includes/api/ApiMain.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Sep 4, 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  * @defgroup API API
  26  */
  27
  28 use MediaWiki\Logger\LoggerFactory;
  29
  30 /**
  31  * This is the main API class, used for both external and internal processing.
  32  * When executed, it will create the requested formatter object,
  33  * instantiate and execute an object associated with the needed action,
  34  * and use formatter to print results.
  35  * In case of an exception, an error message will be printed using the same formatter.
  36  *
  37  * To use API from another application, run it using FauxRequest object, in which
  38  * case any internal exceptions will not be handled but passed up to the caller.
  39  * After successful execution, use getResult() for the resulting data.
  40  *
  41  * @ingroup API
  42  */
  43 class ApiMain extends ApiBase {
  44         /**
  45          * When no format parameter is given, this format will be used
  46          */
  47         const API_DEFAULT_FORMAT = 'jsonfm';
  48
  49         /**
  50          * When no uselang parameter is given, this language will be used
  51          */
  52         const API_DEFAULT_USELANG = 'user';
  53
  54         /**
  55          * List of available modules: action name => module class
  56          */
  57         private static $Modules = [
  58                 'login' => 'ApiLogin',
  59                 'clientlogin' => 'ApiClientLogin',
  60                 'logout' => 'ApiLogout',
  61                 'createaccount' => 'ApiAMCreateAccount',
  62                 'linkaccount' => 'ApiLinkAccount',
  63                 'unlinkaccount' => 'ApiRemoveAuthenticationData',
  64                 'changeauthenticationdata' => 'ApiChangeAuthenticationData',
  65                 'removeauthenticationdata' => 'ApiRemoveAuthenticationData',
  66                 'resetpassword' => 'ApiResetPassword',
  67                 'query' => 'ApiQuery',
  68                 'expandtemplates' => 'ApiExpandTemplates',
  69                 'parse' => 'ApiParse',
  70                 'stashedit' => 'ApiStashEdit',
  71                 'opensearch' => 'ApiOpenSearch',
  72                 'feedcontributions' => 'ApiFeedContributions',
  73                 'feedrecentchanges' => 'ApiFeedRecentChanges',
  74                 'feedwatchlist' => 'ApiFeedWatchlist',
  75                 'help' => 'ApiHelp',
  76                 'paraminfo' => 'ApiParamInfo',
  77                 'rsd' => 'ApiRsd',
  78                 'compare' => 'ApiComparePages',
  79                 'tokens' => 'ApiTokens',
  80                 'checktoken' => 'ApiCheckToken',
  81                 'cspreport' => 'ApiCSPReport',
  82
  83                 // Write modules
  84                 'purge' => 'ApiPurge',
  85                 'setnotificationtimestamp' => 'ApiSetNotificationTimestamp',
  86                 'rollback' => 'ApiRollback',
  87                 'delete' => 'ApiDelete',
  88                 'undelete' => 'ApiUndelete',
  89                 'protect' => 'ApiProtect',
  90                 'block' => 'ApiBlock',
  91                 'unblock' => 'ApiUnblock',
  92                 'move' => 'ApiMove',
  93                 'edit' => 'ApiEditPage',
  94                 'upload' => 'ApiUpload',
  95                 'filerevert' => 'ApiFileRevert',
  96                 'emailuser' => 'ApiEmailUser',
  97                 'watch' => 'ApiWatch',
  98                 'patrol' => 'ApiPatrol',
  99                 'import' => 'ApiImport',
 100                 'clearhasmsg' => 'ApiClearHasMsg',
 101                 'userrights' => 'ApiUserrights',
 102                 'options' => 'ApiOptions',
 103                 'imagerotate' => 'ApiImageRotate',
 104                 'revisiondelete' => 'ApiRevisionDelete',
 105                 'managetags' => 'ApiManageTags',
 106                 'tag' => 'ApiTag',
 107                 'mergehistory' => 'ApiMergeHistory',
 108         ];
 109
 110         /**
 111          * List of available formats: format name => format class
 112          */
 113         private static $Formats = [
 114                 'json' => 'ApiFormatJson',
 115                 'jsonfm' => 'ApiFormatJson',
 116                 'php' => 'ApiFormatPhp',
 117                 'phpfm' => 'ApiFormatPhp',
 118                 'xml' => 'ApiFormatXml',
 119                 'xmlfm' => 'ApiFormatXml',
 120                 'rawfm' => 'ApiFormatJson',
 121                 'none' => 'ApiFormatNone',
 122         ];
 123
 124         // @codingStandardsIgnoreStart String contenation on "msg" not allowed to break long line
 125         /**
 126          * List of user roles that are specifically relevant to the API.
 127          * [ 'right' => [ 'msg'    => 'Some message with a $1',
 128          *                'params' => [ $someVarToSubst ] ],
 129          * ];
 130          */
 131         private static $mRights = [
 132                 'writeapi' => [
 133                         'msg' => 'right-writeapi',
 134                         'params' => []
 135                 ],
 136                 'apihighlimits' => [
 137                         'msg' => 'api-help-right-apihighlimits',
 138                         'params' => [ ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 ]
 139                 ]
 140         ];
 141         // @codingStandardsIgnoreEnd
 142
 143         /**
 144          * @var ApiFormatBase
 145          */
 146         private $mPrinter;
 147
 148         private $mModuleMgr, $mResult, $mErrorFormatter = null;
 149         /** @var ApiContinuationManager|null */
 150         private $mContinuationManager;
 151         private $mAction;
 152         private $mEnableWrite;
 153         private $mInternalMode, $mSquidMaxage;
 154         /** @var ApiBase */
 155         private $mModule;
 156
 157         private $mCacheMode = 'private';
 158         private $mCacheControl = [];
 159         private $mParamsUsed = [];
 160
 161         /** @var bool|null Cached return value from self::lacksSameOriginSecurity() */
 162         private $lacksSameOriginSecurity = null;
 163
 164         /**
 165          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 166          *
 167          * @param IContextSource|WebRequest $context If this is an instance of
 168          *    FauxRequest, errors are thrown and no printing occurs
 169          * @param bool $enableWrite Should be set to true if the api may modify data
 170          */
 171         public function __construct( $context = null, $enableWrite = false ) {
 172                 if ( $context === null ) {
 173                         $context = RequestContext::getMain();
 174                 } elseif ( $context instanceof WebRequest ) {
 175                         // BC for pre-1.19
 176                         $request = $context;
 177                         $context = RequestContext::getMain();
 178                 }
 179                 // We set a derivative context so we can change stuff later
 180                 $this->setContext( new DerivativeContext( $context ) );
 181
 182                 if ( isset( $request ) ) {
 183                         $this->getContext()->setRequest( $request );
 184                 } else {
 185                         $request = $this->getRequest();
 186                 }
 187
 188                 $this->mInternalMode = ( $request instanceof FauxRequest );
 189
 190                 // Special handling for the main module: $parent === $this
 191                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 192
 193                 $config = $this->getConfig();
 194
 195                 if ( !$this->mInternalMode ) {
 196                         // Log if a request with a non-whitelisted Origin header is seen
 197                         // with session cookies.
 198                         $originHeader = $request->getHeader( 'Origin' );
 199                         if ( $originHeader === false ) {
 200                                 $origins = [];
 201                         } else {
 202                                 $originHeader = trim( $originHeader );
 203                                 $origins = preg_split( '/\s+/', $originHeader );
 204                         }
 205                         $sessionCookies = array_intersect(
 206                                 array_keys( $_COOKIE ),
 207                                 MediaWiki\Session\SessionManager::singleton()->getVaryCookies()
 208                         );
 209                         if ( $origins && $sessionCookies && (
 210                                 count( $origins ) !== 1 || !self::matchOrigin(
 211                                         $origins[0],
 212                                         $config->get( 'CrossSiteAJAXdomains' ),
 213                                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 214                                 )
 215                         ) ) {
 216                                 LoggerFactory::getInstance( 'cors' )->warning(
 217                                         'Non-whitelisted CORS request with session cookies', [
 218                                                 'origin' => $originHeader,
 219                                                 'cookies' => $sessionCookies,
 220                                                 'ip' => $request->getIP(),
 221                                                 'userAgent' => $this->getUserAgent(),
 222                                                 'wiki' => wfWikiID(),
 223                                         ]
 224                                 );
 225                         }
 226
 227                         // If we're in a mode that breaks the same-origin policy, strip
 228                         // user credentials for security.
 229                         if ( $this->lacksSameOriginSecurity() ) {
 230                                 global $wgUser;
 231                                 wfDebug( "API: stripping user credentials when the same-origin policy is not applied\n" );
 232                                 $wgUser = new User();
 233                                 $this->getContext()->setUser( $wgUser );
 234                         }
 235                 }
 236
 237                 $this->mResult = new ApiResult( $this->getConfig()->get( 'APIMaxResultSize' ) );
 238
 239                 // Setup uselang. This doesn't use $this->getParameter()
 240                 // because we're not ready to handle errors yet.
 241                 $uselang = $request->getVal( 'uselang', self::API_DEFAULT_USELANG );
 242                 if ( $uselang === 'user' ) {
 243                         // Assume the parent context is going to return the user language
 244                         // for uselang=user (see T85635).
