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                 if ( $this->getParameter( 'curtimestamp' ) ) {
 740                         $result->addValue( null, 'curtimestamp', wfTimestamp( TS_ISO_8601, time() ),
 741                                 ApiResult::NO_SIZE_CHECK );
 742                 }
 743
 744                 $params = $this->extractRequestParams();
 745
 746                 $this->mAction = $params['action'];
 747
 748                 if ( !is_string( $this->mAction ) ) {
 749                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 750                 }
 751
 752                 return $params;
 753         }
 754
 755         /**
 756          * Set up the module for response
 757          * @return ApiBase The module that will handle this action
 758          */
 759         protected function setupModule() {
 760                 // Instantiate the module requested by the user
 761                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
 762                 if ( $module === null ) {
 763                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 764                 }
 765                 $moduleParams = $module->extractRequestParams();
 766
 767                 // Check token, if necessary
 768                 if ( $module->needsToken() === true ) {
 769                         throw new MWException(
 770                                 "Module '{$module->getModuleName()}' must be updated for the new token handling. " .
 771                                 "See documentation for ApiBase::needsToken for details."
 772                         );
 773                 }
 774                 if ( $module->needsToken() ) {
 775                         if ( !$module->mustBePosted() ) {
 776                                 throw new MWException(
 777                                         "Module '{$module->getModuleName()}' must require POST to use tokens."
 778                                 );
 779                         }
 780
 781                         if ( !isset( $moduleParams['token'] ) ) {
 782                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 783                         }
 784
 785                         if ( array_key_exists(
 786                                 $module->encodeParamName( 'token' ),
 787                                 $this->getRequest()->getQueryValues()
 788                         ) ) {
 789                                 $this->dieUsage(
 790                                         "The '{$module->encodeParamName( 'token' )}' parameter must be POSTed",
 791                                         'mustposttoken'
 792                                 );
 793                         }
 794
 795                         if ( !$module->validateToken( $moduleParams['token'], $moduleParams ) ) {
 796                                 $this->dieUsageMsg( 'sessionfailure' );
 797                         }
 798                 }
 799
 800                 return $module;
 801         }
 802
 803         /**
 804          * Check the max lag if necessary
 805          * @param ApiBase $module Api module being used
 806          * @param array $params Array an array containing the request parameters.
 807          * @return bool True on success, false should exit immediately
 808          */
 809         protected function checkMaxLag( $module, $params ) {
 810                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 811                         // Check for maxlag
 812                         $maxLag = $params['maxlag'];
 813                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 814                         if ( $lag > $maxLag ) {
 815                                 $response = $this->getRequest()->response();
 816
 817                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 818                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 819
 820                                 if ( $this->getConfig()->get( 'ShowHostnames' ) ) {
 821                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 822                                 }
 823
 824                                 $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 825                         }
 826                 }
 827
 828                 return true;
 829         }
 830
 831         /**
 832          * Check for sufficient permissions to execute
 833          * @param ApiBase $module An Api module
 834          */
 835         protected function checkExecutePermissions( $module ) {
 836                 $user = $this->getUser();
 837                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
 838                         !$user->isAllowed( 'read' )
 839                 ) {
 840                         $this->dieUsageMsg( 'readrequired' );
 841                 }
 842                 if ( $module->isWriteMode() ) {
 843                         if ( !$this->mEnableWrite ) {
 844                                 $this->dieUsageMsg( 'writedisabled' );
 845                         }
 846                         if ( !$user->isAllowed( 'writeapi' ) ) {
 847                                 $this->dieUsageMsg( 'writerequired' );
 848                         }
 849                         if ( wfReadOnly() ) {
 850                                 $this->dieReadOnly();
 851                         }
 852                 }
 853
 854                 // Allow extensions to stop execution for arbitrary reasons.
