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                 } else {
 175                         $request = $this->getRequest();
 176                 }
 177
 178                 $this->mInternalMode = ( $request instanceof FauxRequest );
 179
 180                 // Special handling for the main module: $parent === $this
 181                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 182
 183                 $config = $this->getConfig();
 184
 185                 if ( !$this->mInternalMode ) {
 186                         // Log if a request with a non-whitelisted Origin header is seen
 187                         // with session cookies.
 188                         $originHeader = $request->getHeader( 'Origin' );
 189                         if ( $originHeader === false ) {
 190                                 $origins = [];
 191                         } else {
 192                                 $originHeader = trim( $originHeader );
 193                                 $origins = preg_split( '/\s+/', $originHeader );
 194                         }
 195                         $sessionCookies = array_intersect(
 196                                 array_keys( $_COOKIE ),
 197                                 MediaWiki\Session\SessionManager::singleton()->getVaryCookies()
 198                         );
 199                         if ( $origins && $sessionCookies && (
 200                                 count( $origins ) !== 1 || !self::matchOrigin(
 201                                         $origins[0],
 202                                         $config->get( 'CrossSiteAJAXdomains' ),
 203                                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 204                                 )
 205                         ) ) {
 206                                 MediaWiki\Logger\LoggerFactory::getInstance( 'cors' )->warning(
 207                                         'Non-whitelisted CORS request with session cookies', [
 208                                                 'origin' => $originHeader,
 209                                                 'cookies' => $sessionCookies,
 210                                                 'ip' => $request->getIP(),
 211                                                 'userAgent' => $this->getUserAgent(),
 212                                                 'wiki' => wfWikiID(),
 213                                         ]
 214                                 );
 215                         }
 216
 217                         // If we're in a mode that breaks the same-origin policy, strip
 218                         // user credentials for security.
 219                         if ( $this->lacksSameOriginSecurity() ) {
 220                                 global $wgUser;
 221                                 wfDebug( "API: stripping user credentials when the same-origin policy is not applied\n" );
 222                                 $wgUser = new User();
 223                                 $this->getContext()->setUser( $wgUser );
 224                         }
 225                 }
 226
 227                 $uselang = $this->getParameter( 'uselang' );
 228                 if ( $uselang === 'user' ) {
 229                         // Assume the parent context is going to return the user language
 230                         // for uselang=user (see T85635).
 231                 } else {
 232                         if ( $uselang === 'content' ) {
 233                                 global $wgContLang;
 234                                 $uselang = $wgContLang->getCode();
 235                         }
 236                         $code = RequestContext::sanitizeLangCode( $uselang );
 237                         $this->getContext()->setLanguage( $code );
 238                         if ( !$this->mInternalMode ) {
 239                                 global $wgLang;
 240                                 $wgLang = $this->getContext()->getLanguage();
 241                                 RequestContext::getMain()->setLanguage( $wgLang );
 242                         }
 243                 }
 244
 245                 $this->mModuleMgr = new ApiModuleManager( $this );
 246                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 247                 $this->mModuleMgr->addModules( $config->get( 'APIModules' ), 'action' );
 248                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 249                 $this->mModuleMgr->addModules( $config->get( 'APIFormatModules' ), 'format' );
 250
 251                 Hooks::run( 'ApiMain::moduleManager', [ $this->mModuleMgr ] );
 252
 253                 $this->mResult = new ApiResult( $this->getConfig()->get( 'APIMaxResultSize' ) );
 254                 $this->mErrorFormatter = new ApiErrorFormatter_BackCompat( $this->mResult );
 255                 $this->mResult->setErrorFormatter( $this->mErrorFormatter );
 256                 $this->mResult->setMainForContinuation( $this );
 257                 $this->mContinuationManager = null;
 258                 $this->mEnableWrite = $enableWrite;
 259
 260                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 261                 $this->mCommit = false;
 262         }
 263
 264         /**
 265          * Return true if the API was started by other PHP code using FauxRequest
 266          * @return bool
 267          */
 268         public function isInternalMode() {
 269                 return $this->mInternalMode;
 270         }
 271
 272         /**
 273          * Get the ApiResult object associated with current request
 274          *
 275          * @return ApiResult
 276          */
 277         public function getResult() {
 278                 return $this->mResult;
 279         }
 280
 281         /**
 282          * Get the security flag for the current request
 283          * @return bool
 284          */
 285         public function lacksSameOriginSecurity() {
 286                 if ( $this->lacksSameOriginSecurity !== null ) {
 287                         return $this->lacksSameOriginSecurity;
 288                 }
 289
 290                 $request = $this->getRequest();
 291
 292                 // JSONP mode
 293                 if ( $request->getVal( 'callback' ) !== null ) {
 294                         $this->lacksSameOriginSecurity = true;
 295                         return true;
 296                 }
 297
 298                 // Header to be used from XMLHTTPRequest when the request might
 299                 // otherwise be used for XSS.
 300                 if ( $request->getHeader( 'Treat-as-Untrusted' ) !== false ) {
 301                         $this->lacksSameOriginSecurity = true;
 302                         return true;
 303                 }
 304
 305                 // Allow extensions to override.
 306                 $this->lacksSameOriginSecurity = !Hooks::run( 'RequestHasSameOriginSecurity', [ $request ] );
 307                 return $this->lacksSameOriginSecurity;
 308         }
 309
 310         /**
 311          * Get the ApiErrorFormatter object associated with current request
 312          * @return ApiErrorFormatter
 313          */
 314         public function getErrorFormatter() {
 315                 return $this->mErrorFormatter;
 316         }
 317
 318         /**
 319          * Get the continuation manager
 320          * @return ApiContinuationManager|null
 321          */
 322         public function getContinuationManager() {
 323                 return $this->mContinuationManager;
 324         }
 325
 326         /**
 327          * Set the continuation manager
 328          * @param ApiContinuationManager|null
 329          */
 330         public function setContinuationManager( $manager ) {
 331                 if ( $manager !== null ) {
 332                         if ( !$manager instanceof ApiContinuationManager ) {
 333                                 throw new InvalidArgumentException( __METHOD__ . ': Was passed ' .
 334                                         is_object( $manager ) ? get_class( $manager ) : gettype( $manager )
 335                                 );
 336                         }
 337                         if ( $this->mContinuationManager !== null ) {
 338                                 throw new UnexpectedValueException(
 339                                         __METHOD__ . ': tried to set manager from ' . $manager->getSource() .
 340                                         ' when a manager is already set from ' . $this->mContinuationManager->getSource()
 341                                 );
 342                         }
 343                 }
 344                 $this->mContinuationManager = $manager;
 345         }
 346
 347         /**
 348          * Get the API module object. Only works after executeAction()
 349          *
 350          * @return ApiBase
 351          */
 352         public function getModule() {
 353                 return $this->mModule;
 354         }
 355
 356         /**
 357          * Get the result formatter object. Only works after setupExecuteAction()
 358          *
 359          * @return ApiFormatBase
 360          */
 361         public function getPrinter() {
 362                 return $this->mPrinter;
 363         }
 364
 365         /**
 366          * Set how long the response should be cached.
 367          *
 368          * @param int $maxage
 369          */
 370         public function setCacheMaxAge( $maxage ) {
 371                 $this->setCacheControl( [
 372                         'max-age' => $maxage,
 373                         's-maxage' => $maxage
 374                 ] );
 375         }
 376
 377         /**
 378          * Set the type of caching headers which will be sent.
 379          *
 380          * @param string $mode One of:
 381          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 382          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 383          *         not provided by any of these means, the object will be private.
 384          *    - 'private':    Cache this object only in private client-side caches.
 385          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 386          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 387          *         set consistently for a given URL, it cannot be set differently depending on
 388          *         things like the contents of the database, or whether the user is logged in.
 389          *
 390          *  If the wiki does not allow anonymous users to read it, the mode set here
 391          *  will be ignored, and private caching headers will always be sent. In other words,
 392          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 393          *  view.
 394          *
 395          *  For user-dependent data, the private mode should generally be used. The
 396          *  anon-public-user-private mode should only be used where there is a particularly
 397          *  good performance reason for caching the anonymous response, but where the
 398          *  response to logged-in users may differ, or may contain private data.
