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 = 'xmlfm';
  46
  47         /**
  48          * List of available modules: action name => module class
  49          */
  50         private static $Modules = array(
  51                 'login' => 'ApiLogin',
  52                 'logout' => 'ApiLogout',
  53                 'createaccount' => 'ApiCreateAccount',
  54                 'query' => 'ApiQuery',
  55                 'expandtemplates' => 'ApiExpandTemplates',
  56                 'parse' => 'ApiParse',
  57                 'opensearch' => 'ApiOpenSearch',
  58                 'feedcontributions' => 'ApiFeedContributions',
  59                 'feedrecentchanges' => 'ApiFeedRecentChanges',
  60                 'feedwatchlist' => 'ApiFeedWatchlist',
  61                 'help' => 'ApiHelp',
  62                 'paraminfo' => 'ApiParamInfo',
  63                 'rsd' => 'ApiRsd',
  64                 'compare' => 'ApiComparePages',
  65                 'tokens' => 'ApiTokens',
  66
  67                 // Write modules
  68                 'purge' => 'ApiPurge',
  69                 'setnotificationtimestamp' => 'ApiSetNotificationTimestamp',
  70                 'rollback' => 'ApiRollback',
  71                 'delete' => 'ApiDelete',
  72                 'undelete' => 'ApiUndelete',
  73                 'protect' => 'ApiProtect',
  74                 'block' => 'ApiBlock',
  75                 'unblock' => 'ApiUnblock',
  76                 'move' => 'ApiMove',
  77                 'edit' => 'ApiEditPage',
  78                 'upload' => 'ApiUpload',
  79                 'filerevert' => 'ApiFileRevert',
  80                 'emailuser' => 'ApiEmailUser',
  81                 'watch' => 'ApiWatch',
  82                 'patrol' => 'ApiPatrol',
  83                 'import' => 'ApiImport',
  84                 'userrights' => 'ApiUserrights',
  85                 'options' => 'ApiOptions',
  86                 'imagerotate' => 'ApiImageRotate',
  87                 'revisiondelete' => 'ApiRevisionDelete',
  88         );
  89
  90         /**
  91          * List of available formats: format name => format class
  92          */
  93         private static $Formats = array(
  94                 'json' => 'ApiFormatJson',
  95                 'jsonfm' => 'ApiFormatJson',
  96                 'php' => 'ApiFormatPhp',
  97                 'phpfm' => 'ApiFormatPhp',
  98                 'wddx' => 'ApiFormatWddx',
  99                 'wddxfm' => 'ApiFormatWddx',
 100                 'xml' => 'ApiFormatXml',
 101                 'xmlfm' => 'ApiFormatXml',
 102                 'yaml' => 'ApiFormatYaml',
 103                 'yamlfm' => 'ApiFormatYaml',
 104                 'rawfm' => 'ApiFormatJson',
 105                 'txt' => 'ApiFormatTxt',
 106                 'txtfm' => 'ApiFormatTxt',
 107                 'dbg' => 'ApiFormatDbg',
 108                 'dbgfm' => 'ApiFormatDbg',
 109                 'dump' => 'ApiFormatDump',
 110                 'dumpfm' => 'ApiFormatDump',
 111                 'none' => 'ApiFormatNone',
 112         );
 113
 114         // @codingStandardsIgnoreStart String contenation on "msg" not allowed to break long line
 115         /**
 116          * List of user roles that are specifically relevant to the API.
 117          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 118          *                           'params' => array ( $someVarToSubst ) ),
 119          *                          );
 120          */
 121         private static $mRights = array(
 122                 'writeapi' => array(
 123                         'msg' => 'Use of the write API',
 124                         'params' => array()
 125                 ),
 126                 'apihighlimits' => array(
 127                         'msg' => 'Use higher limits in API queries (Slow queries: $1 results; Fast queries: $2 results). The limits for slow queries also apply to multivalue parameters.',
 128                         'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
 129                 )
 130         );
 131         // @codingStandardsIgnoreEnd
 132
 133         /**
 134          * @var ApiFormatBase
 135          */
 136         private $mPrinter;
 137
 138         private $mModuleMgr, $mResult;
 139         private $mAction;
 140         private $mEnableWrite;
 141         private $mInternalMode, $mSquidMaxage, $mModule;
 142
 143         private $mCacheMode = 'private';
 144         private $mCacheControl = array();
 145         private $mParamsUsed = array();
 146
 147         /**
 148          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 149          *
 150          * @param IContextSource|WebRequest $context If this is an instance of
 151          *    FauxRequest, errors are thrown and no printing occurs
 152          * @param bool $enableWrite Should be set to true if the api may modify data
 153          */
 154         public function __construct( $context = null, $enableWrite = false ) {
 155                 if ( $context === null ) {
 156                         $context = RequestContext::getMain();
 157                 } elseif ( $context instanceof WebRequest ) {
 158                         // BC for pre-1.19
 159                         $request = $context;
 160                         $context = RequestContext::getMain();
 161                 }
 162                 // We set a derivative context so we can change stuff later
 163                 $this->setContext( new DerivativeContext( $context ) );
 164
 165                 if ( isset( $request ) ) {
 166                         $this->getContext()->setRequest( $request );
 167                 }
 168
 169                 $this->mInternalMode = ( $this->getRequest() instanceof FauxRequest );
 170
 171                 // Special handling for the main module: $parent === $this
 172                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 173
 174                 if ( !$this->mInternalMode ) {
 175                         // Impose module restrictions.
 176                         // If the current user cannot read,
 177                         // Remove all modules other than login
 178                         global $wgUser;
 179
 180                         if ( $this->getVal( 'callback' ) !== null ) {
 181                                 // JSON callback allows cross-site reads.
 182                                 // For safety, strip user credentials.
