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 /**
  29  * This is the main API class, used for both external and internal processing.
  30  * When executed, it will create the requested formatter object,
  31  * instantiate and execute an object associated with the needed action,
  32  * and use formatter to print results.
  33  * In case of an exception, an error message will be printed using the same formatter.
  34  *
  35  * To use API from another application, run it using FauxRequest object, in which
  36  * case any internal exceptions will not be handled but passed up to the caller.
  37  * After successful execution, use getResult() for the resulting data.
  38  *
  39  * @ingroup API
  40  */
  41 class ApiMain extends ApiBase {
  42         /**
  43          * When no format parameter is given, this format will be used
  44          */
  45         const API_DEFAULT_FORMAT = 'jsonfm';
  46
  47         /**
  48          * List of available modules: action name => module class
  49          */
  50         private static $Modules = [
  51                 'login' => 'ApiLogin',
  52                 'clientlogin' => 'ApiClientLogin',
  53                 'logout' => 'ApiLogout',
  54                 'createaccount' => 'ApiAMCreateAccount',
  55                 'linkaccount' => 'ApiLinkAccount',
  56                 'unlinkaccount' => 'ApiRemoveAuthenticationData',
  57                 'changeauthenticationdata' => 'ApiChangeAuthenticationData',
  58                 'removeauthenticationdata' => 'ApiRemoveAuthenticationData',
  59                 'resetpassword' => 'ApiResetPassword',
  60                 'query' => 'ApiQuery',
  61                 'expandtemplates' => 'ApiExpandTemplates',
  62                 'parse' => 'ApiParse',
  63                 'stashedit' => 'ApiStashEdit',
  64                 'opensearch' => 'ApiOpenSearch',
  65                 'feedcontributions' => 'ApiFeedContributions',
  66                 'feedrecentchanges' => 'ApiFeedRecentChanges',
  67                 'feedwatchlist' => 'ApiFeedWatchlist',
  68                 'help' => 'ApiHelp',
  69                 'paraminfo' => 'ApiParamInfo',
  70                 'rsd' => 'ApiRsd',
  71                 'compare' => 'ApiComparePages',
  72                 'tokens' => 'ApiTokens',
  73                 'checktoken' => 'ApiCheckToken',
  74
  75                 // Write modules
  76                 'purge' => 'ApiPurge',
  77                 'setnotificationtimestamp' => 'ApiSetNotificationTimestamp',
  78                 'rollback' => 'ApiRollback',
  79                 'delete' => 'ApiDelete',
  80                 'undelete' => 'ApiUndelete',
  81                 'protect' => 'ApiProtect',
  82                 'block' => 'ApiBlock',
  83                 'unblock' => 'ApiUnblock',
  84                 'move' => 'ApiMove',
  85                 'edit' => 'ApiEditPage',
  86                 'upload' => 'ApiUpload',
  87                 'filerevert' => 'ApiFileRevert',
  88                 'emailuser' => 'ApiEmailUser',
  89                 'watch' => 'ApiWatch',
  90                 'patrol' => 'ApiPatrol',
  91                 'import' => 'ApiImport',
  92                 'clearhasmsg' => 'ApiClearHasMsg',
  93                 'userrights' => 'ApiUserrights',
  94                 'options' => 'ApiOptions',
  95                 'imagerotate' => 'ApiImageRotate',
  96                 'revisiondelete' => 'ApiRevisionDelete',
  97                 'managetags' => 'ApiManageTags',
  98                 'tag' => 'ApiTag',
  99                 'mergehistory' => 'ApiMergeHistory',
 100         ];
 101
 102         /**
 103          * List of available formats: format name => format class
 104          */
 105         private static $Formats = [
 106                 'json' => 'ApiFormatJson',
 107                 'jsonfm' => 'ApiFormatJson',
 108                 'php' => 'ApiFormatPhp',
 109                 'phpfm' => 'ApiFormatPhp',
 110                 'xml' => 'ApiFormatXml',
 111                 'xmlfm' => 'ApiFormatXml',
 112                 'rawfm' => 'ApiFormatJson',
 113                 'none' => 'ApiFormatNone',
 114         ];
 115
 116         // @codingStandardsIgnoreStart String contenation on "msg" not allowed to break long line
 117         /**
 118          * List of user roles that are specifically relevant to the API.
 119          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 120          *                           'params' => array ( $someVarToSubst ) ),
 121          *                          );
 122          */
 123         private static $mRights = [
 124                 'writeapi' => [
 125                         'msg' => 'right-writeapi',
 126                         'params' => []
 127                 ],
 128                 'apihighlimits' => [
 129                         'msg' => 'api-help-right-apihighlimits',
 130                         'params' => [ ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 ]
 131                 ]
 132         ];
 133         // @codingStandardsIgnoreEnd
 134
 135         /**
 136          * @var ApiFormatBase
 137          */
 138         private $mPrinter;
 139
 140         private $mModuleMgr, $mResult, $mErrorFormatter, $mContinuationManager;
 141         private $mAction;
 142         private $mEnableWrite;
 143         private $mInternalMode, $mSquidMaxage;
 144         /** @var ApiBase */
 145         private $mModule;
 146
 147         private $mCacheMode = 'private';
 148         private $mCacheControl = [];
 149         private $mParamsUsed = [];
 150
 151         /** @var bool|null Cached return value from self::lacksSameOriginSecurity() */
 152         private $lacksSameOriginSecurity = null;
 153
 154         /**
 155          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 156          *
 157          * @param IContextSource|WebRequest $context If this is an instance of
 158          *    FauxRequest, errors are thrown and no printing occurs
 159          * @param bool $enableWrite Should be set to true if the api may modify data
 160          */
 161         public function __construct( $context = null, $enableWrite = false ) {
 162                 if ( $context === null ) {
 163                         $context = RequestContext::getMain();
 164                 } elseif ( $context instanceof WebRequest ) {
 165                         // BC for pre-1.19
 166                         $request = $context;
 167                         $context = RequestContext::getMain();
 168                 }
 169                 // We set a derivative context so we can change stuff later
 170                 $this->setContext( new DerivativeContext( $context ) );
 171
 172                 if ( isset( $request ) ) {
 173                         $this->getContext()->setRequest( $request );
 174                 }
 175
 176                 $this->mInternalMode = ( $this->getRequest() instanceof FauxRequest );
 177
 178                 // Special handling for the main module: $parent === $this
 179                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 180
 181                 if ( !$this->mInternalMode ) {
 182                         // Impose module restrictions.
 183                         // If the current user cannot read,
 184                         // Remove all modules other than login
 185                         global $wgUser;
 186
 187                         if ( $this->lacksSameOriginSecurity() ) {
 188                                 // If we're in a mode that breaks the same-origin policy, strip
 189                                 // user credentials for security.
 190                                 wfDebug( "API: stripping user credentials when the same-origin policy is not applied\n" );
 191                                 $wgUser = new User();
 192                                 $this->getContext()->setUser( $wgUser );
 193                         }
 194                 }
 195
 196                 $uselang = $this->getParameter( 'uselang' );
 197                 if ( $uselang === 'user' ) {
 198                         // Assume the parent context is going to return the user language
 199                         // for uselang=user (see T85635).
 200                 } else {
 201                         if ( $uselang === 'content' ) {
 202                                 global $wgContLang;
 203                                 $uselang = $wgContLang->getCode();
 204                         }
 205                         $code = RequestContext::sanitizeLangCode( $uselang );
 206                         $this->getContext()->setLanguage( $code );
 207                         if ( !$this->mInternalMode ) {
 208                                 global $wgLang;
 209                                 $wgLang = $this->getContext()->getLanguage();
 210                                 RequestContext::getMain()->setLanguage( $wgLang );
 211                         }
 212                 }
 213
 214                 $config = $this->getConfig();
 215                 $this->mModuleMgr = new ApiModuleManager( $this );
 216                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 217                 $this->mModuleMgr->addModules( $config->get( 'APIModules' ), 'action' );
 218                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 219                 $this->mModuleMgr->addModules( $config->get( 'APIFormatModules' ), 'format' );
 220
 221                 Hooks::run( 'ApiMain::moduleManager', [ $this->mModuleMgr ] );
 222
 223                 $this->mResult = new ApiResult( $this->getConfig()->get( 'APIMaxResultSize' ) );
 224                 $this->mErrorFormatter = new ApiErrorFormatter_BackCompat( $this->mResult );
 225                 $this->mResult->setErrorFormatter( $this->mErrorFormatter );
 226                 $this->mResult->setMainForContinuation( $this );
 227                 $this->mContinuationManager = null;
 228                 $this->mEnableWrite = $enableWrite;
 229
 230                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 231                 $this->mCommit = false;
 232         }
 233
 234         /**
 235          * Return true if the API was started by other PHP code using FauxRequest
 236          * @return bool
 237          */
 238         public function isInternalMode() {
 239                 return $this->mInternalMode;
 240         }
 241
 242         /**
 243          * Get the ApiResult object associated with current request
 244          *
 245          * @return ApiResult
 246          */
 247         public function getResult() {
 248                 return $this->mResult;
 249         }
 250
 251         /**
 252          * Get the security flag for the current request
 253          * @return bool
 254          */
 255         public function lacksSameOriginSecurity() {
 256                 if ( $this->lacksSameOriginSecurity !== null ) {
 257                         return $this->lacksSameOriginSecurity;
 258                 }
 259
 260                 $request = $this->getRequest();
 261
 262                 // JSONP mode
 263                 if ( $request->getVal( 'callback' ) !== null ) {
 264                         $this->lacksSameOriginSecurity = true;
 265                         return true;
 266                 }
 267
 268                 // Anonymous CORS
 269                 if ( $request->getVal( 'origin' ) === '*' ) {
 270                         $this->lacksSameOriginSecurity = true;
 271                         return true;
 272                 }
 273
 274                 // Header to be used from XMLHTTPRequest when the request might
 275                 // otherwise be used for XSS.