 399          *
 400          *  If this function is never called, then the default will be the private mode.
 401          */
 402         public function setCacheMode( $mode ) {
 403                 if ( !in_array( $mode, [ 'private', 'public', 'anon-public-user-private' ] ) ) {
 404                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 405
 406                         // Ignore for forwards-compatibility
 407                         return;
 408                 }
 409
 410                 if ( !User::isEveryoneAllowed( 'read' ) ) {
 411                         // Private wiki, only private headers
 412                         if ( $mode !== 'private' ) {
 413                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 414
 415                                 return;
 416                         }
 417                 }
 418
 419                 if ( $mode === 'public' && $this->getParameter( 'uselang' ) === 'user' ) {
 420                         // User language is used for i18n, so we don't want to publicly
 421                         // cache. Anons are ok, because if they have non-default language
 422                         // then there's an appropriate Vary header set by whatever set
 423                         // their non-default language.
 424                         wfDebug( __METHOD__ . ": downgrading cache mode 'public' to " .
 425                                 "'anon-public-user-private' due to uselang=user\n" );
 426                         $mode = 'anon-public-user-private';
 427                 }
 428
 429                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 430                 $this->mCacheMode = $mode;
 431         }
 432
 433         /**
 434          * Set directives (key/value pairs) for the Cache-Control header.
 435          * Boolean values will be formatted as such, by including or omitting
 436          * without an equals sign.
 437          *
 438          * Cache control values set here will only be used if the cache mode is not
 439          * private, see setCacheMode().
 440          *
 441          * @param array $directives
 442          */
 443         public function setCacheControl( $directives ) {
 444                 $this->mCacheControl = $directives + $this->mCacheControl;
 445         }
 446
 447         /**
 448          * Create an instance of an output formatter by its name
 449          *
 450          * @param string $format
 451          *
 452          * @return ApiFormatBase
 453          */
 454         public function createPrinterByName( $format ) {
 455                 $printer = $this->mModuleMgr->getModule( $format, 'format' );
 456                 if ( $printer === null ) {
 457                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 458                 }
 459
 460                 return $printer;
 461         }
 462
 463         /**
 464          * Execute api request. Any errors will be handled if the API was called by the remote client.
 465          */
 466         public function execute() {
 467                 if ( $this->mInternalMode ) {
 468                         $this->executeAction();
 469                 } else {
 470                         $this->executeActionWithErrorHandling();
 471                 }
 472         }
 473
 474         /**
 475          * Execute an action, and in case of an error, erase whatever partial results
 476          * have been accumulated, and replace it with an error message and a help screen.
 477          */
 478         protected function executeActionWithErrorHandling() {
 479                 // Verify the CORS header before executing the action
 480                 if ( !$this->handleCORS() ) {
 481                         // handleCORS() has sent a 403, abort
 482                         return;
 483                 }
 484
 485                 // Exit here if the request method was OPTIONS
 486                 // (assume there will be a followup GET or POST)
 487                 if ( $this->getRequest()->getMethod() === 'OPTIONS' ) {
 488                         return;
 489                 }
 490
 491                 // In case an error occurs during data output,
 492                 // clear the output buffer and print just the error information
 493                 $obLevel = ob_get_level();
 494                 ob_start();
 495
 496                 $t = microtime( true );
 497                 $isError = false;
 498                 try {
 499                         $this->executeAction();
 500                         $runTime = microtime( true ) - $t;
 501                         $this->logRequest( $runTime );
 502                         if ( $this->mModule->isWriteMode() && $this->getRequest()->wasPosted() ) {
 503                                 $this->getStats()->timing(
 504                                         'api.' . $this->mModule->getModuleName() . '.executeTiming', 1000 * $runTime
 505                                 );
 506                         }
 507                 } catch ( Exception $e ) {
 508                         $this->handleException( $e );
 509                         $this->logRequest( microtime( true ) - $t, $e );
 510                         $isError = true;
 511                 }
 512
 513                 // Commit DBs and send any related cookies and headers
 514                 MediaWiki::preOutputCommit( $this->getContext() );
 515
 516                 // Send cache headers after any code which might generate an error, to
 517                 // avoid sending public cache headers for errors.
 518                 $this->sendCacheHeaders( $isError );
 519
 520                 // Executing the action might have already messed with the output
 521                 // buffers.
 522                 while ( ob_get_level() > $obLevel ) {
 523                         ob_end_flush();
 524                 }
 525         }
 526
 527         /**
 528          * Handle an exception as an API response
 529          *
 530          * @since 1.23
 531          * @param Exception $e
 532          */
 533         protected function handleException( Exception $e ) {
 534                 // Bug 63145: Rollback any open database transactions
 535                 if ( !( $e instanceof UsageException ) ) {
 536                         // UsageExceptions are intentional, so don't rollback if that's the case
 537                         try {
 538                                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 539                         } catch ( DBError $e2 ) {
 540                                 // Rollback threw an exception too. Log it, but don't interrupt
 541                                 // our regularly scheduled exception handling.
 542                                 MWExceptionHandler::logException( $e2 );
 543                         }
 544                 }
 545
 546                 // Allow extra cleanup and logging
 547                 Hooks::run( 'ApiMain::onException', [ $this, $e ] );
 548
 549                 // Log it
 550                 if ( !( $e instanceof UsageException ) ) {
 551                         MWExceptionHandler::logException( $e );
 552                 }
 553
 554                 // Handle any kind of exception by outputting properly formatted error message.
 555                 // If this fails, an unhandled exception should be thrown so that global error
 556                 // handler will process and log it.
 557
 558                 $errCode = $this->substituteResultWithError( $e );
 559
 560                 // Error results should not be cached
 561                 $this->setCacheMode( 'private' );
 562
 563                 $response = $this->getRequest()->response();
 564                 $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 565                 if ( $e->getCode() === 0 ) {
 566                         $response->header( $headerStr );
 567                 } else {
 568                         $response->header( $headerStr, true, $e->getCode() );
 569                 }
 570
 571                 // Reset and print just the error message
 572                 ob_clean();
 573
 574                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 575                 $this->createErrorPrinter();
 576
 577                 try {
 578                         $this->printResult( true );
 579                 } catch ( UsageException $ex ) {
 580                         // The error printer itself is failing. Try suppressing its request
 581                         // parameters and redo.
 582                         $this->setWarning(
 583                                 'Error printer failed (will retry without params): ' . $ex->getMessage()
 584                         );
 585                         $this->mPrinter = null;
 586                         $this->createErrorPrinter();
 587                         $this->mPrinter->forceDefaultParams();
 588                         $this->printResult( true );
 589                 }
 590         }
 591
 592         /**
 593          * Handle an exception from the ApiBeforeMain hook.
 594          *
 595          * This tries to print the exception as an API response, to be more
 596          * friendly to clients. If it fails, it will rethrow the exception.
 597          *
 598          * @since 1.23
 599          * @param Exception $e
 600          * @throws Exception
 601          */
 602         public static function handleApiBeforeMainException( Exception $e ) {
 603                 ob_start();
 604
 605                 try {
 606                         $main = new self( RequestContext::getMain(), false );
 607                         $main->handleException( $e );
 608                         $main->logRequest( 0, $e );
 609                 } catch ( Exception $e2 ) {
 610                         // Nope, even that didn't work. Punt.
 611                         throw $e;
 612                 }
 613
 614                 // Reset cache headers
 615                 $main->sendCacheHeaders( true );
 616
 617                 ob_end_flush();
 618         }
 619
 620         /**
 621          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 622          *
 623          * If no origin parameter is present, nothing happens.
 624          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 625          * is set and false is returned.
 626          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 627          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 628          * headers are set.