 183                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 184                                 $wgUser = new User();
 185                                 $this->getContext()->setUser( $wgUser );
 186                         }
 187                 }
 188
 189                 $config = $this->getConfig();
 190                 $this->mModuleMgr = new ApiModuleManager( $this );
 191                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 192                 $this->mModuleMgr->addModules( $config->get( 'APIModules' ), 'action' );
 193                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 194                 $this->mModuleMgr->addModules( $config->get( 'APIFormatModules' ), 'format' );
 195
 196                 $this->mResult = new ApiResult( $this );
 197                 $this->mEnableWrite = $enableWrite;
 198
 199                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 200                 $this->mCommit = false;
 201         }
 202
 203         /**
 204          * Return true if the API was started by other PHP code using FauxRequest
 205          * @return bool
 206          */
 207         public function isInternalMode() {
 208                 return $this->mInternalMode;
 209         }
 210
 211         /**
 212          * Get the ApiResult object associated with current request
 213          *
 214          * @return ApiResult
 215          */
 216         public function getResult() {
 217                 return $this->mResult;
 218         }
 219
 220         /**
 221          * Get the API module object. Only works after executeAction()
 222          *
 223          * @return ApiBase
 224          */
 225         public function getModule() {
 226                 return $this->mModule;
 227         }
 228
 229         /**
 230          * Get the result formatter object. Only works after setupExecuteAction()
 231          *
 232          * @return ApiFormatBase
 233          */
 234         public function getPrinter() {
 235                 return $this->mPrinter;
 236         }
 237
 238         /**
 239          * Set how long the response should be cached.
 240          *
 241          * @param int $maxage
 242          */
 243         public function setCacheMaxAge( $maxage ) {
 244                 $this->setCacheControl( array(
 245                         'max-age' => $maxage,
 246                         's-maxage' => $maxage
 247                 ) );
 248         }
 249
 250         /**
 251          * Set the type of caching headers which will be sent.
 252          *
 253          * @param string $mode One of:
 254          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 255          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 256          *         not provided by any of these means, the object will be private.
 257          *    - 'private':    Cache this object only in private client-side caches.
 258          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 259          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 260          *         set consistently for a given URL, it cannot be set differently depending on
 261          *         things like the contents of the database, or whether the user is logged in.
 262          *
 263          *  If the wiki does not allow anonymous users to read it, the mode set here
 264          *  will be ignored, and private caching headers will always be sent. In other words,
 265          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 266          *  view.
 267          *
 268          *  For user-dependent data, the private mode should generally be used. The
 269          *  anon-public-user-private mode should only be used where there is a particularly
 270          *  good performance reason for caching the anonymous response, but where the
 271          *  response to logged-in users may differ, or may contain private data.
 272          *
 273          *  If this function is never called, then the default will be the private mode.
 274          */
 275         public function setCacheMode( $mode ) {
 276                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 277                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 278
 279                         // Ignore for forwards-compatibility
 280                         return;
 281                 }
 282
 283                 if ( !User::isEveryoneAllowed( 'read' ) ) {
 284                         // Private wiki, only private headers
 285                         if ( $mode !== 'private' ) {
 286                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 287
 288                                 return;
 289                         }
 290                 }
 291
 292                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 293                 $this->mCacheMode = $mode;
 294         }
 295
 296         /**
 297          * Set directives (key/value pairs) for the Cache-Control header.
 298          * Boolean values will be formatted as such, by including or omitting
 299          * without an equals sign.
 300          *
 301          * Cache control values set here will only be used if the cache mode is not
 302          * private, see setCacheMode().
 303          *
 304          * @param array $directives
 305          */
 306         public function setCacheControl( $directives ) {
 307                 $this->mCacheControl = $directives + $this->mCacheControl;
 308         }
 309
 310         /**
 311          * Create an instance of an output formatter by its name
 312          *
 313          * @param string $format
 314          *
 315          * @return ApiFormatBase
 316          */
 317         public function createPrinterByName( $format ) {
 318                 $printer = $this->mModuleMgr->getModule( $format, 'format' );
 319                 if ( $printer === null ) {
 320                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 321                 }
 322
 323                 return $printer;
 324         }
 325
 326         /**
 327          * Execute api request. Any errors will be handled if the API was called by the remote client.
 328          */
 329         public function execute() {
 330                 $this->profileIn();
 331                 if ( $this->mInternalMode ) {
 332                         $this->executeAction();
 333                 } else {
 334                         $this->executeActionWithErrorHandling();
 335                 }
 336
 337                 $this->profileOut();
 338         }
 339
 340         /**
 341          * Execute an action, and in case of an error, erase whatever partial results
 342          * have been accumulated, and replace it with an error message and a help screen.
 343          */
 344         protected function executeActionWithErrorHandling() {
 345                 // Verify the CORS header before executing the action
 346                 if ( !$this->handleCORS() ) {
 347                         // handleCORS() has sent a 403, abort
 348                         return;
 349                 }
 350
 351                 // Exit here if the request method was OPTIONS
 352                 // (assume there will be a followup GET or POST)
 353                 if ( $this->getRequest()->getMethod() === 'OPTIONS' ) {
 354                         return;
 355                 }
 356
 357                 // In case an error occurs during data output,
 358                 // clear the output buffer and print just the error information
 359                 ob_start();
 360
 361                 $t = microtime( true );
 362                 try {
 363                         $this->executeAction();
 364                 } catch ( Exception $e ) {
 365                         $this->handleException( $e );
 366                 }
 367
 368                 // Log the request whether or not there was an error
 369                 $this->logRequest( microtime( true ) - $t );
 370
 371                 // Send cache headers after any code which might generate an error, to
 372                 // avoid sending public cache headers for errors.
