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                 'validatepassword' => 'ApiValidatePassword',
  83
  84                 // Write modules
  85                 'purge' => 'ApiPurge',
  86                 'setnotificationtimestamp' => 'ApiSetNotificationTimestamp',
  87                 'rollback' => 'ApiRollback',
  88                 'delete' => 'ApiDelete',
  89                 'undelete' => 'ApiUndelete',
  90                 'protect' => 'ApiProtect',
  91                 'block' => 'ApiBlock',
  92                 'unblock' => 'ApiUnblock',
  93                 'move' => 'ApiMove',
  94                 'edit' => 'ApiEditPage',
  95                 'upload' => 'ApiUpload',
  96                 'filerevert' => 'ApiFileRevert',
  97                 'emailuser' => 'ApiEmailUser',
  98                 'watch' => 'ApiWatch',
  99                 'patrol' => 'ApiPatrol',
 100                 'import' => 'ApiImport',
 101                 'clearhasmsg' => 'ApiClearHasMsg',
 102                 'userrights' => 'ApiUserrights',
 103                 'options' => 'ApiOptions',
 104                 'imagerotate' => 'ApiImageRotate',
 105                 'revisiondelete' => 'ApiRevisionDelete',
 106                 'managetags' => 'ApiManageTags',
 107                 'tag' => 'ApiTag',
 108                 'mergehistory' => 'ApiMergeHistory',
 109         ];
 110
 111         /**
 112          * List of available formats: format name => format class
 113          */
 114         private static $Formats = [
 115                 'json' => 'ApiFormatJson',
 116                 'jsonfm' => 'ApiFormatJson',
 117                 'php' => 'ApiFormatPhp',
 118                 'phpfm' => 'ApiFormatPhp',
 119                 'xml' => 'ApiFormatXml',
 120                 'xmlfm' => 'ApiFormatXml',
 121                 'rawfm' => 'ApiFormatJson',
 122                 'none' => 'ApiFormatNone',
 123         ];
 124
 125         // @codingStandardsIgnoreStart String contenation on "msg" not allowed to break long line
 126         /**
 127          * List of user roles that are specifically relevant to the API.
 128          * [ 'right' => [ 'msg'    => 'Some message with a $1',
 129          *                'params' => [ $someVarToSubst ] ],
 130          * ];
 131          */
 132         private static $mRights = [
 133                 'writeapi' => [
 134                         'msg' => 'right-writeapi',
 135                         'params' => []
 136                 ],
 137                 'apihighlimits' => [
 138                         'msg' => 'api-help-right-apihighlimits',
 139                         'params' => [ ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 ]
 140                 ]
 141         ];
 142         // @codingStandardsIgnoreEnd
 143
 144         /**
 145          * @var ApiFormatBase
 146          */
 147         private $mPrinter;
 148
 149         private $mModuleMgr, $mResult, $mErrorFormatter = null;
 150         /** @var ApiContinuationManager|null */
 151         private $mContinuationManager;
 152         private $mAction;
 153         private $mEnableWrite;
 154         private $mInternalMode, $mSquidMaxage;
 155         /** @var ApiBase */
 156         private $mModule;
 157
 158         private $mCacheMode = 'private';
 159         private $mCacheControl = [];
 160         private $mParamsUsed = [];
 161
 162         /** @var bool|null Cached return value from self::lacksSameOriginSecurity() */
 163         private $lacksSameOriginSecurity = null;
 164
 165         /**
 166          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 167          *
 168          * @param IContextSource|WebRequest $context If this is an instance of
 169          *    FauxRequest, errors are thrown and no printing occurs
 170          * @param bool $enableWrite Should be set to true if the api may modify data
 171          */
 172         public function __construct( $context = null, $enableWrite = false ) {
 173                 if ( $context === null ) {
 174                         $context = RequestContext::getMain();
 175                 } elseif ( $context instanceof WebRequest ) {
 176                         // BC for pre-1.19
 177                         $request = $context;
 178                         $context = RequestContext::getMain();
 179                 }
 180                 // We set a derivative context so we can change stuff later
 181                 $this->setContext( new DerivativeContext( $context ) );
 182
 183                 if ( isset( $request ) ) {
 184                         $this->getContext()->setRequest( $request );
 185                 } else {
 186                         $request = $this->getRequest();
 187                 }
 188
 189                 $this->mInternalMode = ( $request instanceof FauxRequest );
 190
 191                 // Special handling for the main module: $parent === $this
 192                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 193
 194                 $config = $this->getConfig();
 195
 196                 if ( !$this->mInternalMode ) {
 197                         // Log if a request with a non-whitelisted Origin header is seen
 198                         // with session cookies.
 199                         $originHeader = $request->getHeader( 'Origin' );
 200                         if ( $originHeader === false ) {
 201                                 $origins = [];
 202                         } else {
 203                                 $originHeader = trim( $originHeader );
 204                                 $origins = preg_split( '/\s+/', $originHeader );
 205                         }
 206                         $sessionCookies = array_intersect(
 207                                 array_keys( $_COOKIE ),
 208                                 MediaWiki\Session\SessionManager::singleton()->getVaryCookies()
 209                         );
 210                         if ( $origins && $sessionCookies && (
 211                                 count( $origins ) !== 1 || !self::matchOrigin(
 212                                         $origins[0],
 213                                         $config->get( 'CrossSiteAJAXdomains' ),
 214                                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 215                                 )
 216                         ) ) {
 217                                 LoggerFactory::getInstance( 'cors' )->warning(
 218                                         'Non-whitelisted CORS request with session cookies', [
 219                                                 'origin' => $originHeader,
 220                                                 'cookies' => $sessionCookies,
 221                                                 'ip' => $request->getIP(),
 222                                                 'userAgent' => $this->getUserAgent(),
 223                                                 'wiki' => wfWikiID(),
 224                                         ]
 225                                 );
 226                         }
 227
 228                         // If we're in a mode that breaks the same-origin policy, strip
 229                         // user credentials for security.
 230                         if ( $this->lacksSameOriginSecurity() ) {
 231                                 global $wgUser;
 232                                 wfDebug( "API: stripping user credentials when the same-origin policy is not applied\n" );
 233                                 $wgUser = new User();
 234                                 $this->getContext()->setUser( $wgUser );
 235                         }
 236                 }
 237
 238                 $this->mResult = new ApiResult( $this->getConfig()->get( 'APIMaxResultSize' ) );
 239
 240                 // Setup uselang. This doesn't use $this->getParameter()
 241                 // because we're not ready to handle errors yet.
 242                 $uselang = $request->getVal( 'uselang', self::API_DEFAULT_USELANG );
 243                 if ( $uselang === 'user' ) {
 244                         // Assume the parent context is going to return the user language
 245                         // for uselang=user (see T85635).
 246                 } else {
 247                         if ( $uselang === 'content' ) {
 248                                 global $wgContLang;
 249                                 $uselang = $wgContLang->getCode();
 250                         }
 251                         $code = RequestContext::sanitizeLangCode( $uselang );
 252                         $this->getContext()->setLanguage( $code );
 253                         if ( !$this->mInternalMode ) {
 254                                 global $wgLang;
 255                                 $wgLang = $this->getContext()->getLanguage();
 256                                 RequestContext::getMain()->setLanguage( $wgLang );
 257                         }
 258                 }
 259
 260                 // Set up the error formatter. This doesn't use $this->getParameter()
 261                 // because we're not ready to handle errors yet.