 276                 if ( $request->getHeader( 'Treat-as-Untrusted' ) !== false ) {
 277                         $this->lacksSameOriginSecurity = true;
 278                         return true;
 279                 }
 280
 281                 // Allow extensions to override.
 282                 $this->lacksSameOriginSecurity = !Hooks::run( 'RequestHasSameOriginSecurity', [ $request ] );
 283                 return $this->lacksSameOriginSecurity;
 284         }
 285
 286         /**
 287          * Get the ApiErrorFormatter object associated with current request
 288          * @return ApiErrorFormatter
 289          */
 290         public function getErrorFormatter() {
 291                 return $this->mErrorFormatter;
 292         }
 293
 294         /**
 295          * Get the continuation manager
 296          * @return ApiContinuationManager|null
 297          */
 298         public function getContinuationManager() {
 299                 return $this->mContinuationManager;
 300         }
 301
 302         /**
 303          * Set the continuation manager
 304          * @param ApiContinuationManager|null
 305          */
 306         public function setContinuationManager( $manager ) {
 307                 if ( $manager !== null ) {
 308                         if ( !$manager instanceof ApiContinuationManager ) {
 309                                 throw new InvalidArgumentException( __METHOD__ . ': Was passed ' .
 310                                         is_object( $manager ) ? get_class( $manager ) : gettype( $manager )
 311                                 );
 312                         }
 313                         if ( $this->mContinuationManager !== null ) {
 314                                 throw new UnexpectedValueException(
 315                                         __METHOD__ . ': tried to set manager from ' . $manager->getSource() .
 316                                         ' when a manager is already set from ' . $this->mContinuationManager->getSource()
 317                                 );
 318                         }
 319                 }
 320                 $this->mContinuationManager = $manager;
 321         }
 322
 323         /**
 324          * Get the API module object. Only works after executeAction()
 325          *
 326          * @return ApiBase
 327          */
 328         public function getModule() {
 329                 return $this->mModule;
 330         }
 331
 332         /**
 333          * Get the result formatter object. Only works after setupExecuteAction()
 334          *
 335          * @return ApiFormatBase
 336          */
 337         public function getPrinter() {
 338                 return $this->mPrinter;
 339         }
 340
 341         /**
 342          * Set how long the response should be cached.
 343          *
 344          * @param int $maxage
 345          */
 346         public function setCacheMaxAge( $maxage ) {
 347                 $this->setCacheControl( [
 348                         'max-age' => $maxage,
 349                         's-maxage' => $maxage
 350                 ] );
 351         }
 352
 353         /**
 354          * Set the type of caching headers which will be sent.
 355          *
 356          * @param string $mode One of:
 357          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 358          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 359          *         not provided by any of these means, the object will be private.
 360          *    - 'private':    Cache this object only in private client-side caches.
 361          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 362          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 363          *         set consistently for a given URL, it cannot be set differently depending on
 364          *         things like the contents of the database, or whether the user is logged in.
 365          *
 366          *  If the wiki does not allow anonymous users to read it, the mode set here
 367          *  will be ignored, and private caching headers will always be sent. In other words,
 368          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 369          *  view.
 370          *
 371          *  For user-dependent data, the private mode should generally be used. The
 372          *  anon-public-user-private mode should only be used where there is a particularly
 373          *  good performance reason for caching the anonymous response, but where the
 374          *  response to logged-in users may differ, or may contain private data.
 375          *
 376          *  If this function is never called, then the default will be the private mode.
 377          */
 378         public function setCacheMode( $mode ) {
 379                 if ( !in_array( $mode, [ 'private', 'public', 'anon-public-user-private' ] ) ) {
 380                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 381
 382                         // Ignore for forwards-compatibility
 383                         return;
 384                 }
 385
 386                 if ( !User::isEveryoneAllowed( 'read' ) ) {
 387                         // Private wiki, only private headers
 388                         if ( $mode !== 'private' ) {
 389                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 390
 391                                 return;
 392                         }
 393                 }
 394
 395                 if ( $mode === 'public' && $this->getParameter( 'uselang' ) === 'user' ) {
 396                         // User language is used for i18n, so we don't want to publicly
 397                         // cache. Anons are ok, because if they have non-default language
 398                         // then there's an appropriate Vary header set by whatever set
 399                         // their non-default language.
 400                         wfDebug( __METHOD__ . ": downgrading cache mode 'public' to " .
 401                                 "'anon-public-user-private' due to uselang=user\n" );
 402                         $mode = 'anon-public-user-private';
 403                 }
 404
 405                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 406                 $this->mCacheMode = $mode;
 407         }
 408
 409         /**
 410          * Set directives (key/value pairs) for the Cache-Control header.
 411          * Boolean values will be formatted as such, by including or omitting
 412          * without an equals sign.
 413          *
 414          * Cache control values set here will only be used if the cache mode is not
 415          * private, see setCacheMode().
 416          *
 417          * @param array $directives
 418          */
 419         public function setCacheControl( $directives ) {
 420                 $this->mCacheControl = $directives + $this->mCacheControl;
 421         }
 422
 423         /**
 424          * Create an instance of an output formatter by its name
 425          *
 426          * @param string $format
 427          *
 428          * @return ApiFormatBase
 429          */
 430         public function createPrinterByName( $format ) {
 431                 $printer = $this->mModuleMgr->getModule( $format, 'format' );
 432                 if ( $printer === null ) {
 433                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 434                 }
 435
 436                 return $printer;
 437         }
 438
 439         /**
 440          * Execute api request. Any errors will be handled if the API was called by the remote client.
 441          */
 442         public function execute() {
 443                 if ( $this->mInternalMode ) {
 444                         $this->executeAction();
 445                 } else {
 446                         $this->executeActionWithErrorHandling();
 447                 }
 448         }
 449
 450         /**
 451          * Execute an action, and in case of an error, erase whatever partial results
 452          * have been accumulated, and replace it with an error message and a help screen.
 453          */
 454         protected function executeActionWithErrorHandling() {
 455                 // Verify the CORS header before executing the action
 456                 if ( !$this->handleCORS() ) {
 457                         // handleCORS() has sent a 403, abort
 458                         return;
 459                 }
 460
 461                 // Exit here if the request method was OPTIONS
 462                 // (assume there will be a followup GET or POST)
 463                 if ( $this->getRequest()->getMethod() === 'OPTIONS' ) {
 464                         return;
 465                 }
 466
 467                 // In case an error occurs during data output,
 468                 // clear the output buffer and print just the error information
 469                 $obLevel = ob_get_level();
 470                 ob_start();
 471
 472                 $t = microtime( true );
 473                 $isError = false;
 474                 try {
 475                         $this->executeAction();
 476                         $runTime = microtime( true ) - $t;
 477                         $this->logRequest( $runTime );
 478                         if ( $this->mModule->isWriteMode() && $this->getRequest()->wasPosted() ) {
 479                                 $this->getStats()->timing(
 480                                         'api.' . $this->mModule->getModuleName() . '.executeTiming', 1000 * $runTime
 481                                 );
 482                         }
 483                 } catch ( Exception $e ) {
 484                         $this->handleException( $e );
 485                         $this->logRequest( microtime( true ) - $t, $e );
 486                         $isError = true;
 487                 }
 488
 489                 // Commit DBs and send any related cookies and headers
 490                 MediaWiki::preOutputCommit( $this->getContext() );
 491
 492                 // Send cache headers after any code which might generate an error, to
 493                 // avoid sending public cache headers for errors.
 494                 $this->sendCacheHeaders( $isError );
 495
 496                 // Executing the action might have already messed with the output
 497                 // buffers.