 373                 $this->sendCacheHeaders();
 374
 375                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 376                         echo wfReportTime();
 377                 }
 378
 379                 ob_end_flush();
 380         }
 381
 382         /**
 383          * Handle an exception as an API response
 384          *
 385          * @since 1.23
 386          * @param Exception $e
 387          */
 388         protected function handleException( Exception $e ) {
 389                 // Bug 63145: Rollback any open database transactions
 390                 if ( !( $e instanceof UsageException ) ) {
 391                         // UsageExceptions are intentional, so don't rollback if that's the case
 392                         MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 393                 }
 394
 395                 // Allow extra cleanup and logging
 396                 wfRunHooks( 'ApiMain::onException', array( $this, $e ) );
 397
 398                 // Log it
 399                 if ( !( $e instanceof UsageException ) ) {
 400                         MWExceptionHandler::logException( $e );
 401                 }
 402
 403                 // Handle any kind of exception by outputting properly formatted error message.
 404                 // If this fails, an unhandled exception should be thrown so that global error
 405                 // handler will process and log it.
 406
 407                 $errCode = $this->substituteResultWithError( $e );
 408
 409                 // Error results should not be cached
 410                 $this->setCacheMode( 'private' );
 411
 412                 $response = $this->getRequest()->response();
 413                 $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 414                 if ( $e->getCode() === 0 ) {
 415                         $response->header( $headerStr );
 416                 } else {
 417                         $response->header( $headerStr, true, $e->getCode() );
 418                 }
 419
 420                 // Reset and print just the error message
 421                 ob_clean();
 422
 423                 // If the error occurred during printing, do a printer->profileOut()
 424                 $this->mPrinter->safeProfileOut();
 425                 $this->printResult( true );
 426         }
 427
 428         /**
 429          * Handle an exception from the ApiBeforeMain hook.
 430          *
 431          * This tries to print the exception as an API response, to be more
 432          * friendly to clients. If it fails, it will rethrow the exception.
 433          *
 434          * @since 1.23
 435          * @param Exception $e
 436          */
 437         public static function handleApiBeforeMainException( Exception $e ) {
 438                 ob_start();
 439
 440                 try {
 441                         $main = new self( RequestContext::getMain(), false );
 442                         $main->handleException( $e );
 443                 } catch ( Exception $e2 ) {
 444                         // Nope, even that didn't work. Punt.
 445                         throw $e;
 446                 }
 447
 448                 // Log the request and reset cache headers
 449                 $main->logRequest( 0 );
 450                 $main->sendCacheHeaders();
 451
 452                 ob_end_flush();
 453         }
 454
 455         /**
 456          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 457          *
 458          * If no origin parameter is present, nothing happens.
 459          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 460          * is set and false is returned.
 461          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 462          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 463          * headers are set.
 464          *
 465          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 466          */
 467         protected function handleCORS() {
 468                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 469                 if ( $originParam === null ) {
 470                         // No origin parameter, nothing to do
 471                         return true;
 472                 }
 473
 474                 $request = $this->getRequest();
 475                 $response = $request->response();
 476                 // Origin: header is a space-separated list of origins, check all of them
 477                 $originHeader = $request->getHeader( 'Origin' );
 478                 if ( $originHeader === false ) {
 479                         $origins = array();
 480                 } else {
 481                         $origins = explode( ' ', $originHeader );
 482                 }
 483
 484                 if ( !in_array( $originParam, $origins ) ) {
 485                         // origin parameter set but incorrect
 486                         // Send a 403 response
 487                         $message = HttpStatus::getMessage( 403 );
 488                         $response->header( "HTTP/1.1 403 $message", true, 403 );
 489                         $response->header( 'Cache-Control: no-cache' );
 490                         echo "'origin' parameter does not match Origin header\n";
 491
 492                         return false;
 493                 }
 494
 495                 $config = $this->getConfig();
 496                 $matchOrigin = self::matchOrigin(
 497                         $originParam,
 498                         $config->get( 'CrossSiteAJAXdomains' ),
 499                         $config->get( 'CrossSiteAJAXdomainExceptions' )
 500                 );
 501
 502                 if ( $matchOrigin ) {
 503                         $response->header( "Access-Control-Allow-Origin: $originParam" );
 504                         $response->header( 'Access-Control-Allow-Credentials: true' );
 505                         $this->getOutput()->addVaryHeader( 'Origin' );
 506                 }
 507
 508                 return true;
 509         }
 510
 511         /**
 512          * Attempt to match an Origin header against a set of rules and a set of exceptions
 513          * @param string $value Origin header
 514          * @param array $rules Set of wildcard rules
 515          * @param array $exceptions Set of wildcard rules
 516          * @return bool True if $value matches a rule in $rules and doesn't match
 517          *    any rules in $exceptions, false otherwise
 518          */
 519         protected static function matchOrigin( $value, $rules, $exceptions ) {
 520                 foreach ( $rules as $rule ) {
 521                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 522                                 // Rule matches, check exceptions
 523                                 foreach ( $exceptions as $exc ) {
 524                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 525                                                 return false;
 526                                         }
 527                                 }
 528
 529                                 return true;
 530                         }
 531                 }
 532
 533                 return false;
 534         }
 535
 536         /**
 537          * Helper function to convert wildcard string into a regex
 538          * '*' => '.*?'
 539          * '?' => '.'