 245                 } else {
 246                         if ( $uselang === 'content' ) {
 247                                 global $wgContLang;
 248                                 $uselang = $wgContLang->getCode();
 249                         }
 250                         $code = RequestContext::sanitizeLangCode( $uselang );
 251                         $this->getContext()->setLanguage( $code );
 252                         if ( !$this->mInternalMode ) {
 253                                 global $wgLang;
 254                                 $wgLang = $this->getContext()->getLanguage();
 255                                 RequestContext::getMain()->setLanguage( $wgLang );
 256                         }
 257                 }
 258
 259                 // Set up the error formatter. This doesn't use $this->getParameter()
 260                 // because we're not ready to handle errors yet.
 261                 $errorFormat = $request->getVal( 'errorformat', 'bc' );
 262                 $errorLangCode = $request->getVal( 'errorlang', 'uselang' );
 263                 $errorsUseDB = $request->getCheck( 'errorsuselocal' );
 264                 if ( in_array( $errorFormat, [ 'plaintext', 'wikitext', 'html', 'raw', 'none' ], true ) ) {
 265                         if ( $errorLangCode === 'uselang' ) {
 266                                 $errorLang = $this->getLanguage();
 267                         } elseif ( $errorLangCode === 'content' ) {
 268                                 global $wgContLang;
 269                                 $errorLang = $wgContLang;
 270                         } else {
 271                                 $errorLangCode = RequestContext::sanitizeLangCode( $errorLangCode );
 272                                 $errorLang = Language::factory( $errorLangCode );
 273                         }
 274                         $this->mErrorFormatter = new ApiErrorFormatter(
 275                                 $this->mResult, $errorLang, $errorFormat, $errorsUseDB
 276                         );
 277                 } else {
 278                         $this->mErrorFormatter = new ApiErrorFormatter_BackCompat( $this->mResult );
 279                 }
 280                 $this->mResult->setErrorFormatter( $this->getErrorFormatter() );
 281
 282                 $this->mModuleMgr = new ApiModuleManager( $this );
 283                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 284                 $this->mModuleMgr->addModules( $config->get( 'APIModules' ), 'action' );
 285                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 286                 $this->mModuleMgr->addModules( $config->get( 'APIFormatModules' ), 'format' );
 287
 288                 Hooks::run( 'ApiMain::moduleManager', [ $this->mModuleMgr ] );
 289
 290                 $this->mContinuationManager = null;
 291                 $this->mEnableWrite = $enableWrite;
 292
 293                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 294                 $this->mCommit = false;
 295         }
 296
 297         /**
 298          * Return true if the API was started by other PHP code using FauxRequest
 299          * @return bool
 300          */
 301         public function isInternalMode() {
 302                 return $this->mInternalMode;
 303         }
 304
 305         /**
 306          * Get the ApiResult object associated with current request
 307          *
 308          * @return ApiResult
 309          */
 310         public function getResult() {
 311                 return $this->mResult;
 312         }
 313
 314         /**
 315          * Get the security flag for the current request
 316          * @return bool
 317          */
 318         public function lacksSameOriginSecurity() {
 319                 if ( $this->lacksSameOriginSecurity !== null ) {
 320                         return $this->lacksSameOriginSecurity;
 321                 }
 322
 323                 $request = $this->getRequest();
 324
 325                 // JSONP mode
 326                 if ( $request->getVal( 'callback' ) !== null ) {
 327                         $this->lacksSameOriginSecurity = true;
 328                         return true;
 329                 }
 330
 331                 // Anonymous CORS
 332                 if ( $request->getVal( 'origin' ) === '*' ) {
 333                         $this->lacksSameOriginSecurity = true;
 334                         return true;
 335                 }
 336
 337                 // Header to be used from XMLHTTPRequest when the request might
 338                 // otherwise be used for XSS.
 339                 if ( $request->getHeader( 'Treat-as-Untrusted' ) !== false ) {
 340                         $this->lacksSameOriginSecurity = true;
 341                         return true;
 342                 }
 343
 344                 // Allow extensions to override.
 345                 $this->lacksSameOriginSecurity = !Hooks::run( 'RequestHasSameOriginSecurity', [ $request ] );
 346                 return $this->lacksSameOriginSecurity;
 347         }
 348
 349         /**
 350          * Get the ApiErrorFormatter object associated with current request
 351          * @return ApiErrorFormatter
 352          */
 353         public function getErrorFormatter() {
 354                 return $this->mErrorFormatter;
 355         }
 356
 357         /**
 358          * Get the continuation manager
 359          * @return ApiContinuationManager|null
 360          */
 361         public function getContinuationManager() {
 362                 return $this->mContinuationManager;
 363         }
 364
 365         /**
 366          * Set the continuation manager
 367          * @param ApiContinuationManager|null
 368          */
 369         public function setContinuationManager( $manager ) {
 370                 if ( $manager !== null ) {
 371                         if ( !$manager instanceof ApiContinuationManager ) {
 372                                 throw new InvalidArgumentException( __METHOD__ . ': Was passed ' .
 373                                         is_object( $manager ) ? get_class( $manager ) : gettype( $manager )
 374                                 );
 375                         }
 376                         if ( $this->mContinuationManager !== null ) {
 377                                 throw new UnexpectedValueException(
 378                                         __METHOD__ . ': tried to set manager from ' . $manager->getSource() .
 379                                         ' when a manager is already set from ' . $this->mContinuationManager->getSource()
 380                                 );
 381                         }
 382                 }
 383                 $this->mContinuationManager = $manager;
 384         }
 385
 386         /**
 387          * Get the API module object. Only works after executeAction()
 388          *
 389          * @return ApiBase
 390          */
 391         public function getModule() {
 392                 return $this->mModule;
 393         }
 394
 395         /**
 396          * Get the result formatter object. Only works after setupExecuteAction()
 397          *
 398          * @return ApiFormatBase
 399          */
 400         public function getPrinter() {
 401                 return $this->mPrinter;
 402         }
 403
 404         /**
 405          * Set how long the response should be cached.
 406          *
 407          * @param int $maxage
 408          */
 409         public function setCacheMaxAge( $maxage ) {
 410                 $this->setCacheControl( [
 411                         'max-age' => $maxage,
 412                         's-maxage' => $maxage
 413                 ] );
 414         }
 415
 416         /**
 417          * Set the type of caching headers which will be sent.
 418          *
 419          * @param string $mode One of:
 420          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 421          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 422          *         not provided by any of these means, the object will be private.
 423          *    - 'private':    Cache this object only in private client-side caches.
 424          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 425          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 426          *         set consistently for a given URL, it cannot be set differently depending on
 427          *         things like the contents of the database, or whether the user is logged in.
 428          *
 429          *  If the wiki does not allow anonymous users to read it, the mode set here
 430          *  will be ignored, and private caching headers will always be sent. In other words,
 431          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 432          *  view.
 433          *
 434          *  For user-dependent data, the private mode should generally be used. The
 435          *  anon-public-user-private mode should only be used where there is a particularly
 436          *  good performance reason for caching the anonymous response, but where the
 437          *  response to logged-in users may differ, or may contain private data.
 438          *
 439          *  If this function is never called, then the default will be the private mode.
 440          */
 441         public function setCacheMode( $mode ) {
 442                 if ( !in_array( $mode, [ 'private', 'public', 'anon-public-user-private' ] ) ) {
 443                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 444
 445                         // Ignore for forwards-compatibility
 446                         return;
 447                 }
 448
 449                 if ( !User::isEveryoneAllowed( 'read' ) ) {
 450                         // Private wiki, only private headers
 451                         if ( $mode !== 'private' ) {
 452                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 453
 454                                 return;
 455                         }
 456                 }
 457
 458                 if ( $mode === 'public' && $this->getParameter( 'uselang' ) === 'user' ) {
 459                         // User language is used for i18n, so we don't want to publicly
 460                         // cache. Anons are ok, because if they have non-default language
 461                         // then there's an appropriate Vary header set by whatever set
 462                         // their non-default language.
 463                         wfDebug( __METHOD__ . ": downgrading cache mode 'public' to " .
 464                                 "'anon-public-user-private' due to uselang=user\n" );
 465                         $mode = 'anon-public-user-private';
 466                 }
 467
 468                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 469                 $this->mCacheMode = $mode;
 470         }
 471
 472         /**
 473          * Set directives (key/value pairs) for the Cache-Control header.
 474          * Boolean values will be formatted as such, by including or omitting
 475          * without an equals sign.
 476          *
 477          * Cache control values set here will only be used if the cache mode is not
 478          * private, see setCacheMode().
 479          *
 480          * @param array $directives
 481          */
 482         public function setCacheControl( $directives ) {
 483                 $this->mCacheControl = $directives + $this->mCacheControl;
 484         }
 485
 486         /**
 487          * Create an instance of an output formatter by its name
 488          *
 489          * @param string $format
 490          *
 491          * @return ApiFormatBase
 492          */
 493         public function createPrinterByName( $format ) {
 494                 $printer = $this->mModuleMgr->getModule( $format, 'format' );
 495                 if ( $printer === null ) {
 496                         $this->dieWithError(
 497                                 [ 'apierror-unknownformat', wfEscapeWikiText( $format ) ], 'unknown_format'
 498                         );
 499                 }
 500
 501                 return $printer;
 502         }
 503
 504         /**
 505          * Execute api request. Any errors will be handled if the API was called by the remote client.
