export XML without wrapping it in an XML result (same format as Special:Export). Can only be used with export',
 707                         'iwurl' => 'Whether to get the full URL if the title is an interwiki link',
 708                         'continue' => array(
 709                                 'When present, formats query-continue as key-value pairs that should simply be merged into the original request.',
 710                                 'This parameter must be set to an empty string in the initial query.',
 711                                 'This parameter is recommended for all new development, and will be made default in the next API version.' ),
 712                 );
 713         }
 714
 715         public function getDescription() {
 716                 return array(
 717                         'Query API module allows applications to get needed pieces of data from the MediaWiki databases,',
 718                         'and is loosely based on the old query.php interface.',
 719                         'All data modifications will first have to use query to acquire a token to prevent abuse from malicious sites'
 720                 );
 721         }
 722
 723         public function getPossibleErrors() {
 724                 return array_merge(
 725                         parent::getPossibleErrors(),
 726                         $this->getPageSet()->getPossibleErrors()
 727                 );
 728         }
 729
 730         public function getExamples() {
 731                 return array(
 732                         'api.php?action=query&prop=revisions&meta=siteinfo&titles=Main%20Page&rvprop=user|comment&continue=',
 733                         'api.php?action=query&generator=allpages&gapprefix=API/&prop=revisions&continue=',
 734                 );
 735         }
 736
 737         public function getHelpUrls() {
 738                 return array(
 739                         'https://www.mediawiki.org/wiki/API:Meta',
 740                         'https://www.mediawiki.org/wiki/API:Properties',
 741                         'https://www.mediawiki.org/wiki/API:Lists',
 742                 );
 743         }
 744 }