 262                 $errorFormat = $request->getVal( 'errorformat', 'bc' );
 263                 $errorLangCode = $request->getVal( 'errorlang', 'uselang' );
 264                 $errorsUseDB = $request->getCheck( 'errorsuselocal' );
 265                 if ( in_array( $errorFormat, [ 'plaintext', 'wikitext', 'html', 'raw', 'none' ], true ) ) {
 266                         if ( $errorLangCode === 'uselang' ) {
 267                                 $errorLang = $this->getLanguage();
 268                         } elseif ( $errorLangCode === 'content' ) {
 269                                 global $wgContLang;
 270                                 $errorLang = $wgContLang;
 271                         } else {
 272                                 $errorLangCode = RequestContext::sanitizeLangCode( $errorLangCode );
 273                                 $errorLang = Language::factory( $errorLangCode );
 274                         }
 275                         $this->mErrorFormatter = new ApiErrorFormatter(
 276                                 $this->mResult, $errorLang, $errorFormat, $errorsUseDB
 277                         );
 278                 } else {
 279                         $this->mErrorFormatter = new ApiErrorFormatter_BackCompat( $this->mResult );
 280                 }
 281                 $this->mResult->setErrorFormatter( $this->getErrorFormatter() );
 282
 283                 $this->mModuleMgr = new ApiModuleManager( $this );
 284                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 285                 $this->mModuleMgr->addModules( $config->get( 'APIModules' ), 'action' );
 286                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 287                 $this->mModuleMgr->addModules( $config->get( 'APIFormatModules' ), 'format' );
 288
 289                 Hooks::run( 'ApiMain::moduleManager', [ $this->mModuleMgr ] );
 290
 291                 $this->mContinuationManager = null;
 292                 $this->mEnableWrite = $enableWrite;
 293
 294                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 295                 $this->mCommit = false;
 296         }
 297
 298         /**
 299          * Return true if the API was started by other PHP code using FauxRequest
 300          * @return bool
 301          */
 302         public function isInternalMode() {
 303                 return $this->mInternalMode;
 304         }
 305
 306         /**
 307          * Get the ApiResult object associated with current request
 308          *
 309          * @return ApiResult
 310          */
 311         public function getResult() {
 312                 return $this->mResult;
 313         }
 314
 315         /**
 316          * Get the security flag for the current request
 317          * @return bool
 318          */
 319         public function lacksSameOriginSecurity() {
 320                 if ( $this->lacksSameOriginSecurity !== null ) {
 321                         return $this->lacksSameOriginSecurity;
 322                 }
 323
 324                 $request = $this->getRequest();
 325
 326                 // JSONP mode
 327                 if ( $request->getVal( 'callback' ) !== null ) {
 328                         $this->lacksSameOriginSecurity = true;
 329                         return true;
 330                 }
 331
 332                 // Anonymous CORS
 333                 if ( $request->getVal( 'origin' ) === '*' ) {
 334                         $this->lacksSameOriginSecurity = true;
 335                         return true;
 336                 }
 337
 338                 // Header to be used from XMLHTTPRequest when the request might
 339                 // otherwise be used for XSS.
 340                 if ( $request->getHeader( 'Treat-as-Untrusted' ) !== false ) {
 341                         $this->lacksSameOriginSecurity = true;
 342                         return true;
 343                 }
 344
 345                 // Allow extensions to override.
 346                 $this->lacksSameOriginSecurity = !Hooks::run( 'RequestHasSameOriginSecurity', [ $request ] );
 347                 return $this->lacksSameOriginSecurity;
 348         }
 349
 350         /**
 351          * Get the ApiErrorFormatter object associated with current request
 352          * @return ApiErrorFormatter
 353          */
 354         public function getErrorFormatter() {
 355                 return $this->mErrorFormatter;
 356         }
 357
 358         /**
 359          * Get the continuation manager
 360          * @return ApiContinuationManager|null
 361          */
 362         public function getContinuationManager() {
 363                 return $this->mContinuationManager;
 364         }
 365
 366         /**
 367          * Set the continuation manager
 368          * @param ApiContinuationManager|null
 369          */
 370         public function setContinuationManager( $manager ) {
 371                 if ( $manager !== null ) {
 372                         if ( !$manager instanceof ApiContinuationManager ) {
 373                                 throw new InvalidArgumentException( __METHOD__ . ': Was passed ' .
 374                                         is_object( $manager ) ? get_class( $manager ) : gettype( $manager )
 375                                 );
 376                         }
 377                         if ( $this->mContinuationManager !== null ) {
 378                                 throw new UnexpectedValueException(
 379                                         __METHOD__ . ': tried to set manager from ' . $manager->getSource() .
 380                                         ' when a manager is already set from ' . $this->mContinuationManager->getSource()
 381                                 );
 382                         }
 383                 }
 384                 $this->mContinuationManager = $manager;
 385         }
 386
 387         /**
 388          * Get the API module object. Only works after executeAction()
 389          *
 390          * @return ApiBase
 391          */
 392         public function getModule() {
 393                 return $this->mModule;
 394         }
 395
 396         /**
 397          * Get the result formatter object. Only works after setupExecuteAction()
 398          *
 399          * @return ApiFormatBase
 400          */
 401         public function getPrinter() {
 402                 return $this->mPrinter;
 403         }
 404
 405         /**
 406          * Set how long the response should be cached.
 407          *
 408          * @param int $maxage
 409          */
 410         public function setCacheMaxAge( $maxage ) {
 411                 $this->setCacheControl( [
 412                         'max-age' => $maxage,
 413                         's-maxage' => $maxage
 414                 ] );
 415         }
 416
 417         /**
 418          * Set the type of caching headers which will be sent.
 419          *
 420          * @param string $mode One of:
 421          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 422          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 423          *         not provided by any of these means, the object will be private.
 424          *    - 'private':    Cache this object only in private client-side caches.
 425          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 426          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 427          *         set consistently for a given URL, it cannot be set differently depending on
 428          *         things like the contents of the database, or whether the user is logged in.
 429          *
 430          *  If the wiki does not allow anonymous users to read it, the mode set here
 431          *  will be ignored, and private caching headers will always be sent. In other words,
 432          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 433          *  view.
 434          *
 435          *  For user-dependent data, the private mode should generally be used. The
 436          *  anon-public-user-private mode should only be used where there is a particularly
 437          *  good performance reason for caching the anonymous response, but where the
 438          *  response to logged-in users may differ, or may contain private data.
 439          *
 440          *  If this function is never called, then the default will be the private mode.
 441          */
 442         public function setCacheMode( $mode ) {
 443                 if ( !in_array( $mode, [ 'private', 'public', 'anon-public-user-private' ] ) ) {
 444                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 445
 446                         // Ignore for forwards-compatibility
 447                         return;
 448                 }
 449
 450                 if ( !User::isEveryoneAllowed( 'read' ) ) {
 451                         // Private wiki, only private headers
 452                         if ( $mode !== 'private' ) {
 453                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 454
 455                                 return;
 456                         }
 457                 }
 458
 459                 if ( $mode === 'public' && $this->getParameter( 'uselang' ) === 'user' ) {
 460                         // User language is used for i18n, so we don't want to publicly
 461                         // cache. Anons are ok, because if they have non-default language
 462                         // then there's an appropriate Vary header set by whatever set
 463                         // their non-default language.
 464                         wfDebug( __METHOD__ . ": downgrading cache mode 'public' to " .
 465                                 "'anon-public-user-private' due to uselang=user\n" );
 466                         $mode = 'anon-public-user-private';
 467                 }
 468
 469                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 470                 $this->mCacheMode = $mode;
 471         }
 472
 473         /**
 474          * Set directives (key/value pairs) for the Cache-Control header.
 475          * Boolean values will be formatted as such, by including or omitting
 476          * without an equals sign.
 477          *
 478          * Cache control values set here will only be used if the cache mode is not
 479          * private, see setCacheMode().
 480          *
 481          * @param array $directives
 482          */
 483         public function setCacheControl( $directives ) {
 484                 $this->mCacheControl = $directives + $this->mCacheControl;
 485         }
 486
 487         /**
 488          * Create an instance of an output formatter by its name
 489          *
 490          * @param string $format
 491          *
 492          * @return ApiFormatBase
 493          */
 494         public function createPrinterByName( $format ) {
 495                 $printer = $this->mModuleMgr->getModule( $format, 'format' );
 496                 if ( $printer === null ) {
 497                         $this->dieWithError(
 498                                 [ 'apierror-unknownformat', wfEscapeWikiText( $format ) ], 'unknown_format'
 499                         );
 500                 }
 501
 502                 return $printer;
 503         }
 504
 505         /**
 506          * Execute api request. Any errors will be handled if the API was called by the remote client.
 507          */
 508         public function execute() {
 509                 if ( $this->mInternalMode ) {
 510                         $this->executeAction();
 511                 } else {
 512                         $this->executeActionWithErrorHandling();
 513                 }
 514         }
 515
 516         /**
 517          * Execute an action, and in case of an error, erase whatever partial results
 518          * have been accumulated, and replace it with an error message and a help screen.
 519          */
 520         protected function executeActionWithErrorHandling() {
 521                 // Verify the CORS header before executing the action
 522                 if ( !$this->handleCORS() ) {
 523                         // handleCORS() has sent a 403, abort
 524                         return;
 525                 }
 526
 527                 // Exit here if the request method was OPTIONS
 528                 // (assume there will be a followup GET or POST)
 529                 if ( $this->getRequest()->getMethod() === 'OPTIONS' ) {
 530                         return;
 531                 }
 532
 533                 // In case an error occurs during data output,
 534                 // clear the output buffer and print just the error information
 535                 $obLevel = ob_get_level();
 536                 ob_start();
 537
 538                 $t = microtime( true );
 539                 $isError = false;
 540                 try {
 541                         $this->executeAction();
 542                         $runTime = microtime( true ) - $t;
 543                         $this->logRequest( $runTime );
 544                         if ( $this->mModule->isWriteMode() && $this->getRequest()->wasPosted() ) {
 545                                 $this->getStats()->timing(
 546                                         'api.' . $this->mModule->getModuleName() . '.executeTiming', 1000 * $runTime
 547                                 );
 548                         }
 549                 } catch ( Exception $e ) {
 550                         $this->handleException( $e );
 551                         $this->logRequest( microtime( true ) - $t, $e );
 552                         $isError = true;
 553                 }
 554
 555                 // Commit DBs and send any related cookies and headers
 556                 MediaWiki::preOutputCommit( $this->getContext() );
 557
 558                 // Send cache headers after any code which might generate an error, to
 559                 // avoid sending public cache headers for errors.