 629          * http://www.w3.org/TR/cors/#resource-requests
 630          * http://www.w3.org/TR/cors/#resource-preflight-requests
 631          *
 632          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 633          */
 634         protected function handleCORS() {
 635                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 636                 if ( $originParam === null ) {
 637                         // No origin parameter, nothing to do
 638                         return true;
 639                 }
 640
 641                 $request = $this->getRequest();
 642                 $response = $request->response();
 643
 644                 // Origin: header is a space-separated list of origins, check all of them
 645                 $originHeader = $request->getHeader( 'Origin' );
 646                 if ( $originHeader === false ) {
 647                         $origins = [];
 648                 } else {
 649                         $originHeader = trim( $originHeader );
 650                         $origins = preg_split( '/\s+/', $originHeader );
 651                 }
 652
 653                 if ( !in_array( $originParam, $origins ) ) {
 654                         // origin parameter set but incorrect
 655                         // Send a 403 response
 656                         $response->statusHeader( 403 );
 657                         $response->header( 'Cache-Control: no-cache' );
 658                         echo "'origin' parameter does not match Origin header\n";
 659
 660                         return false;
 661                 }
 662
 663                 $config = $this->getConfig();
 664                 $matchOrigin = count( $origins ) === 1 && self::matchOrigin(
 665                         $originParam,
 666                         $config->get( 'CrossSiteAJAXdomains' ),
 667                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 668                 );
 669
 670                 if ( $matchOrigin ) {
 671                         $requestedMethod = $request->getHeader( 'Access-Control-Request-Method' );
 672                         $preflight = $request->getMethod() === 'OPTIONS' && $requestedMethod !== false;
 673                         if ( $preflight ) {
 674                                 // This is a CORS preflight request
 675                                 if ( $requestedMethod !== 'POST' && $requestedMethod !== 'GET' ) {
 676                                         // If method is not a case-sensitive match, do not set any additional headers and terminate.
 677                                         return true;
 678                                 }
 679                                 // We allow the actual request to send the following headers
 680                                 $requestedHeaders = $request->getHeader( 'Access-Control-Request-Headers' );
 681                                 if ( $requestedHeaders !== false ) {
 682                                         if ( !self::matchRequestedHeaders( $requestedHeaders ) ) {
 683                                                 return true;
 684                                         }
 685                                         $response->header( 'Access-Control-Allow-Headers: ' . $requestedHeaders );
 686                                 }
 687
 688                                 // We only allow the actual request to be GET or POST
 689                                 $response->header( 'Access-Control-Allow-Methods: POST, GET' );
 690                         }
 691
 692                         $response->header( "Access-Control-Allow-Origin: $originHeader" );
 693                         $response->header( 'Access-Control-Allow-Credentials: true' );
 694                         // http://www.w3.org/TR/resource-timing/#timing-allow-origin
 695                         $response->header( "Timing-Allow-Origin: $originHeader" );
 696
 697                         if ( !$preflight ) {
 698                                 $response->header(
 699                                         'Access-Control-Expose-Headers: MediaWiki-API-Error, Retry-After, X-Database-Lag'
 700                                 );
 701                         }
 702                 }
 703
 704                 $this->getOutput()->addVaryHeader( 'Origin' );
 705                 return true;
 706         }
 707
 708         /**
 709          * Attempt to match an Origin header against a set of rules and a set of exceptions
 710          * @param string $value Origin header
 711          * @param array $rules Set of wildcard rules
 712          * @param array $exceptions Set of wildcard rules
 713          * @return bool True if $value matches a rule in $rules and doesn't match
 714          *    any rules in $exceptions, false otherwise
 715          */
 716         protected static function matchOrigin( $value, $rules, $exceptions ) {
 717                 foreach ( $rules as $rule ) {
 718                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 719                                 // Rule matches, check exceptions
 720                                 foreach ( $exceptions as $exc ) {
 721                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 722                                                 return false;
 723                                         }
 724                                 }
 725
 726                                 return true;
 727                         }
 728                 }
 729
 730                 return false;
 731         }
 732
 733         /**
 734          * Attempt to validate the value of Access-Control-Request-Headers against a list
 735          * of headers that we allow the follow up request to send.
 736          *
 737          * @param string $requestedHeaders Comma seperated list of HTTP headers
 738          * @return bool True if all requested headers are in the list of allowed headers
 739          */
 740         protected static function matchRequestedHeaders( $requestedHeaders ) {
 741                 if ( trim( $requestedHeaders ) === '' ) {
 742                         return true;
 743                 }
 744                 $requestedHeaders = explode( ',', $requestedHeaders );
 745                 $allowedAuthorHeaders = array_flip( [
 746                         /* simple headers (see spec) */
 747                         'accept',
 748                         'accept-language',
 749                         'content-language',
 750                         'content-type',
 751                         /* non-authorable headers in XHR, which are however requested by some UAs */
 752                         'accept-encoding',
 753                         'dnt',
 754                         'origin',
 755                         /* MediaWiki whitelist */
 756                         'api-user-agent',
 757                 ] );
 758                 foreach ( $requestedHeaders as $rHeader ) {
 759                         $rHeader = strtolower( trim( $rHeader ) );
 760                         if ( !isset( $allowedAuthorHeaders[$rHeader] ) ) {
 761                                 wfDebugLog( 'api', 'CORS preflight failed on requested header: ' . $rHeader );
 762                                 return false;
 763                         }
 764                 }
 765                 return true;
 766         }
 767
 768         /**
 769          * Helper function to convert wildcard string into a regex
 770          * '*' => '.*?'
 771          * '?' => '.'
 772          *
 773          * @param string $wildcard String with wildcards
 774          * @return string Regular expression
 775          */
 776         protected static function wildcardToRegex( $wildcard ) {
 777                 $wildcard = preg_quote( $wildcard, '/' );
 778                 $wildcard = str_replace(
 779                         [ '\*', '\?' ],
 780                         [ '.*?', '.' ],
 781                         $wildcard
 782                 );
 783
 784                 return "/^https?:\/\/$wildcard$/";
 785         }
 786
 787         /**
 788          * Send caching headers
 789          * @param bool $isError Whether an error response is being output
 790          * @since 1.26 added $isError parameter
 791          */
 792         protected function sendCacheHeaders( $isError ) {
 793                 $response = $this->getRequest()->response();
 794                 $out = $this->getOutput();
 795
 796                 $out->addVaryHeader( 'Treat-as-Untrusted' );
 797
 798                 $config = $this->getConfig();
 799
 800                 if ( $config->get( 'VaryOnXFP' ) ) {
 801                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 802                 }
 803
 804                 if ( !$isError && $this->mModule &&
 805                         ( $this->getRequest()->getMethod() === 'GET' || $this->getRequest()->getMethod() === 'HEAD' )
 806                 ) {
 807                         $etag = $this->mModule->getConditionalRequestData( 'etag' );
 808                         if ( $etag !== null ) {
 809                                 $response->header( "ETag: $etag" );
 810                         }
 811                         $lastMod = $this->mModule->getConditionalRequestData( 'last-modified' );
 812                         if ( $lastMod !== null ) {
 813                                 $response->header( 'Last-Modified: ' . wfTimestamp( TS_RFC2822, $lastMod ) );
 814                         }
 815                 }
 816
 817                 // The logic should be:
 818                 // $this->mCacheControl['max-age'] is set?
 819                 //    Use it, the module knows better than our guess.
 820                 // !$this->mModule || $this->mModule->isWriteMode(), and mCacheMode is private?
 821                 //    Use 0 because we can guess caching is probably the wrong thing to do.
 822                 // Use $this->getParameter( 'maxage' ), which already defaults to 0.
 823                 $maxage = 0;
 824                 if ( isset( $this->mCacheControl['max-age'] ) ) {
 825                         $maxage = $this->mCacheControl['max-age'];
 826                 } elseif ( ( $this->mModule && !$this->mModule->isWriteMode() ) ||
 827                         $this->mCacheMode !== 'private'
 828                 ) {
 829                         $maxage = $this->getParameter( 'maxage' );
 830                 }
 831                 $privateCache = 'private, must-revalidate, max-age=' . $maxage;
 832
 833                 if ( $this->mCacheMode == 'private' ) {
 834                         $response->header( "Cache-Control: $privateCache" );
 835                         return;
 836                 }
 837
 838                 $useKeyHeader = $config->get( 'UseKeyHeader' );
 839                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 840                         $out->addVaryHeader( 'Cookie' );
 841                         $response->header( $out->getVaryHeader() );
 842                         if ( $useKeyHeader ) {
 843                                 $response->header( $out->getKeyHeader() );
 844                                 if ( $out->haveCacheVaryCookies() ) {
 845                                         // Logged in, mark this request private
 846                                         $response->header( "Cache-Control: $privateCache" );
 847                                         return;
 848                                 }
 849                                 // Logged out, send normal public headers below
 850                         } elseif ( MediaWiki\Session\SessionManager::getGlobalSession()->isPersistent() ) {
 851                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 852                                 // Mark request private
 853                                 $response->header( "Cache-Control: $privateCache" );
 854
 855                                 return;
 856                         } // else no Key and anonymous, send public headers below
 857                 }
 858
 859                 // Send public headers
 860                 $response->header( $out->getVaryHeader() );
 861                 if ( $useKeyHeader ) {
 862                         $response->header( $out->getKeyHeader() );
 863                 }
 864
 865                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 866                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 867                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 868                 }
 869                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 870                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 871                 }
 872
 873                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 874                         // Public cache not requested
 875                         // Sending a Vary header in this case is harmless, and protects us
 876                         // against conditional calls of setCacheMaxAge().