 506          */
 507         public function execute() {
 508                 if ( $this->mInternalMode ) {
 509                         $this->executeAction();
 510                 } else {
 511                         $this->executeActionWithErrorHandling();
 512                 }
 513         }
 514
 515         /**
 516          * Execute an action, and in case of an error, erase whatever partial results
 517          * have been accumulated, and replace it with an error message and a help screen.
 518          */
 519         protected function executeActionWithErrorHandling() {
 520                 // Verify the CORS header before executing the action
 521                 if ( !$this->handleCORS() ) {
 522                         // handleCORS() has sent a 403, abort
 523                         return;
 524                 }
 525
 526                 // Exit here if the request method was OPTIONS
 527                 // (assume there will be a followup GET or POST)
 528                 if ( $this->getRequest()->getMethod() === 'OPTIONS' ) {
 529                         return;
 530                 }
 531
 532                 // In case an error occurs during data output,
 533                 // clear the output buffer and print just the error information
 534                 $obLevel = ob_get_level();
 535                 ob_start();
 536
 537                 $t = microtime( true );
 538                 $isError = false;
 539                 try {
 540                         $this->executeAction();
 541                         $runTime = microtime( true ) - $t;
 542                         $this->logRequest( $runTime );
 543                         if ( $this->mModule->isWriteMode() && $this->getRequest()->wasPosted() ) {
 544                                 $this->getStats()->timing(
 545                                         'api.' . $this->mModule->getModuleName() . '.executeTiming', 1000 * $runTime
 546                                 );
 547                         }
 548                 } catch ( Exception $e ) {
 549                         $this->handleException( $e );
 550                         $this->logRequest( microtime( true ) - $t, $e );
 551                         $isError = true;
 552                 }
 553
 554                 // Commit DBs and send any related cookies and headers
 555                 MediaWiki::preOutputCommit( $this->getContext() );
 556
 557                 // Send cache headers after any code which might generate an error, to
 558                 // avoid sending public cache headers for errors.
 559                 $this->sendCacheHeaders( $isError );
 560
 561                 // Executing the action might have already messed with the output
 562                 // buffers.
 563                 while ( ob_get_level() > $obLevel ) {
 564                         ob_end_flush();
 565                 }
 566         }
 567
 568         /**
 569          * Handle an exception as an API response
 570          *
 571          * @since 1.23
 572          * @param Exception $e
 573          */
 574         protected function handleException( Exception $e ) {
 575                 // Bug 63145: Rollback any open database transactions
 576                 if ( !( $e instanceof ApiUsageException || $e instanceof UsageException ) ) {
 577                         // UsageExceptions are intentional, so don't rollback if that's the case
 578                         try {
 579                                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 580                         } catch ( DBError $e2 ) {
 581                                 // Rollback threw an exception too. Log it, but don't interrupt
 582                                 // our regularly scheduled exception handling.
 583                                 MWExceptionHandler::logException( $e2 );
 584                         }
 585                 }
 586
 587                 // Allow extra cleanup and logging
 588                 Hooks::run( 'ApiMain::onException', [ $this, $e ] );
 589
 590                 // Log it
 591                 if ( !( $e instanceof ApiUsageException || $e instanceof UsageException ) ) {
 592                         MWExceptionHandler::logException( $e );
 593                 }
 594
 595                 // Handle any kind of exception by outputting properly formatted error message.
 596                 // If this fails, an unhandled exception should be thrown so that global error
 597                 // handler will process and log it.
 598
 599                 $errCodes = $this->substituteResultWithError( $e );
 600
 601                 // Error results should not be cached
 602                 $this->setCacheMode( 'private' );
 603
 604                 $response = $this->getRequest()->response();
 605                 $headerStr = 'MediaWiki-API-Error: ' . join( ', ', $errCodes );
 606                 $response->header( $headerStr );
 607
 608                 // Reset and print just the error message
 609                 ob_clean();
 610
 611                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 612                 $this->createErrorPrinter();
 613
 614                 $failed = false;
 615                 try {
 616                         $this->printResult( $e->getCode() );
 617                 } catch ( ApiUsageException $ex ) {
 618                         // The error printer itself is failing. Try suppressing its request
 619                         // parameters and redo.
 620                         $failed = true;
 621                         $this->addWarning( 'apiwarn-errorprinterfailed' );
 622                         foreach ( $ex->getStatusValue()->getErrors() as $error ) {
 623                                 try {
 624                                         $this->mPrinter->addWarning( $error );
 625                                 } catch ( Exception $ex2 ) {
 626                                         // WTF?
 627                                         $this->addWarning( $error );
 628                                 }
 629                         }
 630                 } catch ( UsageException $ex ) {
 631                         // The error printer itself is failing. Try suppressing its request
 632                         // parameters and redo.
 633                         $failed = true;
 634                         $this->addWarning(
 635                                 [ 'apiwarn-errorprinterfailed-ex', $ex->getMessage() ], 'errorprinterfailed'
 636                         );
 637                 }
 638                 if ( $failed ) {
 639                         $this->mPrinter = null;
 640                         $this->createErrorPrinter();
 641                         $this->mPrinter->forceDefaultParams();
 642                         if ( $e->getCode() ) {
 643                                 $response->statusHeader( 200 ); // Reset in case the fallback doesn't want a non-200
 644                         }
 645                         $this->printResult( $e->getCode() );
 646                 }
 647         }
 648
 649         /**
 650          * Handle an exception from the ApiBeforeMain hook.
 651          *
 652          * This tries to print the exception as an API response, to be more
 653          * friendly to clients. If it fails, it will rethrow the exception.
 654          *
 655          * @since 1.23
 656          * @param Exception $e
 657          * @throws Exception
 658          */
 659         public static function handleApiBeforeMainException( Exception $e ) {
 660                 ob_start();
 661
 662                 try {
 663                         $main = new self( RequestContext::getMain(), false );
 664                         $main->handleException( $e );
 665                         $main->logRequest( 0, $e );
 666                 } catch ( Exception $e2 ) {
 667                         // Nope, even that didn't work. Punt.
 668                         throw $e;
 669                 }
 670
 671                 // Reset cache headers
 672                 $main->sendCacheHeaders( true );
 673
 674                 ob_end_flush();
 675         }
 676
 677         /**
 678          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 679          *
 680          * If no origin parameter is present, nothing happens.
 681          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 682          * is set and false is returned.
 683          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 684          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 685          * headers are set.
 686          * https://www.w3.org/TR/cors/#resource-requests
 687          * https://www.w3.org/TR/cors/#resource-preflight-requests
 688          *
 689          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 690          */
 691         protected function handleCORS() {
 692                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 693                 if ( $originParam === null ) {
 694                         // No origin parameter, nothing to do
 695                         return true;
 696                 }
 697
 698                 $request = $this->getRequest();
 699                 $response = $request->response();
 700
 701                 $matchOrigin = false;
 702                 $allowTiming = false;
 703                 $varyOrigin = true;
 704
 705                 if ( $originParam === '*' ) {
 706                         // Request for anonymous CORS
 707                         $matchOrigin = true;
 708                         $allowOrigin = '*';
 709                         $allowCredentials = 'false';
 710                         $varyOrigin = false; // No need to vary
 711                 } else {
 712                         // Non-anonymous CORS, check we allow the domain
 713
 714                         // Origin: header is a space-separated list of origins, check all of them
 715                         $originHeader = $request->getHeader( 'Origin' );
 716                         if ( $originHeader === false ) {
 717                                 $origins = [];
 718                         } else {
 719                                 $originHeader = trim( $originHeader );
 720                                 $origins = preg_split( '/\s+/', $originHeader );
 721                         }
 722
 723                         if ( !in_array( $originParam, $origins ) ) {
 724                                 // origin parameter set but incorrect
 725                                 // Send a 403 response
 726                                 $response->statusHeader( 403 );
 727                                 $response->header( 'Cache-Control: no-cache' );
 728                                 echo "'origin' parameter does not match Origin header\n";
 729
 730                                 return false;
 731                         }
 732
 733                         $config = $this->getConfig();
 734                         $matchOrigin = count( $origins ) === 1 && self::matchOrigin(
 735                                 $originParam,
 736                                 $config->get( 'CrossSiteAJAXdomains' ),
 737                                 $config->get( 'CrossSiteAJAXdomainExceptions' )
 738                         );
 739
 740                         $allowOrigin = $originHeader;
 741                         $allowCredentials = 'true';
 742                         $allowTiming = $originHeader;
 743                 }
 744
 745                 if ( $matchOrigin ) {
 746                         $requestedMethod = $request->getHeader( 'Access-Control-Request-Method' );
 747                         $preflight = $request->getMethod() === 'OPTIONS' && $requestedMethod !== false;
 748                         if ( $preflight ) {
 749                                 // This is a CORS preflight request
 750                                 if ( $requestedMethod !== 'POST' && $requestedMethod !== 'GET' ) {
 751                                         // If method is not a case-sensitive match, do not set any additional headers and terminate.