 498                 while ( ob_get_level() > $obLevel ) {
 499                         ob_end_flush();
 500                 }
 501         }
 502
 503         /**
 504          * Handle an exception as an API response
 505          *
 506          * @since 1.23
 507          * @param Exception $e
 508          */
 509         protected function handleException( Exception $e ) {
 510                 // Bug 63145: Rollback any open database transactions
 511                 if ( !( $e instanceof UsageException ) ) {
 512                         // UsageExceptions are intentional, so don't rollback if that's the case
 513                         try {
 514                                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 515                         } catch ( DBError $e2 ) {
 516                                 // Rollback threw an exception too. Log it, but don't interrupt
 517                                 // our regularly scheduled exception handling.
 518                                 MWExceptionHandler::logException( $e2 );
 519                         }
 520                 }
 521
 522                 // Allow extra cleanup and logging
 523                 Hooks::run( 'ApiMain::onException', [ $this, $e ] );
 524
 525                 // Log it
 526                 if ( !( $e instanceof UsageException ) ) {
 527                         MWExceptionHandler::logException( $e );
 528                 }
 529
 530                 // Handle any kind of exception by outputting properly formatted error message.
 531                 // If this fails, an unhandled exception should be thrown so that global error
 532                 // handler will process and log it.
 533
 534                 $errCode = $this->substituteResultWithError( $e );
 535
 536                 // Error results should not be cached
 537                 $this->setCacheMode( 'private' );
 538
 539                 $response = $this->getRequest()->response();
 540                 $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 541                 if ( $e->getCode() === 0 ) {
 542                         $response->header( $headerStr );
 543                 } else {
 544                         $response->header( $headerStr, true, $e->getCode() );
 545                 }
 546
 547                 // Reset and print just the error message
 548                 ob_clean();
 549
 550                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 551                 $this->createErrorPrinter();
 552
 553                 try {
 554                         $this->printResult( true );
 555                 } catch ( UsageException $ex ) {
 556                         // The error printer itself is failing. Try suppressing its request
 557                         // parameters and redo.
 558                         $this->setWarning(
 559                                 'Error printer failed (will retry without params): ' . $ex->getMessage()
 560                         );
 561                         $this->mPrinter = null;
 562                         $this->createErrorPrinter();
 563                         $this->mPrinter->forceDefaultParams();
 564                         $this->printResult( true );
 565                 }
 566         }
 567
 568         /**
 569          * Handle an exception from the ApiBeforeMain hook.
 570          *
 571          * This tries to print the exception as an API response, to be more
 572          * friendly to clients. If it fails, it will rethrow the exception.
 573          *
 574          * @since 1.23
 575          * @param Exception $e
 576          * @throws Exception
 577          */
 578         public static function handleApiBeforeMainException( Exception $e ) {
 579                 ob_start();
 580
 581                 try {
 582                         $main = new self( RequestContext::getMain(), false );
 583                         $main->handleException( $e );
 584                         $main->logRequest( 0, $e );
 585                 } catch ( Exception $e2 ) {
 586                         // Nope, even that didn't work. Punt.
 587                         throw $e;
 588                 }
 589
 590                 // Reset cache headers
 591                 $main->sendCacheHeaders( true );
 592
 593                 ob_end_flush();
 594         }
 595
 596         /**
 597          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 598          *
 599          * If no origin parameter is present, nothing happens.
 600          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 601          * is set and false is returned.
 602          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 603          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 604          * headers are set.
 605          * http://www.w3.org/TR/cors/#resource-requests
 606          * http://www.w3.org/TR/cors/#resource-preflight-requests
 607          *
 608          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 609          */
 610         protected function handleCORS() {
 611                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 612                 if ( $originParam === null ) {
 613                         // No origin parameter, nothing to do
 614                         return true;
 615                 }
 616
 617                 $request = $this->getRequest();
 618                 $response = $request->response();
 619
 620                 $matchOrigin = false;
 621                 $allowTiming = false;
 622                 $varyOrigin = true;
 623
 624                 if ( $originParam === '*' ) {
 625                         // Request for anonymous CORS
 626                         $matchOrigin = true;
 627                         $allowOrigin = '*';
 628                         $allowCredentials = 'false';
 629                         $varyOrigin = false; // No need to vary
 630                 } else {
 631                         // Non-anonymous CORS, check we allow the domain
 632
 633                         // Origin: header is a space-separated list of origins, check all of them
 634                         $originHeader = $request->getHeader( 'Origin' );
 635                         if ( $originHeader === false ) {
 636                                 $origins = [];
 637                         } else {
 638                                 $originHeader = trim( $originHeader );
 639                                 $origins = preg_split( '/\s+/', $originHeader );
 640                         }
 641
 642                         if ( !in_array( $originParam, $origins ) ) {
 643                                 // origin parameter set but incorrect
 644                                 // Send a 403 response
 645                                 $response->statusHeader( 403 );
 646                                 $response->header( 'Cache-Control: no-cache' );
 647                                 echo "'origin' parameter does not match Origin header\n";
 648
 649                                 return false;
 650                         }
 651
 652                         $config = $this->getConfig();
 653                         $matchOrigin = count( $origins ) === 1 && self::matchOrigin(
 654                                 $originParam,
 655                                 $config->get( 'CrossSiteAJAXdomains' ),
 656                                 $config->get( 'CrossSiteAJAXdomainExceptions' )
 657                         );
 658
 659                         $allowOrigin = $originHeader;
 660                         $allowCredentials = 'true';
 661                         $allowTiming = $originHeader;
 662                 }
 663
 664                 if ( $matchOrigin ) {
 665                         $requestedMethod = $request->getHeader( 'Access-Control-Request-Method' );
 666                         $preflight = $request->getMethod() === 'OPTIONS' && $requestedMethod !== false;
 667                         if ( $preflight ) {
 668                                 // This is a CORS preflight request
 669                                 if ( $requestedMethod !== 'POST' && $requestedMethod !== 'GET' ) {
 670                                         // If method is not a case-sensitive match, do not set any additional headers and terminate.
 671                                         return true;
 672                                 }
 673                                 // We allow the actual request to send the following headers
 674                                 $requestedHeaders = $request->getHeader( 'Access-Control-Request-Headers' );
 675                                 if ( $requestedHeaders !== false ) {
 676                                         if ( !self::matchRequestedHeaders( $requestedHeaders ) ) {
 677                                                 return true;
 678                                         }
 679                                         $response->header( 'Access-Control-Allow-Headers: ' . $requestedHeaders );
 680                                 }
 681
 682                                 // We only allow the actual request to be GET or POST
 683                                 $response->header( 'Access-Control-Allow-Methods: POST, GET' );
 684                         }
 685
 686                         $response->header( "Access-Control-Allow-Origin: $allowOrigin" );
 687                         $response->header( "Access-Control-Allow-Credentials: $allowCredentials" );
 688                         // http://www.w3.org/TR/resource-timing/#timing-allow-origin
 689                         if ( $allowTiming !== false ) {
 690                                 $response->header( "Timing-Allow-Origin: $allowTiming" );
 691                         }
 692
 693                         if ( !$preflight ) {
 694                                 $response->header(
 695                                         'Access-Control-Expose-Headers: MediaWiki-API-Error, Retry-After, X-Database-Lag'
 696                                 );
 697                         }
 698                 }
 699
 700                 if ( $varyOrigin ) {
 701                         $this->getOutput()->addVaryHeader( 'Origin' );
 702                 }
 703
 704                 return true;
 705         }
 706
 707         /**
 708          * Attempt to match an Origin header against a set of rules and a set of exceptions
 709          * @param string $value Origin header
 710          * @param array $rules Set of wildcard rules
 711          * @param array $exceptions Set of wildcard rules
 712          * @return bool True if $value matches a rule in $rules and doesn't match
 713          *    any rules in $exceptions, false otherwise
 714          */
 715         protected static function matchOrigin( $value, $rules, $exceptions ) {
 716                 foreach ( $rules as $rule ) {
 717                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 718                                 // Rule matches, check exceptions
 719                                 foreach ( $exceptions as $exc ) {
 720                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 721                                                 return false;
 722                                         }
 723                                 }
 724
 725                                 return true;
 726                         }
 727                 }
 728
 729                 return false;
 730         }
 731
 732         /**
 733          * Attempt to validate the value of Access-Control-Request-Headers against a list
 734          * of headers that we allow the follow up request to send.
 735          *
 736          * @param string $requestedHeaders Comma seperated list of HTTP headers
 737          * @return bool True if all requested headers are in the list of allowed headers
 738          */
 739         protected static function matchRequestedHeaders( $requestedHeaders ) {
 740                 if ( trim( $requestedHeaders ) === '' ) {
 741                         return true;
 742                 }
 743                 $requestedHeaders = explode( ',', $requestedHeaders );
 744                 $allowedAuthorHeaders = array_flip( [
 745                         /* simple headers (see spec) */
 746                         'accept',
 747                         'accept-language',
 748                         'content-language',
 749                         'content-type',
 750                         /* non-authorable headers in XHR, which are however requested by some UAs */
 751                         'accept-encoding',
 752                         'dnt',
 753                         'origin',
 754                         /* MediaWiki whitelist */
 755                         'api-user-agent',
 756                 ] );
 757                 foreach ( $requestedHeaders as $rHeader ) {
 758                         $rHeader = strtolower( trim( $rHeader ) );
 759                         if ( !isset( $allowedAuthorHeaders[$rHeader] ) ) {
 760                                 wfDebugLog( 'api', 'CORS preflight failed on requested header: ' . $rHeader );
 761                                 return false;
 762                         }
 763                 }
 764                 return true;
 765         }
 766
 767         /**
 768          * Helper function to convert wildcard string into a regex
 769          * '*' => '.*?'