 877                         $response->header( "Cache-Control: $privateCache" );
 878
 879                         return;
 880                 }
 881
 882                 $this->mCacheControl['public'] = true;
 883
 884                 // Send an Expires header
 885                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 886                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 887                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 888
 889                 // Construct the Cache-Control header
 890                 $ccHeader = '';
 891                 $separator = '';
 892                 foreach ( $this->mCacheControl as $name => $value ) {
 893                         if ( is_bool( $value ) ) {
 894                                 if ( $value ) {
 895                                         $ccHeader .= $separator . $name;
 896                                         $separator = ', ';
 897                                 }
 898                         } else {
 899                                 $ccHeader .= $separator . "$name=$value";
 900                                 $separator = ', ';
 901                         }
 902                 }
 903
 904                 $response->header( "Cache-Control: $ccHeader" );
 905         }
 906
 907         /**
 908          * Create the printer for error output
 909          */
 910         private function createErrorPrinter() {
 911                 if ( !isset( $this->mPrinter ) ) {
 912                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 913                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
 914                                 $value = self::API_DEFAULT_FORMAT;
 915                         }
 916                         $this->mPrinter = $this->createPrinterByName( $value );
 917                 }
 918
 919                 // Printer may not be able to handle errors. This is particularly
 920                 // likely if the module returns something for getCustomPrinter().
 921                 if ( !$this->mPrinter->canPrintErrors() ) {
 922                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
 923                 }
 924         }
 925
 926         /**
 927          * Create an error message for the given exception.
 928          *
 929          * If the exception is a UsageException then
 930          * UsageException::getMessageArray() will be called to create the message.
 931          *
 932          * @param Exception $e
 933          * @return array ['code' => 'some string', 'info' => 'some other string']
 934          * @since 1.27
 935          */
 936         protected function errorMessageFromException( $e ) {
 937                 if ( $e instanceof UsageException ) {
 938                         // User entered incorrect parameters - generate error response
 939                         $errMessage = $e->getMessageArray();
 940                 } else {
 941                         $config = $this->getConfig();
 942                         // Something is seriously wrong
 943                         if ( ( $e instanceof DBQueryError ) && !$config->get( 'ShowSQLErrors' ) ) {
 944                                 $info = 'Database query error';
 945                         } else {
 946                                 $info = "Exception Caught: {$e->getMessage()}";
 947                         }
 948
 949                         $errMessage = [
 950                                 'code' => 'internal_api_error_' . get_class( $e ),
 951                                 'info' => '[' . WebRequest::getRequestId() . '] ' . $info,
 952                         ];
 953                 }
 954                 return $errMessage;
 955         }
 956
 957         /**
 958          * Replace the result data with the information about an exception.
 959          * Returns the error code
 960          * @param Exception $e
 961          * @return string
 962          */
 963         protected function substituteResultWithError( $e ) {
 964                 $result = $this->getResult();
 965                 $config = $this->getConfig();
 966
 967                 $errMessage = $this->errorMessageFromException( $e );
 968                 if ( $e instanceof UsageException ) {
 969                         // User entered incorrect parameters - generate error response
 970                         $link = wfExpandUrl( wfScript( 'api' ) );
 971                         ApiResult::setContentValue( $errMessage, 'docref', "See $link for API usage" );
 972                 } else {
 973                         // Something is seriously wrong
 974                         if ( $config->get( 'ShowExceptionDetails' ) ) {
 975                                 ApiResult::setContentValue(
 976                                         $errMessage,
 977                                         'trace',
 978                                         MWExceptionHandler::getRedactedTraceAsString( $e )
 979                                 );
 980                         }
 981                 }
 982
 983                 // Remember all the warnings to re-add them later
 984                 $warnings = $result->getResultData( [ 'warnings' ] );
 985
 986                 $result->reset();
 987                 // Re-add the id
 988                 $requestid = $this->getParameter( 'requestid' );
 989                 if ( !is_null( $requestid ) ) {
 990                         $result->addValue( null, 'requestid', $requestid, ApiResult::NO_SIZE_CHECK );
 991                 }
 992                 if ( $config->get( 'ShowHostnames' ) ) {
 993                         // servedby is especially useful when debugging errors
 994                         $result->addValue( null, 'servedby', wfHostname(), ApiResult::NO_SIZE_CHECK );
 995                 }
 996                 if ( $warnings !== null ) {
 997                         $result->addValue( null, 'warnings', $warnings, ApiResult::NO_SIZE_CHECK );
 998                 }
 999
1000                 $result->addValue( null, 'error', $errMessage, ApiResult::NO_SIZE_CHECK );
1001
1002                 return $errMessage['code'];
1003         }
1004
1005         /**
1006          * Set up for the execution.
1007          * @return array
1008          */
1009         protected function setupExecuteAction() {
1010                 // First add the id to the top element
1011                 $result = $this->getResult();
1012                 $requestid = $this->getParameter( 'requestid' );
1013                 if ( !is_null( $requestid ) ) {
1014                         $result->addValue( null, 'requestid', $requestid );
1015                 }
1016
1017                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1018                         $servedby = $this->getParameter( 'servedby' );
1019                         if ( $servedby ) {
1020                                 $result->addValue( null, 'servedby', wfHostname() );
1021                         }
1022                 }
1023
1024                 if ( $this->getParameter( 'curtimestamp' ) ) {
1025                         $result->addValue( null, 'curtimestamp', wfTimestamp( TS_ISO_8601, time() ),
1026                                 ApiResult::NO_SIZE_CHECK );
1027                 }
1028
1029                 $params = $this->extractRequestParams();
1030
1031                 $this->mAction = $params['action'];
1032
1033                 if ( !is_string( $this->mAction ) ) {
1034                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
1035                 }
1036
1037                 return $params;
1038         }
1039
1040         /**
1041          * Set up the module for response
1042          * @return ApiBase The module that will handle this action
1043          * @throws MWException
1044          * @throws UsageException
1045          */
1046         protected function setupModule() {
1047                 // Instantiate the module requested by the user
1048                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
1049                 if ( $module === null ) {
1050                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
1051                 }
1052                 $moduleParams = $module->extractRequestParams();
1053
1054                 // Check token, if necessary
1055                 if ( $module->needsToken() === true ) {
1056                         throw new MWException(
1057                                 "Module '{$module->getModuleName()}' must be updated for the new token handling. " .
1058                                 'See documentation for ApiBase::needsToken for details.'
1059                         );
1060                 }
1061                 if ( $module->needsToken() ) {
1062                         if ( !$module->mustBePosted() ) {
1063                                 throw new MWException(
1064                                         "Module '{$module->getModuleName()}' must require POST to use tokens."
1065                                 );
1066                         }
1067
1068                         if ( !isset( $moduleParams['token'] ) ) {
1069                                 $this->dieUsageMsg( [ 'missingparam', 'token' ] );
1070                         }
1071
1072                         if ( !$this->getConfig()->get( 'DebugAPI' ) &&
1073                                 array_key_exists(
1074                                         $module->encodeParamName( 'token' ),
1075                                         $this->getRequest()->getQueryValues()
1076                                 )
1077                         ) {
1078                                 $this->dieUsage(
1079                                         "The '{$module->encodeParamName( 'token' )}' parameter was " .
