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                 'filerepoinfo' => 'ApiQueryFileRepoInfo',
 106         );
 107
 108         /**
 109          * @var ApiPageSet
 110          */
 111         private $mPageSet;
 112
 113         private $mParams;
 114         private $mNamedDB = array();
 115         private $mModuleMgr;
 116         private $mGeneratorContinue;
 117         private $mUseLegacyContinue;
 118
 119         /**
 120          * @param $main ApiMain
 121          * @param $action string
 122          */
 123         public function __construct( $main, $action ) {
 124                 parent::__construct( $main, $action );
 125
 126                 $this->mModuleMgr = new ApiModuleManager( $this );
 127
 128                 // Allow custom modules to be added in LocalSettings.php
 129                 global $wgAPIPropModules, $wgAPIListModules, $wgAPIMetaModules;
 130                 $this->mModuleMgr->addModules( self::$QueryPropModules, 'prop' );
 131                 $this->mModuleMgr->addModules( $wgAPIPropModules, 'prop' );
 132                 $this->mModuleMgr->addModules( self::$QueryListModules, 'list' );
 133                 $this->mModuleMgr->addModules( $wgAPIListModules, 'list' );
 134                 $this->mModuleMgr->addModules( self::$QueryMetaModules, 'meta' );
 135                 $this->mModuleMgr->addModules( $wgAPIMetaModules, 'meta' );
 136
 137                 // Create PageSet that will process titles/pageids/revids/generator
 138                 $this->mPageSet = new ApiPageSet( $this );
 139         }
 140
 141         /**
 142          * Overrides to return this instance's module manager.
 143          * @return ApiModuleManager
 144          */
 145         public function getModuleManager() {
 146                 return $this->mModuleMgr;
 147         }
 148
 149         /**
 150          * Get the query database connection with the given name.
 151          * If no such connection has been requested before, it will be created.
 152          * Subsequent calls with the same $name will return the same connection
 153          * as the first, regardless of the values of $db and $groups
 154          * @param string $name Name to assign to the database connection
 155          * @param int $db One of the DB_* constants
 156          * @param array $groups Query groups
 157          * @return DatabaseBase
 158          */
 159         public function getNamedDB( $name, $db, $groups ) {
 160                 if ( !array_key_exists( $name, $this->mNamedDB ) ) {
 161                         $this->profileDBIn();
 162                         $this->mNamedDB[$name] = wfGetDB( $db, $groups );
 163                         $this->profileDBOut();
 164                 }
 165                 return $this->mNamedDB[$name];
 166         }
 167
 168         /**
 169          * Gets the set of pages the user has requested (or generated)
 170          * @return ApiPageSet
 171          */
 172         public function getPageSet() {
 173                 return $this->mPageSet;
 174         }
 175
 176         /**
 177          * Get the array mapping module names to class names
 178          * @deprecated since 1.21, use getModuleManager()'s methods instead
 179          * @return array array(modulename => classname)
 180          */
 181         public function getModules() {
 182                 wfDeprecated( __METHOD__, '1.21' );
 183                 return $this->getModuleManager()->getNamesWithClasses();
 184         }
 185
 186         /**
 187          * Get the generators array mapping module names to class names
 188          * @deprecated since 1.21, list of generators is maintained by ApiPageSet
 189          * @return array array(modulename => classname)
 190          */
 191         public function getGenerators() {
 192                 wfDeprecated( __METHOD__, '1.21' );
 193                 $gens = array();
 194                 foreach ( $this->mModuleMgr->getNamesWithClasses() as $name => $class ) {
 195                         if ( is_subclass_of( $class, 'ApiQueryGeneratorBase' ) ) {
 196                                 $gens[$name] = $class;
 197                         }
 198                 }
 199                 return $gens;
 200         }
 201
 202         /**
 203          * Get whether the specified module is a prop, list or a meta query module
 204          * @deprecated since 1.21, use getModuleManager()->getModuleGroup()
 205          * @param string $moduleName Name of the module to find type for
 206          * @return mixed string or null
 207          */
 208         function getModuleType( $moduleName ) {
 209                 return $this->getModuleManager()->getModuleGroup( $moduleName );
 210         }
 211
 212         /**
 213          * @return ApiFormatRaw|null
 214          */
 215         public function getCustomPrinter() {
 216                 // If &exportnowrap is set, use the raw formatter
 217                 if ( $this->getParameter( 'export' ) &&
 218                                 $this->getParameter( 'exportnowrap' ) )
 219                 {
 220                         return new ApiFormatRaw( $this->getMain(),
 221                                 $this->getMain()->createPrinterByName( 'xml' ) );
 222                 } else {
 223                         return null;
 224                 }
 225         }
 226
 227         /**
 228          * Query execution happens in the following steps:
 229          * #1 Create a PageSet object with any pages requested by the user
 230          * #2 If using a generator, execute it to get a new ApiPageSet object
 231          * #3 Instantiate all requested modules.