 770          * '?' => '.'
 771          *
 772          * @param string $wildcard String with wildcards
 773          * @return string Regular expression
 774          */
 775         protected static function wildcardToRegex( $wildcard ) {
 776                 $wildcard = preg_quote( $wildcard, '/' );
 777                 $wildcard = str_replace(
 778                         [ '\*', '\?' ],
 779                         [ '.*?', '.' ],
 780                         $wildcard
 781                 );
 782
 783                 return "/^https?:\/\/$wildcard$/";
 784         }
 785
 786         /**
 787          * Send caching headers
 788          * @param bool $isError Whether an error response is being output
 789          * @since 1.26 added $isError parameter
 790          */
 791         protected function sendCacheHeaders( $isError ) {
 792                 $response = $this->getRequest()->response();
 793                 $out = $this->getOutput();
 794
 795                 $out->addVaryHeader( 'Treat-as-Untrusted' );
 796
 797                 $config = $this->getConfig();
 798
 799                 if ( $config->get( 'VaryOnXFP' ) ) {
 800                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 801                 }
 802
 803                 if ( !$isError && $this->mModule &&
 804                         ( $this->getRequest()->getMethod() === 'GET' || $this->getRequest()->getMethod() === 'HEAD' )
 805                 ) {
 806                         $etag = $this->mModule->getConditionalRequestData( 'etag' );
 807                         if ( $etag !== null ) {
 808                                 $response->header( "ETag: $etag" );
 809                         }
 810                         $lastMod = $this->mModule->getConditionalRequestData( 'last-modified' );
 811                         if ( $lastMod !== null ) {
 812                                 $response->header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $lastMod ) );
 813                         }
 814                 }
 815
 816                 // The logic should be:
 817                 // $this->mCacheControl['max-age'] is set?
 818                 //    Use it, the module knows better than our guess.
 819                 // !$this->mModule || $this->mModule->isWriteMode(), and mCacheMode is private?
 820                 //    Use 0 because we can guess caching is probably the wrong thing to do.
 821                 // Use $this->getParameter( 'maxage' ), which already defaults to 0.
 822                 $maxage = 0;
 823                 if ( isset( $this->mCacheControl['max-age'] ) ) {
 824                         $maxage = $this->mCacheControl['max-age'];
 825                 } elseif ( ( $this->mModule && !$this->mModule->isWriteMode() ) ||
 826                         $this->mCacheMode !== 'private'
 827                 ) {
 828                         $maxage = $this->getParameter( 'maxage' );
 829                 }
 830                 $privateCache = 'private, must-revalidate, max-age=' . $maxage;
 831
 832                 if ( $this->mCacheMode == 'private' ) {
 833                         $response->header( "Cache-Control: $privateCache" );
 834                         return;
 835                 }
 836
 837                 $useKeyHeader = $config->get( 'UseKeyHeader' );
 838                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 839                         $out->addVaryHeader( 'Cookie' );
 840                         $response->header( $out->getVaryHeader() );
 841                         if ( $useKeyHeader ) {
 842                                 $response->header( $out->getKeyHeader() );
 843                                 if ( $out->haveCacheVaryCookies() ) {
 844                                         // Logged in, mark this request private
 845                                         $response->header( "Cache-Control: $privateCache" );
 846                                         return;
 847                                 }
 848                                 // Logged out, send normal public headers below
 849                         } elseif ( MediaWiki\Session\SessionManager::getGlobalSession()->isPersistent() ) {
 850                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 851                                 // Mark request private
 852                                 $response->header( "Cache-Control: $privateCache" );
 853
 854                                 return;
 855                         } // else no Key and anonymous, send public headers below
 856                 }
 857
 858                 // Send public headers
 859                 $response->header( $out->getVaryHeader() );
 860                 if ( $useKeyHeader ) {
 861                         $response->header( $out->getKeyHeader() );
 862                 }
 863
 864                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 865                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 866                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 867                 }
 868                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 869                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 870                 }
 871
 872                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 873                         // Public cache not requested
 874                         // Sending a Vary header in this case is harmless, and protects us
 875                         // against conditional calls of setCacheMaxAge().
 876                         $response->header( "Cache-Control: $privateCache" );
 877
 878                         return;
 879                 }
 880
 881                 $this->mCacheControl['public'] = true;
 882
 883                 // Send an Expires header
 884                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 885                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 886                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 887
 888                 // Construct the Cache-Control header
 889                 $ccHeader = '';
 890                 $separator = '';
 891                 foreach ( $this->mCacheControl as $name => $value ) {
 892                         if ( is_bool( $value ) ) {
 893                                 if ( $value ) {
 894                                         $ccHeader .= $separator . $name;
 895                                         $separator = ', ';
 896                                 }
 897                         } else {
 898                                 $ccHeader .= $separator . "$name=$value";
 899                                 $separator = ', ';
 900                         }
 901                 }
 902
 903                 $response->header( "Cache-Control: $ccHeader" );
 904         }
 905
 906         /**
 907          * Create the printer for error output
 908          */
 909         private function createErrorPrinter() {
 910                 if ( !isset( $this->mPrinter ) ) {
 911                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 912                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
 913                                 $value = self::API_DEFAULT_FORMAT;
 914                         }
 915                         $this->mPrinter = $this->createPrinterByName( $value );
 916                 }
 917
 918                 // Printer may not be able to handle errors. This is particularly
 919                 // likely if the module returns something for getCustomPrinter().
 920                 if ( !$this->mPrinter->canPrintErrors() ) {
 921                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
 922                 }
 923         }
 924
 925         /**
 926          * Create an error message for the given exception.
 927          *
 928          * If the exception is a UsageException then
 929          * UsageException::getMessageArray() will be called to create the message.
 930          *
 931          * @param Exception $e
 932          * @return array ['code' => 'some string', 'info' => 'some other string']
 933          * @since 1.27
 934          */
 935         protected function errorMessageFromException( $e ) {
 936                 if ( $e instanceof UsageException ) {
 937                         // User entered incorrect parameters - generate error response
 938                         $errMessage = $e->getMessageArray();
 939                 } else {
 940                         $config = $this->getConfig();
 941                         // Something is seriously wrong
 942                         if ( ( $e instanceof DBQueryError ) && !$config->get( 'ShowSQLErrors' ) ) {
 943                                 $info = 'Database query error';
 944                         } else {
 945                                 $info = "Exception Caught: {$e->getMessage()}";
 946                         }
 947
 948                         $errMessage = [
 949                                 'code' => 'internal_api_error_' . get_class( $e ),
 950                                 'info' => '[' . WebRequest::getRequestId() . '] ' . $info,
 951                         ];
 952                 }
 953                 return $errMessage;
 954         }
 955
 956         /**
 957          * Replace the result data with the information about an exception.
 958          * Returns the error code
 959          * @param Exception $e
 960          * @return string
 961          */
 962         protected function substituteResultWithError( $e ) {
 963                 $result = $this->getResult();
 964                 $config = $this->getConfig();
 965
 966                 $errMessage = $this->errorMessageFromException( $e );
 967                 if ( $e instanceof UsageException ) {
 968                         // User entered incorrect parameters - generate error response
 969                         $link = wfExpandUrl( wfScript( 'api' ) );
 970                         ApiResult::setContentValue( $errMessage, 'docref', "See $link for API usage" );
 971                 } else {
 972                         // Something is seriously wrong
 973                         if ( $config->get( 'ShowExceptionDetails' ) ) {
 974                                 ApiResult::setContentValue(
 975                                         $errMessage,
 976                                         'trace',
 977                                         MWExceptionHandler::getRedactedTraceAsString( $e )
 978                                 );
 979                         }
 980                 }
 981
 982                 // Remember all the warnings to re-add them later
 983                 $warnings = $result->getResultData( [ 'warnings' ] );
 984
 985                 $result->reset();
 986                 // Re-add the id
 987                 $requestid = $this->getParameter( 'requestid' );
 988                 if ( !is_null( $requestid ) ) {
 989                         $result->addValue( null, 'requestid', $requestid, ApiResult::NO_SIZE_CHECK );
 990                 }
 991                 if ( $config->get( 'ShowHostnames' ) ) {
 992                         // servedby is especially useful when debugging errors
 993                         $result->addValue( null, 'servedby', wfHostname(), ApiResult::NO_SIZE_CHECK );
 994                 }
 995                 if ( $warnings !== null ) {
 996                         $result->addValue( null, 'warnings', $warnings, ApiResult::NO_SIZE_CHECK );
 997                 }
 998
 999                 $result->addValue( null, 'error', $errMessage, ApiResult::NO_SIZE_CHECK );
1000
1001                 return $errMessage['code'];
1002         }
1003
1004         /**
1005          * Set up for the execution.