1080                                                 'found in the query string, but must be in the POST body',
1081                                         'mustposttoken'
1082                                 );
1083                         }
1084
1085                         if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
1086                                 $this->dieUsageMsg( 'sessionfailure' );
1087                         }
1088                 }
1089
1090                 return $module;
1091         }
1092
1093         /**
1094          * Check the max lag if necessary
1095          * @param ApiBase $module Api module being used
1096          * @param array $params Array an array containing the request parameters.
1097          * @return bool True on success, false should exit immediately
1098          */
1099         protected function checkMaxLag( $module, $params ) {
1100                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
1101                         $maxLag = $params['maxlag'];
1102                         list( $host, $lag ) = wfGetLB()->getMaxLag();
1103                         if ( $lag > $maxLag ) {
1104                                 $response = $this->getRequest()->response();
1105
1106                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
1107                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
1108
1109                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
1110                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
1111                                 }
1112
1113                                 $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
1114                         }
1115                 }
1116
1117                 return true;
1118         }
1119
1120         /**
1121          * Check selected RFC 7232 precondition headers
1122          *
1123          * RFC 7232 envisions a particular model where you send your request to "a
1124          * resource", and for write requests that you can read "the resource" by
1125          * changing the method to GET. When the API receives a GET request, it
1126          * works out even though "the resource" from RFC 7232's perspective might
1127          * be many resources from MediaWiki's perspective. But it totally fails for
1128          * a POST, since what HTTP sees as "the resource" is probably just
1129          * "/api.php" with all the interesting bits in the body.
1130          *
1131          * Therefore, we only support RFC 7232 precondition headers for GET (and
1132          * HEAD). That means we don't need to bother with If-Match and
1133          * If-Unmodified-Since since they only apply to modification requests.
1134          *
1135          * And since we don't support Range, If-Range is ignored too.
1136          *
1137          * @since 1.26
1138          * @param ApiBase $module Api module being used
1139          * @return bool True on success, false should exit immediately
1140          */
1141         protected function checkConditionalRequestHeaders( $module ) {
1142                 if ( $this->mInternalMode ) {
1143                         // No headers to check in internal mode
1144                         return true;
1145                 }
1146
1147                 if ( $this->getRequest()->getMethod() !== 'GET' && $this->getRequest()->getMethod() !== 'HEAD' ) {
1148                         // Don't check POSTs
1149                         return true;
1150                 }
1151
1152                 $return304 = false;
1153
1154                 $ifNoneMatch = array_diff(
1155                         $this->getRequest()->getHeader( 'If-None-Match', WebRequest::GETHEADER_LIST ) ?: [],
1156                         [ '' ]
1157                 );
1158                 if ( $ifNoneMatch ) {
1159                         if ( $ifNoneMatch === [ '*' ] ) {
1160                                 // API responses always "exist"
1161                                 $etag = '*';
1162                         } else {
1163                                 $etag = $module->getConditionalRequestData( 'etag' );
1164                         }
1165                 }
1166                 if ( $ifNoneMatch && $etag !== null ) {
1167                         $test = substr( $etag, 0, 2 ) === 'W/' ? substr( $etag, 2 ) : $etag;
1168                         $match = array_map( function ( $s ) {
1169                                 return substr( $s, 0, 2 ) === 'W/' ? substr( $s, 2 ) : $s;
1170                         }, $ifNoneMatch );
1171                         $return304 = in_array( $test, $match, true );
1172                 } else {
1173                         $value = trim( $this->getRequest()->getHeader( 'If-Modified-Since' ) );
1174
1175                         // Some old browsers sends sizes after the date, like this:
1176                         //  Wed, 20 Aug 2003 06:51:19 GMT; length=5202
1177                         // Ignore that.
1178                         $i = strpos( $value, ';' );
1179                         if ( $i !== false ) {
1180                                 $value = trim( substr( $value, 0, $i ) );
1181                         }
1182
1183                         if ( $value !== '' ) {
1184                                 try {
1185                                         $ts = new MWTimestamp( $value );
1186                                         if (
1187                                                 // RFC 7231 IMF-fixdate
1188                                                 $ts->getTimestamp( TS_RFC2822 ) === $value ||
1189                                                 // RFC 850
1190                                                 $ts->format( 'l, d-M-y H:i:s' ) . ' GMT' === $value ||
1191                                                 // asctime (with and without space-padded day)
1192                                                 $ts->format( 'D M j H:i:s Y' ) === $value ||
1193                                                 $ts->format( 'D M  j H:i:s Y' ) === $value
1194                                         ) {
1195                                                 $lastMod = $module->getConditionalRequestData( 'last-modified' );
1196                                                 if ( $lastMod !== null ) {
1197                                                         // Mix in some MediaWiki modification times
1198                                                         $modifiedTimes = [
1199                                                                 'page' => $lastMod,
1200                                                                 'user' => $this->getUser()->getTouched(),
1201                                                                 'epoch' => $this->getConfig()->get( 'CacheEpoch' ),
1202                                                         ];
1203                                                         if ( $this->getConfig()->get( 'UseSquid' ) ) {
1204                                                                 // T46570: the core page itself may not change, but resources might
1205                                                                 $modifiedTimes['sepoch'] = wfTimestamp(
1206                                                                         TS_MW, time() - $this->getConfig()->get( 'SquidMaxage' )
1207                                                                 );
1208                                                         }
1209                                                         Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this->getOutput() ] );
1210                                                         $lastMod = max( $modifiedTimes );
1211                                                         $return304 = wfTimestamp( TS_MW, $lastMod ) <= $ts->getTimestamp( TS_MW );
1212                                                 }
1213                                         }
1214                                 } catch ( TimestampException $e ) {
1215                                         // Invalid timestamp, ignore it
1216                                 }
1217                         }
1218                 }
1219
1220                 if ( $return304 ) {
1221                         $this->getRequest()->response()->statusHeader( 304 );
1222
1223                         // Avoid outputting the compressed representation of a zero-length body
1224                         MediaWiki\suppressWarnings();
1225                         ini_set( 'zlib.output_compression', 0 );
1226                         MediaWiki\restoreWarnings();
1227                         wfClearOutputBuffers();
1228
1229                         return false;
1230                 }
1231
1232                 return true;
1233         }
1234
1235         /**
1236          * Check for sufficient permissions to execute
1237          * @param ApiBase $module An Api module
1238          */
1239         protected function checkExecutePermissions( $module ) {
1240                 $user = $this->getUser();
1241                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
1242                         !$user->isAllowed( 'read' )
1243                 ) {
1244                         $this->dieUsageMsg( 'readrequired' );
1245                 }
1246
1247                 if ( $module->isWriteMode() ) {
1248                         if ( !$this->mEnableWrite ) {
1249                                 $this->dieUsageMsg( 'writedisabled' );
1250                         } elseif ( !$user->isAllowed( 'writeapi' ) ) {
1251                                 $this->dieUsageMsg( 'writerequired' );
1252                         } elseif ( $this->getRequest()->getHeader( 'Promise-Non-Write-API-Action' ) ) {
1253                                 $this->dieUsage(
1254                                         'Promise-Non-Write-API-Action HTTP header cannot be sent to write API modules',
1255                                         'promised-nonwrite-api'
1256                                 );
1257                         }
1258
1259                         $this->checkReadOnly( $module );
1260                 }
1261
1262                 // Allow extensions to stop execution for arbitrary reasons.