 560                 $this->sendCacheHeaders( $isError );
 561
 562                 // Executing the action might have already messed with the output
 563                 // buffers.
 564                 while ( ob_get_level() > $obLevel ) {
 565                         ob_end_flush();
 566                 }
 567         }
 568
 569         /**
 570          * Handle an exception as an API response
 571          *
 572          * @since 1.23
 573          * @param Exception $e
 574          */
 575         protected function handleException( Exception $e ) {
 576                 // Bug 63145: Rollback any open database transactions
 577                 if ( !( $e instanceof ApiUsageException || $e instanceof UsageException ) ) {
 578                         // UsageExceptions are intentional, so don't rollback if that's the case
 579                         try {
 580                                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 581                         } catch ( DBError $e2 ) {
 582                                 // Rollback threw an exception too. Log it, but don't interrupt
 583                                 // our regularly scheduled exception handling.
 584                                 MWExceptionHandler::logException( $e2 );
 585                         }
 586                 }
 587
 588                 // Allow extra cleanup and logging
 589                 Hooks::run( 'ApiMain::onException', [ $this, $e ] );
 590
 591                 // Log it
 592                 if ( !( $e instanceof ApiUsageException || $e instanceof UsageException ) ) {
 593                         MWExceptionHandler::logException( $e );
 594                 }
 595
 596                 // Handle any kind of exception by outputting properly formatted error message.
 597                 // If this fails, an unhandled exception should be thrown so that global error
 598                 // handler will process and log it.
 599
 600                 $errCodes = $this->substituteResultWithError( $e );
 601
 602                 // Error results should not be cached
 603                 $this->setCacheMode( 'private' );
 604
 605                 $response = $this->getRequest()->response();
 606                 $headerStr = 'MediaWiki-API-Error: ' . join( ', ', $errCodes );
 607                 $response->header( $headerStr );
 608
 609                 // Reset and print just the error message
 610                 ob_clean();
 611
 612                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 613                 $this->createErrorPrinter();
 614
 615                 $failed = false;
 616                 try {
 617                         $this->printResult( $e->getCode() );
 618                 } catch ( ApiUsageException $ex ) {
 619                         // The error printer itself is failing. Try suppressing its request
 620                         // parameters and redo.
 621                         $failed = true;
 622                         $this->addWarning( 'apiwarn-errorprinterfailed' );
 623                         foreach ( $ex->getStatusValue()->getErrors() as $error ) {
 624                                 try {
 625                                         $this->mPrinter->addWarning( $error );
 626                                 } catch ( Exception $ex2 ) {
 627                                         // WTF?
 628                                         $this->addWarning( $error );
 629                                 }
 630                         }
 631                 } catch ( UsageException $ex ) {
 632                         // The error printer itself is failing. Try suppressing its request
 633                         // parameters and redo.
 634                         $failed = true;
 635                         $this->addWarning(
 636                                 [ 'apiwarn-errorprinterfailed-ex', $ex->getMessage() ], 'errorprinterfailed'
 637                         );
 638                 }
 639                 if ( $failed ) {
 640                         $this->mPrinter = null;
 641                         $this->createErrorPrinter();
 642                         $this->mPrinter->forceDefaultParams();
 643                         if ( $e->getCode() ) {
 644                                 $response->statusHeader( 200 ); // Reset in case the fallback doesn't want a non-200
 645                         }
 646                         $this->printResult( $e->getCode() );
 647                 }
 648         }
 649
 650         /**
 651          * Handle an exception from the ApiBeforeMain hook.
 652          *
 653          * This tries to print the exception as an API response, to be more
 654          * friendly to clients. If it fails, it will rethrow the exception.
 655          *
 656          * @since 1.23
 657          * @param Exception $e
 658          * @throws Exception
 659          */
 660         public static function handleApiBeforeMainException( Exception $e ) {
 661                 ob_start();
 662
 663                 try {
 664                         $main = new self( RequestContext::getMain(), false );
 665                         $main->handleException( $e );
 666                         $main->logRequest( 0, $e );
 667                 } catch ( Exception $e2 ) {
 668                         // Nope, even that didn't work. Punt.
 669                         throw $e;
 670                 }
 671
 672                 // Reset cache headers
 673                 $main->sendCacheHeaders( true );
 674
 675                 ob_end_flush();
 676         }
 677
 678         /**
 679          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 680          *
 681          * If no origin parameter is present, nothing happens.
 682          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 683          * is set and false is returned.
 684          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 685          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 686          * headers are set.
 687          * https://www.w3.org/TR/cors/#resource-requests
 688          * https://www.w3.org/TR/cors/#resource-preflight-requests
 689          *
 690          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 691          */
 692         protected function handleCORS() {
 693                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 694                 if ( $originParam === null ) {
 695                         // No origin parameter, nothing to do
 696                         return true;
 697                 }
 698
 699                 $request = $this->getRequest();
 700                 $response = $request->response();
 701
 702                 $matchOrigin = false;
 703                 $allowTiming = false;
 704                 $varyOrigin = true;
 705
 706                 if ( $originParam === '*' ) {
 707                         // Request for anonymous CORS
 708                         $matchOrigin = true;
 709                         $allowOrigin = '*';
 710                         $allowCredentials = 'false';
 711                         $varyOrigin = false; // No need to vary
 712                 } else {
 713                         // Non-anonymous CORS, check we allow the domain
 714
 715                         // Origin: header is a space-separated list of origins, check all of them
 716                         $originHeader = $request->getHeader( 'Origin' );
 717                         if ( $originHeader === false ) {
 718                                 $origins = [];
 719                         } else {
 720                                 $originHeader = trim( $originHeader );
 721                                 $origins = preg_split( '/\s+/', $originHeader );
 722                         }
 723
 724                         if ( !in_array( $originParam, $origins ) ) {
 725                                 // origin parameter set but incorrect
 726                                 // Send a 403 response
 727                                 $response->statusHeader( 403 );
 728                                 $response->header( 'Cache-Control: no-cache' );
 729                                 echo "'origin' parameter does not match Origin header\n";
 730
 731                                 return false;
 732                         }
 733
 734                         $config = $this->getConfig();
 735                         $matchOrigin = count( $origins ) === 1 && self::matchOrigin(
 736                                 $originParam,
 737                                 $config->get( 'CrossSiteAJAXdomains' ),
 738                                 $config->get( 'CrossSiteAJAXdomainExceptions' )
 739                         );
 740
 741                         $allowOrigin = $originHeader;
 742                         $allowCredentials = 'true';
 743                         $allowTiming = $originHeader;
 744                 }
 745
 746                 if ( $matchOrigin ) {
 747                         $requestedMethod = $request->getHeader( 'Access-Control-Request-Method' );
 748                         $preflight = $request->getMethod() === 'OPTIONS' && $requestedMethod !== false;
 749                         if ( $preflight ) {
 750                                 // This is a CORS preflight request
 751                                 if ( $requestedMethod !== 'POST' && $requestedMethod !== 'GET' ) {
 752                                         // If method is not a case-sensitive match, do not set any additional headers and terminate.
 753                                         return true;
 754                                 }
 755                                 // We allow the actual request to send the following headers
 756                                 $requestedHeaders = $request->getHeader( 'Access-Control-Request-Headers' );
 757                                 if ( $requestedHeaders !== false ) {
 758                                         if ( !self::matchRequestedHeaders( $requestedHeaders ) ) {
 759                                                 return true;
 760                                         }
 761                                         $response->header( 'Access-Control-Allow-Headers: ' . $requestedHeaders );
 762                                 }
 763
 764                                 // We only allow the actual request to be GET or POST
 765                                 $response->header( 'Access-Control-Allow-Methods: POST, GET' );
 766                         }
 767
 768                         $response->header( "Access-Control-Allow-Origin: $allowOrigin" );
 769                         $response->header( "Access-Control-Allow-Credentials: $allowCredentials" );
 770                         // https://www.w3.org/TR/resource-timing/#timing-allow-origin
 771                         if ( $allowTiming !== false ) {
 772                                 $response->header( "Timing-Allow-Origin: $allowTiming" );
 773                         }
 774
 775                         if ( !$preflight ) {
 776                                 $response->header(
 777                                         'Access-Control-Expose-Headers: MediaWiki-API-Error, Retry-After, X-Database-Lag'
 778                                 );
 779                         }
 780                 }
 781
 782                 if ( $varyOrigin ) {
 783                         $this->getOutput()->addVaryHeader( 'Origin' );
 784                 }
 785
 786                 return true;
 787         }
 788
 789         /**
 790          * Attempt to match an Origin header against a set of rules and a set of exceptions
 791          * @param string $value Origin header
 792          * @param array $rules Set of wildcard rules
 793          * @param array $exceptions Set of wildcard rules
 794          * @return bool True if $value matches a rule in $rules and doesn't match
 795          *    any rules in $exceptions, false otherwise
 796          */
 797         protected static function matchOrigin( $value, $rules, $exceptions ) {
 798                 foreach ( $rules as $rule ) {
 799                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 800                                 // Rule matches, check exceptions
 801                                 foreach ( $exceptions as $exc ) {
 802                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 803                                                 return false;
 804                                         }
 805                                 }
 806
 807                                 return true;
 808                         }
 809                 }
 810
 811                 return false;
 812         }
 813
 814         /**
 815          * Attempt to validate the value of Access-Control-Request-Headers against a list
 816          * of headers that we allow the follow up request to send.