1006          * @return array
1007          */
1008         protected function setupExecuteAction() {
1009                 // First add the id to the top element
1010                 $result = $this->getResult();
1011                 $requestid = $this->getParameter( 'requestid' );
1012                 if ( !is_null( $requestid ) ) {
1013                         $result->addValue( null, 'requestid', $requestid );
1014                 }
1015
1016                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1017                         $servedby = $this->getParameter( 'servedby' );
1018                         if ( $servedby ) {
1019                                 $result->addValue( null, 'servedby', wfHostname() );
1020                         }
1021                 }
1022
1023                 if ( $this->getParameter( 'curtimestamp' ) ) {
1024                         $result->addValue( null, 'curtimestamp', wfTimestamp( TS_ISO_8601, time() ),
1025                                 ApiResult::NO_SIZE_CHECK );
1026                 }
1027
1028                 $params = $this->extractRequestParams();
1029
1030                 $this->mAction = $params['action'];
1031
1032                 if ( !is_string( $this->mAction ) ) {
1033                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
1034                 }
1035
1036                 return $params;
1037         }
1038
1039         /**
1040          * Set up the module for response
1041          * @return ApiBase The module that will handle this action
1042          * @throws MWException
1043          * @throws UsageException
1044          */
1045         protected function setupModule() {
1046                 // Instantiate the module requested by the user
1047                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
1048                 if ( $module === null ) {
1049                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
1050                 }
1051                 $moduleParams = $module->extractRequestParams();
1052
1053                 // Check token, if necessary
1054                 if ( $module->needsToken() === true ) {
1055                         throw new MWException(
1056                                 "Module '{$module->getModuleName()}' must be updated for the new token handling. " .
1057                                 'See documentation for ApiBase::needsToken for details.'
1058                         );
1059                 }
1060                 if ( $module->needsToken() ) {
1061                         if ( !$module->mustBePosted() ) {
1062                                 throw new MWException(
1063                                         "Module '{$module->getModuleName()}' must require POST to use tokens."
1064                                 );
1065                         }
1066
1067                         if ( !isset( $moduleParams['token'] ) ) {
1068                                 $this->dieUsageMsg( [ 'missingparam', 'token' ] );
1069                         }
1070
1071                         if ( !$this->getConfig()->get( 'DebugAPI' ) &&
1072                                 array_key_exists(
1073                                         $module->encodeParamName( 'token' ),
1074                                         $this->getRequest()->getQueryValues()
1075                                 )
1076                         ) {
1077                                 $this->dieUsage(
1078                                         "The '{$module->encodeParamName( 'token' )}' parameter was " .
1079                                                 'found in the query string, but must be in the POST body',
1080                                         'mustposttoken'
1081                                 );
1082                         }
1083
1084                         if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
1085                                 $this->dieUsageMsg( 'sessionfailure' );
1086                         }
1087                 }
1088
1089                 return $module;
1090         }
1091
1092         /**
1093          * Check the max lag if necessary
1094          * @param ApiBase $module Api module being used
1095          * @param array $params Array an array containing the request parameters.
1096          * @return bool True on success, false should exit immediately
1097          */
1098         protected function checkMaxLag( $module, $params ) {
1099                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
1100                         $maxLag = $params['maxlag'];
1101                         list( $host, $lag ) = wfGetLB()->getMaxLag();
1102                         if ( $lag > $maxLag ) {
1103                                 $response = $this->getRequest()->response();
1104
1105                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
1106                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
1107
1108                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1109                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
1110                                 }
1111
1112                                 $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
1113                         }
1114                 }
1115
1116                 return true;
1117         }
1118
1119         /**
1120          * Check selected RFC 7232 precondition headers
1121          *
1122          * RFC 7232 envisions a particular model where you send your request to "a
1123          * resource", and for write requests that you can read "the resource" by
1124          * changing the method to GET. When the API receives a GET request, it
1125          * works out even though "the resource" from RFC 7232's perspective might
1126          * be many resources from MediaWiki's perspective. But it totally fails for
1127          * a POST, since what HTTP sees as "the resource" is probably just
1128          * "/api.php" with all the interesting bits in the body.
1129          *
1130          * Therefore, we only support RFC 7232 precondition headers for GET (and
1131          * HEAD). That means we don't need to bother with If-Match and
1132          * If-Unmodified-Since since they only apply to modification requests.
1133          *
1134          * And since we don't support Range, If-Range is ignored too.
1135          *
1136          * @since 1.26
1137          * @param ApiBase $module Api module being used
1138          * @return bool True on success, false should exit immediately
1139          */
1140         protected function checkConditionalRequestHeaders( $module ) {
1141                 if ( $this->mInternalMode ) {
1142                         // No headers to check in internal mode
1143                         return true;
1144                 }
1145
1146                 if ( $this->getRequest()->getMethod() !== 'GET' && $this->getRequest()->getMethod() !== 'HEAD' ) {
1147                         // Don't check POSTs
1148                         return true;
1149                 }
1150
1151                 $return304 = false;
1152
1153                 $ifNoneMatch = array_diff(
1154                         $this->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST ) ?: [],
1155                         [ '' ]
1156                 );
1157                 if ( $ifNoneMatch ) {
1158                         if ( $ifNoneMatch === [ '*' ] ) {
1159                                 // API responses always "exist"
1160                                 $etag = '*';
1161                         } else {
1162                                 $etag = $module->getConditionalRequestData( 'etag' );
1163                         }
1164                 }
1165                 if ( $ifNoneMatch && $etag !== null ) {
1166                         $test = substr( $etag, 0, 2 ) === 'W/' ? substr( $etag, 2 ) : $etag;
1167                         $match = array_map( function ( $s ) {
1168                                 return substr( $s, 0, 2 ) === 'W/' ? substr( $s, 2 ) : $s;
1169                         }, $ifNoneMatch );
1170                         $return304 = in_array( $test, $match, true );
1171                 } else {
1172                         $value = trim( $this->getRequest()->getHeader( 'If-Modified-Since' ) );
1173
1174                         // Some old browsers sends sizes after the date, like this:
1175                         //  Wed, 20 Aug 2003 06:51:19 GMT; length=5202
1176                         // Ignore that.
1177                         $i = strpos( $value, ';' );
1178                         if ( $i !== false ) {
1179                                 $value = trim( substr( $value, 0, $i ) );
1180                         }
1181
1182                         if ( $value !== '' ) {
1183                                 try {
1184                                         $ts = new MWTimestamp( $value );
1185                                         if (
1186                                                 // RFC 7231 IMF-fixdate
1187                                                 $ts->getTimestamp( TS_RFC2822 ) === $value ||
1188                                                 // RFC 850
1189                                                 $ts->format( 'l, d-M-y H:i:s' ) . ' GMT' === $value ||
1190                                                 // asctime (with and without space-padded day)
1191                                                 $ts->format( 'D M j H:i:s Y' ) === $value ||
1192                                                 $ts->format( 'D M  j H:i:s Y' ) === $value
1193                                         ) {
1194                                                 $lastMod = $module->getConditionalRequestData( 'last-modified' );
1195                                                 if ( $lastMod !== null ) {
1196                                                         // Mix in some MediaWiki modification times
1197                                                         $modifiedTimes = [
1198                                                                 'page' => $lastMod,
1199                                                                 'user' => $this->getUser()->getTouched(),
1200                                                                 'epoch' => $this->getConfig()->get( 'CacheEpoch' ),
1201                                                         ];
1202                                                         if ( $this->getConfig()->get( 'UseSquid' ) ) {
1203                                                                 // T46570: the core page itself may not change, but resources might
1204                                                                 $modifiedTimes['sepoch'] = wfTimestamp(
1205                                                                         TS_MW, time() - $this->getConfig()->get( 'SquidMaxage' )
1206                                                                 );
1207                                                         }
1208                                                         Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this->getOutput() ] );
1209                                                         $lastMod = max( $modifiedTimes );
1210                                                         $return304 = wfTimestamp( TS_MW, $lastMod ) <= $ts->getTimestamp( TS_MW );
1211                                                 }
1212                                         }
1213                                 } catch ( TimestampException $e ) {
1214                                         // Invalid timestamp, ignore it
1215                                 }
1216                         }
1217                 }
1218
1219                 if ( $return304 ) {
1220                         $this->getRequest()->response()->statusHeader( 304 );
1221
1222                         // Avoid outputting the compressed representation of a zero-length body
1223                         MediaWiki\suppressWarnings();
1224                         ini_set( 'zlib.output_compression', 0 );
1225                         MediaWiki\restoreWarnings();
1226                         wfClearOutputBuffers();
1227
1228                         return false;
1229                 }
1230
1231                 return true;
1232         }
1233
1234         /**
1235          * Check for sufficient permissions to execute
1236          * @param ApiBase $module An Api module
1237          */
1238         protected function checkExecutePermissions( $module ) {
1239                 $user = $this->getUser();
1240                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
1241                         !$user->isAllowed( 'read' )
1242                 ) {
1243                         $this->dieUsageMsg( 'readrequired' );
1244                 }
1245
1246                 if ( $module->isWriteMode() ) {
1247                         if ( !$this->mEnableWrite ) {
1248                                 $this->dieUsageMsg( 'writedisabled' );
1249                         } elseif ( !$user->isAllowed( 'writeapi' ) ) {
1250                                 $this->dieUsageMsg( 'writerequired' );
1251                         } elseif ( $this->getRequest()->getHeader( 'Promise-Non-Write-API-Action' ) ) {
1252                                 $this->dieUsage(
1253                                         'Promise-Non-Write-API-Action HTTP header cannot be sent to write API modules',
1254                                         'promised-nonwrite-api'
1255                                 );
1256                         }
1257
1258                         $this->checkReadOnly( $module );
1259                 }
1260
1261                 // Allow extensions to stop execution for arbitrary reasons.