1263                 $message = false;
1264                 if ( !Hooks::run( 'ApiCheckCanExecute', [ $module, $user, &$message ] ) ) {
1265                         $this->dieUsageMsg( $message );
1266                 }
1267         }
1268
1269         /**
1270          * Check if the DB is read-only for this user
1271          * @param ApiBase $module An Api module
1272          */
1273         protected function checkReadOnly( $module ) {
1274                 if ( wfReadOnly() ) {
1275                         $this->dieReadOnly();
1276                 }
1277
1278                 if ( $module->isWriteMode()
1279                         && in_array( 'bot', $this->getUser()->getGroups() )
1280                         && wfGetLB()->getServerCount() > 1
1281                 ) {
1282                         $this->checkBotReadOnly();
1283                 }
1284         }
1285
1286         /**
1287          * Check whether we are readonly for bots
1288          */
1289         private function checkBotReadOnly() {
1290                 // Figure out how many servers have passed the lag threshold
1291                 $numLagged = 0;
1292                 $lagLimit = $this->getConfig()->get( 'APIMaxLagThreshold' );
1293                 $laggedServers = [];
1294                 $loadBalancer = wfGetLB();
1295                 foreach ( $loadBalancer->getLagTimes() as $serverIndex => $lag ) {
1296                         if ( $lag > $lagLimit ) {
1297                                 ++$numLagged;
1298                                 $laggedServers[] = $loadBalancer->getServerName( $serverIndex ) . " ({$lag}s)";
1299                         }
1300                 }
1301
1302                 // If a majority of slaves are too lagged then disallow writes
1303                 $slaveCount = wfGetLB()->getServerCount() - 1;
1304                 if ( $numLagged >= ceil( $slaveCount / 2 ) ) {
1305                         $laggedServers = implode( ', ', $laggedServers );
1306                         wfDebugLog(
1307                                 'api-readonly',
1308                                 "Api request failed as read only because the following DBs are lagged: $laggedServers"
1309                         );
1310
1311                         $parsed = $this->parseMsg( [ 'readonlytext' ] );
1312                         $this->dieUsage(
1313                                 $parsed['info'],
1314                                 $parsed['code'],
1315                                 /* http error */
1316                                 0,
1317                                 [ 'readonlyreason' => "Waiting for $numLagged lagged database(s)" ]
1318                         );
1319                 }
1320         }
1321
1322         /**
1323          * Check asserts of the user's rights
1324          * @param array $params
1325          */
1326         protected function checkAsserts( $params ) {
1327                 if ( isset( $params['assert'] ) ) {
1328                         $user = $this->getUser();
1329                         switch ( $params['assert'] ) {
1330                                 case 'user':
1331                                         if ( $user->isAnon() ) {
1332                                                 $this->dieUsage( 'Assertion that the user is logged in failed', 'assertuserfailed' );
1333                                         }
1334                                         break;
1335                                 case 'bot':
1336                                         if ( !$user->isAllowed( 'bot' ) ) {
1337                                                 $this->dieUsage( 'Assertion that the user has the bot right failed', 'assertbotfailed' );
1338                                         }
1339                                         break;
1340                         }
1341                 }
1342         }
1343
1344         /**
1345          * Check POST for external response and setup result printer
1346          * @param ApiBase $module An Api module
1347          * @param array $params An array with the request parameters
1348          */
1349         protected function setupExternalResponse( $module, $params ) {
1350                 $request = $this->getRequest();
1351                 if ( !$request->wasPosted() && $module->mustBePosted() ) {
1352                         // Module requires POST. GET request might still be allowed
1353                         // if $wgDebugApi is true, otherwise fail.
1354                         $this->dieUsageMsgOrDebug( [ 'mustbeposted', $this->mAction ] );
1355                 }
1356
1357                 // See if custom printer is used
1358                 $this->mPrinter = $module->getCustomPrinter();
1359                 if ( is_null( $this->mPrinter ) ) {
1360                         // Create an appropriate printer
1361                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
1362                 }
1363
1364                 if ( $request->getProtocol() === 'http' && (
1365                         $request->getSession()->shouldForceHTTPS() ||
1366                         ( $this->getUser()->isLoggedIn() &&
1367                                 $this->getUser()->requiresHTTPS() )
1368                 ) ) {
1369                         $this->logFeatureUsage( 'https-expected' );
1370                         $this->setWarning( 'HTTP used when HTTPS was expected' );
1371                 }
1372         }
1373
1374         /**
1375          * Execute the actual module, without any error handling
1376          */
1377         protected function executeAction() {
1378                 $params = $this->setupExecuteAction();
1379                 $module = $this->setupModule();
1380                 $this->mModule = $module;
1381
1382                 if ( !$this->mInternalMode ) {
1383                         $this->setRequestExpectations( $module );
1384                 }
1385
1386                 $this->checkExecutePermissions( $module );
1387
1388                 if ( !$this->checkMaxLag( $module, $params ) ) {
1389                         return;
1390                 }
1391
1392                 if ( !$this->checkConditionalRequestHeaders( $module ) ) {
1393                         return;
1394                 }
1395
1396                 if ( !$this->mInternalMode ) {
1397                         $this->setupExternalResponse( $module, $params );
1398                 }
1399
1400                 $this->checkAsserts( $params );
1401
1402                 // Execute
1403                 $module->execute();
1404                 Hooks::run( 'APIAfterExecute', [ &$module ] );
1405
1406                 $this->reportUnusedParams();
1407
1408                 if ( !$this->mInternalMode ) {
1409                         // append Debug information
1410                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
1411
1412                         // Print result data
1413                         $this->printResult( false );
1414                 }
1415         }
1416
1417         /**
1418          * Set database connection, query, and write expectations given this module request
1419          * @param ApiBase $module
1420          */
1421         protected function setRequestExpectations( ApiBase $module ) {
1422                 $limits = $this->getConfig()->get( 'TrxProfilerLimits' );
1423                 $trxProfiler = Profiler::instance()->getTransactionProfiler();
1424                 if ( $this->getRequest()->hasSafeMethod() ) {
1425                         $trxProfiler->setExpectations( $limits['GET'], __METHOD__ );
1426                 } elseif ( $this->getRequest()->wasPosted() && !$module->isWriteMode() ) {
1427                         $trxProfiler->setExpectations( $limits['POST-nonwrite'], __METHOD__ );
1428                         $this->getRequest()->markAsSafeRequest();
1429                 } else {
1430                         $trxProfiler->setExpectations( $limits['POST'], __METHOD__ );
1431                 }
1432         }
1433
1434         /**
1435          * Log the preceding request
1436          * @param float $time Time in seconds
1437          * @param Exception $e Exception caught while processing the request
1438          */
1439         protected function logRequest( $time, $e = null ) {
1440                 $request = $this->getRequest();
1441                 $logCtx = [
1442                         'ts' => time(),
1443                         'ip' => $request->getIP(),
1444                         'userAgent' => $this->getUserAgent(),
1445                         'wiki' => wfWikiID(),
1446                         'timeSpentBackend' => (int) round( $time * 1000 ),
1447                         'hadError' => $e !== null,
1448                         'errorCodes' => [],
1449                         'params' => [],
1450                 ];
1451
1452                 if ( $e ) {
1453                         $logCtx['errorCodes'][] = $this->errorMessageFromException( $e )['code'];
1454                 }
1455
1456                 // Construct space separated message for 'api' log channel
1457                 $msg = "API {$request->getMethod()} " .
1458                         wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
1459                         " {$logCtx['ip']} " .
1460                         "T={$logCtx['timeSpentBackend']}ms";
1461
1462                 foreach ( $this->getParamsUsed() as $name ) {
1463                         $value = $request->getVal( $name );
1464                         if ( $value === null ) {
1465                                 continue;
1466                         }
1467
1468                         if ( strlen( $value ) > 256 ) {
1469                                 $value = substr( $value, 0, 256 );
1470                                 $encValue = $this->encodeRequestLogValue( $value ) . '[...]';
1471                         } else {
1472                                 $encValue = $this->encodeRequestLogValue( $value );
1473                         }
1474
1475                         $logCtx['params'][$name] = $value;
1476                         $msg .= " {$name}={$encValue}";
1477                 }
1478
1479                 wfDebugLog( 'api', $msg, 'private' );
1480                 // ApiAction channel is for structured data consumers
1481                 wfDebugLog( 'ApiAction', '', 'private', $logCtx );
1482         }
1483
1484         /**
1485          * Encode a value in a format suitable for a space-separated log line.
1486          * @param string $s
1487          * @return string
1488          */
1489         protected function encodeRequestLogValue( $s ) {
1490                 static $table;
1491                 if ( !$table ) {
1492                         $chars = ';@$!*(),/:';
1493                         $numChars = strlen( $chars );
1494                         for ( $i = 0; $i < $numChars; $i++ ) {
1495                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
1496                         }
1497                 }
1498
1499                 return strtr( rawurlencode( $s ), $table );
1500         }
1501
1502         /**
1503          * Get the request parameters used in the course of the preceding execute() request
1504          * @return array
1505          */
1506         protected function getParamsUsed() {
1507                 return array_keys( $this->mParamsUsed );
1508         }
1509
1510         /**
1511          * Mark parameters as used
1512          * @param string|string[] $params
1513          */
1514         public function markParamsUsed( $params ) {
1515                 $this->mParamsUsed += array_fill_keys( (array)$params, true );
1516         }
1517
1518         /**
1519          * Get a request value, and register the fact that it was used, for logging.