 752                                         return true;
 753                                 }
 754                                 // We allow the actual request to send the following headers
 755                                 $requestedHeaders = $request->getHeader( 'Access-Control-Request-Headers' );
 756                                 if ( $requestedHeaders !== false ) {
 757                                         if ( !self::matchRequestedHeaders( $requestedHeaders ) ) {
 758                                                 return true;
 759                                         }
 760                                         $response->header( 'Access-Control-Allow-Headers: ' . $requestedHeaders );
 761                                 }
 762
 763                                 // We only allow the actual request to be GET or POST
 764                                 $response->header( 'Access-Control-Allow-Methods: POST, GET' );
 765                         }
 766
 767                         $response->header( "Access-Control-Allow-Origin: $allowOrigin" );
 768                         $response->header( "Access-Control-Allow-Credentials: $allowCredentials" );
 769                         // https://www.w3.org/TR/resource-timing/#timing-allow-origin
 770                         if ( $allowTiming !== false ) {
 771                                 $response->header( "Timing-Allow-Origin: $allowTiming" );
 772                         }
 773
 774                         if ( !$preflight ) {
 775                                 $response->header(
 776                                         'Access-Control-Expose-Headers: MediaWiki-API-Error, Retry-After, X-Database-Lag'
 777                                 );
 778                         }
 779                 }
 780
 781                 if ( $varyOrigin ) {
 782                         $this->getOutput()->addVaryHeader( 'Origin' );
 783                 }
 784
 785                 return true;
 786         }
 787
 788         /**
 789          * Attempt to match an Origin header against a set of rules and a set of exceptions
 790          * @param string $value Origin header
 791          * @param array $rules Set of wildcard rules
 792          * @param array $exceptions Set of wildcard rules
 793          * @return bool True if $value matches a rule in $rules and doesn't match
 794          *    any rules in $exceptions, false otherwise
 795          */
 796         protected static function matchOrigin( $value, $rules, $exceptions ) {
 797                 foreach ( $rules as $rule ) {
 798                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 799                                 // Rule matches, check exceptions
 800                                 foreach ( $exceptions as $exc ) {
 801                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 802                                                 return false;
 803                                         }
 804                                 }
 805
 806                                 return true;
 807                         }
 808                 }
 809
 810                 return false;
 811         }
 812
 813         /**
 814          * Attempt to validate the value of Access-Control-Request-Headers against a list
 815          * of headers that we allow the follow up request to send.
 816          *
 817          * @param string $requestedHeaders Comma seperated list of HTTP headers
 818          * @return bool True if all requested headers are in the list of allowed headers
 819          */
 820         protected static function matchRequestedHeaders( $requestedHeaders ) {
 821                 if ( trim( $requestedHeaders ) === '' ) {
 822                         return true;
 823                 }
 824                 $requestedHeaders = explode( ',', $requestedHeaders );
 825                 $allowedAuthorHeaders = array_flip( [
 826                         /* simple headers (see spec) */
 827                         'accept',
 828                         'accept-language',
 829                         'content-language',
 830                         'content-type',
 831                         /* non-authorable headers in XHR, which are however requested by some UAs */
 832                         'accept-encoding',
 833                         'dnt',
 834                         'origin',
 835                         /* MediaWiki whitelist */
 836                         'api-user-agent',
 837                 ] );
 838                 foreach ( $requestedHeaders as $rHeader ) {
 839                         $rHeader = strtolower( trim( $rHeader ) );
 840                         if ( !isset( $allowedAuthorHeaders[$rHeader] ) ) {
 841                                 wfDebugLog( 'api', 'CORS preflight failed on requested header: ' . $rHeader );
 842                                 return false;
 843                         }
 844                 }
 845                 return true;
 846         }
 847
 848         /**
 849          * Helper function to convert wildcard string into a regex
 850          * '*' => '.*?'
 851          * '?' => '.'
 852          *
 853          * @param string $wildcard String with wildcards
 854          * @return string Regular expression
 855          */
 856         protected static function wildcardToRegex( $wildcard ) {
 857                 $wildcard = preg_quote( $wildcard, '/' );
 858                 $wildcard = str_replace(
 859                         [ '\*', '\?' ],
 860                         [ '.*?', '.' ],
 861                         $wildcard
 862                 );
 863
 864                 return "/^https?:\/\/$wildcard$/";
 865         }
 866
 867         /**
 868          * Send caching headers
 869          * @param bool $isError Whether an error response is being output
 870          * @since 1.26 added $isError parameter
 871          */
 872         protected function sendCacheHeaders( $isError ) {
 873                 $response = $this->getRequest()->response();
 874                 $out = $this->getOutput();
 875
 876                 $out->addVaryHeader( 'Treat-as-Untrusted' );
 877
 878                 $config = $this->getConfig();
 879
 880                 if ( $config->get( 'VaryOnXFP' ) ) {
 881                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 882                 }
 883
 884                 if ( !$isError && $this->mModule &&
 885                         ( $this->getRequest()->getMethod() === 'GET' || $this->getRequest()->getMethod() === 'HEAD' )
 886                 ) {
 887                         $etag = $this->mModule->getConditionalRequestData( 'etag' );
 888                         if ( $etag !== null ) {
 889                                 $response->header( "ETag: $etag" );
 890                         }
 891                         $lastMod = $this->mModule->getConditionalRequestData( 'last-modified' );
 892                         if ( $lastMod !== null ) {
 893                                 $response->header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $lastMod ) );
 894                         }
 895                 }
 896
 897                 // The logic should be:
 898                 // $this->mCacheControl['max-age'] is set?
 899                 //    Use it, the module knows better than our guess.
 900                 // !$this->mModule || $this->mModule->isWriteMode(), and mCacheMode is private?
 901                 //    Use 0 because we can guess caching is probably the wrong thing to do.
 902                 // Use $this->getParameter( 'maxage' ), which already defaults to 0.
 903                 $maxage = 0;
 904                 if ( isset( $this->mCacheControl['max-age'] ) ) {
 905                         $maxage = $this->mCacheControl['max-age'];
 906                 } elseif ( ( $this->mModule && !$this->mModule->isWriteMode() ) ||
 907                         $this->mCacheMode !== 'private'
 908                 ) {
 909                         $maxage = $this->getParameter( 'maxage' );
 910                 }
 911                 $privateCache = 'private, must-revalidate, max-age=' . $maxage;
 912
 913                 if ( $this->mCacheMode == 'private' ) {
 914                         $response->header( "Cache-Control: $privateCache" );
 915                         return;
 916                 }
 917
 918                 $useKeyHeader = $config->get( 'UseKeyHeader' );
 919                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 920                         $out->addVaryHeader( 'Cookie' );
 921                         $response->header( $out->getVaryHeader() );
 922                         if ( $useKeyHeader ) {
 923                                 $response->header( $out->getKeyHeader() );
 924                                 if ( $out->haveCacheVaryCookies() ) {
 925                                         // Logged in, mark this request private
 926                                         $response->header( "Cache-Control: $privateCache" );
 927                                         return;
 928                                 }
 929                                 // Logged out, send normal public headers below
 930                         } elseif ( MediaWiki\Session\SessionManager::getGlobalSession()->isPersistent() ) {
 931                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 932                                 // Mark request private
 933                                 $response->header( "Cache-Control: $privateCache" );
 934
 935                                 return;
 936                         } // else no Key and anonymous, send public headers below
 937                 }
 938
 939                 // Send public headers
 940                 $response->header( $out->getVaryHeader() );
 941                 if ( $useKeyHeader ) {
 942                         $response->header( $out->getKeyHeader() );
 943                 }
 944
 945                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 946                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 947                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 948                 }
 949                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 950                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 951                 }
 952
 953                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 954                         // Public cache not requested
 955                         // Sending a Vary header in this case is harmless, and protects us
 956                         // against conditional calls of setCacheMaxAge().
 957                         $response->header( "Cache-Control: $privateCache" );
 958
 959                         return;
 960                 }
 961
 962                 $this->mCacheControl['public'] = true;
 963
 964                 // Send an Expires header
 965                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 966                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 967                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 968
 969                 // Construct the Cache-Control header
 970                 $ccHeader = '';
 971                 $separator = '';
 972                 foreach ( $this->mCacheControl as $name => $value ) {
 973                         if ( is_bool( $value ) ) {
 974                                 if ( $value ) {
 975                                         $ccHeader .= $separator . $name;
 976                                         $separator = ', ';
 977                                 }
 978                         } else {
 979                                 $ccHeader .= $separator . "$name=$value";
 980                                 $separator = ', ';
 981                         }
 982                 }
 983
 984                 $response->header( "Cache-Control: $ccHeader" );
 985         }
 986
 987         /**
 988          * Create the printer for error output
 989          */
 990         private function createErrorPrinter() {
 991                 if ( !isset( $this->mPrinter ) ) {
 992                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 993                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
 994                                 $value = self::API_DEFAULT_FORMAT;
 995                         }
 996                         $this->mPrinter = $this->createPrinterByName( $value );
 997                 }
 998
 999                 // Printer may not be able to handle errors. This is particularly
1000                 // likely if the module returns something for getCustomPrinter().