 540          *
 541          * @param string $wildcard String with wildcards
 542          * @return string Regular expression
 543          */
 544         protected static function wildcardToRegex( $wildcard ) {
 545                 $wildcard = preg_quote( $wildcard, '/' );
 546                 $wildcard = str_replace(
 547                         array( '\*', '\?' ),
 548                         array( '.*?', '.' ),
 549                         $wildcard
 550                 );
 551
 552                 return "/https?:\/\/$wildcard/";
 553         }
 554
 555         protected function sendCacheHeaders() {
 556                 $response = $this->getRequest()->response();
 557                 $out = $this->getOutput();
 558
 559                 $config = $this->getConfig();
 560
 561                 if ( $config->get( 'VaryOnXFP' ) ) {
 562                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 563                 }
 564
 565                 if ( $this->mCacheMode == 'private' ) {
 566                         $response->header( 'Cache-Control: private' );
 567                         return;
 568                 }
 569
 570                 $useXVO = $config->get( 'UseXVO' );
 571                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 572                         $out->addVaryHeader( 'Cookie' );
 573                         $response->header( $out->getVaryHeader() );
 574                         if ( $useXVO ) {
 575                                 $response->header( $out->getXVO() );
 576                                 if ( $out->haveCacheVaryCookies() ) {
 577                                         // Logged in, mark this request private
 578                                         $response->header( 'Cache-Control: private' );
 579                                         return;
 580                                 }
 581                                 // Logged out, send normal public headers below
 582                         } elseif ( session_id() != '' ) {
 583                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 584                                 // Mark request private
 585                                 $response->header( 'Cache-Control: private' );
 586
 587                                 return;
 588                         } // else no XVO and anonymous, send public headers below
 589                 }
 590
 591                 // Send public headers
 592                 $response->header( $out->getVaryHeader() );
 593                 if ( $useXVO ) {
 594                         $response->header( $out->getXVO() );
 595                 }
 596
 597                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 598                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 599                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 600                 }
 601                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 602                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 603                 }
 604
 605                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 606                         // Public cache not requested
 607                         // Sending a Vary header in this case is harmless, and protects us
 608                         // against conditional calls of setCacheMaxAge().
 609                         $response->header( 'Cache-Control: private' );
 610
 611                         return;
 612                 }
 613
 614                 $this->mCacheControl['public'] = true;
 615
 616                 // Send an Expires header
 617                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 618                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 619                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 620
 621                 // Construct the Cache-Control header
 622                 $ccHeader = '';
 623                 $separator = '';
 624                 foreach ( $this->mCacheControl as $name => $value ) {
 625                         if ( is_bool( $value ) ) {
 626                                 if ( $value ) {
 627                                         $ccHeader .= $separator . $name;
 628                                         $separator = ', ';
 629                                 }
 630                         } else {
 631                                 $ccHeader .= $separator . "$name=$value";
 632                                 $separator = ', ';
 633                         }
 634                 }
 635
 636                 $response->header( "Cache-Control: $ccHeader" );
 637         }
 638
 639         /**
 640          * Replace the result data with the information about an exception.
 641          * Returns the error code
 642          * @param Exception $e
 643          * @return string
 644          */
 645         protected function substituteResultWithError( $e ) {
 646                 $result = $this->getResult();
 647
 648                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 649                 if ( !isset( $this->mPrinter ) ) {
 650                         // The printer has not been created yet. Try to manually get formatter value.
 651                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 652                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
 653                                 $value = self::API_DEFAULT_FORMAT;
 654                         }
 655
 656                         $this->mPrinter = $this->createPrinterByName( $value );
 657                 }
 658
 659                 // Printer may not be able to handle errors. This is particularly
 660                 // likely if the module returns something for getCustomPrinter().
 661                 if ( !$this->mPrinter->canPrintErrors() ) {
 662                         $this->mPrinter->safeProfileOut();
 663                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
 664                 }
 665
 666                 // Update raw mode flag for the selected printer.
 667                 $result->setRawMode( $this->mPrinter->getNeedsRawData() );
 668
 669                 $config = $this->getConfig();
 670
 671                 if ( $e instanceof UsageException ) {
 672                         // User entered incorrect parameters - print usage screen
 673                         $errMessage = $e->getMessageArray();
 674
 675                         // Only print the help message when this is for the developer, not runtime
 676                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 677                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 678                         }
 679                 } else {
 680                         // Something is seriously wrong
 681                         if ( ( $e instanceof DBQueryError ) && !$config->get( 'ShowSQLErrors' ) ) {
 682                                 $info = 'Database query error';
 683                         } else {
 684                                 $info = "Exception Caught: {$e->getMessage()}";
 685                         }
 686
 687                         $errMessage = array(
 688                                 'code' => 'internal_api_error_' . get_class( $e ),
 689                                 'info' => $info,
 690                         );
 691                         ApiResult::setContent(
 692                                 $errMessage,
 693                                 $config->get( 'ShowExceptionDetails' ) ? "\n\n{$e->getTraceAsString()}\n\n" : ''
 694                         );
 695                 }
 696
 697                 // Remember all the warnings to re-add them later
 698                 $oldResult = $result->getData();
 699                 $warnings = isset( $oldResult['warnings'] ) ? $oldResult['warnings'] : null;
 700
 701                 $result->reset();
 702                 // Re-add the id
 703                 $requestid = $this->getParameter( 'requestid' );
 704                 if ( !is_null( $requestid ) ) {
 705                         $result->addValue( null, 'requestid', $requestid, ApiResult::NO_SIZE_CHECK );
 706                 }
 707                 if ( $config->get( 'ShowHostnames' ) ) {
 708                         // servedby is especially useful when debugging errors
 709                         $result->addValue( null, 'servedby', wfHostName(), ApiResult::NO_SIZE_CHECK );
 710                 }
 711                 if ( $warnings !== null ) {
 712                         $result->addValue( null, 'warnings', $warnings, ApiResult::NO_SIZE_CHECK );
 713                 }
 714
 715                 $result->addValue( null, 'error', $errMessage, ApiResult::NO_SIZE_CHECK );
 716
 717                 return $errMessage['code'];
 718         }
 719
 720         /**
 721          * Set up for the execution.