1520          * @param string $name
1521          * @param mixed $default
1522          * @return mixed
1523          */
1524         public function getVal( $name, $default = null ) {
1525                 $this->mParamsUsed[$name] = true;
1526
1527                 $ret = $this->getRequest()->getVal( $name );
1528                 if ( $ret === null ) {
1529                         if ( $this->getRequest()->getArray( $name ) !== null ) {
1530                                 // See bug 10262 for why we don't just implode( '|', ... ) the
1531                                 // array.
1532                                 $this->setWarning(
1533                                         "Parameter '$name' uses unsupported PHP array syntax"
1534                                 );
1535                         }
1536                         $ret = $default;
1537                 }
1538                 return $ret;
1539         }
1540
1541         /**
1542          * Get a boolean request value, and register the fact that the parameter
1543          * was used, for logging.
1544          * @param string $name
1545          * @return bool
1546          */
1547         public function getCheck( $name ) {
1548                 return $this->getVal( $name, null ) !== null;
1549         }
1550
1551         /**
1552          * Get a request upload, and register the fact that it was used, for logging.
1553          *
1554          * @since 1.21
1555          * @param string $name Parameter name
1556          * @return WebRequestUpload
1557          */
1558         public function getUpload( $name ) {
1559                 $this->mParamsUsed[$name] = true;
1560
1561                 return $this->getRequest()->getUpload( $name );
1562         }
1563
1564         /**
1565          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1566          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1567          */
1568         protected function reportUnusedParams() {
1569                 $paramsUsed = $this->getParamsUsed();
1570                 $allParams = $this->getRequest()->getValueNames();
1571
1572                 if ( !$this->mInternalMode ) {
1573                         // Printer has not yet executed; don't warn that its parameters are unused
1574                         $printerParams = array_map(
1575                                 [ $this->mPrinter, 'encodeParamName' ],
1576                                 array_keys( $this->mPrinter->getFinalParams() ?: [] )
1577                         );
1578                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1579                 } else {
1580                         $unusedParams = array_diff( $allParams, $paramsUsed );
1581                 }
1582
1583                 if ( count( $unusedParams ) ) {
1584                         $s = count( $unusedParams ) > 1 ? 's' : '';
1585                         $this->setWarning( "Unrecognized parameter$s: '" . implode( $unusedParams, "', '" ) . "'" );
1586                 }
1587         }
1588
1589         /**
1590          * Print results using the current printer
1591          *
1592          * @param bool $isError
1593          */
1594         protected function printResult( $isError ) {
1595                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1596                         $this->setWarning( 'SECURITY WARNING: $wgDebugAPI is enabled' );
1597                 }
1598
1599                 $printer = $this->mPrinter;
1600                 $printer->initPrinter( false );
1601                 $printer->execute();
1602                 $printer->closePrinter();
1603         }
1604
1605         /**
1606          * @return bool
1607          */
1608         public function isReadMode() {
1609                 return false;
1610         }
1611
1612         /**
1613          * See ApiBase for description.
1614          *
1615          * @return array
1616          */
1617         public function getAllowedParams() {
1618                 return [
1619                         'action' => [
1620                                 ApiBase::PARAM_DFLT => 'help',
1621                                 ApiBase::PARAM_TYPE => 'submodule',
1622                         ],
1623                         'format' => [
1624                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1625                                 ApiBase::PARAM_TYPE => 'submodule',
1626                         ],
1627                         'maxlag' => [
1628                                 ApiBase::PARAM_TYPE => 'integer'
1629                         ],
1630                         'smaxage' => [
1631                                 ApiBase::PARAM_TYPE => 'integer',
1632                                 ApiBase::PARAM_DFLT => 0
1633                         ],
1634                         'maxage' => [
1635                                 ApiBase::PARAM_TYPE => 'integer',
1636                                 ApiBase::PARAM_DFLT => 0
1637                         ],
1638                         'assert' => [
1639                                 ApiBase::PARAM_TYPE => [ 'user', 'bot' ]
1640                         ],
1641                         'requestid' => null,
1642                         'servedby' => false,
1643                         'curtimestamp' => false,
1644                         'origin' => null,
1645                         'uselang' => [
1646                                 ApiBase::PARAM_DFLT => 'user',
1647                         ],
1648                 ];
1649         }
1650
1651         /** @see ApiBase::getExamplesMessages() */
1652         protected function getExamplesMessages() {
1653                 return [
1654                         'action=help'
1655                                 => 'apihelp-help-example-main',
1656                         'action=help&recursivesubmodules=1'
1657                                 => 'apihelp-help-example-recursive',
1658                 ];
1659         }
1660
1661         public function modifyHelp( array &$help, array $options, array &$tocData ) {
1662                 // Wish PHP had an "array_insert_before". Instead, we have to manually
1663                 // reindex the array to get 'permissions' in the right place.
1664                 $oldHelp = $help;
1665                 $help = [];
1666                 foreach ( $oldHelp as $k => $v ) {
1667                         if ( $k === 'submodules' ) {
1668                                 $help['permissions'] = '';
1669                         }
1670                         $help[$k] = $v;
1671                 }
1672                 $help['datatypes'] = '';
1673                 $help['credits'] = '';
1674
1675                 // Fill 'permissions'
1676                 $help['permissions'] .= Html::openElement( 'div',
1677                         [ 'class' => 'apihelp-block apihelp-permissions' ] );
1678                 $m = $this->msg( 'api-help-permissions' );
1679                 if ( !$m->isDisabled() ) {
1680                         $help['permissions'] .= Html::rawElement( 'div', [ 'class' => 'apihelp-block-head' ],
1681                                 $m->numParams( count( self::$mRights ) )->parse()
1682                         );
1683                 }
1684                 $help['permissions'] .= Html::openElement( 'dl' );
1685                 foreach ( self::$mRights as $right => $rightMsg ) {
1686                         $help['permissions'] .= Html::element( 'dt', null, $right );
1687
1688                         $rightMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )->parse();
1689                         $help['permissions'] .= Html::rawElement( 'dd', null, $rightMsg );
1690
1691                         $groups = array_map( function ( $group ) {
1692                                 return $group == '*' ? 'all' : $group;
1693                         }, User::getGroupsWithPermission( $right ) );
1694
1695                         $help['permissions'] .= Html::rawElement( 'dd', null,
1696                                 $this->msg( 'api-help-permissions-granted-to' )
1697                                         ->numParams( count( $groups ) )
1698                                         ->params( $this->getLanguage()->commaList( $groups ) )
1699                                         ->parse()
1700                         );
1701                 }
1702                 $help['permissions'] .= Html::closeElement( 'dl' );
1703                 $help['permissions'] .= Html::closeElement( 'div' );
1704
1705                 // Fill 'datatypes' and 'credits', if applicable
1706                 if ( empty( $options['nolead'] ) ) {
1707                         $level = $options['headerlevel'];
1708                         $tocnumber = &$options['tocnumber'];
1709
1710                         $header = $this->msg( 'api-help-datatypes-header' )->parse();
1711
1712                         // Add an additional span with sanitized ID
1713                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1714                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/datatypes' ) ] ) .
1715                                         $header;
1716                         }
1717                         $help['datatypes'] .= Html::rawElement( 'h' . min( 6, $level ),
1718                                 [ 'id' => 'main/datatypes', 'class' => 'apihelp-header' ],
1719                                 $header
1720                         );
1721                         $help['datatypes'] .= $this->msg( 'api-help-datatypes' )->parseAsBlock();
1722                         if ( !isset( $tocData['main/datatypes'] ) ) {
1723                                 $tocnumber[$level]++;
1724                                 $tocData['main/datatypes'] = [
1725                                         'toclevel' => count( $tocnumber ),
1726                                         'level' => $level,
1727                                         'anchor' => 'main/datatypes',
1728                                         'line' => $header,
1729                                         'number' => implode( '.', $tocnumber ),
1730                                         'index' => false,
1731                                 ];
1732                         }
1733
1734                         // Add an additional span with sanitized ID
1735                         if ( !$this->getConfig()->get( 'ExperimentalHtmlIds' ) ) {
1736                                 $header = Html::element( 'span', [ 'id' => Sanitizer::escapeId( 'main/credits' ) ] ) .