 855                 $message = false;
 856                 if ( !wfRunHooks( 'ApiCheckCanExecute', array( $module, $user, &$message ) ) ) {
 857                         $this->dieUsageMsg( $message );
 858                 }
 859         }
 860
 861         /**
 862          * Check asserts of the user's rights
 863          * @param array $params
 864          */
 865         protected function checkAsserts( $params ) {
 866                 if ( isset( $params['assert'] ) ) {
 867                         $user = $this->getUser();
 868                         switch ( $params['assert'] ) {
 869                                 case 'user':
 870                                         if ( $user->isAnon() ) {
 871                                                 $this->dieUsage( 'Assertion that the user is logged in failed', 'assertuserfailed' );
 872                                         }
 873                                         break;
 874                                 case 'bot':
 875                                         if ( !$user->isAllowed( 'bot' ) ) {
 876                                                 $this->dieUsage( 'Assertion that the user has the bot right failed', 'assertbotfailed' );
 877                                         }
 878                                         break;
 879                         }
 880                 }
 881         }
 882
 883         /**
 884          * Check POST for external response and setup result printer
 885          * @param ApiBase $module An Api module
 886          * @param array $params An array with the request parameters
 887          */
 888         protected function setupExternalResponse( $module, $params ) {
 889                 if ( !$this->getRequest()->wasPosted() && $module->mustBePosted() ) {
 890                         // Module requires POST. GET request might still be allowed
 891                         // if $wgDebugApi is true, otherwise fail.
 892                         $this->dieUsageMsgOrDebug( array( 'mustbeposted', $this->mAction ) );
 893                 }
 894
 895                 // See if custom printer is used
 896                 $this->mPrinter = $module->getCustomPrinter();
 897                 if ( is_null( $this->mPrinter ) ) {
 898                         // Create an appropriate printer
 899                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 900                 }
 901
 902                 if ( $this->mPrinter->getNeedsRawData() ) {
 903                         $this->getResult()->setRawMode();
 904                 }
 905         }
 906
 907         /**
 908          * Execute the actual module, without any error handling
 909          */
 910         protected function executeAction() {
 911                 $params = $this->setupExecuteAction();
 912                 $module = $this->setupModule();
 913                 $this->mModule = $module;
 914
 915                 $this->checkExecutePermissions( $module );
 916
 917                 if ( !$this->checkMaxLag( $module, $params ) ) {
 918                         return;
 919                 }
 920
 921                 if ( !$this->mInternalMode ) {
 922                         $this->setupExternalResponse( $module, $params );
 923                 }
 924
 925                 $this->checkAsserts( $params );
 926
 927                 // Execute
 928                 $module->profileIn();
 929                 $module->execute();
 930                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 931                 $module->profileOut();
 932
 933                 $this->reportUnusedParams();
 934
 935                 if ( !$this->mInternalMode ) {
 936                         //append Debug information
 937                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
 938
 939                         // Print result data
 940                         $this->printResult( false );
 941                 }
 942         }
 943
 944         /**
 945          * Log the preceding request
 946          * @param int $time Time in seconds
 947          */
 948         protected function logRequest( $time ) {
 949                 $request = $this->getRequest();
 950                 $milliseconds = $time === null ? '?' : round( $time * 1000 );
 951                 $s = 'API' .
 952                         ' ' . $request->getMethod() .
 953                         ' ' . wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
 954                         ' ' . $request->getIP() .
 955                         ' T=' . $milliseconds . 'ms';
 956                 foreach ( $this->getParamsUsed() as $name ) {
 957                         $value = $request->getVal( $name );
 958                         if ( $value === null ) {
 959                                 continue;
 960                         }
 961                         $s .= ' ' . $name . '=';
 962                         if ( strlen( $value ) > 256 ) {
 963                                 $encValue = $this->encodeRequestLogValue( substr( $value, 0, 256 ) );
 964                                 $s .= $encValue . '[...]';
 965                         } else {
 966                                 $s .= $this->encodeRequestLogValue( $value );
 967                         }
 968                 }
 969                 $s .= "\n";
 970                 wfDebugLog( 'api', $s, 'private' );
 971         }
 972
 973         /**
 974          * Encode a value in a format suitable for a space-separated log line.