1001                 if ( !$this->mPrinter->canPrintErrors() ) {
1002                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
1003                 }
1004         }
1005
1006         /**
1007          * Create an error message for the given exception.
1008          *
1009          * If an ApiUsageException, errors/warnings will be extracted from the
1010          * embedded StatusValue.
1011          *
1012          * If a base UsageException, the getMessageArray() method will be used to
1013          * extract the code and English message for a single error (no warnings).
1014          *
1015          * Any other exception will be returned with a generic code and wrapper
1016          * text around the exception's (presumably English) message as a single
1017          * error (no warnings).
1018          *
1019          * @param Exception $e
1020          * @param string $type 'error' or 'warning'
1021          * @return ApiMessage[]
1022          * @since 1.27
1023          */
1024         protected function errorMessagesFromException( $e, $type = 'error' ) {
1025                 $messages = [];
1026                 if ( $e instanceof ApiUsageException ) {
1027                         foreach ( $e->getStatusValue()->getErrorsByType( $type ) as $error ) {
1028                                 $messages[] = ApiMessage::create( $error );
1029                         }
1030                 } elseif ( $type !== 'error' ) {
1031                         // None of the rest have any messages for non-error types
1032                 } elseif ( $e instanceof UsageException ) {
1033                         // User entered incorrect parameters - generate error response
1034                         $data = $e->getMessageArray();
1035                         $code = $data['code'];
1036                         $info = $data['info'];
1037                         unset( $data['code'], $data['info'] );
1038                         $messages[] = new ApiRawMessage( [ '$1', $info ], $code, $data );
1039                 } else {
1040                         // Something is seriously wrong
1041                         $config = $this->getConfig();
1042                         $code = 'internal_api_error_' . get_class( $e );
1043                         if ( ( $e instanceof DBQueryError ) && !$config->get( 'ShowSQLErrors' ) ) {
1044                                 $params = [ 'apierror-databaseerror', WebRequest::getRequestId() ];
1045                         } else {
1046                                 $params = [
1047                                         'apierror-exceptioncaught',
1048                                         WebRequest::getRequestId(),
1049                                         wfEscapeWikiText( $e->getMessage() )
1050                                 ];
1051                         }
1052                         $messages[] = ApiMessage::create( $params, $code );
1053                 }
1054                 return $messages;
1055         }
1056
1057         /**
1058          * Replace the result data with the information about an exception.
1059          * @param Exception $e
1060          * @return string[] Error codes
1061          */
1062         protected function substituteResultWithError( $e ) {
1063                 $result = $this->getResult();
1064                 $formatter = $this->getErrorFormatter();
1065                 $config = $this->getConfig();
1066                 $errorCodes = [];
1067
1068                 // Remember existing warnings and errors across the reset
1069                 $errors = $result->getResultData( [ 'errors' ] );
1070                 $warnings = $result->getResultData( [ 'warnings' ] );
1071                 $result->reset();
1072                 if ( $warnings !== null ) {
1073                         $result->addValue( null, 'warnings', $warnings, ApiResult::NO_SIZE_CHECK );
1074                 }
1075                 if ( $errors !== null ) {
1076                         $result->addValue( null, 'errors', $errors, ApiResult::NO_SIZE_CHECK );
1077
1078                         // Collect the copied error codes for the return value
1079                         foreach ( $errors as $error ) {
1080                                 if ( isset( $error['code'] ) ) {
1081                                         $errorCodes[$error['code']] = true;
1082                                 }
1083                         }
1084                 }
1085
1086                 // Add errors from the exception
1087                 $modulePath = $e instanceof ApiUsageException ? $e->getModulePath() : null;
1088                 foreach ( $this->errorMessagesFromException( $e, 'error' ) as $msg ) {
1089                         $errorCodes[$msg->getApiCode()] = true;
1090                         $formatter->addError( $modulePath, $msg );
1091                 }
1092                 foreach ( $this->errorMessagesFromException( $e, 'warning' ) as $msg ) {
1093                         $formatter->addWarning( $modulePath, $msg );
1094                 }
1095
1096                 // Add additional data. Path depends on whether we're in BC mode or not.
1097                 // Data depends on the type of exception.
1098                 if ( $formatter instanceof ApiErrorFormatter_BackCompat ) {
1099                         $path = [ 'error' ];
1100                 } else {
1101                         $path = null;
1102                 }
1103                 if ( $e instanceof ApiUsageException || $e instanceof UsageException ) {
1104                         $link = wfExpandUrl( wfScript( 'api' ) );
1105                         $result->addContentValue(
1106                                 $path,
1107                                 'docref',
1108                                 $this->msg( 'api-usage-docref', $link )->inLanguage( $formatter->getLanguage() )->text()
1109                         );
1110                 } else {
1111                         if ( $config->get( 'ShowExceptionDetails' ) ) {
1112                                 $result->addContentValue(
1113                                         $path,
1114                                         'trace',
1115                                         $this->msg( 'api-exception-trace',
1116                                                 get_class( $e ),
1117                                                 $e->getFile(),
1118                                                 $e->getLine(),
1119                                                 MWExceptionHandler::getRedactedTraceAsString( $e )
1120                                         )->inLanguage( $formatter->getLanguage() )->text()
1121                                 );
1122                         }
1123                 }
1124
1125                 // Add the id and such
1126                 $this->addRequestedFields( [ 'servedby' ] );
1127
1128                 return array_keys( $errorCodes );
1129         }
1130
1131         /**
1132          * Add requested fields to the result
1133          * @param string[] $force Which fields to force even if not requested. Accepted values are:
1134          *  - servedby
1135          */
1136         protected function addRequestedFields( $force = [] ) {
1137                 $result = $this->getResult();
1138
1139                 $requestid = $this->getParameter( 'requestid' );
1140                 if ( $requestid !== null ) {
1141                         $result->addValue( null, 'requestid', $requestid, ApiResult::NO_SIZE_CHECK );
1142                 }
1143
1144                 if ( $this->getConfig()->get( 'ShowHostnames' ) && (
1145                         in_array( 'servedby', $force, true ) || $this->getParameter( 'servedby' )
1146                 ) ) {
1147                         $result->addValue( null, 'servedby', wfHostname(), ApiResult::NO_SIZE_CHECK );
1148                 }
1149
1150                 if ( $this->getParameter( 'curtimestamp' ) ) {
1151                         $result->addValue( null, 'curtimestamp', wfTimestamp( TS_ISO_8601, time() ),
1152                                 ApiResult::NO_SIZE_CHECK );
1153                 }
1154
1155                 if ( $this->getParameter( 'responselanginfo' ) ) {
1156                         $result->addValue( null, 'uselang', $this->getLanguage()->getCode(),
1157                                 ApiResult::NO_SIZE_CHECK );
1158                         $result->addValue( null, 'errorlang', $this->getErrorFormatter()->getLanguage()->getCode(),
1159                                 ApiResult::NO_SIZE_CHECK );
1160                 }
1161         }
1162
1163         /**
1164          * Set up for the execution.
1165          * @return array
1166          */
1167         protected function setupExecuteAction() {
1168                 $this->addRequestedFields();
1169
1170                 $params = $this->extractRequestParams();
1171                 $this->mAction = $params['action'];
1172
1173                 return $params;
1174         }
1175
1176         /**
1177          * Set up the module for response
1178          * @return ApiBase The module that will handle this action
1179          * @throws MWException
1180          * @throws ApiUsageException
1181          */
1182         protected function setupModule() {
1183                 // Instantiate the module requested by the user
1184                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
1185                 if ( $module === null ) {
1186                         $this->dieWithError(
1187                                 [ 'apierror-unknownaction', wfEscapeWikiText( $this->mAction ) ], 'unknown_action'
1188                         );
1189                 }
1190                 $moduleParams = $module->extractRequestParams();
1191
1192                 // Check token, if necessary
1193                 if ( $module->needsToken() === true ) {
1194                         throw new MWException(
1195                                 "Module '{$module->getModuleName()}' must be updated for the new token handling. " .
1196                                 'See documentation for ApiBase::needsToken for details.'
1197                         );
1198                 }
1199                 if ( $module->needsToken() ) {
1200                         if ( !$module->mustBePosted() ) {
1201                                 throw new MWException(
1202                                         "Module '{$module->getModuleName()}' must require POST to use tokens."
1203                                 );
1204                         }
1205
1206                         if ( !isset( $moduleParams['token'] ) ) {
1207                                 $module->dieWithError( [ 'apierror-missingparam', 'token' ] );
1208                         }
1209
1210                         $module->requirePostedParameters( [ 'token' ] );
1211
1212                         if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
1213                                 $module->dieWithError( 'apierror-badtoken' );
1214                         }
1215                 }
1216
1217                 return $module;
1218         }
1219
1220         /**
1221          * Check the max lag if necessary
1222          * @param ApiBase $module Api module being used
1223          * @param array $params Array an array containing the request parameters.