 722          * @return array
 723          */
 724         protected function setupExecuteAction() {
 725                 // First add the id to the top element
 726                 $result = $this->getResult();
 727                 $requestid = $this->getParameter( 'requestid' );
 728                 if ( !is_null( $requestid ) ) {
 729                         $result->addValue( null, 'requestid', $requestid );
 730                 }
 731
 732                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
 733                         $servedby = $this->getParameter( 'servedby' );
 734                         if ( $servedby ) {
 735                                 $result->addValue( null, 'servedby', wfHostName() );
 736                         }
 737                 }
 738
 739                 $params = $this->extractRequestParams();
 740
 741                 $this->mAction = $params['action'];
 742
 743                 if ( !is_string( $this->mAction ) ) {
 744                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 745                 }
 746
 747                 return $params;
 748         }
 749
 750         /**
 751          * Set up the module for response
 752          * @return ApiBase The module that will handle this action
 753          */
 754         protected function setupModule() {
 755                 // Instantiate the module requested by the user
 756                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
 757                 if ( $module === null ) {
 758                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 759                 }
 760                 $moduleParams = $module->extractRequestParams();
 761
 762                 // Die if token required, but not provided
 763                 $salt = $module->getTokenSalt();
 764                 if ( $salt !== false ) {
 765                         if ( !isset( $moduleParams['token'] ) ) {
 766                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 767                         }
 768
 769                         if ( !$this->getUser()->matchEditToken(
 770                                 $moduleParams['token'],
 771                                 $salt,
 772                                 $this->getContext()->getRequest() )
 773                         ) {
 774                                 $this->dieUsageMsg( 'sessionfailure' );
 775                         }
 776                 }
 777
 778                 return $module;
 779         }
 780
 781         /**
 782          * Check the max lag if necessary
 783          * @param ApiBase $module Api module being used
 784          * @param array $params Array an array containing the request parameters.
 785          * @return bool True on success, false should exit immediately
 786          */
 787         protected function checkMaxLag( $module, $params ) {
 788                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 789                         // Check for maxlag
 790                         $maxLag = $params['maxlag'];
 791                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 792                         if ( $lag > $maxLag ) {
 793                                 $response = $this->getRequest()->response();
 794
 795                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 796                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 797
 798                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
 799                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 800                                 }
 801
 802                                 $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 803                         }
 804                 }
 805
 806                 return true;
 807         }
 808
 809         /**
 810          * Check for sufficient permissions to execute
 811          * @param ApiBase $module An Api module
 812          */
 813         protected function checkExecutePermissions( $module ) {
 814                 $user = $this->getUser();
 815                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
 816                         !$user->isAllowed( 'read' )
 817                 ) {
 818                         $this->dieUsageMsg( 'readrequired' );
 819                 }
 820                 if ( $module->isWriteMode() ) {
 821                         if ( !$this->mEnableWrite ) {
 822                                 $this->dieUsageMsg( 'writedisabled' );
 823                         }
 824                         if ( !$user->isAllowed( 'writeapi' ) ) {
 825                                 $this->dieUsageMsg( 'writerequired' );
 826                         }
 827                         if ( wfReadOnly() ) {
 828                                 $this->dieReadOnly();
 829                         }
 830                 }
 831
 832                 // Allow extensions to stop execution for arbitrary reasons.
 833                 $message = false;
 834                 if ( !wfRunHooks( 'ApiCheckCanExecute', array( $module, $user, &$message ) ) ) {
 835                         $this->dieUsageMsg( $message );
 836                 }
 837         }
 838
 839         /**
 840          * Check asserts of the user's rights
 841          * @param array $params
 842          */
 843         protected function checkAsserts( $params ) {
 844                 if ( isset( $params['assert'] ) ) {
 845                         $user = $this->getUser();
 846                         switch ( $params['assert'] ) {
 847                                 case 'user':
 848                                         if ( $user->isAnon() ) {
 849                                                 $this->dieUsage( 'Assertion that the user is logged in failed', 'assertuserfailed' );
 850                                         }
 851                                         break;
 852                                 case 'bot':
 853                                         if ( !$user->isAllowed( 'bot' ) ) {
 854                                                 $this->dieUsage( 'Assertion that the user has the bot right failed', 'assertbotfailed' );
 855                                         }
 856                                         break;
 857                         }
 858                 }
 859         }
 860
 861         /**
 862          * Check POST for external response and setup result printer
 863          * @param ApiBase $module An Api module
 864          * @param array $params An array with the request parameters
 865          */
 866         protected function setupExternalResponse( $module, $params ) {
 867                 if ( !$this->getRequest()->wasPosted() && $module->mustBePosted() ) {
 868                         // Module requires POST. GET request might still be allowed
 869                         // if $wgDebugApi is true, otherwise fail.
 870                         $this->dieUsageMsgOrDebug( array( 'mustbeposted', $this->mAction ) );
 871                 }
 872
 873                 // See if custom printer is used
 874                 $this->mPrinter = $module->getCustomPrinter();
 875                 if ( is_null( $this->mPrinter ) ) {
 876                         // Create an appropriate printer
 877                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 878                 }
 879
 880                 if ( $this->mPrinter->getNeedsRawData() ) {
 881                         $this->getResult()->setRawMode();
 882                 }
 883         }
 884
 885         /**
 886          * Execute the actual module, without any error handling
 887          */
 888         protected function executeAction() {
 889                 $params = $this->setupExecuteAction();
 890                 $module = $this->setupModule();
 891                 $this->mModule = $module;
 892
 893                 $this->checkExecutePermissions( $module );
 894
 895                 if ( !$this->checkMaxLag( $module, $params ) ) {
 896                         return;
 897                 }
 898
 899                 if ( !$this->mInternalMode ) {
 900                         $this->setupExternalResponse( $module, $params );
 901                 }
 902
 903                 $this->checkAsserts( $params );
 904
 905                 // Execute
 906                 $module->profileIn();
 907                 $module->execute();
 908                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 909                 $module->profileOut();
 910
 911                 $this->reportUnusedParams();
 912
 913                 if ( !$this->mInternalMode ) {
 914                         //append Debug information
 915                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
 916
 917                         // Print result data
 918                         $this->printResult( false );
 919                 }
 920         }
 921
 922         /**
 923          * Log the preceding request
 924          * @param int $time Time in seconds
 925          */
 926         protected function logRequest( $time ) {
 927                 $request = $this->getRequest();
 928                 $milliseconds = $time === null ? '?' : round( $time * 1000 );
 929                 $s = 'API' .