1262                 $message = false;
1263                 if ( !Hooks::run( 'ApiCheckCanExecute', [ $module, $user, &$message ] ) ) {
1264                         $this->dieUsageMsg( $message );
1265                 }
1266         }
1267
1268         /**
1269          * Check if the DB is read-only for this user
1270          * @param ApiBase $module An Api module
1271          */
1272         protected function checkReadOnly( $module ) {
1273                 if ( wfReadOnly() ) {
1274                         $this->dieReadOnly();
1275                 }
1276
1277                 if ( $module->isWriteMode()
1278                         && in_array( 'bot', $this->getUser()->getGroups() )
1279                         && wfGetLB()->getServerCount() > 1
1280                 ) {
1281                         $this->checkBotReadOnly();
1282                 }
1283         }
1284
1285         /**
1286          * Check whether we are readonly for bots
1287          */
1288         private function checkBotReadOnly() {
1289                 // Figure out how many servers have passed the lag threshold
1290                 $numLagged = 0;
1291                 $lagLimit = $this->getConfig()->get( 'APIMaxLagThreshold' );
1292                 $laggedServers = [];
1293                 $loadBalancer = wfGetLB();
1294                 foreach ( $loadBalancer->getLagTimes() as $serverIndex => $lag ) {
1295                         if ( $lag > $lagLimit ) {
1296                                 ++$numLagged;
1297                                 $laggedServers[] = $loadBalancer->getServerName( $serverIndex ) . " ({$lag}s)";
1298                         }
1299                 }
1300
1301                 // If a majority of slaves are too lagged then disallow writes
1302                 $slaveCount = wfGetLB()->getServerCount() - 1;
1303                 if ( $numLagged >= ceil( $slaveCount / 2 ) ) {
1304                         $laggedServers = implode( ', ', $laggedServers );
1305                         wfDebugLog(
1306                                 'api-readonly',
1307                                 "Api request failed as read only because the following DBs are lagged: $laggedServers"
1308                         );
1309
1310                         $parsed = $this->parseMsg( [ 'readonlytext' ] );
1311                         $this->dieUsage(
1312                                 $parsed['info'],
1313                                 $parsed['code'],
1314                                 /* http error */
1315                                 0,
1316                                 [ 'readonlyreason' => "Waiting for $numLagged lagged database(s)" ]
1317                         );
1318                 }
1319         }
1320
1321         /**
1322          * Check asserts of the user's rights
1323          * @param array $params
1324          */
1325         protected function checkAsserts( $params ) {
1326                 if ( isset( $params['assert'] ) ) {
1327                         $user = $this->getUser();
1328                         switch ( $params['assert'] ) {
1329                                 case 'user':
1330                                         if ( $user->isAnon() ) {
1331                                                 $this->dieUsage( 'Assertion that the user is logged in failed', 'assertuserfailed' );
1332                                         }
1333                                         break;
1334                                 case 'bot':
1335                                         if ( !$user->isAllowed( 'bot' ) ) {
1336                                                 $this->dieUsage( 'Assertion that the user has the bot right failed', 'assertbotfailed' );
1337                                         }
1338                                         break;
1339                         }
1340                 }
1341         }
1342
1343         /**
1344          * Check POST for external response and setup result printer
1345          * @param ApiBase $module An Api module
1346          * @param array $params An array with the request parameters
1347          */
1348         protected function setupExternalResponse( $module, $params ) {
1349                 $request = $this->getRequest();
1350                 if ( !$request->wasPosted() && $module->mustBePosted() ) {
1351                         // Module requires POST. GET request might still be allowed
1352                         // if $wgDebugApi is true, otherwise fail.
1353                         $this->dieUsageMsgOrDebug( [ 'mustbeposted', $this->mAction ] );
1354                 }
1355
1356                 // See if custom printer is used
1357                 $this->mPrinter = $module->getCustomPrinter();
1358                 if ( is_null( $this->mPrinter ) ) {
1359                         // Create an appropriate printer
1360                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
1361                 }
1362
1363                 if ( $request->getProtocol() === 'http' && (
1364                         $request->getSession()->shouldForceHTTPS() ||
1365                         ( $this->getUser()->isLoggedIn() &&
1366                                 $this->getUser()->requiresHTTPS() )
1367                 ) ) {
1368                         $this->logFeatureUsage( 'https-expected' );
1369                         $this->setWarning( 'HTTP used when HTTPS was expected' );
1370                 }
1371         }
1372
1373         /**
1374          * Execute the actual module, without any error handling
1375          */
1376         protected function executeAction() {
1377                 $params = $this->setupExecuteAction();
1378                 $module = $this->setupModule();
1379                 $this->mModule = $module;
1380
1381                 if ( !$this->mInternalMode ) {
1382                         $this->setRequestExpectations( $module );
1383                 }
1384
1385                 $this->checkExecutePermissions( $module );
1386
1387                 if ( !$this->checkMaxLag( $module, $params ) ) {
1388                         return;
1389                 }
1390
1391                 if ( !$this->checkConditionalRequestHeaders( $module ) ) {
1392                         return;
1393                 }
1394
1395                 if ( !$this->mInternalMode ) {
1396                         $this->setupExternalResponse( $module, $params );
1397                 }
1398
1399                 $this->checkAsserts( $params );
1400
1401                 // Execute
1402                 $module->execute();
1403                 Hooks::run( 'APIAfterExecute', [ &$module ] );
1404
1405                 $this->reportUnusedParams();
1406
1407                 if ( !$this->mInternalMode ) {
1408                         // append Debug information
1409                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
1410
1411                         // Print result data
1412                         $this->printResult( false );
1413                 }
1414         }
1415
1416         /**
1417          * Set database connection, query, and write expectations given this module request
1418          * @param ApiBase $module
1419          */
1420         protected function setRequestExpectations( ApiBase $module ) {
1421                 $limits = $this->getConfig()->get( 'TrxProfilerLimits' );
1422                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1423                 if ( $this->getRequest()->hasSafeMethod() ) {
1424                         $trxProfiler->setExpectations( $limits['GET'], __METHOD__ );
1425                 } elseif ( $this->getRequest()->wasPosted() && !$module->isWriteMode() ) {
1426                         $trxProfiler->setExpectations( $limits['POST-nonwrite'], __METHOD__ );
1427                         $this->getRequest()->markAsSafeRequest();
1428                 } else {
1429                         $trxProfiler->setExpectations( $limits['POST'], __METHOD__ );
1430                 }
1431         }
1432
1433         /**
1434          * Log the preceding request
1435          * @param float $time Time in seconds
1436          * @param Exception $e Exception caught while processing the request
1437          */
1438         protected function logRequest( $time, $e = null ) {
1439                 $request = $this->getRequest();
1440                 $logCtx = [
1441                         'ts' => time(),
1442                         'ip' => $request->getIP(),
1443                         'userAgent' => $this->getUserAgent(),
1444                         'wiki' => wfWikiID(),
1445                         'timeSpentBackend' => (int) round( $time * 1000 ),
1446                         'hadError' => $e !== null,
1447                         'errorCodes' => [],
1448                         'params' => [],
1449                 ];
1450
1451                 if ( $e ) {
1452                         $logCtx['errorCodes'][] = $this->errorMessageFromException( $e )['code'];
1453                 }
1454
1455                 // Construct space separated message for 'api' log channel
1456                 $msg = "API {$request->getMethod()} " .