1224          * @return bool True on success, false should exit immediately
1225          */
1226         protected function checkMaxLag( $module, $params ) {
1227                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
1228                         $maxLag = $params['maxlag'];
1229                         list( $host, $lag ) = wfGetLB()->getMaxLag();
1230                         if ( $lag > $maxLag ) {
1231                                 $response = $this->getRequest()->response();
1232
1233                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
1234                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
1235
1236                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1237                                         $this->dieWithError( [ 'apierror-maxlag', $lag, $host ] );
1238                                 }
1239
1240                                 $this->dieWithError( [ 'apierror-maxlag-generic', $lag ], 'maxlag' );
1241                         }
1242                 }
1243
1244                 return true;
1245         }
1246
1247         /**
1248          * Check selected RFC 7232 precondition headers
1249          *
1250          * RFC 7232 envisions a particular model where you send your request to "a
1251          * resource", and for write requests that you can read "the resource" by
1252          * changing the method to GET. When the API receives a GET request, it
1253          * works out even though "the resource" from RFC 7232's perspective might
1254          * be many resources from MediaWiki's perspective. But it totally fails for
1255          * a POST, since what HTTP sees as "the resource" is probably just
1256          * "/api.php" with all the interesting bits in the body.
1257          *
1258          * Therefore, we only support RFC 7232 precondition headers for GET (and
1259          * HEAD). That means we don't need to bother with If-Match and
1260          * If-Unmodified-Since since they only apply to modification requests.
1261          *
1262          * And since we don't support Range, If-Range is ignored too.
1263          *
1264          * @since 1.26
1265          * @param ApiBase $module Api module being used
1266          * @return bool True on success, false should exit immediately
1267          */
1268         protected function checkConditionalRequestHeaders( $module ) {
1269                 if ( $this->mInternalMode ) {
1270                         // No headers to check in internal mode
1271                         return true;
1272                 }
1273
1274                 if ( $this->getRequest()->getMethod() !== 'GET' && $this->getRequest()->getMethod() !== 'HEAD' ) {
1275                         // Don't check POSTs
1276                         return true;
1277                 }
1278
1279                 $return304 = false;
1280
1281                 $ifNoneMatch = array_diff(
1282                         $this->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST ) ?: [],
1283                         [ '' ]
1284                 );
1285                 if ( $ifNoneMatch ) {
1286                         if ( $ifNoneMatch === [ '*' ] ) {
1287                                 // API responses always "exist"
1288                                 $etag = '*';
1289                         } else {
1290                                 $etag = $module->getConditionalRequestData( 'etag' );
1291                         }
1292                 }
1293                 if ( $ifNoneMatch && $etag !== null ) {
1294                         $test = substr( $etag, 0, 2 ) === 'W/' ? substr( $etag, 2 ) : $etag;
1295                         $match = array_map( function ( $s ) {
1296                                 return substr( $s, 0, 2 ) === 'W/' ? substr( $s, 2 ) : $s;
1297                         }, $ifNoneMatch );
1298                         $return304 = in_array( $test, $match, true );
1299                 } else {
1300                         $value = trim( $this->getRequest()->getHeader( 'If-Modified-Since' ) );
1301
1302                         // Some old browsers sends sizes after the date, like this:
1303                         //  Wed, 20 Aug 2003 06:51:19 GMT; length=5202
1304                         // Ignore that.
1305                         $i = strpos( $value, ';' );
1306                         if ( $i !== false ) {
1307                                 $value = trim( substr( $value, 0, $i ) );
1308                         }
1309
1310                         if ( $value !== '' ) {
1311                                 try {
1312                                         $ts = new MWTimestamp( $value );
1313                                         if (
1314                                                 // RFC 7231 IMF-fixdate
1315                                                 $ts->getTimestamp( TS_RFC2822 ) === $value ||
1316                                                 // RFC 850
1317                                                 $ts->format( 'l, d-M-y H:i:s' ) . ' GMT' === $value ||
1318                                                 // asctime (with and without space-padded day)
1319                                                 $ts->format( 'D M j H:i:s Y' ) === $value ||
1320                                                 $ts->format( 'D M  j H:i:s Y' ) === $value
1321                                         ) {
1322                                                 $lastMod = $module->getConditionalRequestData( 'last-modified' );
1323                                                 if ( $lastMod !== null ) {
1324                                                         // Mix in some MediaWiki modification times
1325                                                         $modifiedTimes = [
1326                                                                 'page' => $lastMod,
1327                                                                 'user' => $this->getUser()->getTouched(),
1328                                                                 'epoch' => $this->getConfig()->get( 'CacheEpoch' ),
1329                                                         ];
1330                                                         if ( $this->getConfig()->get( 'UseSquid' ) ) {
1331                                                                 // T46570: the core page itself may not change, but resources might
1332                                                                 $modifiedTimes['sepoch'] = wfTimestamp(
1333                                                                         TS_MW, time() - $this->getConfig()->get( 'SquidMaxage' )
1334                                                                 );
1335                                                         }
1336                                                         Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this->getOutput() ] );
1337                                                         $lastMod = max( $modifiedTimes );
1338                                                         $return304 = wfTimestamp( TS_MW, $lastMod ) <= $ts->getTimestamp( TS_MW );
1339                                                 }
1340                                         }
1341                                 } catch ( TimestampException $e ) {
1342                                         // Invalid timestamp, ignore it
1343                                 }
1344                         }
1345                 }
1346
1347                 if ( $return304 ) {
1348                         $this->getRequest()->response()->statusHeader( 304 );
1349
1350                         // Avoid outputting the compressed representation of a zero-length body
1351                         MediaWiki\suppressWarnings();
1352                         ini_set( 'zlib.output_compression', 0 );
1353                         MediaWiki\restoreWarnings();
1354                         wfClearOutputBuffers();
1355
1356                         return false;
1357                 }
1358
1359                 return true;
1360         }
1361
1362         /**
1363          * Check for sufficient permissions to execute
1364          * @param ApiBase $module An Api module
1365          */
1366         protected function checkExecutePermissions( $module ) {
1367                 $user = $this->getUser();
1368                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
1369                         !$user->isAllowed( 'read' )
1370                 ) {
1371                         $this->dieWithError( 'apierror-readapidenied' );
1372                 }
1373
1374                 if ( $module->isWriteMode() ) {
1375                         if ( !$this->mEnableWrite ) {
1376                                 $this->dieWithError( 'apierror-noapiwrite' );
1377                         } elseif ( !$user->isAllowed( 'writeapi' ) ) {
1378                                 $this->dieWithError( 'apierror-writeapidenied' );
1379                         } elseif ( $this->getRequest()->getHeader( 'Promise-Non-Write-API-Action' ) ) {
1380                                 $this->dieWithError( 'apierror-promised-nonwrite-api' );
1381                         }
1382
1383                         $this->checkReadOnly( $module );
1384                 }
1385
1386                 // Allow extensions to stop execution for arbitrary reasons.
1387                 $message = false;
1388                 if ( !Hooks::run( 'ApiCheckCanExecute', [ $module, $user, &$message ] ) ) {
1389                         $this->dieWithError( $message );
1390                 }
1391         }
1392
1393         /**
1394          * Check if the DB is read-only for this user
1395          * @param ApiBase $module An Api module
1396          */
1397         protected function checkReadOnly( $module ) {
1398                 if ( wfReadOnly() ) {
1399                         $this->dieReadOnly();
1400                 }
1401
1402                 if ( $module->isWriteMode()
1403                         && $this->getUser()->isBot()
1404                         && wfGetLB()->getServerCount() > 1
1405                 ) {
1406                         $this->checkBotReadOnly();
1407                 }
1408         }
1409
1410         /**
1411          * Check whether we are readonly for bots
1412          */
1413         private function checkBotReadOnly() {
1414                 // Figure out how many servers have passed the lag threshold
1415                 $numLagged = 0;
1416                 $lagLimit = $this->getConfig()->get( 'APIMaxLagThreshold' );
1417                 $laggedServers = [];
1418                 $loadBalancer = wfGetLB();
1419                 foreach ( $loadBalancer->getLagTimes() as $serverIndex => $lag ) {
1420                         if ( $lag > $lagLimit ) {
1421                                 ++$numLagged;
1422                                 $laggedServers[] = $loadBalancer->getServerName( $serverIndex ) . " ({$lag}s)";
1423                         }
1424                 }
1425
1426                 // If a majority of replica DBs are too lagged then disallow writes
1427                 $replicaCount = wfGetLB()->getServerCount() - 1;
1428                 if ( $numLagged >= ceil( $replicaCount / 2 ) ) {
1429                         $laggedServers = implode( ', ', $laggedServers );
1430                         wfDebugLog(
1431                                 'api-readonly',
1432                                 "Api request failed as read only because the following DBs are lagged: $laggedServers"
1433                         );
1434
1435                         $this->dieWithError(
1436                                 'readonly_lag',
1437                                 'readonly',
1438                                 [ 'readonlyreason' => "Waiting for $numLagged lagged database(s)" ]
1439                         );
1440                 }
1441         }
1442
1443         /**
1444          * Check asserts of the user's rights
1445          * @param array $params
1446          */
1447         protected function checkAsserts( $params ) {
1448                 if ( isset( $params['assert'] ) ) {
1449                         $user = $this->getUser();
1450                         switch ( $params['assert'] ) {
1451                                 case 'user':
1452                                         if ( $user->isAnon() ) {
1453                                                 $this->dieWithError( 'apierror-assertuserfailed' );
1454                                         }
1455                                         break;
1456                                 case 'bot':
1457                                         if ( !$user->isAllowed( 'bot' ) ) {
1458                                                 $this->dieWithError( 'apierror-assertbotfailed' );
1459                                         }
1460                                         break;
1461                         }
1462                 }
1463                 if ( isset( $params['assertuser'] ) ) {
1464                         $assertUser = User::newFromName( $params['assertuser'], false );
1465                         if ( !$assertUser || !$this->getUser()->equals( $assertUser ) ) {
1466                                 $this->dieWithError(
1467                                         [ 'apierror-assertnameduserfailed', wfEscapeWikiText( $params['assertuser'] ) ]
1468                                 );
1469                         }
1470                 }
1471         }
1472
1473         /**
1474          * Check POST for external response and setup result printer
1475          * @param ApiBase $module An Api module
1476          * @param array $params An array with the request parameters
1477          */
1478         protected function setupExternalResponse( $module, $params ) {
1479                 $request = $this->getRequest();
1480                 if ( !$request->wasPosted() && $module->mustBePosted() ) {
1481                         // Module requires POST. GET request might still be allowed
1482                         // if $wgDebugApi is true, otherwise fail.