 930                         ' ' . $request->getMethod() .
 931                         ' ' . wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
 932                         ' ' . $request->getIP() .
 933                         ' T=' . $milliseconds . 'ms';
 934                 foreach ( $this->getParamsUsed() as $name ) {
 935                         $value = $request->getVal( $name );
 936                         if ( $value === null ) {
 937                                 continue;
 938                         }
 939                         $s .= ' ' . $name . '=';
 940                         if ( strlen( $value ) > 256 ) {
 941                                 $encValue = $this->encodeRequestLogValue( substr( $value, 0, 256 ) );
 942                                 $s .= $encValue . '[...]';
 943                         } else {
 944                                 $s .= $this->encodeRequestLogValue( $value );
 945                         }
 946                 }
 947                 $s .= "\n";
 948                 wfDebugLog( 'api', $s, 'private' );
 949         }
 950
 951         /**
 952          * Encode a value in a format suitable for a space-separated log line.
 953          * @param string $s
 954          * @return string
 955          */
 956         protected function encodeRequestLogValue( $s ) {
 957                 static $table;
 958                 if ( !$table ) {
 959                         $chars = ';@$!*(),/:';
 960                         $numChars = strlen( $chars );
 961                         for ( $i = 0; $i < $numChars; $i++ ) {
 962                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
 963                         }
 964                 }
 965
 966                 return strtr( rawurlencode( $s ), $table );
 967         }
 968
 969         /**
 970          * Get the request parameters used in the course of the preceding execute() request
 971          * @return array
 972          */
 973         protected function getParamsUsed() {
 974                 return array_keys( $this->mParamsUsed );
 975         }
 976
 977         /**
 978          * Get a request value, and register the fact that it was used, for logging.
 979          * @param string $name
 980          * @param mixed $default
 981          * @return mixed
 982          */
 983         public function getVal( $name, $default = null ) {
 984                 $this->mParamsUsed[$name] = true;
 985
 986                 $ret = $this->getRequest()->getVal( $name );
 987                 if ( $ret === null ) {
 988                         if ( $this->getRequest()->getArray( $name ) !== null ) {
 989                                 // See bug 10262 for why we don't just join( '|', ... ) the
 990                                 // array.
 991                                 $this->setWarning(
 992                                         "Parameter '$name' uses unsupported PHP array syntax"
 993                                 );
 994                         }
 995                         $ret = $default;
 996                 }
 997                 return $ret;
 998         }
 999
1000         /**
1001          * Get a boolean request value, and register the fact that the parameter
1002          * was used, for logging.
1003          * @param string $name
1004          * @return bool
1005          */
1006         public function getCheck( $name ) {
1007                 return $this->getVal( $name, null ) !== null;
1008         }
1009
1010         /**
1011          * Get a request upload, and register the fact that it was used, for logging.
1012          *
1013          * @since 1.21
1014          * @param string $name Parameter name
1015          * @return WebRequestUpload
1016          */
1017         public function getUpload( $name ) {
1018                 $this->mParamsUsed[$name] = true;
1019
1020                 return $this->getRequest()->getUpload( $name );
1021         }
1022
1023         /**
1024          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1025          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1026          */
1027         protected function reportUnusedParams() {
1028                 $paramsUsed = $this->getParamsUsed();
1029                 $allParams = $this->getRequest()->getValueNames();
1030
1031                 if ( !$this->mInternalMode ) {
1032                         // Printer has not yet executed; don't warn that its parameters are unused
1033                         $printerParams = array_map(
1034                                 array( $this->mPrinter, 'encodeParamName' ),
1035                                 array_keys( $this->mPrinter->getFinalParams() ?: array() )
1036                         );
1037                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1038                 } else {
1039                         $unusedParams = array_diff( $allParams, $paramsUsed );
1040                 }
1041
1042                 if ( count( $unusedParams ) ) {
1043                         $s = count( $unusedParams ) > 1 ? 's' : '';
1044                         $this->setWarning( "Unrecognized parameter$s: '" . implode( $unusedParams, "', '" ) . "'" );
1045                 }
1046         }
1047
1048         /**
1049          * Print results using the current printer
1050          *
1051          * @param bool $isError
1052          */
1053         protected function printResult( $isError ) {
1054                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1055                         $this->setWarning( 'SECURITY WARNING: $wgDebugAPI is enabled' );
1056                 }
1057
1058                 $this->getResult()->cleanUpUTF8();
1059                 $printer = $this->mPrinter;
1060                 $printer->profileIn();
1061
1062                 /**
1063                  * If the help message is requested in the default (xmlfm) format,
1064                  * tell the printer not to escape ampersands so that our links do
1065                  * not break.
1066                  */
1067                 $isHelp = $isError || $this->mAction == 'help';
1068                 $printer->setUnescapeAmps( $isHelp && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
1069
1070                 $printer->initPrinter( $isHelp );
1071
1072                 $printer->execute();
1073                 $printer->closePrinter();
1074                 $printer->profileOut();
1075         }
1076
1077         /**
1078          * @return bool
1079          */
1080         public function isReadMode() {
1081                 return false;
1082         }
1083
1084         /**
1085          * See ApiBase for description.
1086          *
1087          * @return array
1088          */
1089         public function getAllowedParams() {
1090                 return array(
1091                         'format' => array(
1092                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1093                                 ApiBase::PARAM_TYPE => $this->mModuleMgr->getNames( 'format' )
1094                         ),
1095                         'action' => array(
1096                                 ApiBase::PARAM_DFLT => 'help',
1097                                 ApiBase::PARAM_TYPE => $this->mModuleMgr->getNames( 'action' )
1098                         ),
1099                         'maxlag' => array(
1100                                 ApiBase::PARAM_TYPE => 'integer'
1101                         ),
1102                         'smaxage' => array(
1103                                 ApiBase::PARAM_TYPE => 'integer',
1104                                 ApiBase::PARAM_DFLT => 0
1105                         ),
1106                         'maxage' => array(
1107                                 ApiBase::PARAM_TYPE => 'integer',
1108                                 ApiBase::PARAM_DFLT => 0
1109                         ),
1110                         'assert' => array(
1111                                 ApiBase::PARAM_TYPE => array( 'user', 'bot' )
1112                         ),
1113                         'requestid' => null,
1114                         'servedby' => false,
1115                         'origin' => null,
1116                 );
1117         }
1118
1119         /**
1120          * See ApiBase for description.