1457                         wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
1458                         " {$logCtx['ip']} " .
1459                         "T={$logCtx['timeSpentBackend']}ms";
1460
1461                 foreach ( $this->getParamsUsed() as $name ) {
1462                         $value = $request->getVal( $name );
1463                         if ( $value === null ) {
1464                                 continue;
1465                         }
1466
1467                         if ( strlen( $value ) > 256 ) {
1468                                 $value = substr( $value, 0, 256 );
1469                                 $encValue = $this->encodeRequestLogValue( $value ) . '[...]';
1470                         } else {
1471                                 $encValue = $this->encodeRequestLogValue( $value );
1472                         }
1473
1474                         $logCtx['params'][$name] = $value;
1475                         $msg .= " {$name}={$encValue}";
1476                 }
1477
1478                 wfDebugLog( 'api', $msg, 'private' );
1479                 // ApiAction channel is for structured data consumers
1480                 wfDebugLog( 'ApiAction', '', 'private', $logCtx );
1481         }
1482
1483         /**
1484          * Encode a value in a format suitable for a space-separated log line.
1485          * @param string $s
1486          * @return string
1487          */
1488         protected function encodeRequestLogValue( $s ) {
1489                 static $table;
1490                 if ( !$table ) {
1491                         $chars = ';@$!*(),/:';
1492                         $numChars = strlen( $chars );
1493                         for ( $i = 0; $i < $numChars; $i++ ) {
1494                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
1495                         }
1496                 }
1497
1498                 return strtr( rawurlencode( $s ), $table );
1499         }
1500
1501         /**
1502          * Get the request parameters used in the course of the preceding execute() request
1503          * @return array
1504          */
1505         protected function getParamsUsed() {
1506                 return array_keys( $this->mParamsUsed );
1507         }
1508
1509         /**
1510          * Mark parameters as used
1511          * @param string|string[] $params
1512          */
1513         public function markParamsUsed( $params ) {
1514                 $this->mParamsUsed += array_fill_keys( (array)$params, true );
1515         }
1516
1517         /**
1518          * Get a request value, and register the fact that it was used, for logging.
1519          * @param string $name
1520          * @param mixed $default
1521          * @return mixed
1522          */
1523         public function getVal( $name, $default = null ) {
1524                 $this->mParamsUsed[$name] = true;
1525
1526                 $ret = $this->getRequest()->getVal( $name );
1527                 if ( $ret === null ) {
1528                         if ( $this->getRequest()->getArray( $name ) !== null ) {
1529                                 // See bug 10262 for why we don't just implode( '|', ... ) the
1530                                 // array.
1531                                 $this->setWarning(
1532                                         "Parameter '$name' uses unsupported PHP array syntax"
1533                                 );
1534                         }
1535                         $ret = $default;
1536                 }
1537                 return $ret;
1538         }
1539
1540         /**
1541          * Get a boolean request value, and register the fact that the parameter
1542          * was used, for logging.
1543          * @param string $name
1544          * @return bool
1545          */
1546         public function getCheck( $name ) {
1547                 return $this->getVal( $name, null ) !== null;
1548         }
1549
1550         /**
1551          * Get a request upload, and register the fact that it was used, for logging.
1552          *
1553          * @since 1.21
1554          * @param string $name Parameter name
1555          * @return WebRequestUpload
1556          */
1557         public function getUpload( $name ) {
1558                 $this->mParamsUsed[$name] = true;
1559
1560                 return $this->getRequest()->getUpload( $name );
1561         }
1562
1563         /**
1564          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1565          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1566          */
1567         protected function reportUnusedParams() {
1568                 $paramsUsed = $this->getParamsUsed();
1569                 $allParams = $this->getRequest()->getValueNames();
1570
1571                 if ( !$this->mInternalMode ) {
1572                         // Printer has not yet executed; don't warn that its parameters are unused
1573                         $printerParams = array_map(
1574                                 [ $this->mPrinter, 'encodeParamName' ],
1575                                 array_keys( $this->mPrinter->getFinalParams() ?: [] )
1576                         );
1577                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1578                 } else {
1579                         $unusedParams = array_diff( $allParams, $paramsUsed );
1580                 }
1581
1582                 if ( count( $unusedParams ) ) {
1583                         $s = count( $unusedParams ) > 1 ? 's' : '';
1584                         $this->setWarning( "Unrecognized parameter$s: '" . implode( $unusedParams, "', '" ) . "'" );
1585                 }
1586         }
1587
1588         /**
1589          * Print results using the current printer
1590          *
1591          * @param bool $isError
1592          */
1593         protected function printResult( $isError ) {
1594                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1595                         $this->setWarning( 'SECURITY WARNING: $wgDebugAPI is enabled' );
1596                 }
1597
1598                 $printer = $this->mPrinter;
1599                 $printer->initPrinter( false );
1600                 $printer->execute();
1601                 $printer->closePrinter();
1602         }
1603
1604         /**
1605          * @return bool
1606          */
1607         public function isReadMode() {
1608                 return false;
1609         }
1610
1611         /**
1612          * See ApiBase for description.
1613          *
1614          * @return array
1615          */
1616         public function getAllowedParams() {
1617                 return [
1618                         'action' => [
1619                                 ApiBase::PARAM_DFLT => 'help',
1620                                 ApiBase::PARAM_TYPE => 'submodule',
1621                         ],
1622                         'format' => [
1623                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1624                                 ApiBase::PARAM_TYPE => 'submodule',
1625                         ],
1626                         'maxlag' => [
1627                                 ApiBase::PARAM_TYPE => 'integer'
1628                         ],
1629                         'smaxage' => [
1630                                 ApiBase::PARAM_TYPE => 'integer',
1631                                 ApiBase::PARAM_DFLT => 0
1632                         ],
1633                         'maxage' => [
1634                                 ApiBase::PARAM_TYPE => 'integer',
1635                                 ApiBase::PARAM_DFLT => 0
1636                         ],
1637                         'assert' => [
1638                                 ApiBase::PARAM_TYPE => [ 'user', 'bot' ]
1639                         ],
1640                         'requestid' => null,
1641                         'servedby' => false,
1642                         'curtimestamp' => false,
1643                         'origin' => null,
1644                         'uselang' => [
1645                                 ApiBase::PARAM_DFLT => 'user',
1646                         ],
1647                 ];
1648         }
1649
1650         /** @see ApiBase::getExamplesMessages() */
1651         protected function getExamplesMessages() {
1652                 return [
1653                         'action=help'
1654                                 => 'apihelp-help-example-main',
1655                         'action=help&recursivesubmodules=1'
1656                                 => 'apihelp-help-example-recursive',
1657                 ];
1658         }
1659
1660         public function modifyHelp( array &$help, array $options, array &$tocData ) {
1661                 // Wish PHP had an "array_insert_before". Instead, we have to manually
1662                 // reindex the array to get 'permissions' in the right place.
1663                 $oldHelp = $help;
1664                 $help = [];
1665                 foreach ( $oldHelp as $k => $v ) {
1666                         if ( $k === 'submodules' ) {
1667                                 $help['permissions'] = '';
1668                         }
1669                         $help[$k] = $v;
1670                 }
1671                 $help['datatypes'] = '';
1672                 $help['credits'] = '';
1673
1674                 // Fill 'permissions'
1675                 $help['permissions'] .= Html::openElement( 'div',
1676                         [ 'class' => 'apihelp-block apihelp-permissions' ] );
1677                 $m = $this->msg( 'api-help-permissions' );
1678                 if ( !$m->isDisabled() ) {
1679                         $help['permissions'] .= Html::rawElement( 'div', [ 'class' => 'apihelp-block-head' ],
1680                                 $m->numParams( count( self::$mRights ) )->parse()
1681                         );
1682                 }
1683                 $help['permissions'] .= Html::openElement( 'dl' );
1684                 foreach ( self::$mRights as $right => $rightMsg ) {
1685                         $help['permissions'] .= Html::element( 'dt', null, $right );
1686
1687                         $rightMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )->parse();
1688                         $help['permissions'] .= Html::rawElement( 'dd', null, $rightMsg );
1689
1690                         $groups = array_map( function ( $group ) {
1691                                 return $group == '*' ? 'all' : $group;
1692                         }, User::getGroupsWithPermission( $right ) );
1693
1694                         $help['permissions'] .= Html::rawElement( 'dd', null,
1695                                 $this->msg( 'api-help-permissions-granted-to' )
1696                                         ->numParams( count( $groups ) )
1697                                         ->params( $this->getLanguage()->commaList( $groups ) )
1698                                         ->parse()
1699                         );
1700                 }
1701                 $help['permissions'] .= Html::closeElement( 'dl' );
1702                 $help['permissions'] .= Html::closeElement( 'div' );
1703
1704                 // Fill 'datatypes' and 'credits', if applicable
1705                 if ( empty( $options['nolead'] ) ) {
1706                         $level = $options['headerlevel'];
1707                         $tocnumber = &$options['tocnumber'];
1708
1709                         $header = $this->msg( 'api-help-datatypes-header' )->parse();
1710
1711                         // Add an additional span with sanitized ID
1712                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1713                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/datatypes' ) ] ) .