1483                         $this->dieWithErrorOrDebug( [ 'apierror-mustbeposted', $this->mAction ] );
1484                 }
1485
1486                 // See if custom printer is used
1487                 $this->mPrinter = $module->getCustomPrinter();
1488                 if ( is_null( $this->mPrinter ) ) {
1489                         // Create an appropriate printer
1490                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
1491                 }
1492
1493                 if ( $request->getProtocol() === 'http' && (
1494                         $request->getSession()->shouldForceHTTPS() ||
1495                         ( $this->getUser()->isLoggedIn() &&
1496                                 $this->getUser()->requiresHTTPS() )
1497                 ) ) {
1498                         $this->addDeprecation( 'apiwarn-deprecation-httpsexpected', 'https-expected' );
1499                 }
1500         }
1501
1502         /**
1503          * Execute the actual module, without any error handling
1504          */
1505         protected function executeAction() {
1506                 $params = $this->setupExecuteAction();
1507                 $module = $this->setupModule();
1508                 $this->mModule = $module;
1509
1510                 if ( !$this->mInternalMode ) {
1511                         $this->setRequestExpectations( $module );
1512                 }
1513
1514                 $this->checkExecutePermissions( $module );
1515
1516                 if ( !$this->checkMaxLag( $module, $params ) ) {
1517                         return;
1518                 }
1519
1520                 if ( !$this->checkConditionalRequestHeaders( $module ) ) {
1521                         return;
1522                 }
1523
1524                 if ( !$this->mInternalMode ) {
1525                         $this->setupExternalResponse( $module, $params );
1526                 }
1527
1528                 $this->checkAsserts( $params );
1529
1530                 // Execute
1531                 $module->execute();
1532                 Hooks::run( 'APIAfterExecute', [ &$module ] );
1533
1534                 $this->reportUnusedParams();
1535
1536                 if ( !$this->mInternalMode ) {
1537                         // append Debug information
1538                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
1539
1540                         // Print result data
1541                         $this->printResult();
1542                 }
1543         }
1544
1545         /**
1546          * Set database connection, query, and write expectations given this module request
1547          * @param ApiBase $module
1548          */
1549         protected function setRequestExpectations( ApiBase $module ) {
1550                 $limits = $this->getConfig()->get( 'TrxProfilerLimits' );
1551                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1552                 $trxProfiler->setLogger( LoggerFactory::getInstance( 'DBPerformance' ) );
1553                 if ( $this->getRequest()->hasSafeMethod() ) {
1554                         $trxProfiler->setExpectations( $limits['GET'], __METHOD__ );
1555                 } elseif ( $this->getRequest()->wasPosted() && !$module->isWriteMode() ) {
1556                         $trxProfiler->setExpectations( $limits['POST-nonwrite'], __METHOD__ );
1557                         $this->getRequest()->markAsSafeRequest();
1558                 } else {
1559                         $trxProfiler->setExpectations( $limits['POST'], __METHOD__ );
1560                 }
1561         }
1562
1563         /**
1564          * Log the preceding request
1565          * @param float $time Time in seconds
1566          * @param Exception $e Exception caught while processing the request
1567          */
1568         protected function logRequest( $time, $e = null ) {
1569                 $request = $this->getRequest();
1570                 $logCtx = [
1571                         'ts' => time(),
1572                         'ip' => $request->getIP(),
1573                         'userAgent' => $this->getUserAgent(),
1574                         'wiki' => wfWikiID(),
1575                         'timeSpentBackend' => (int)round( $time * 1000 ),
1576                         'hadError' => $e !== null,
1577                         'errorCodes' => [],
1578                         'params' => [],
1579                 ];
1580
1581                 if ( $e ) {
1582                         foreach ( $this->errorMessagesFromException( $e ) as $msg ) {
1583                                 $logCtx['errorCodes'][] = $msg->getApiCode();
1584                         }
1585                 }
1586
1587                 // Construct space separated message for 'api' log channel
1588                 $msg = "API {$request->getMethod()} " .
1589                         wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
1590                         " {$logCtx['ip']} " .
1591                         "T={$logCtx['timeSpentBackend']}ms";
1592
1593                 foreach ( $this->getParamsUsed() as $name ) {
1594                         $value = $request->getVal( $name );
1595                         if ( $value === null ) {
1596                                 continue;
1597                         }
1598
1599                         if ( strlen( $value ) > 256 ) {
1600                                 $value = substr( $value, 0, 256 );
1601                                 $encValue = $this->encodeRequestLogValue( $value ) . '[...]';
1602                         } else {
1603                                 $encValue = $this->encodeRequestLogValue( $value );
1604                         }
1605
1606                         $logCtx['params'][$name] = $value;
1607                         $msg .= " {$name}={$encValue}";
1608                 }
1609
1610                 wfDebugLog( 'api', $msg, 'private' );
1611                 // ApiAction channel is for structured data consumers
1612                 wfDebugLog( 'ApiAction', '', 'private', $logCtx );
1613         }
1614
1615         /**
1616          * Encode a value in a format suitable for a space-separated log line.
1617          * @param string $s
1618          * @return string
1619          */
1620         protected function encodeRequestLogValue( $s ) {
1621                 static $table;
1622                 if ( !$table ) {
1623                         $chars = ';@$!*(),/:';
1624                         $numChars = strlen( $chars );
1625                         for ( $i = 0; $i < $numChars; $i++ ) {
1626                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
1627                         }
1628                 }
1629
1630                 return strtr( rawurlencode( $s ), $table );
1631         }
1632
1633         /**
1634          * Get the request parameters used in the course of the preceding execute() request
1635          * @return array
1636          */
1637         protected function getParamsUsed() {
1638                 return array_keys( $this->mParamsUsed );
1639         }
1640
1641         /**
1642          * Mark parameters as used
1643          * @param string|string[] $params
1644          */
1645         public function markParamsUsed( $params ) {
1646                 $this->mParamsUsed += array_fill_keys( (array)$params, true );
1647         }
1648
1649         /**
1650          * Get a request value, and register the fact that it was used, for logging.
1651          * @param string $name
1652          * @param mixed $default
1653          * @return mixed
1654          */
1655         public function getVal( $name, $default = null ) {
1656                 $this->mParamsUsed[$name] = true;
1657
1658                 $ret = $this->getRequest()->getVal( $name );
1659                 if ( $ret === null ) {
1660                         if ( $this->getRequest()->getArray( $name ) !== null ) {
1661                                 // See bug 10262 for why we don't just implode( '|', ... ) the
1662                                 // array.
1663                                 $this->addWarning( [ 'apiwarn-unsupportedarray', $name ] );
1664                         }
1665                         $ret = $default;
1666                 }
1667                 return $ret;
1668         }
1669
1670         /**
1671          * Get a boolean request value, and register the fact that the parameter
1672          * was used, for logging.
1673          * @param string $name
1674          * @return bool
1675          */
1676         public function getCheck( $name ) {
1677                 return $this->getVal( $name, null ) !== null;
1678         }
1679
1680         /**
1681          * Get a request upload, and register the fact that it was used, for logging.