1121          *
1122          * @return array
1123          */
1124         public function getParamDescription() {
1125                 return array(
1126                         'format' => 'The format of the output',
1127                         'action' => 'What action you would like to perform. See below for module help',
1128                         'maxlag' => array(
1129                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
1130                                 'To save actions causing any more site replication lag, this parameter can make the client',
1131                                 'wait until the replication lag is less than the specified value.',
1132                                 'In case of a replag error, error code "maxlag" is returned, with the message like',
1133                                 '"Waiting for $host: $lag seconds lagged\n".',
1134                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
1135                         ),
1136                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
1137                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
1138                         'assert' => 'Verify the user is logged in if set to "user", or has the bot userright if "bot"',
1139                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
1140                         'servedby' => 'Include the hostname that served the request in the ' .
1141                                 'results. Unconditionally shown on error',
1142                         'origin' => array(
1143                                 'When accessing the API using a cross-domain AJAX request (CORS), set this to the',
1144                                 'originating domain. This must be included in any pre-flight request, and',
1145                                 'therefore must be part of the request URI (not the POST body). This must match',
1146                                 'one of the origins in the Origin: header exactly, so it has to be set to ',
1147                                 'something like http://en.wikipedia.org or https://meta.wikimedia.org . If this',
1148                                 'parameter does not match the Origin: header, a 403 response will be returned. If',
1149                                 'this parameter matches the Origin: header and the origin is whitelisted, an',
1150                                 'Access-Control-Allow-Origin header will be set.',
1151                         ),
1152                 );
1153         }
1154
1155         /**
1156          * See ApiBase for description.
1157          *
1158          * @return array
1159          */
1160         public function getDescription() {
1161                 return array(
1162                         '',
1163                         '',
1164                         '**********************************************************************************************',
1165                         '**                                                                                          **',
1166                         '**                This is an auto-generated MediaWiki API documentation page                **',
1167                         '**                                                                                          **',
1168                         '**                               Documentation and Examples:                                **',
1169                         '**                            https://www.mediawiki.org/wiki/API                            **',
1170                         '**                                                                                          **',
1171                         '**********************************************************************************************',
1172                         '',
1173                         'Status:                All features shown on this page should be working, but the API',
1174                         '                       is still in active development, and may change at any time.',
1175                         '                       Make sure to monitor our mailing list for any updates.',
1176                         '',
1177                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
1178                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
1179                         '                       header and the error code sent back will be set to the same value.',
1180                         '',
1181                         '                       In the case of an invalid action being passed, these will have a value',
1182                         '                       of "unknown_action".',
1183                         '',
1184                         '                       For more information see https://www.mediawiki.org' .
1185                                 '/wiki/API:Errors_and_warnings',
1186                         '',
1187                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
1188                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
1189                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
1190                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
1191                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&' .
1192                                 'bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
1193                         '',
1194                         '',
1195                         '',
1196                         '',
1197                         '',
1198                 );
1199         }
1200
1201         /**
1202          * @return array
1203          */
1204         public function getPossibleErrors() {
1205                 return array_merge( parent::getPossibleErrors(), array(
1206                         array( 'readonlytext' ),
1207                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
1208                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
1209                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
1210                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
1211                         array( 'code' => 'assertuserfailed', 'info' => 'Assertion that the user is logged in failed' ),
1212                         array(
1213                                 'code' => 'assertbotfailed',
1214                                 'info' => 'Assertion that the user has the bot right failed'
1215                         ),
1216                 ) );
1217         }
1218
1219         /**
1220          * Returns an array of strings with credits for the API
1221          * @return array
1222          */
1223         protected function getCredits() {
1224                 return array(
1225                         'API developers:',
1226                         '    Roan Kattouw (lead developer Sep 2007-2009)',
1227                         '    Victor Vasiliev',
1228                         '    Bryan Tong Minh',
1229                         '    Sam Reed',
1230                         '    Yuri Astrakhan (creator, lead developer Sep 2006-Sep 2007, 2012-2013)',
1231                         '    Brad Jorsch (lead developer 2013-now)',
1232                         '',
1233                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
1234                         'or file a bug report at https://bugzilla.wikimedia.org/'
1235                 );
1236         }
1237
1238         /**
1239          * Sets whether the pretty-printer should format *bold* and $italics$
1240          *
1241          * @param bool $help
1242          */
1243         public function setHelp( $help = true ) {
1244                 $this->mPrinter->setHelp( $help );
1245         }
1246
1247         /**
1248          * Override the parent to generate help messages for all available modules.