 817          *
 818          * @param string $requestedHeaders Comma seperated list of HTTP headers
 819          * @return bool True if all requested headers are in the list of allowed headers
 820          */
 821         protected static function matchRequestedHeaders( $requestedHeaders ) {
 822                 if ( trim( $requestedHeaders ) === '' ) {
 823                         return true;
 824                 }
 825                 $requestedHeaders = explode( ',', $requestedHeaders );
 826                 $allowedAuthorHeaders = array_flip( [
 827                         /* simple headers (see spec) */
 828                         'accept',
 829                         'accept-language',
 830                         'content-language',
 831                         'content-type',
 832                         /* non-authorable headers in XHR, which are however requested by some UAs */
 833                         'accept-encoding',
 834                         'dnt',
 835                         'origin',
 836                         /* MediaWiki whitelist */
 837                         'api-user-agent',
 838                 ] );
 839                 foreach ( $requestedHeaders as $rHeader ) {
 840                         $rHeader = strtolower( trim( $rHeader ) );
 841                         if ( !isset( $allowedAuthorHeaders[$rHeader] ) ) {
 842                                 wfDebugLog( 'api', 'CORS preflight failed on requested header: ' . $rHeader );
 843                                 return false;
 844                         }
 845                 }
 846                 return true;
 847         }
 848
 849         /**
 850          * Helper function to convert wildcard string into a regex
 851          * '*' => '.*?'
 852          * '?' => '.'
 853          *
 854          * @param string $wildcard String with wildcards
 855          * @return string Regular expression
 856          */
 857         protected static function wildcardToRegex( $wildcard ) {
 858                 $wildcard = preg_quote( $wildcard, '/' );
 859                 $wildcard = str_replace(
 860                         [ '\*', '\?' ],
 861                         [ '.*?', '.' ],
 862                         $wildcard
 863                 );
 864
 865                 return "/^https?:\/\/$wildcard$/";
 866         }
 867
 868         /**
 869          * Send caching headers
 870          * @param bool $isError Whether an error response is being output
 871          * @since 1.26 added $isError parameter
 872          */
 873         protected function sendCacheHeaders( $isError ) {
 874                 $response = $this->getRequest()->response();
 875                 $out = $this->getOutput();
 876
 877                 $out->addVaryHeader( 'Treat-as-Untrusted' );
 878
 879                 $config = $this->getConfig();
 880
 881                 if ( $config->get( 'VaryOnXFP' ) ) {
 882                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 883                 }
 884
 885                 if ( !$isError && $this->mModule &&
 886                         ( $this->getRequest()->getMethod() === 'GET' || $this->getRequest()->getMethod() === 'HEAD' )
 887                 ) {
 888                         $etag = $this->mModule->getConditionalRequestData( 'etag' );
 889                         if ( $etag !== null ) {
 890                                 $response->header( "ETag: $etag" );
 891                         }
 892                         $lastMod = $this->mModule->getConditionalRequestData( 'last-modified' );
 893                         if ( $lastMod !== null ) {
 894                                 $response->header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $lastMod ) );
 895                         }
 896                 }
 897
 898                 // The logic should be:
 899                 // $this->mCacheControl['max-age'] is set?
 900                 //    Use it, the module knows better than our guess.
 901                 // !$this->mModule || $this->mModule->isWriteMode(), and mCacheMode is private?
 902                 //    Use 0 because we can guess caching is probably the wrong thing to do.
 903                 // Use $this->getParameter( 'maxage' ), which already defaults to 0.
 904                 $maxage = 0;
 905                 if ( isset( $this->mCacheControl['max-age'] ) ) {
 906                         $maxage = $this->mCacheControl['max-age'];
 907                 } elseif ( ( $this->mModule && !$this->mModule->isWriteMode() ) ||
 908                         $this->mCacheMode !== 'private'
 909                 ) {
 910                         $maxage = $this->getParameter( 'maxage' );
 911                 }
 912                 $privateCache = 'private, must-revalidate, max-age=' . $maxage;
 913
 914                 if ( $this->mCacheMode == 'private' ) {
 915                         $response->header( "Cache-Control: $privateCache" );
 916                         return;
 917                 }
 918
 919                 $useKeyHeader = $config->get( 'UseKeyHeader' );
 920                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 921                         $out->addVaryHeader( 'Cookie' );
 922                         $response->header( $out->getVaryHeader() );
 923                         if ( $useKeyHeader ) {
 924                                 $response->header( $out->getKeyHeader() );
 925                                 if ( $out->haveCacheVaryCookies() ) {
 926                                         // Logged in, mark this request private
 927                                         $response->header( "Cache-Control: $privateCache" );
 928                                         return;
 929                                 }
 930                                 // Logged out, send normal public headers below
 931                         } elseif ( MediaWiki\Session\SessionManager::getGlobalSession()->isPersistent() ) {
 932                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 933                                 // Mark request private
 934                                 $response->header( "Cache-Control: $privateCache" );
 935
 936                                 return;
 937                         } // else no Key and anonymous, send public headers below
 938                 }
 939
 940                 // Send public headers
 941                 $response->header( $out->getVaryHeader() );
 942                 if ( $useKeyHeader ) {
 943                         $response->header( $out->getKeyHeader() );
 944                 }
 945
 946                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 947                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 948                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 949                 }
 950                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 951                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 952                 }
 953
 954                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 955                         // Public cache not requested
 956                         // Sending a Vary header in this case is harmless, and protects us
 957                         // against conditional calls of setCacheMaxAge().
 958                         $response->header( "Cache-Control: $privateCache" );
 959
 960                         return;
 961                 }
 962
 963                 $this->mCacheControl['public'] = true;
 964
 965                 // Send an Expires header
 966                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 967                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 968                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 969
 970                 // Construct the Cache-Control header
 971                 $ccHeader = '';
 972                 $separator = '';
 973                 foreach ( $this->mCacheControl as $name => $value ) {
 974                         if ( is_bool( $value ) ) {
 975                                 if ( $value ) {
 976                                         $ccHeader .= $separator . $name;
 977                                         $separator = ', ';
 978                                 }
 979                         } else {
 980                                 $ccHeader .= $separator . "$name=$value";
 981                                 $separator = ', ';
 982                         }
 983                 }
 984
 985                 $response->header( "Cache-Control: $ccHeader" );
 986         }
 987
 988         /**
 989          * Create the printer for error output
 990          */
 991         private function createErrorPrinter() {
 992                 if ( !isset( $this->mPrinter ) ) {
 993                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 994                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
 995                                 $value = self::API_DEFAULT_FORMAT;
 996                         }
 997                         $this->mPrinter = $this->createPrinterByName( $value );
 998                 }
 999
1000                 // Printer may not be able to handle errors. This is particularly
1001                 // likely if the module returns something for getCustomPrinter().
1002                 if ( !$this->mPrinter->canPrintErrors() ) {
1003                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
1004                 }
1005         }
1006
1007         /**
1008          * Create an error message for the given exception.
1009          *
1010          * If an ApiUsageException, errors/warnings will be extracted from the
1011          * embedded StatusValue.
1012          *
1013          * If a base UsageException, the getMessageArray() method will be used to
1014          * extract the code and English message for a single error (no warnings).
1015          *
1016          * Any other exception will be returned with a generic code and wrapper
1017          * text around the exception's (presumably English) message as a single
1018          * error (no warnings).