 975          * @param string $s
 976          * @return string
 977          */
 978         protected function encodeRequestLogValue( $s ) {
 979                 static $table;
 980                 if ( !$table ) {
 981                         $chars = ';@$!*(),/:';
 982                         $numChars = strlen( $chars );
 983                         for ( $i = 0; $i < $numChars; $i++ ) {
 984                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
 985                         }
 986                 }
 987
 988                 return strtr( rawurlencode( $s ), $table );
 989         }
 990
 991         /**
 992          * Get the request parameters used in the course of the preceding execute() request
 993          * @return array
 994          */
 995         protected function getParamsUsed() {
 996                 return array_keys( $this->mParamsUsed );
 997         }
 998
 999         /**
1000          * Get a request value, and register the fact that it was used, for logging.
1001          * @param string $name
1002          * @param mixed $default
1003          * @return mixed
1004          */
1005         public function getVal( $name, $default = null ) {
1006                 $this->mParamsUsed[$name] = true;
1007
1008                 $ret = $this->getRequest()->getVal( $name );
1009                 if ( $ret === null ) {
1010                         if ( $this->getRequest()->getArray( $name ) !== null ) {
1011                                 // See bug 10262 for why we don't just join( '|', ... ) the
1012                                 // array.
1013                                 $this->setWarning(
1014                                         "Parameter '$name' uses unsupported PHP array syntax"
1015                                 );
1016                         }
1017                         $ret = $default;
1018                 }
1019                 return $ret;
1020         }
1021
1022         /**
1023          * Get a boolean request value, and register the fact that the parameter
1024          * was used, for logging.
1025          * @param string $name
1026          * @return bool
1027          */
1028         public function getCheck( $name ) {
1029                 return $this->getVal( $name, null ) !== null;
1030         }
1031
1032         /**
1033          * Get a request upload, and register the fact that it was used, for logging.
1034          *
1035          * @since 1.21
1036          * @param string $name Parameter name
1037          * @return WebRequestUpload
1038          */
1039         public function getUpload( $name ) {
1040                 $this->mParamsUsed[$name] = true;
1041
1042                 return $this->getRequest()->getUpload( $name );
1043         }
1044
1045         /**
1046          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1047          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1048          */
1049         protected function reportUnusedParams() {
1050                 $paramsUsed = $this->getParamsUsed();
1051                 $allParams = $this->getRequest()->getValueNames();
1052
1053                 if ( !$this->mInternalMode ) {
1054                         // Printer has not yet executed; don't warn that its parameters are unused
1055                         $printerParams = array_map(
1056                                 array( $this->mPrinter, 'encodeParamName' ),
1057                                 array_keys( $this->mPrinter->getFinalParams() ?: array() )
1058                         );
1059                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1060                 } else {
1061                         $unusedParams = array_diff( $allParams, $paramsUsed );
1062                 }
1063
1064                 if ( count( $unusedParams ) ) {
1065                         $s = count( $unusedParams ) > 1 ? 's' : '';
1066                         $this->setWarning( "Unrecognized parameter$s: '" . implode( $unusedParams, "', '" ) . "'" );
1067                 }
1068         }
1069
1070         /**
1071          * Print results using the current printer
1072          *
1073          * @param bool $isError
1074          */
1075         protected function printResult( $isError ) {
1076                 if ( $this->getConfig()->get( 'DebugAPI' ) !== false ) {
1077                         $this->setWarning( 'SECURITY WARNING: $wgDebugAPI is enabled' );
1078                 }
1079
1080                 $this->getResult()->cleanUpUTF8();
1081                 $printer = $this->mPrinter;
1082                 $printer->profileIn();
1083
1084                 /**
1085                  * If the help message is requested in the default (xmlfm) format,
1086                  * tell the printer not to escape ampersands so that our links do
1087                  * not break.
1088                  */
1089                 $isHelp = $isError || $this->mAction == 'help';
1090                 $printer->setUnescapeAmps( $isHelp && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
1091
1092                 $printer->initPrinter( $isHelp );
1093
1094                 $printer->execute();
1095                 $printer->closePrinter();
1096                 $printer->profileOut();
1097         }
1098
1099         /**
1100          * @return bool
1101          */
1102         public function isReadMode() {
1103                 return false;
1104         }
1105
1106         /**
1107          * See ApiBase for description.