1249          *
1250          * @return string
1251          */
1252         public function makeHelpMsg() {
1253                 global $wgMemc;
1254                 $this->setHelp();
1255                 // Get help text from cache if present
1256                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
1257                         str_replace( ' ', '_', SpecialVersion::getVersion( 'nodb' ) ) );
1258
1259                 $cacheHelpTimeout = $this->getConfig()->get( 'APICacheHelpTimeout' );
1260                 if ( $cacheHelpTimeout > 0 ) {
1261                         $cached = $wgMemc->get( $key );
1262                         if ( $cached ) {
1263                                 return $cached;
1264                         }
1265                 }
1266                 $retval = $this->reallyMakeHelpMsg();
1267                 if ( $cacheHelpTimeout > 0 ) {
1268                         $wgMemc->set( $key, $retval, $cacheHelpTimeout );
1269                 }
1270
1271                 return $retval;
1272         }
1273
1274         /**
1275          * @return mixed|string
1276          */
1277         public function reallyMakeHelpMsg() {
1278                 $this->setHelp();
1279
1280                 // Use parent to make default message for the main module
1281                 $msg = parent::makeHelpMsg();
1282
1283                 $astriks = str_repeat( '*** ', 14 );
1284                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
1285
1286                 foreach ( $this->mModuleMgr->getNames( 'action' ) as $name ) {
1287                         $module = $this->mModuleMgr->getModule( $name );
1288                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1289
1290                         $msg2 = $module->makeHelpMsg();
1291                         if ( $msg2 !== false ) {
1292                                 $msg .= $msg2;
1293                         }
1294                         $msg .= "\n";
1295                 }
1296
1297                 $msg .= "\n$astriks Permissions $astriks\n\n";
1298                 foreach ( self::$mRights as $right => $rightMsg ) {
1299                         $groups = User::getGroupsWithPermission( $right );
1300                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg['msg'], $rightMsg['params'] ) .
1301                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1302                 }
1303
1304                 $msg .= "\n$astriks Formats  $astriks\n\n";
1305                 foreach ( $this->mModuleMgr->getNames( 'format' ) as $name ) {
1306                         $module = $this->mModuleMgr->getModule( $name );
1307                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1308                         $msg2 = $module->makeHelpMsg();
1309                         if ( $msg2 !== false ) {
1310                                 $msg .= $msg2;
1311                         }
1312                         $msg .= "\n";
1313                 }
1314
1315                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
1316
1317                 return $msg;
1318         }
1319
1320         /**
1321          * @param ApiBase $module
1322          * @param string $paramName What type of request is this? e.g. action,
1323          *    query, list, prop, meta, format
1324          * @return string
1325          */
1326         public static function makeHelpMsgHeader( $module, $paramName ) {
1327                 $modulePrefix = $module->getModulePrefix();
1328                 if ( strval( $modulePrefix ) !== '' ) {
1329                         $modulePrefix = "($modulePrefix) ";
1330                 }
1331
1332                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1333         }
1334
1335         private $mCanApiHighLimits = null;
1336
1337         /**
1338          * Check whether the current user is allowed to use high limits
1339          * @return bool
1340          */
1341         public function canApiHighLimits() {
1342                 if ( !isset( $this->mCanApiHighLimits ) ) {
1343                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1344                 }
1345
1346                 return $this->mCanApiHighLimits;
1347         }
1348
1349         /**
1350          * Check whether the user wants us to show version information in the API help
1351          * @return bool
1352          * @deprecated since 1.21, always returns false
1353          */
1354         public function getShowVersions() {
1355                 wfDeprecated( __METHOD__, '1.21' );
1356
1357                 return false;
1358         }
1359
1360         /**
1361          * Overrides to return this instance's module manager.
1362          * @return ApiModuleManager
1363          */
1364         public function getModuleManager() {
1365                 return $this->mModuleMgr;
1366         }
1367
1368         /**
1369          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1370          * classes who wish to add their own modules to their lexicon or override the
1371          * behavior of inherent ones.
1372          *
1373          * @deprecated since 1.21, Use getModuleManager()->addModule() instead.
1374          * @param string $name The identifier for this module.
1375          * @param ApiBase $class The class where this module is implemented.
1376          */
1377         protected function addModule( $name, $class ) {
1378                 $this->getModuleManager()->addModule( $name, 'action', $class );
1379         }
1380
1381         /**
1382          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1383          * classes who wish to add to or modify current formatters.
1384          *
1385          * @deprecated since 1.21, Use getModuleManager()->addModule() instead.
1386          * @param string $name The identifier for this format.
1387          * @param ApiFormatBase $class The class implementing this format.
1388          */
1389         protected function addFormat( $name, $class ) {
1390                 $this->getModuleManager()->addModule( $name, 'format', $class );
1391         }
1392
1393         /**
1394          * Get the array mapping module names to class names
1395          * @deprecated since 1.21, Use getModuleManager()'s methods instead.
1396          * @return array
1397          */
1398         function getModules() {
1399                 return $this->getModuleManager()->getNamesWithClasses( 'action' );
1400         }
1401
1402         /**
1403          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1404          *
1405          * @since 1.18
1406          * @deprecated since 1.21, Use getModuleManager()'s methods instead.
1407          * @return array
1408          */
1409         public function getFormats() {
1410                 return $this->getModuleManager()->getNamesWithClasses( 'format' );
1411         }
1412 }
1413
1414 /**
1415  * This exception will be thrown when dieUsage is called to stop module execution.
1416  * The exception handling code will print a help screen explaining how this API may be used.
1417  *
1418  * @ingroup API
1419  */
1420 class UsageException extends MWException {
1421
1422         private $mCodestr;
1423
1424         /**
1425          * @var null|array
1426          */
1427         private $mExtraData;
1428
1429         /**
1430          * @param string $message
1431          * @param string $codestr
1432          * @param int $code
1433          * @param array|null $extradata
1434          */
1435         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1436                 parent::__construct( $message, $code );
1437                 $this->mCodestr = $codestr;
1438                 $this->mExtraData = $extradata;
1439         }
1440
1441         /**
1442          * @return string
1443          */
1444         public function getCodeString() {
1445                 return $this->mCodestr;
1446         }
1447
1448         /**
1449          * @return array
1450          */
1451         public function getMessageArray() {
1452                 $result = array(
1453                         'code' => $this->mCodestr,
1454                         'info' => $this->getMessage()
1455                 );
1456                 if ( is_array( $this->mExtraData ) ) {
1457                         $result = array_merge( $result, $this->mExtraData );
1458                 }
1459
1460                 return $result;
1461         }
1462
1463         /**
1464          * @return string
1465          */
1466         public function __toString() {
1467                 return "{$this->getCodeString()}: {$this->getMessage()}";
1468         }
1469 }