1019          *
1020          * @param Exception $e
1021          * @param string $type 'error' or 'warning'
1022          * @return ApiMessage[]
1023          * @since 1.27
1024          */
1025         protected function errorMessagesFromException( $e, $type = 'error' ) {
1026                 $messages = [];
1027                 if ( $e instanceof ApiUsageException ) {
1028                         foreach ( $e->getStatusValue()->getErrorsByType( $type ) as $error ) {
1029                                 $messages[] = ApiMessage::create( $error );
1030                         }
1031                 } elseif ( $type !== 'error' ) {
1032                         // None of the rest have any messages for non-error types
1033                 } elseif ( $e instanceof UsageException ) {
1034                         // User entered incorrect parameters - generate error response
1035                         $data = $e->getMessageArray();
1036                         $code = $data['code'];
1037                         $info = $data['info'];
1038                         unset( $data['code'], $data['info'] );
1039                         $messages[] = new ApiRawMessage( [ '$1', $info ], $code, $data );
1040                 } else {
1041                         // Something is seriously wrong
1042                         $config = $this->getConfig();
1043                         $code = 'internal_api_error_' . get_class( $e );
1044                         if ( ( $e instanceof DBQueryError ) && !$config->get( 'ShowSQLErrors' ) ) {
1045                                 $params = [ 'apierror-databaseerror', WebRequest::getRequestId() ];
1046                         } else {
1047                                 $params = [
1048                                         'apierror-exceptioncaught',
1049                                         WebRequest::getRequestId(),
1050                                         $e instanceof ILocalizedException
1051                                                 ? $e->getMessageObject()
1052                                                 : wfEscapeWikiText( $e->getMessage() )
1053                                 ];
1054                         }
1055                         $messages[] = ApiMessage::create( $params, $code );
1056                 }
1057                 return $messages;
1058         }
1059
1060         /**
1061          * Replace the result data with the information about an exception.
1062          * @param Exception $e
1063          * @return string[] Error codes
1064          */
1065         protected function substituteResultWithError( $e ) {
1066                 $result = $this->getResult();
1067                 $formatter = $this->getErrorFormatter();
1068                 $config = $this->getConfig();
1069                 $errorCodes = [];
1070
1071                 // Remember existing warnings and errors across the reset
1072                 $errors = $result->getResultData( [ 'errors' ] );
1073                 $warnings = $result->getResultData( [ 'warnings' ] );
1074                 $result->reset();
1075                 if ( $warnings !== null ) {
1076                         $result->addValue( null, 'warnings', $warnings, ApiResult::NO_SIZE_CHECK );
1077                 }
1078                 if ( $errors !== null ) {
1079                         $result->addValue( null, 'errors', $errors, ApiResult::NO_SIZE_CHECK );
1080
1081                         // Collect the copied error codes for the return value
1082                         foreach ( $errors as $error ) {
1083                                 if ( isset( $error['code'] ) ) {
1084                                         $errorCodes[$error['code']] = true;
1085                                 }
1086                         }
1087                 }
1088
1089                 // Add errors from the exception
1090                 $modulePath = $e instanceof ApiUsageException ? $e->getModulePath() : null;
1091                 foreach ( $this->errorMessagesFromException( $e, 'error' ) as $msg ) {
1092                         $errorCodes[$msg->getApiCode()] = true;
1093                         $formatter->addError( $modulePath, $msg );
1094                 }
1095                 foreach ( $this->errorMessagesFromException( $e, 'warning' ) as $msg ) {
1096                         $formatter->addWarning( $modulePath, $msg );
1097                 }
1098
1099                 // Add additional data. Path depends on whether we're in BC mode or not.
1100                 // Data depends on the type of exception.
1101                 if ( $formatter instanceof ApiErrorFormatter_BackCompat ) {
1102                         $path = [ 'error' ];
1103                 } else {
1104                         $path = null;
1105                 }
1106                 if ( $e instanceof ApiUsageException || $e instanceof UsageException ) {
1107                         $link = wfExpandUrl( wfScript( 'api' ) );
1108                         $result->addContentValue(
1109                                 $path,
1110                                 'docref',
1111                                 $this->msg( 'api-usage-docref', $link )->inLanguage( $formatter->getLanguage() )->text()
1112                         );
1113                 } else {
1114                         if ( $config->get( 'ShowExceptionDetails' ) ) {
1115                                 $result->addContentValue(
1116                                         $path,
1117                                         'trace',
1118                                         $this->msg( 'api-exception-trace',
1119                                                 get_class( $e ),
1120                                                 $e->getFile(),
1121                                                 $e->getLine(),
1122                                                 MWExceptionHandler::getRedactedTraceAsString( $e )
1123                                         )->inLanguage( $formatter->getLanguage() )->text()
1124                                 );
1125                         }
1126                 }
1127
1128                 // Add the id and such
1129                 $this->addRequestedFields( [ 'servedby' ] );
1130
1131                 return array_keys( $errorCodes );
1132         }
1133
1134         /**
1135          * Add requested fields to the result
1136          * @param string[] $force Which fields to force even if not requested. Accepted values are:
1137          *  - servedby
1138          */
1139         protected function addRequestedFields( $force = [] ) {
1140                 $result = $this->getResult();
1141
1142                 $requestid = $this->getParameter( 'requestid' );
1143                 if ( $requestid !== null ) {
1144                         $result->addValue( null, 'requestid', $requestid, ApiResult::NO_SIZE_CHECK );
1145                 }
1146
1147                 if ( $this->getConfig()->get( 'ShowHostnames' ) && (
1148                         in_array( 'servedby', $force, true ) || $this->getParameter( 'servedby' )
1149                 ) ) {
1150                         $result->addValue( null, 'servedby', wfHostname(), ApiResult::NO_SIZE_CHECK );
1151                 }
1152
1153                 if ( $this->getParameter( 'curtimestamp' ) ) {
1154                         $result->addValue( null, 'curtimestamp', wfTimestamp( TS_ISO_8601, time() ),
1155                                 ApiResult::NO_SIZE_CHECK );
1156                 }
1157
1158                 if ( $this->getParameter( 'responselanginfo' ) ) {
1159                         $result->addValue( null, 'uselang', $this->getLanguage()->getCode(),
1160                                 ApiResult::NO_SIZE_CHECK );
1161                         $result->addValue( null, 'errorlang', $this->getErrorFormatter()->getLanguage()->getCode(),
1162                                 ApiResult::NO_SIZE_CHECK );
1163                 }
1164         }
1165
1166         /**
1167          * Set up for the execution.
1168          * @return array
1169          */
1170         protected function setupExecuteAction() {
1171                 $this->addRequestedFields();
1172
1173                 $params = $this->extractRequestParams();
1174                 $this->mAction = $params['action'];
1175
1176                 return $params;
1177         }
1178
1179         /**
1180          * Set up the module for response
1181          * @return ApiBase The module that will handle this action
1182          * @throws MWException
1183          * @throws ApiUsageException
1184          */
1185         protected function setupModule() {
1186                 // Instantiate the module requested by the user
1187                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
1188                 if ( $module === null ) {
1189                         $this->dieWithError(
1190                                 [ 'apierror-unknownaction', wfEscapeWikiText( $this->mAction ) ], 'unknown_action'
1191                         );
1192                 }
1193                 $moduleParams = $module->extractRequestParams();
1194
1195                 // Check token, if necessary
1196                 if ( $module->needsToken() === true ) {
1197                         throw new MWException(
1198                                 "Module '{$module->getModuleName()}' must be updated for the new token handling. " .
1199                                 'See documentation for ApiBase::needsToken for details.'
1200                         );
1201                 }
1202                 if ( $module->needsToken() ) {
1203                         if ( !$module->mustBePosted() ) {
1204                                 throw new MWException(
1205                                         "Module '{$module->getModuleName()}' must require POST to use tokens."
1206                                 );
1207                         }
1208
1209                         if ( !isset( $moduleParams['token'] ) ) {
1210                                 $module->dieWithError( [ 'apierror-missingparam', 'token' ] );
1211                         }
1212
1213                         $module->requirePostedParameters( [ 'token' ] );
1214
1215                         if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
1216                                 $module->dieWithError( 'apierror-badtoken' );
1217                         }
1218                 }
1219
1220                 return $module;
1221         }
1222
1223         /**
1224          * Check the max lag if necessary
1225          * @param ApiBase $module Api module being used
1226          * @param array $params Array an array containing the request parameters.
1227          * @return bool True on success, false should exit immediately
1228          */
1229         protected function checkMaxLag( $module, $params ) {
1230                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
1231                         $maxLag = $params['maxlag'];
1232                         list( $host, $lag ) = wfGetLB()->getMaxLag();
1233                         if ( $lag > $maxLag ) {
1234                                 $response = $this->getRequest()->response();
1235
1236                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
1237                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
1238
1239                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1240                                         $this->dieWithError( [ 'apierror-maxlag', $lag, $host ] );
1241                                 }
1242
1243                                 $this->dieWithError( [ 'apierror-maxlag-generic', $lag ], 'maxlag' );
1244                         }
1245                 }
1246
1247                 return true;
1248         }
1249
1250         /**
1251          * Check selected RFC 7232 precondition headers
1252          *
1253          * RFC 7232 envisions a particular model where you send your request to "a
1254          * resource", and for write requests that you can read "the resource" by
1255          * changing the method to GET. When the API receives a GET request, it
1256          * works out even though "the resource" from RFC 7232's perspective might
1257          * be many resources from MediaWiki's perspective. But it totally fails for
1258          * a POST, since what HTTP sees as "the resource" is probably just
1259          * "/api.php" with all the interesting bits in the body.