1108          *
1109          * @return array
1110          */
1111         public function getAllowedParams() {
1112                 return array(
1113                         'format' => array(
1114                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1115                                 ApiBase::PARAM_TYPE => 'submodule',
1116                         ),
1117                         'action' => array(
1118                                 ApiBase::PARAM_DFLT => 'help',
1119                                 ApiBase::PARAM_TYPE => 'submodule',
1120                         ),
1121                         'maxlag' => array(
1122                                 ApiBase::PARAM_TYPE => 'integer'
1123                         ),
1124                         'smaxage' => array(
1125                                 ApiBase::PARAM_TYPE => 'integer',
1126                                 ApiBase::PARAM_DFLT => 0
1127                         ),
1128                         'maxage' => array(
1129                                 ApiBase::PARAM_TYPE => 'integer',
1130                                 ApiBase::PARAM_DFLT => 0
1131                         ),
1132                         'assert' => array(
1133                                 ApiBase::PARAM_TYPE => array( 'user', 'bot' )
1134                         ),
1135                         'requestid' => null,
1136                         'servedby' => false,
1137                         'curtimestamp' => false,
1138                         'origin' => null,
1139                 );
1140         }
1141
1142         /**
1143          * See ApiBase for description.
1144          *
1145          * @return array
1146          */
1147         public function getParamDescription() {
1148                 return array(
1149                         'format' => 'The format of the output',
1150                         'action' => 'What action you would like to perform. See below for module help',
1151                         'maxlag' => array(
1152                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
1153                                 'To save actions causing any more site replication lag, this parameter can make the client',
1154                                 'wait until the replication lag is less than the specified value.',
1155                                 'In case of a replag error, error code "maxlag" is returned, with the message like',
1156                                 '"Waiting for $host: $lag seconds lagged\n".',
1157                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
1158                         ),
1159                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
1160                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
1161                         'assert' => 'Verify the user is logged in if set to "user", or has the bot userright if "bot"',
1162                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
1163                         'servedby' => 'Include the hostname that served the request in the ' .
1164                                 'results. Unconditionally shown on error',
1165                         'curtimestamp' => 'Include the current timestamp in the result.',
1166                         'origin' => array(
1167                                 'When accessing the API using a cross-domain AJAX request (CORS), set this to the',
1168                                 'originating domain. This must be included in any pre-flight request, and',
1169                                 'therefore must be part of the request URI (not the POST body). This must match',
1170                                 'one of the origins in the Origin: header exactly, so it has to be set to ',
1171                                 'something like http://en.wikipedia.org or https://meta.wikimedia.org . If this',
1172                                 'parameter does not match the Origin: header, a 403 response will be returned. If',
1173                                 'this parameter matches the Origin: header and the origin is whitelisted, an',
1174                                 'Access-Control-Allow-Origin header will be set.',
1175                         ),
1176                 );
1177         }
1178
1179         /**
1180          * See ApiBase for description.
1181          *
1182          * @return array
1183          */
1184         public function getDescription() {
1185                 return array(
1186                         '',
1187                         '',
1188                         '**********************************************************************************************',
1189                         '**                                                                                          **',
1190                         '**                This is an auto-generated MediaWiki API documentation page                **',
1191                         '**                                                                                          **',
1192                         '**                               Documentation and Examples:                                **',
1193                         '**                            https://www.mediawiki.org/wiki/API                            **',
1194                         '**                                                                                          **',
1195                         '**********************************************************************************************',
1196                         '',
1197                         'Status:                All features shown on this page should be working, but the API',
1198                         '                       is still in active development, and may change at any time.',
1199                         '                       Make sure to monitor our mailing list for any updates.',
1200                         '',
1201                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
1202                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
1203                         '                       header and the error code sent back will be set to the same value.',
1204                         '',
1205                         '                       In the case of an invalid action being passed, these will have a value',
1206                         '                       of "unknown_action".',
1207                         '',
1208                         '                       For more information see https://www.mediawiki.org' .