 232          *    This way the PageSet object will know what shared data is required,
 233          *    and minimize DB calls.
 234          * #4 Output all normalization and redirect resolution information
 235          * #5 Execute all requested modules
 236          */
 237         public function execute() {
 238                 $this->mParams = $this->extractRequestParams();
 239
 240                 // $pagesetParams is a array of parameter names used by the pageset generator
 241                 //   or null if pageset has already finished and is no longer needed
 242                 // $completeModules is a set of complete modules with the name as key
 243                 $this->initContinue( $pagesetParams, $completeModules );
 244
 245                 // Instantiate requested modules
 246                 $allModules = array();
 247                 $this->instantiateModules( $allModules, 'prop' );
 248                 $propModules = $allModules; // Keep a copy
 249                 $this->instantiateModules( $allModules, 'list' );
 250                 $this->instantiateModules( $allModules, 'meta' );
 251
 252                 // Filter modules based on continue parameter
 253                 $modules = $this->initModules( $allModules, $completeModules, $pagesetParams !== null );
 254
 255                 // Execute pageset if in legacy mode or if pageset is not done
 256                 if ( $completeModules === null || $pagesetParams !== null ) {
 257                         // Populate page/revision information
 258                         $this->mPageSet->execute();
 259                         // Record page information (title, namespace, if exists, etc)
 260                         $this->outputGeneralPageInfo();
 261                 } else {
 262                         $this->mPageSet->executeDryRun();
 263                 }
 264
 265                 $cacheMode = $this->mPageSet->getCacheMode();
 266
 267                 // Execute all unfinished modules
 268                 /** @var $module ApiQueryBase */
 269                 foreach ( $modules as $module ) {
 270                         $params = $module->extractRequestParams();
 271                         $cacheMode = $this->mergeCacheMode(
 272                                 $cacheMode, $module->getCacheMode( $params ) );
 273                         $module->profileIn();
 274                         $module->execute();
 275                         wfRunHooks( 'APIQueryAfterExecute', array( &$module ) );
 276                         $module->profileOut();
 277                 }
 278
 279                 // Set the cache mode
 280                 $this->getMain()->setCacheMode( $cacheMode );
 281
 282                 if ( $completeModules === null ) {
 283                         return; // Legacy continue, we are done
 284                 }
 285
 286                 // Reformat query-continue result section
 287                 $result = $this->getResult();
 288                 $qc = $result->getData();
 289                 if ( isset( $qc['query-continue'] ) ) {
 290                         $qc = $qc['query-continue'];
 291                         $result->unsetValue( null, 'query-continue' );
 292                 } elseif ( $this->mGeneratorContinue !== null ) {
 293                         $qc = array();
 294                 } else {
 295                         // no more "continue"s, we are done!