1260          *
1261          * Therefore, we only support RFC 7232 precondition headers for GET (and
1262          * HEAD). That means we don't need to bother with If-Match and
1263          * If-Unmodified-Since since they only apply to modification requests.
1264          *
1265          * And since we don't support Range, If-Range is ignored too.
1266          *
1267          * @since 1.26
1268          * @param ApiBase $module Api module being used
1269          * @return bool True on success, false should exit immediately
1270          */
1271         protected function checkConditionalRequestHeaders( $module ) {
1272                 if ( $this->mInternalMode ) {
1273                         // No headers to check in internal mode
1274                         return true;
1275                 }
1276
1277                 if ( $this->getRequest()->getMethod() !== 'GET' && $this->getRequest()->getMethod() !== 'HEAD' ) {
1278                         // Don't check POSTs
1279                         return true;
1280                 }
1281
1282                 $return304 = false;
1283
1284                 $ifNoneMatch = array_diff(
1285                         $this->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST ) ?: [],
1286                         [ '' ]
1287                 );
1288                 if ( $ifNoneMatch ) {
1289                         if ( $ifNoneMatch === [ '*' ] ) {
1290                                 // API responses always "exist"
1291                                 $etag = '*';
1292                         } else {
1293                                 $etag = $module->getConditionalRequestData( 'etag' );
1294                         }
1295                 }
1296                 if ( $ifNoneMatch && $etag !== null ) {
1297                         $test = substr( $etag, 0, 2 ) === 'W/' ? substr( $etag, 2 ) : $etag;
1298                         $match = array_map( function ( $s ) {
1299                                 return substr( $s, 0, 2 ) === 'W/' ? substr( $s, 2 ) : $s;
1300                         }, $ifNoneMatch );
1301                         $return304 = in_array( $test, $match, true );
1302                 } else {
1303                         $value = trim( $this->getRequest()->getHeader( 'If-Modified-Since' ) );
1304
1305                         // Some old browsers sends sizes after the date, like this:
1306                         //  Wed, 20 Aug 2003 06:51:19 GMT; length=5202
1307                         // Ignore that.
1308                         $i = strpos( $value, ';' );
1309                         if ( $i !== false ) {
1310                                 $value = trim( substr( $value, 0, $i ) );
1311                         }
1312
1313                         if ( $value !== '' ) {
1314                                 try {
1315                                         $ts = new MWTimestamp( $value );
1316                                         if (
1317                                                 // RFC 7231 IMF-fixdate
1318                                                 $ts->getTimestamp( TS_RFC2822 ) === $value ||
1319                                                 // RFC 850
1320                                                 $ts->format( 'l, d-M-y H:i:s' ) . ' GMT' === $value ||
1321                                                 // asctime (with and without space-padded day)
1322                                                 $ts->format( 'D M j H:i:s Y' ) === $value ||
1323                                                 $ts->format( 'D M  j H:i:s Y' ) === $value
1324                                         ) {
1325                                                 $lastMod = $module->getConditionalRequestData( 'last-modified' );
1326                                                 if ( $lastMod !== null ) {
1327                                                         // Mix in some MediaWiki modification times
1328                                                         $modifiedTimes = [
1329                                                                 'page' => $lastMod,
1330                                                                 'user' => $this->getUser()->getTouched(),
1331                                                                 'epoch' => $this->getConfig()->get( 'CacheEpoch' ),
1332                                                         ];
1333                                                         if ( $this->getConfig()->get( 'UseSquid' ) ) {
1334                                                                 // T46570: the core page itself may not change, but resources might
1335                                                                 $modifiedTimes['sepoch'] = wfTimestamp(
1336                                                                         TS_MW, time() - $this->getConfig()->get( 'SquidMaxage' )
1337                                                                 );
1338                                                         }
1339                                                         Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this->getOutput() ] );
1340                                                         $lastMod = max( $modifiedTimes );
1341                                                         $return304 = wfTimestamp( TS_MW, $lastMod ) <= $ts->getTimestamp( TS_MW );
1342                                                 }
1343                                         }
1344                                 } catch ( TimestampException $e ) {
1345                                         // Invalid timestamp, ignore it
1346                                 }
1347                         }
1348                 }
1349
1350                 if ( $return304 ) {
1351                         $this->getRequest()->response()->statusHeader( 304 );
1352
1353                         // Avoid outputting the compressed representation of a zero-length body
1354                         MediaWiki\suppressWarnings();
1355                         ini_set( 'zlib.output_compression', 0 );
1356                         MediaWiki\restoreWarnings();
1357                         wfClearOutputBuffers();
1358
1359                         return false;
1360                 }
1361
1362                 return true;
1363         }
1364
1365         /**
1366          * Check for sufficient permissions to execute
1367          * @param ApiBase $module An Api module
1368          */
1369         protected function checkExecutePermissions( $module ) {
1370                 $user = $this->getUser();
1371                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
1372                         !$user->isAllowed( 'read' )
1373                 ) {
1374                         $this->dieWithError( 'apierror-readapidenied' );
1375                 }
1376
1377                 if ( $module->isWriteMode() ) {
1378                         if ( !$this->mEnableWrite ) {
1379                                 $this->dieWithError( 'apierror-noapiwrite' );
1380                         } elseif ( !$user->isAllowed( 'writeapi' ) ) {
1381                                 $this->dieWithError( 'apierror-writeapidenied' );
1382                         } elseif ( $this->getRequest()->getHeader( 'Promise-Non-Write-API-Action' ) ) {
1383                                 $this->dieWithError( 'apierror-promised-nonwrite-api' );
1384                         }
1385
1386                         $this->checkReadOnly( $module );
1387                 }
1388
1389                 // Allow extensions to stop execution for arbitrary reasons.
1390                 $message = false;
1391                 if ( !Hooks::run( 'ApiCheckCanExecute', [ $module, $user, &$message ] ) ) {
1392                         $this->dieWithError( $message );
1393                 }
1394         }
1395
1396         /**
1397          * Check if the DB is read-only for this user
1398          * @param ApiBase $module An Api module
1399          */
1400         protected function checkReadOnly( $module ) {
1401                 if ( wfReadOnly() ) {
1402                         $this->dieReadOnly();
1403                 }
1404
1405                 if ( $module->isWriteMode()
1406                         && $this->getUser()->isBot()
1407                         && wfGetLB()->getServerCount() > 1
1408                 ) {
1409                         $this->checkBotReadOnly();
1410                 }
1411         }
1412
1413         /**
1414          * Check whether we are readonly for bots
1415          */
1416         private function checkBotReadOnly() {
1417                 // Figure out how many servers have passed the lag threshold
1418                 $numLagged = 0;
1419                 $lagLimit = $this->getConfig()->get( 'APIMaxLagThreshold' );
1420                 $laggedServers = [];
1421                 $loadBalancer = wfGetLB();
1422                 foreach ( $loadBalancer->getLagTimes() as $serverIndex => $lag ) {
1423                         if ( $lag > $lagLimit ) {
1424                                 ++$numLagged;
1425                                 $laggedServers[] = $loadBalancer->getServerName( $serverIndex ) . " ({$lag}s)";
1426                         }
1427                 }
1428
1429                 // If a majority of replica DBs are too lagged then disallow writes
1430                 $replicaCount = wfGetLB()->getServerCount() - 1;
1431                 if ( $numLagged >= ceil( $replicaCount / 2 ) ) {
1432                         $laggedServers = implode( ', ', $laggedServers );
1433                         wfDebugLog(
1434                                 'api-readonly',
1435                                 "Api request failed as read only because the following DBs are lagged: $laggedServers"
1436                         );
1437
1438                         $this->dieWithError(
1439                                 'readonly_lag',
1440                                 'readonly',
1441                                 [ 'readonlyreason' => "Waiting for $numLagged lagged database(s)" ]
1442                         );
1443                 }
1444         }
1445
1446         /**
1447          * Check asserts of the user's rights
1448          * @param array $params
1449          */
1450         protected function checkAsserts( $params ) {
1451                 if ( isset( $params['assert'] ) ) {
1452                         $user = $this->getUser();
1453                         switch ( $params['assert'] ) {
1454                                 case 'user':
1455                                         if ( $user->isAnon() ) {
1456                                                 $this->dieWithError( 'apierror-assertuserfailed' );
1457                                         }
1458                                         break;
1459                                 case 'bot':
1460                                         if ( !$user->isAllowed( 'bot' ) ) {
1461                                                 $this->dieWithError( 'apierror-assertbotfailed' );
1462                                         }
1463                                         break;
1464                         }
1465                 }
1466                 if ( isset( $params['assertuser'] ) ) {
1467                         $assertUser = User::newFromName( $params['assertuser'], false );
1468                         if ( !$assertUser || !$this->getUser()->equals( $assertUser ) ) {
1469                                 $this->dieWithError(
1470                                         [ 'apierror-assertnameduserfailed', wfEscapeWikiText( $params['assertuser'] ) ]
1471                                 );
1472                         }
1473                 }
1474         }
1475
1476         /**
1477          * Check POST for external response and setup result printer
1478          * @param ApiBase $module An Api module
1479          * @param array $params An array with the request parameters
1480          */
1481         protected function setupExternalResponse( $module, $params ) {
1482                 $request = $this->getRequest();
1483                 if ( !$request->wasPosted() && $module->mustBePosted() ) {
1484                         // Module requires POST. GET request might still be allowed
1485                         // if $wgDebugApi is true, otherwise fail.