1209                                 '/wiki/API:Errors_and_warnings',
1210                         '',
1211                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
1212                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
1213                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
1214                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
1215                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&' .
1216                                 'bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
1217                         '',
1218                         '',
1219                         '',
1220                         '',
1221                         '',
1222                 );
1223         }
1224
1225         /**
1226          * Returns an array of strings with credits for the API
1227          * @return array
1228          */
1229         protected function getCredits() {
1230                 return array(
1231                         'API developers:',
1232                         '    Roan Kattouw (lead developer Sep 2007-2009)',
1233                         '    Victor Vasiliev',
1234                         '    Bryan Tong Minh',
1235                         '    Sam Reed',
1236                         '    Yuri Astrakhan (creator, lead developer Sep 2006-Sep 2007, 2012-2013)',
1237                         '    Brad Jorsch (lead developer 2013-now)',
1238                         '',
1239                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
1240                         'or file a bug report at https://bugzilla.wikimedia.org/'
1241                 );
1242         }
1243
1244         /**
1245          * Sets whether the pretty-printer should format *bold* and $italics$
1246          *
1247          * @param bool $help
1248          */
1249         public function setHelp( $help = true ) {
1250                 $this->mPrinter->setHelp( $help );
1251         }
1252
1253         /**
1254          * Override the parent to generate help messages for all available modules.
1255          *
1256          * @return string
1257          */
1258         public function makeHelpMsg() {
1259                 global $wgMemc;
1260                 $this->setHelp();
1261                 // Get help text from cache if present
1262                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
1263                         str_replace( ' ', '_', SpecialVersion::getVersion( 'nodb' ) ) );
1264
1265                 $cacheHelpTimeout = $this->getConfig()->get( 'APICacheHelpTimeout' );
1266                 if ( $cacheHelpTimeout > 0 ) {
1267                         $cached = $wgMemc->get( $key );
1268                         if ( $cached ) {
1269                                 return $cached;
1270                         }
1271                 }
1272                 $retval = $this->reallyMakeHelpMsg();
1273                 if ( $cacheHelpTimeout > 0 ) {
1274                         $wgMemc->set( $key, $retval, $cacheHelpTimeout );
1275                 }
1276
1277                 return $retval;
1278         }
1279
1280         /**
1281          * @return mixed|string
1282          */
1283         public function reallyMakeHelpMsg() {
1284                 $this->setHelp();
1285
1286                 // Use parent to make default message for the main module
1287                 $msg = parent::makeHelpMsg();
1288
1289                 $astriks = str_repeat( '*** ', 14 );
1290                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
1291
1292                 foreach ( $this->mModuleMgr->getNames( 'action' ) as $name ) {
1293                         $module = $this->mModuleMgr->getModule( $name );
1294                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1295
1296                         $msg2 = $module->makeHelpMsg();
1297                         if ( $msg2 !== false ) {
1298                                 $msg .= $msg2;
1299                         }
1300                         $msg .= "\n";
1301                 }
1302
1303                 $msg .= "\n$astriks Permissions $astriks\n\n";
1304                 foreach ( self::$mRights as $right => $rightMsg ) {
1305                         $groups = User::getGroupsWithPermission( $right );
1306                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg['msg'], $rightMsg['params'] ) .