1737                                         $header;
1738                         }
1739                         $header = $this->msg( 'api-credits-header' )->parse();
1740                         $help['credits'] .= Html::rawElement( 'h' . min( 6, $level ),
1741                                 [ 'id' => 'main/credits', 'class' => 'apihelp-header' ],
1742                                 $header
1743                         );
1744                         $help['credits'] .= $this->msg( 'api-credits' )->useDatabase( false )->parseAsBlock();
1745                         if ( !isset( $tocData['main/credits'] ) ) {
1746                                 $tocnumber[$level]++;
1747                                 $tocData['main/credits'] = [
1748                                         'toclevel' => count( $tocnumber ),
1749                                         'level' => $level,
1750                                         'anchor' => 'main/credits',
1751                                         'line' => $header,
1752                                         'number' => implode( '.', $tocnumber ),
1753                                         'index' => false,
1754                                 ];
1755                         }
1756                 }
1757         }
1758
1759         private $mCanApiHighLimits = null;
1760
1761         /**
1762          * Check whether the current user is allowed to use high limits
1763          * @return bool
1764          */
1765         public function canApiHighLimits() {
1766                 if ( !isset( $this->mCanApiHighLimits ) ) {
1767                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1768                 }
1769
1770                 return $this->mCanApiHighLimits;
1771         }
1772
1773         /**
1774          * Overrides to return this instance's module manager.
1775          * @return ApiModuleManager
1776          */
1777         public function getModuleManager() {
1778                 return $this->mModuleMgr;
1779         }
1780
1781         /**
1782          * Fetches the user agent used for this request
1783          *
1784          * The value will be the combination of the 'Api-User-Agent' header (if
1785          * any) and the standard User-Agent header (if any).
1786          *
1787          * @return string
1788          */
1789         public function getUserAgent() {
1790                 return trim(
1791                         $this->getRequest()->getHeader( 'Api-user-agent' ) . ' ' .
1792                         $this->getRequest()->getHeader( 'User-agent' )
1793                 );
1794         }
1795
1796         /************************************************************************//**
1797          * @name   Deprecated
1798          * @{
1799          */
1800
1801         /**
1802          * Sets whether the pretty-printer should format *bold* and $italics$
1803          *
1804          * @deprecated since 1.25
1805          * @param bool $help
1806          */
1807         public function setHelp( $help = true ) {
1808                 wfDeprecated( __METHOD__, '1.25' );
1809                 $this->mPrinter->setHelp( $help );
1810         }
1811
1812         /**
1813          * Override the parent to generate help messages for all available modules.
1814          *
1815          * @deprecated since 1.25
1816          * @return string
1817          */
1818         public function makeHelpMsg() {
1819                 wfDeprecated( __METHOD__, '1.25' );
1820
1821                 $this->setHelp();
1822                 $cacheHelpTimeout = $this->getConfig()->get( 'APICacheHelpTimeout' );
1823
1824                 return ObjectCache::getMainWANInstance()->getWithSetCallback(
1825                         wfMemcKey(
1826                                 'apihelp',
1827                                 $this->getModuleName(),
1828                                 str_replace( ' ', '_', SpecialVersion::getVersion( 'nodb' ) )
1829                         ),
1830                         $cacheHelpTimeout > 0 ? $cacheHelpTimeout : WANObjectCache::TTL_UNCACHEABLE,
1831                         [ $this, 'reallyMakeHelpMsg' ]
1832                 );
1833         }
1834
1835         /**
1836          * @deprecated since 1.25
1837          * @return mixed|string
1838          */
1839         public function reallyMakeHelpMsg() {
1840                 wfDeprecated( __METHOD__, '1.25' );
1841                 $this->setHelp();
1842
1843                 // Use parent to make default message for the main module
1844                 $msg = parent::makeHelpMsg();
1845
1846                 $asterisks = str_repeat( '*** ', 14 );
1847                 $msg .= "\n\n$asterisks Modules  $asterisks\n\n";
1848
1849                 foreach ( $this->mModuleMgr->getNames( 'action' ) as $name ) {
1850                         $module = $this->mModuleMgr->getModule( $name );
1851                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1852
1853                         $msg2 = $module->makeHelpMsg();
1854                         if ( $msg2 !== false ) {
1855                                 $msg .= $msg2;
1856                         }
1857                         $msg .= "\n";
1858                 }
1859
1860                 $msg .= "\n$asterisks Permissions $asterisks\n\n";
1861                 foreach ( self::$mRights as $right => $rightMsg ) {
1862                         $rightsMsg = $this->msg( $rightMsg['msg'], $rightMsg['params'] )
1863                                 ->useDatabase( false )
1864                                 ->inLanguage( 'en' )
1865                                 ->text();
1866                         $groups = User::getGroupsWithPermission( $right );
1867                         $msg .= '* ' . $right . " *\n  $rightsMsg" .
1868                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1869                 }
1870
1871                 $msg .= "\n$asterisks Formats  $asterisks\n\n";
1872                 foreach ( $this->mModuleMgr->getNames( 'format' ) as $name ) {
1873                         $module = $this->mModuleMgr->getModule( $name );
1874                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1875                         $msg2 = $module->makeHelpMsg();
1876                         if ( $msg2 !== false ) {
1877                                 $msg .= $msg2;
1878                         }
1879                         $msg .= "\n";
1880                 }
1881
1882                 $credits = $this->msg( 'api-credits' )->useDatabase( 'false' )->inLanguage( 'en' )->text();
1883                 $credits = str_replace( "\n", "\n   ", $credits );
1884                 $msg .= "\n*** Credits: ***\n   $credits\n";
1885
1886                 return $msg;
1887         }
1888
1889         /**
1890          * @deprecated since 1.25
1891          * @param ApiBase $module
1892          * @param string $paramName What type of request is this? e.g. action,
1893          *    query, list, prop, meta, format
1894          * @return string
1895          */
1896         public static function makeHelpMsgHeader( $module, $paramName ) {
1897                 wfDeprecated( __METHOD__, '1.25' );
1898                 $modulePrefix = $module->getModulePrefix();
1899                 if ( strval( $modulePrefix ) !== '' ) {
1900                         $modulePrefix = "($modulePrefix) ";
1901                 }
1902
1903                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1904         }
1905
1906         /**@}*/
1907
1908 }
1909
1910 /**
1911  * This exception will be thrown when dieUsage is called to stop module execution.
1912  *
1913  * @ingroup API
1914  */
1915 class UsageException extends MWException {
1916
1917         private $mCodestr;
1918
1919         /**
1920          * @var null|array
1921          */
1922         private $mExtraData;
1923
1924         /**
1925          * @param string $message
1926          * @param string $codestr
1927          * @param int $code
1928          * @param array|null $extradata
1929          */
1930         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1931                 parent::__construct( $message, $code );
1932                 $this->mCodestr = $codestr;
1933                 $this->mExtraData = $extradata;
1934         }
1935
1936         /**
1937          * @return string
1938          */
1939         public function getCodeString() {
1940                 return $this->mCodestr;
1941         }
1942
1943         /**
1944          * @return array
1945          */
1946         public function getMessageArray() {
1947                 $result = [
1948                         'code' => $this->mCodestr,
1949                         'info' => $this->getMessage()
1950                 ];
1951                 if ( is_array( $this->mExtraData ) ) {
1952                         $result = array_merge( $result, $this->mExtraData );
1953                 }
1954
1955                 return $result;
1956         }
1957
1958         /**
1959          * @return string
1960          */
1961         public function __toString() {
1962                 return "{$this->getCodeString()}: {$this->getMessage()}";
1963         }
1964 }
1965
1966 /**
1967  * For really cool vim folding this needs to be at the end:
1968  * vim: foldmarker=@{,@} foldmethod=marker
1969  */