1486                         $this->dieWithErrorOrDebug( [ 'apierror-mustbeposted', $this->mAction ] );
1487                 }
1488
1489                 // See if custom printer is used
1490                 $this->mPrinter = $module->getCustomPrinter();
1491                 if ( is_null( $this->mPrinter ) ) {
1492                         // Create an appropriate printer
1493                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
1494                 }
1495
1496                 if ( $request->getProtocol() === 'http' && (
1497                         $request->getSession()->shouldForceHTTPS() ||
1498                         ( $this->getUser()->isLoggedIn() &&
1499                                 $this->getUser()->requiresHTTPS() )
1500                 ) ) {
1501                         $this->addDeprecation( 'apiwarn-deprecation-httpsexpected', 'https-expected' );
1502                 }
1503         }
1504
1505         /**
1506          * Execute the actual module, without any error handling
1507          */
1508         protected function executeAction() {
1509                 $params = $this->setupExecuteAction();
1510                 $module = $this->setupModule();
1511                 $this->mModule = $module;
1512
1513                 if ( !$this->mInternalMode ) {
1514                         $this->setRequestExpectations( $module );
1515                 }
1516
1517                 $this->checkExecutePermissions( $module );
1518
1519                 if ( !$this->checkMaxLag( $module, $params ) ) {
1520                         return;
1521                 }
1522
1523                 if ( !$this->checkConditionalRequestHeaders( $module ) ) {
1524                         return;
1525                 }
1526
1527                 if ( !$this->mInternalMode ) {
1528                         $this->setupExternalResponse( $module, $params );
1529                 }
1530
1531                 $this->checkAsserts( $params );
1532
1533                 // Execute
1534                 $module->execute();
1535                 Hooks::run( 'APIAfterExecute', [ &$module ] );
1536
1537                 $this->reportUnusedParams();
1538
1539                 if ( !$this->mInternalMode ) {
1540                         // append Debug information
1541                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
1542
1543                         // Print result data
1544                         $this->printResult();
1545                 }
1546         }
1547
1548         /**
1549          * Set database connection, query, and write expectations given this module request
1550          * @param ApiBase $module
1551          */
1552         protected function setRequestExpectations( ApiBase $module ) {
1553                 $limits = $this->getConfig()->get( 'TrxProfilerLimits' );
1554                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1555                 $trxProfiler->setLogger( LoggerFactory::getInstance( 'DBPerformance' ) );
1556                 if ( $this->getRequest()->hasSafeMethod() ) {
1557                         $trxProfiler->setExpectations( $limits['GET'], __METHOD__ );
1558                 } elseif ( $this->getRequest()->wasPosted() && !$module->isWriteMode() ) {
1559                         $trxProfiler->setExpectations( $limits['POST-nonwrite'], __METHOD__ );
1560                         $this->getRequest()->markAsSafeRequest();
1561                 } else {
1562                         $trxProfiler->setExpectations( $limits['POST'], __METHOD__ );
1563                 }
1564         }
1565
1566         /**
1567          * Log the preceding request
1568          * @param float $time Time in seconds
1569          * @param Exception $e Exception caught while processing the request
1570          */
1571         protected function logRequest( $time, $e = null ) {
1572                 $request = $this->getRequest();
1573                 $logCtx = [
1574                         'ts' => time(),
1575                         'ip' => $request->getIP(),
1576                         'userAgent' => $this->getUserAgent(),
1577                         'wiki' => wfWikiID(),
1578                         'timeSpentBackend' => (int)round( $time * 1000 ),
1579                         'hadError' => $e !== null,
1580                         'errorCodes' => [],
1581                         'params' => [],
1582                 ];
1583
1584                 if ( $e ) {
1585                         foreach ( $this->errorMessagesFromException( $e ) as $msg ) {
1586                                 $logCtx['errorCodes'][] = $msg->getApiCode();
1587                         }
1588                 }
1589
1590                 // Construct space separated message for 'api' log channel
1591                 $msg = "API {$request->getMethod()} " .
1592                         wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
1593                         " {$logCtx['ip']} " .
1594                         "T={$logCtx['timeSpentBackend']}ms";
1595
1596                 foreach ( $this->getParamsUsed() as $name ) {
1597                         $value = $request->getVal( $name );
1598                         if ( $value === null ) {
1599                                 continue;
1600                         }
1601
1602                         if ( strlen( $value ) > 256 ) {
1603                                 $value = substr( $value, 0, 256 );
1604                                 $encValue = $this->encodeRequestLogValue( $value ) . '[...]';
1605                         } else {
1606                                 $encValue = $this->encodeRequestLogValue( $value );
1607                         }
1608
1609                         $logCtx['params'][$name] = $value;
1610                         $msg .= " {$name}={$encValue}";
1611                 }
1612
1613                 wfDebugLog( 'api', $msg, 'private' );
1614                 // ApiAction channel is for structured data consumers
1615                 wfDebugLog( 'ApiAction', '', 'private', $logCtx );
1616         }
1617
1618         /**
1619          * Encode a value in a format suitable for a space-separated log line.
1620          * @param string $s
1621          * @return string
1622          */
1623         protected function encodeRequestLogValue( $s ) {
1624                 static $table;
1625                 if ( !$table ) {
1626                         $chars = ';@$!*(),/:';
1627                         $numChars = strlen( $chars );
1628                         for ( $i = 0; $i < $numChars; $i++ ) {
1629                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
1630                         }
1631                 }
1632
1633                 return strtr( rawurlencode( $s ), $table );
1634         }
1635
1636         /**
1637          * Get the request parameters used in the course of the preceding execute() request
1638          * @return array
1639          */
1640         protected function getParamsUsed() {
1641                 return array_keys( $this->mParamsUsed );
1642         }
1643
1644         /**
1645          * Mark parameters as used
1646          * @param string|string[] $params
1647          */
1648         public function markParamsUsed( $params ) {
1649                 $this->mParamsUsed += array_fill_keys( (array)$params, true );
1650         }
1651
1652         /**
1653          * Get a request value, and register the fact that it was used, for logging.
1654          * @param string $name
1655          * @param mixed $default
1656          * @return mixed
1657          */
1658         public function getVal( $name, $default = null ) {
1659                 $this->mParamsUsed[$name] = true;
1660
1661                 $ret = $this->getRequest()->getVal( $name );
1662                 if ( $ret === null ) {
1663                         if ( $this->getRequest()->getArray( $name ) !== null ) {
1664                                 // See bug 10262 for why we don't just implode( '|', ... ) the
1665                                 // array.
1666                                 $this->addWarning( [ 'apiwarn-unsupportedarray', $name ] );
1667                         }
1668                         $ret = $default;
1669                 }
1670                 return $ret;
1671         }
1672
1673         /**
1674          * Get a boolean request value, and register the fact that the parameter
1675          * was used, for logging.
1676          * @param string $name
1677          * @return bool
1678          */
1679         public function getCheck( $name ) {
1680                 return $this->getVal( $name, null ) !== null;
1681         }
1682
1683         /**
1684          * Get a request upload, and register the fact that it was used, for logging.
1685          *
1686          * @since 1.21
1687          * @param string $name Parameter name
1688          * @return WebRequestUpload
1689          */
1690         public function getUpload( $name ) {
1691                 $this->mParamsUsed[$name] = true;
1692
1693                 return $this->getRequest()->getUpload( $name );
1694         }
1695
1696         /**
1697          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1698          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1699          */
1700         protected function reportUnusedParams() {
1701                 $paramsUsed = $this->getParamsUsed();
1702                 $allParams = $this->getRequest()->getValueNames();
1703
1704                 if ( !$this->mInternalMode ) {
1705                         // Printer has not yet executed; don't warn that its parameters are unused
1706                         $printerParams = $this->mPrinter->encodeParamName(
1707                                 array_keys( $this->mPrinter->getFinalParams() ?: [] )
1708                         );
1709                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1710                 } else {
1711                         $unusedParams = array_diff( $allParams, $paramsUsed );
1712                 }
1713
1714                 if ( count( $unusedParams ) ) {
1715                         $this->addWarning( [
1716                                 'apierror-unrecognizedparams',
1717                                 Message::listParam( array_map( 'wfEscapeWikiText', $unusedParams ), 'comma' ),
1718                                 count( $unusedParams )
1719                         ] );
1720                 }
1721         }
1722
1723         /**
1724          * Print results using the current printer
1725          *
1726          * @param int $httpCode HTTP status code, or 0 to not change
1727          */
1728         protected function printResult( $httpCode = 0 ) {
1729                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1730                         $this->addWarning( 'apiwarn-wgDebugAPI' );
1731                 }
1732
1733                 $printer = $this->mPrinter;
1734                 $printer->initPrinter( false );
1735                 if ( $httpCode ) {
1736                         $printer->setHttpStatus( $httpCode );
1737                 }
1738                 $printer->execute();
1739                 $printer->closePrinter();
1740         }
1741
1742         /**
1743          * @return bool
1744          */
1745         public function isReadMode() {
1746                 return false;
1747         }
1748
1749         /**
1750          * See ApiBase for description.