1307                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1308                 }
1309
1310                 $msg .= "\n$astriks Formats  $astriks\n\n";
1311                 foreach ( $this->mModuleMgr->getNames( 'format' ) as $name ) {
1312                         $module = $this->mModuleMgr->getModule( $name );
1313                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1314                         $msg2 = $module->makeHelpMsg();
1315                         if ( $msg2 !== false ) {
1316                                 $msg .= $msg2;
1317                         }
1318                         $msg .= "\n";
1319                 }
1320
1321                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
1322
1323                 return $msg;
1324         }
1325
1326         /**
1327          * @param ApiBase $module
1328          * @param string $paramName What type of request is this? e.g. action,
1329          *    query, list, prop, meta, format
1330          * @return string
1331          */
1332         public static function makeHelpMsgHeader( $module, $paramName ) {
1333                 $modulePrefix = $module->getModulePrefix();
1334                 if ( strval( $modulePrefix ) !== '' ) {
1335                         $modulePrefix = "($modulePrefix) ";
1336                 }
1337
1338                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1339         }
1340
1341         private $mCanApiHighLimits = null;
1342
1343         /**
1344          * Check whether the current user is allowed to use high limits
1345          * @return bool
1346          */
1347         public function canApiHighLimits() {
1348                 if ( !isset( $this->mCanApiHighLimits ) ) {
1349                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1350                 }
1351
1352                 return $this->mCanApiHighLimits;
1353         }
1354
1355         /**
1356          * Check whether the user wants us to show version information in the API help
1357          * @return bool
1358          * @deprecated since 1.21, always returns false
1359          */
1360         public function getShowVersions() {
1361                 wfDeprecated( __METHOD__, '1.21' );
1362
1363                 return false;
1364         }
1365
1366         /**
1367          * Overrides to return this instance's module manager.
1368          * @return ApiModuleManager
1369          */
1370         public function getModuleManager() {
1371                 return $this->mModuleMgr;
1372         }
1373
1374         /**
1375          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1376          * classes who wish to add their own modules to their lexicon or override the
1377          * behavior of inherent ones.
1378          *
1379          * @deprecated since 1.21, Use getModuleManager()->addModule() instead.
1380          * @param string $name The identifier for this module.
1381          * @param ApiBase $class The class where this module is implemented.
1382          */
1383         protected function addModule( $name, $class ) {
1384                 $this->getModuleManager()->addModule( $name, 'action', $class );
1385         }
1386
1387         /**
1388          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1389          * classes who wish to add to or modify current formatters.
1390          *
1391          * @deprecated since 1.21, Use getModuleManager()->addModule() instead.
1392          * @param string $name The identifier for this format.
1393          * @param ApiFormatBase $class The class implementing this format.
1394          */
1395         protected function addFormat( $name, $class ) {
1396                 $this->getModuleManager()->addModule( $name, 'format', $class );
1397         }
1398
1399         /**
1400          * Get the array mapping module names to class names
1401          * @deprecated since 1.21, Use getModuleManager()'s methods instead.
1402          * @return array
1403          */
1404         function getModules() {
1405                 return $this->getModuleManager()->getNamesWithClasses( 'action' );
1406         }
1407
1408         /**
1409          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1410          *
1411          * @since 1.18
1412          * @deprecated since 1.21, Use getModuleManager()'s methods instead.
1413          * @return array
1414          */
1415         public function getFormats() {
1416                 return $this->getModuleManager()->getNamesWithClasses( 'format' );
1417         }
1418 }
1419
1420 /**
1421  * This exception will be thrown when dieUsage is called to stop module execution.
1422  * The exception handling code will print a help screen explaining how this API may be used.
1423  *
1424  * @ingroup API
1425  */
1426 class UsageException extends MWException {
1427
1428         private $mCodestr;
1429
1430         /**
1431          * @var null|array
1432          */
1433         private $mExtraData;
1434
1435         /**
1436          * @param string $message
1437          * @param string $codestr
1438          * @param int $code
1439          * @param array|null $extradata
1440          */
1441         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1442                 parent::__construct( $message, $code );
1443                 $this->mCodestr = $codestr;
1444                 $this->mExtraData = $extradata;
1445         }
1446
1447         /**
1448          * @return string
1449          */
1450         public function getCodeString() {
1451                 return $this->mCodestr;
1452         }
1453
1454         /**
1455          * @return array
1456          */
1457         public function getMessageArray() {
1458                 $result = array(
1459                         'code' => $this->mCodestr,
1460                         'info' => $this->getMessage()
1461                 );
1462                 if ( is_array( $this->mExtraData ) ) {
1463                         $result = array_merge( $result, $this->mExtraData );
1464                 }
1465
1466                 return $result;
1467         }
1468
1469         /**
1470          * @return string
1471          */
1472         public function __toString() {
1473                 return "{$this->getCodeString()}: {$this->getMessage()}";
1474         }
1475 }