1714                                         $header;
1715                         }
1716                         $help['datatypes'] .= Html::rawElement( 'h' . min( 6, $level ),
1717                                 [ 'id' => 'main/datatypes', 'class' => 'apihelp-header' ],
1718                                 $header
1719                         );
1720                         $help['datatypes'] .= $this->msg( 'api-help-datatypes' )->parseAsBlock();
1721                         if ( !isset( $tocData['main/datatypes'] ) ) {
1722                                 $tocnumber[$level]++;
1723                                 $tocData['main/datatypes'] = [
1724                                         'toclevel' => count( $tocnumber ),
1725                                         'level' => $level,
1726                                         'anchor' => 'main/datatypes',
1727                                         'line' => $header,
1728                                         'number' => implode( '.', $tocnumber ),
1729                                         'index' => false,
1730                                 ];
1731                         }
1732
1733                         // Add an additional span with sanitized ID
1734                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1735                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/credits' ) ] ) .
1736                                         $header;
1737                         }
1738                         $header = $this->msg( 'api-credits-header' )->parse();
1739                         $help['credits'] .= Html::rawElement( 'h' . min( 6, $level ),
1740                                 [ 'id' => 'main/credits', 'class' => 'apihelp-header' ],
1741                                 $header
1742                         );
1743                         $help['credits'] .= $this->msg( 'api-credits' )->useDatabase( false )->parseAsBlock();
1744                         if ( !isset( $tocData['main/credits'] ) ) {
1745                                 $tocnumber[$level]++;
1746                                 $tocData['main/credits'] = [
1747                                         'toclevel' => count( $tocnumber ),
1748                                         'level' => $level,
1749                                         'anchor' => 'main/credits',
1750                                         'line' => $header,
1751                                         'number' => implode( '.', $tocnumber ),
1752                                         'index' => false,
1753                                 ];
1754                         }
1755                 }
1756         }
1757
1758         private $mCanApiHighLimits = null;
1759
1760         /**
1761          * Check whether the current user is allowed to use high limits
1762          * @return bool
1763          */
1764         public function canApiHighLimits() {
1765                 if ( !isset( $this->mCanApiHighLimits ) ) {
1766                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1767                 }
1768
1769                 return $this->mCanApiHighLimits;
1770         }
1771
1772         /**
1773          * Overrides to return this instance's module manager.
1774          * @return ApiModuleManager
1775          */
1776         public function getModuleManager() {
1777                 return $this->mModuleMgr;
1778         }
1779
1780         /**
1781          * Fetches the user agent used for this request
1782          *
1783          * The value will be the combination of the 'Api-User-Agent' header (if
1784          * any) and the standard User-Agent header (if any).
1785          *
1786          * @return string
1787          */
1788         public function getUserAgent() {
1789                 return trim(
1790                         $this->getRequest()->getHeader( 'Api-user-agent' ) . ' ' .
1791                         $this->getRequest()->getHeader( 'User-agent' )
1792                 );
1793         }
1794
1795         /************************************************************************//**
1796          * @name   Deprecated
1797          * @{
1798          */
1799
1800         /**
1801          * Sets whether the pretty-printer should format *bold* and $italics$
1802          *
1803          * @deprecated since 1.25
1804          * @param bool $help
1805          */
1806         public function setHelp( $help = true ) {
1807                 wfDeprecated( __METHOD__, '1.25' );
1808                 $this->mPrinter->setHelp( $help );
1809         }
1810
1811         /**
1812          * Override the parent to generate help messages for all available modules.
1813          *
1814          * @deprecated since 1.25
1815          * @return string
1816          */
1817         public function makeHelpMsg() {
1818                 wfDeprecated( __METHOD__, '1.25' );
1819
1820                 $this->setHelp();
1821                 $cacheHelpTimeout = $this->getConfig()->get( 'APICacheHelpTimeout' );
1822
1823                 return ObjectCache::getMainWANInstance()->getWithSetCallback(
1824                         wfMemcKey(
1825                                 'apihelp',
1826                                 $this->getModuleName(),
1827                                 str_replace( ' ', '_', SpecialVersion::getVersion( 'nodb' ) )
1828                         ),
1829                         $cacheHelpTimeout > 0 ? $cacheHelpTimeout : WANObjectCache::TTL_UNCACHEABLE,
1830                         [ $this, 'reallyMakeHelpMsg' ]
1831                 );
1832         }
1833
1834         /**
1835          * @deprecated since 1.25
1836          * @return mixed|string
1837          */
1838         public function reallyMakeHelpMsg() {
1839                 wfDeprecated( __METHOD__, '1.25' );
1840                 $this->setHelp();
1841
1842                 // Use parent to make default message for the main module
1843                 $msg = parent::makeHelpMsg();
1844
1845                 $asterisks = str_repeat( '*** ', 14 );
1846                 $msg .= "\n\n$asterisks Modules  $asterisks\n\n";
1847
1848                 foreach ( $this->mModuleMgr->getNames( 'action' ) as $name ) {
1849                         $module = $this->mModuleMgr->getModule( $name );
1850                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1851
1852                         $msg2 = $module->makeHelpMsg();
1853                         if ( $msg2 !== false ) {
1854                                 $msg .= $msg2;
1855                         }
1856                         $msg .= "\n";
1857                 }
1858
1859                 $msg .= "\n$asterisks Permissions $asterisks\n\n";
1860                 foreach ( self::$mRights as $right => $rightMsg ) {
1861                         $rightsMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )
1862                                 ->useDatabase( false )
1863                                 ->inLanguage( 'en' )
1864                                 ->text();
1865                         $groups = User::getGroupsWithPermission( $right );
1866                         $msg .= '* ' . $right . " *\n  $rightsMsg" .
1867                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1868                 }
1869
1870                 $msg .= "\n$asterisks Formats  $asterisks\n\n";
1871                 foreach ( $this->mModuleMgr->getNames( 'format' ) as $name ) {
1872                         $module = $this->mModuleMgr->getModule( $name );
1873                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1874                         $msg2 = $module->makeHelpMsg();
1875                         if ( $msg2 !== false ) {
1876                                 $msg .= $msg2;
1877                         }
1878                         $msg .= "\n";
1879                 }
1880
1881                 $credits = $this->msg( 'api-credits' )->useDatabase( 'false' )->inLanguage( 'en' )->text();
1882                 $credits = str_replace( "\n", "\n   ", $credits );
1883                 $msg .= "\n*** Credits: ***\n   $credits\n";
1884
1885                 return $msg;
1886         }
1887
1888         /**
1889          * @deprecated since 1.25
1890          * @param ApiBase $module
1891          * @param string $paramName What type of request is this? e.g. action,
1892          *    query, list, prop, meta, format
1893          * @return string
1894          */
1895         public static function makeHelpMsgHeader( $module, $paramName ) {
1896                 wfDeprecated( __METHOD__, '1.25' );
1897                 $modulePrefix = $module->getModulePrefix();
1898                 if ( strval( $modulePrefix ) !== '' ) {
1899                         $modulePrefix = "($modulePrefix) ";
1900                 }
1901
1902                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1903         }
1904
1905         /**@}*/
1906
1907 }
1908
1909 /**
1910  * This exception will be thrown when dieUsage is called to stop module execution.
1911  *
1912  * @ingroup API
1913  */
1914 class UsageException extends MWException {
1915
1916         private $mCodestr;
1917
1918         /**
1919          * @var null|array
1920          */
1921         private $mExtraData;
1922
1923         /**
1924          * @param string $message
1925          * @param string $codestr
1926          * @param int $code
1927          * @param array|null $extradata
1928          */
1929         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1930                 parent::__construct( $message, $code );
1931                 $this->mCodestr = $codestr;
1932                 $this->mExtraData = $extradata;
1933         }
1934
1935         /**
1936          * @return string
1937          */
1938         public function getCodeString() {
1939                 return $this->mCodestr;
1940         }
1941
1942         /**
1943          * @return array
1944          */
1945         public function getMessageArray() {
1946                 $result = [
1947                         'code' => $this->mCodestr,
1948                         'info' => $this->getMessage()
1949                 ];
1950                 if ( is_array( $this->mExtraData ) ) {
1951                         $result = array_merge( $result, $this->mExtraData );
1952                 }
1953
1954                 return $result;
1955         }
1956
1957         /**
1958          * @return string
1959          */
1960         public function __toString() {
1961                 return "{$this->getCodeString()}: {$this->getMessage()}";
1962         }
1963 }
1964
1965 /**
1966  * For really cool vim folding this needs to be at the end:
1967  * vim: foldmarker=@{,@} foldmethod=marker
1968  */