1682          *
1683          * @since 1.21
1684          * @param string $name Parameter name
1685          * @return WebRequestUpload
1686          */
1687         public function getUpload( $name ) {
1688                 $this->mParamsUsed[$name] = true;
1689
1690                 return $this->getRequest()->getUpload( $name );
1691         }
1692
1693         /**
1694          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1695          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1696          */
1697         protected function reportUnusedParams() {
1698                 $paramsUsed = $this->getParamsUsed();
1699                 $allParams = $this->getRequest()->getValueNames();
1700
1701                 if ( !$this->mInternalMode ) {
1702                         // Printer has not yet executed; don't warn that its parameters are unused
1703                         $printerParams = $this->mPrinter->encodeParamName(
1704                                 array_keys( $this->mPrinter->getFinalParams() ?: [] )
1705                         );
1706                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1707                 } else {
1708                         $unusedParams = array_diff( $allParams, $paramsUsed );
1709                 }
1710
1711                 if ( count( $unusedParams ) ) {
1712                         $this->addWarning( [
1713                                 'apierror-unrecognizedparams',
1714                                 Message::listParam( array_map( 'wfEscapeWikiText', $unusedParams ), 'comma' ),
1715                                 count( $unusedParams )
1716                         ] );
1717                 }
1718         }
1719
1720         /**
1721          * Print results using the current printer
1722          *
1723          * @param int $httpCode HTTP status code, or 0 to not change
1724          */
1725         protected function printResult( $httpCode = 0 ) {
1726                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1727                         $this->addWarning( 'apiwarn-wgDebugAPI' );
1728                 }
1729
1730                 $printer = $this->mPrinter;
1731                 $printer->initPrinter( false );
1732                 if ( $httpCode ) {
1733                         $printer->setHttpStatus( $httpCode );
1734                 }
1735                 $printer->execute();
1736                 $printer->closePrinter();
1737         }
1738
1739         /**
1740          * @return bool
1741          */
1742         public function isReadMode() {
1743                 return false;
1744         }
1745
1746         /**
1747          * See ApiBase for description.
1748          *
1749          * @return array
1750          */
1751         public function getAllowedParams() {
1752                 return [
1753                         'action' => [
1754                                 ApiBase::PARAM_DFLT => 'help',
1755                                 ApiBase::PARAM_TYPE => 'submodule',
1756                         ],
1757                         'format' => [
1758                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1759                                 ApiBase::PARAM_TYPE => 'submodule',
1760                         ],
1761                         'maxlag' => [
1762                                 ApiBase::PARAM_TYPE => 'integer'
1763                         ],
1764                         'smaxage' => [
1765                                 ApiBase::PARAM_TYPE => 'integer',
1766                                 ApiBase::PARAM_DFLT => 0
1767                         ],
1768                         'maxage' => [
1769                                 ApiBase::PARAM_TYPE => 'integer',
1770                                 ApiBase::PARAM_DFLT => 0
1771                         ],
1772                         'assert' => [
1773                                 ApiBase::PARAM_TYPE => [ 'user', 'bot' ]
1774                         ],
1775                         'assertuser' => [
1776                                 ApiBase::PARAM_TYPE => 'user',
1777                         ],
1778                         'requestid' => null,
1779                         'servedby' => false,
1780                         'curtimestamp' => false,
1781                         'responselanginfo' => false,
1782                         'origin' => null,
1783                         'uselang' => [
1784                                 ApiBase::PARAM_DFLT => self::API_DEFAULT_USELANG,
1785                         ],
1786                         'errorformat' => [
1787                                 ApiBase::PARAM_TYPE => [ 'plaintext', 'wikitext', 'html', 'raw', 'none', 'bc' ],
1788                                 ApiBase::PARAM_DFLT => 'bc',
1789                         ],
1790                         'errorlang' => [
1791                                 ApiBase::PARAM_DFLT => 'uselang',
1792                         ],
1793                         'errorsuselocal' => [
1794                                 ApiBase::PARAM_DFLT => false,
1795                         ],
1796                 ];
1797         }
1798
1799         /** @see ApiBase::getExamplesMessages() */
1800         protected function getExamplesMessages() {
1801                 return [
1802                         'action=help'
1803                                 => 'apihelp-help-example-main',
1804                         'action=help&recursivesubmodules=1'
1805                                 => 'apihelp-help-example-recursive',
1806                 ];
1807         }
1808
1809         public function modifyHelp( array &$help, array $options, array &$tocData ) {
1810                 // Wish PHP had an "array_insert_before". Instead, we have to manually
1811                 // reindex the array to get 'permissions' in the right place.
1812                 $oldHelp = $help;
1813                 $help = [];
1814                 foreach ( $oldHelp as $k => $v ) {
1815                         if ( $k === 'submodules' ) {
1816                                 $help['permissions'] = '';
1817                         }
1818                         $help[$k] = $v;
1819                 }
1820                 $help['datatypes'] = '';
1821                 $help['credits'] = '';
1822
1823                 // Fill 'permissions'
1824                 $help['permissions'] .= Html::openElement( 'div',
1825                         [ 'class' => 'apihelp-block apihelp-permissions' ] );
1826                 $m = $this->msg( 'api-help-permissions' );
1827                 if ( !$m->isDisabled() ) {
1828                         $help['permissions'] .= Html::rawElement( 'div', [ 'class' => 'apihelp-block-head' ],
1829                                 $m->numParams( count( self::$mRights ) )->parse()
1830                         );
1831                 }
1832                 $help['permissions'] .= Html::openElement( 'dl' );
1833                 foreach ( self::$mRights as $right => $rightMsg ) {
1834                         $help['permissions'] .= Html::element( 'dt', null, $right );
1835
1836                         $rightMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )->parse();
1837                         $help['permissions'] .= Html::rawElement( 'dd', null, $rightMsg );
1838
1839                         $groups = array_map( function ( $group ) {
1840                                 return $group == '*' ? 'all' : $group;
1841                         }, User::getGroupsWithPermission( $right ) );
1842
1843                         $help['permissions'] .= Html::rawElement( 'dd', null,
1844                                 $this->msg( 'api-help-permissions-granted-to' )
1845                                         ->numParams( count( $groups ) )
1846                                         ->params( Message::listParam( $groups ) )
1847                                         ->parse()
1848                         );
1849                 }
1850                 $help['permissions'] .= Html::closeElement( 'dl' );
1851                 $help['permissions'] .= Html::closeElement( 'div' );
1852
1853                 // Fill 'datatypes' and 'credits', if applicable
1854                 if ( empty( $options['nolead'] ) ) {
1855                         $level = $options['headerlevel'];
1856                         $tocnumber = &$options['tocnumber'];
1857
1858                         $header = $this->msg( 'api-help-datatypes-header' )->parse();
1859
1860                         // Add an additional span with sanitized ID
1861                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1862                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/datatypes' ) ] ) .
1863                                         $header;
1864                         }
1865                         $help['datatypes'] .= Html::rawElement( 'h' . min( 6, $level ),
1866                                 [ 'id' => 'main/datatypes', 'class' => 'apihelp-header' ],
1867                                 $header
1868                         );
1869                         $help['datatypes'] .= $this->msg( 'api-help-datatypes' )->parseAsBlock();
1870                         if ( !isset( $tocData['main/datatypes'] ) ) {
1871                                 $tocnumber[$level]++;
1872                                 $tocData['main/datatypes'] = [
1873                                         'toclevel' => count( $tocnumber ),
1874                                         'level' => $level,
1875                                         'anchor' => 'main/datatypes',
1876                                         'line' => $header,
1877                                         'number' => implode( '.', $tocnumber ),
1878                                         'index' => false,
1879                                 ];
1880                         }
1881
1882                         // Add an additional span with sanitized ID
1883                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1884                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/credits' ) ] ) .
1885                                         $header;
1886                         }
1887                         $header = $this->msg( 'api-credits-header' )->parse();
1888                         $help['credits'] .= Html::rawElement( 'h' . min( 6, $level ),
1889                                 [ 'id' => 'main/credits', 'class' => 'apihelp-header' ],
1890                                 $header
1891                         );
1892                         $help['credits'] .= $this->msg( 'api-credits' )->useDatabase( false )->parseAsBlock();
1893                         if ( !isset( $tocData['main/credits'] ) ) {
1894                                 $tocnumber[$level]++;
1895                                 $tocData['main/credits'] = [
1896                                         'toclevel' => count( $tocnumber ),
1897                                         'level' => $level,
1898                                         'anchor' => 'main/credits',
1899                                         'line' => $header,
1900                                         'number' => implode( '.', $tocnumber ),
1901                                         'index' => false,
1902                                 ];
1903                         }
1904                 }
1905         }
1906
1907         private $mCanApiHighLimits = null;
1908
1909         /**
1910          * Check whether the current user is allowed to use high limits
1911          * @return bool
1912          */
1913         public function canApiHighLimits() {
1914                 if ( !isset( $this->mCanApiHighLimits ) ) {
1915                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1916                 }
1917
1918                 return $this->mCanApiHighLimits;
1919         }
1920
1921         /**
1922          * Overrides to return this instance's module manager.
1923          * @return ApiModuleManager
1924          */
1925         public function getModuleManager() {
1926                 return $this->mModuleMgr;
1927         }
1928
1929         /**
1930          * Fetches the user agent used for this request
1931          *
1932          * The value will be the combination of the 'Api-User-Agent' header (if
1933          * any) and the standard User-Agent header (if any).
1934          *
1935          * @return string
1936          */
1937         public function getUserAgent() {
1938                 return trim(
1939                         $this->getRequest()->getHeader( 'Api-user-agent' ) . ' ' .
1940                         $this->getRequest()->getHeader( 'User-agent' )
1941                 );
1942         }
1943 }
1944
1945 /**
1946  * For really cool vim folding this needs to be at the end:
1947  * vim: foldmarker=@{,@} foldmethod=marker
1948  */