 296                         return;
 297                 }
 298
 299                 // we are done with all the modules that do not have result in query-continue
 300                 $completeModules = array_merge( $completeModules, array_diff_key( $modules, $qc ) );
 301                 if ( $pagesetParams !== null ) {
 302                         // The pageset is still in use, check if all props have finished
 303                         $incompleteProps = array_intersect_key( $propModules, $qc );
 304                         if ( count( $incompleteProps ) > 0 ) {
 305                                 // Properties are not done, continue with the same pageset state - copy current parameters
 306                                 $main = $this->getMain();
 307                                 $contValues = array();
 308                                 foreach ( $pagesetParams as $param ) {
 309                                         // The param name is already prefix-encoded
 310                                         $contValues[$param] = $main->getVal( $param );
 311                                 }
 312                         } elseif ( $this->mGeneratorContinue !== null ) {
 313                                 // Move to the next set of pages produced by pageset, properties need to be restarted
 314                                 $contValues = $this->mGeneratorContinue;
 315                                 $pagesetParams = array_keys( $contValues );
 316                                 $completeModules = array_diff_key( $completeModules, $propModules );
 317                         } else {
 318                                 // Done with the pageset, finish up with the the lists and meta modules
 319                                 $pagesetParams = null;
 320                         }
 321                 }
 322
 323                 $continue = '||' . implode( '|', array_keys( $completeModules ) );
 324                 if ( $pagesetParams !== null ) {
 325                         // list of all pageset parameters to use in the next request
 326                         $continue = implode( '|', $pagesetParams ) . $continue;
 327                 } else {
 328                         // we are done with the pageset
 329                         $contValues = array();
 330                         $continue = '-' . $continue;
 331                 }
 332                 $contValues['continue'] = $continue;
 333                 foreach ( $qc as $qcModule ) {
 334                         foreach ( $qcModule as $qcKey => $qcValue ) {
 335                                 $contValues[$qcKey] = $qcValue;
 336                         }
 337                 }
 338                 $this->getResult()->addValue( null, 'continue', $contValues );
 339         }
 340
 341         /**
 342          * Parse 'continue' parameter into the list of complete modules and a list of generator parameters
 343          * @param array|null $pagesetParams returns list of generator params or null if pageset is done
 344          * @param array|null $completeModules returns list of finished modules (as keys), or null if legacy
 345          */
 346         private function initContinue( &$pagesetParams, &$completeModules ) {
 347                 $pagesetParams = array();
 348                 $continue = $this->mParams['continue'];
 349                 if ( $continue !== null ) {
 350                         $this->mUseLegacyContinue = false;
 351                         if ( $continue !== '' ) {
 352                                 // Format: ' pagesetParam1 | pagesetParam2 || module1 | module2 | module3 | ...
 353                                 // If pageset is done, use '-'
 354                                 $continue = explode( '||', $continue );
 355                                 $this->dieContinueUsageIf( count( $continue ) !== 2 );
 356                                 if ( $continue[0] === '-' ) {
 357                                         $pagesetParams = null; // No need to execute pageset
 358                                 } elseif ( $continue[0] !== '' ) {
 359                                         // list of pageset params that might need to be repeated
 360                                         $pagesetParams = explode( '|', $continue[0] );
 361                                 }
 362                                 $continue = $continue[1];
 363                         }
 364                         if ( $continue !== '' ) {
 365                                 $completeModules = array_flip( explode( '|', $continue ) );
 366                         } else {
 367                                 $completeModules = array();
 368                         }
 369                 } else {
 370                         $this->mUseLegacyContinue = true;
 371                         $completeModules = null;
 372                 }
 373         }
 374
 375         /**
 376          * Validate sub-modules, filter out completed ones, and do requestExtraData()
 377          * @param array $allModules An dict of name=>instance of all modules requested by the client
 378          * @param array|null $completeModules list of finished modules, or null if legacy continue
 379          * @param bool $usePageset True if pageset will be executed
 380          * @return array of modules to be processed during this execution
 381          */
 382         private function initModules( $allModules, $completeModules, $usePageset ) {
 383                 $modules = $allModules;
 384                 $tmp = $completeModules;
 385                 $wasPosted = $this->getRequest()->wasPosted();
 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()->getFinalParamDescription() + 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()->getFinalPossibleErrors()
 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:Query',
 740                         'https://www.mediawiki.org/wiki/API:Meta',
 741                         'https://www.mediawiki.org/wiki/API:Properties',
 742                         'https://www.mediawiki.org/wiki/API:Lists',
 743                 );
 744         }
 745 }