1751          *
1752          * @return array
1753          */
1754         public function getAllowedParams() {
1755                 return [
1756                         'action' => [
1757                                 ApiBase::PARAM_DFLT => 'help',
1758                                 ApiBase::PARAM_TYPE => 'submodule',
1759                         ],
1760                         'format' => [
1761                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1762                                 ApiBase::PARAM_TYPE => 'submodule',
1763                         ],
1764                         'maxlag' => [
1765                                 ApiBase::PARAM_TYPE => 'integer'
1766                         ],
1767                         'smaxage' => [
1768                                 ApiBase::PARAM_TYPE => 'integer',
1769                                 ApiBase::PARAM_DFLT => 0
1770                         ],
1771                         'maxage' => [
1772                                 ApiBase::PARAM_TYPE => 'integer',
1773                                 ApiBase::PARAM_DFLT => 0
1774                         ],
1775                         'assert' => [
1776                                 ApiBase::PARAM_TYPE => [ 'user', 'bot' ]
1777                         ],
1778                         'assertuser' => [
1779                                 ApiBase::PARAM_TYPE => 'user',
1780                         ],
1781                         'requestid' => null,
1782                         'servedby' => false,
1783                         'curtimestamp' => false,
1784                         'responselanginfo' => false,
1785                         'origin' => null,
1786                         'uselang' => [
1787                                 ApiBase::PARAM_DFLT => self::API_DEFAULT_USELANG,
1788                         ],
1789                         'errorformat' => [
1790                                 ApiBase::PARAM_TYPE => [ 'plaintext', 'wikitext', 'html', 'raw', 'none', 'bc' ],
1791                                 ApiBase::PARAM_DFLT => 'bc',
1792                         ],
1793                         'errorlang' => [
1794                                 ApiBase::PARAM_DFLT => 'uselang',
1795                         ],
1796                         'errorsuselocal' => [
1797                                 ApiBase::PARAM_DFLT => false,
1798                         ],
1799                 ];
1800         }
1801
1802         /** @see ApiBase::getExamplesMessages() */
1803         protected function getExamplesMessages() {
1804                 return [
1805                         'action=help'
1806                                 => 'apihelp-help-example-main',
1807                         'action=help&recursivesubmodules=1'
1808                                 => 'apihelp-help-example-recursive',
1809                 ];
1810         }
1811
1812         public function modifyHelp( array &$help, array $options, array &$tocData ) {
1813                 // Wish PHP had an "array_insert_before". Instead, we have to manually
1814                 // reindex the array to get 'permissions' in the right place.
1815                 $oldHelp = $help;
1816                 $help = [];
1817                 foreach ( $oldHelp as $k => $v ) {
1818                         if ( $k === 'submodules' ) {
1819                                 $help['permissions'] = '';
1820                         }
1821                         $help[$k] = $v;
1822                 }
1823                 $help['datatypes'] = '';
1824                 $help['credits'] = '';
1825
1826                 // Fill 'permissions'
1827                 $help['permissions'] .= Html::openElement( 'div',
1828                         [ 'class' => 'apihelp-block apihelp-permissions' ] );
1829                 $m = $this->msg( 'api-help-permissions' );
1830                 if ( !$m->isDisabled() ) {
1831                         $help['permissions'] .= Html::rawElement( 'div', [ 'class' => 'apihelp-block-head' ],
1832                                 $m->numParams( count( self::$mRights ) )->parse()
1833                         );
1834                 }
1835                 $help['permissions'] .= Html::openElement( 'dl' );
1836                 foreach ( self::$mRights as $right => $rightMsg ) {
1837                         $help['permissions'] .= Html::element( 'dt', null, $right );
1838
1839                         $rightMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )->parse();
1840                         $help['permissions'] .= Html::rawElement( 'dd', null, $rightMsg );
1841
1842                         $groups = array_map( function ( $group ) {
1843                                 return $group == '*' ? 'all' : $group;
1844                         }, User::getGroupsWithPermission( $right ) );
1845
1846                         $help['permissions'] .= Html::rawElement( 'dd', null,
1847                                 $this->msg( 'api-help-permissions-granted-to' )
1848                                         ->numParams( count( $groups ) )
1849                                         ->params( Message::listParam( $groups ) )
1850                                         ->parse()
1851                         );
1852                 }
1853                 $help['permissions'] .= Html::closeElement( 'dl' );
1854                 $help['permissions'] .= Html::closeElement( 'div' );
1855
1856                 // Fill 'datatypes' and 'credits', if applicable
1857                 if ( empty( $options['nolead'] ) ) {
1858                         $level = $options['headerlevel'];
1859                         $tocnumber = &$options['tocnumber'];
1860
1861                         $header = $this->msg( 'api-help-datatypes-header' )->parse();
1862
1863                         // Add an additional span with sanitized ID
1864                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1865                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/datatypes' ) ] ) .
1866                                         $header;
1867                         }
1868                         $help['datatypes'] .= Html::rawElement( 'h' . min( 6, $level ),
1869                                 [ 'id' => 'main/datatypes', 'class' => 'apihelp-header' ],
1870                                 $header
1871                         );
1872                         $help['datatypes'] .= $this->msg( 'api-help-datatypes' )->parseAsBlock();
1873                         if ( !isset( $tocData['main/datatypes'] ) ) {
1874                                 $tocnumber[$level]++;
1875                                 $tocData['main/datatypes'] = [
1876                                         'toclevel' => count( $tocnumber ),
1877                                         'level' => $level,
1878                                         'anchor' => 'main/datatypes',
1879                                         'line' => $header,
1880                                         'number' => implode( '.', $tocnumber ),
1881                                         'index' => false,
1882                                 ];
1883                         }
1884
1885                         // Add an additional span with sanitized ID
1886                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1887                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/credits' ) ] ) .
1888                                         $header;
1889                         }
1890                         $header = $this->msg( 'api-credits-header' )->parse();
1891                         $help['credits'] .= Html::rawElement( 'h' . min( 6, $level ),
1892                                 [ 'id' => 'main/credits', 'class' => 'apihelp-header' ],
1893                                 $header
1894                         );
1895                         $help['credits'] .= $this->msg( 'api-credits' )->useDatabase( false )->parseAsBlock();
1896                         if ( !isset( $tocData['main/credits'] ) ) {
1897                                 $tocnumber[$level]++;
1898                                 $tocData['main/credits'] = [
1899                                         'toclevel' => count( $tocnumber ),
1900                                         'level' => $level,
1901                                         'anchor' => 'main/credits',
1902                                         'line' => $header,
1903                                         'number' => implode( '.', $tocnumber ),
1904                                         'index' => false,
1905                                 ];
1906                         }
1907                 }
1908         }
1909
1910         private $mCanApiHighLimits = null;
1911
1912         /**
1913          * Check whether the current user is allowed to use high limits
1914          * @return bool
1915          */
1916         public function canApiHighLimits() {
1917                 if ( !isset( $this->mCanApiHighLimits ) ) {
1918                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1919                 }
1920
1921                 return $this->mCanApiHighLimits;
1922         }
1923
1924         /**
1925          * Overrides to return this instance's module manager.
1926          * @return ApiModuleManager
1927          */
1928         public function getModuleManager() {
1929                 return $this->mModuleMgr;
1930         }
1931
1932         /**
1933          * Fetches the user agent used for this request
1934          *
1935          * The value will be the combination of the 'Api-User-Agent' header (if
1936          * any) and the standard User-Agent header (if any).
1937          *
1938          * @return string
1939          */
1940         public function getUserAgent() {
1941                 return trim(
1942                         $this->getRequest()->getHeader( 'Api-user-agent' ) . ' ' .
1943                         $this->getRequest()->getHeader( 'User-agent' )
1944                 );
1945         }
1946 }
1947
1948 /**
1949  * For really cool vim folding this needs to be at the end:
1950  * vim: foldmarker=@{,@} foldmethod=marker
1951  */