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 $context IContextSource|WebRequest - 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                 global $wgAPIModules, $wgAPIFormatModules;
 190                 $this->mModuleMgr = new ApiModuleManager( $this );
 191                 $this->mModuleMgr->addModules( self::$Modules, 'action' );
 192                 $this->mModuleMgr->addModules( $wgAPIModules, 'action' );
 193                 $this->mModuleMgr->addModules( self::$Formats, 'format' );
 194                 $this->mModuleMgr->addModules( $wgAPIFormatModules, '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 $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 $directives array
 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 $format string
 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                 MWExceptionHandler::rollbackMasterChangesAndLog( $e );
 391
 392                 // Allow extra cleanup and logging
 393                 wfRunHooks( 'ApiMain::onException', array( $this, $e ) );
 394
 395                 // Log it
 396                 if ( !( $e instanceof UsageException ) ) {
 397                         MWExceptionHandler::logException( $e );
 398                 }
 399
 400                 // Handle any kind of exception by outputting properly formatted error message.
 401                 // If this fails, an unhandled exception should be thrown so that global error
 402                 // handler will process and log it.
 403
 404                 $errCode = $this->substituteResultWithError( $e );
 405
 406                 // Error results should not be cached
 407                 $this->setCacheMode( 'private' );
 408
 409                 $response = $this->getRequest()->response();
 410                 $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 411                 if ( $e->getCode() === 0 ) {
 412                         $response->header( $headerStr );
 413                 } else {
 414                         $response->header( $headerStr, true, $e->getCode() );
 415                 }
 416
 417                 // Reset and print just the error message
 418                 ob_clean();
 419
 420                 // If the error occurred during printing, do a printer->profileOut()
 421                 $this->mPrinter->safeProfileOut();
 422                 $this->printResult( true );
 423         }
 424
 425         /**
 426          * Handle an exception from the ApiBeforeMain hook.
 427          *
 428          * This tries to print the exception as an API response, to be more
 429          * friendly to clients. If it fails, it will rethrow the exception.
 430          *
 431          * @since 1.23
 432          * @param Exception $e
 433          */
 434         public static function handleApiBeforeMainException( Exception $e ) {
 435                 ob_start();
 436
 437                 try {
 438                         $main = new self( RequestContext::getMain(), false );
 439                         $main->handleException( $e );
 440                 } catch ( Exception $e2 ) {
 441                         // Nope, even that didn't work. Punt.
 442                         throw $e;
 443                 }
 444
 445                 // Log the request and reset cache headers
 446                 $main->logRequest( 0 );
 447                 $main->sendCacheHeaders();
 448
 449                 ob_end_flush();
 450         }
 451
 452         /**
 453          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 454          *
 455          * If no origin parameter is present, nothing happens.
 456          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 457          * is set and false is returned.
 458          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 459          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 460          * headers are set.
 461          *
 462          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 463          */
 464         protected function handleCORS() {
 465                 global $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions;
 466
 467                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 468                 if ( $originParam === null ) {
 469                         // No origin parameter, nothing to do
 470                         return true;
 471                 }
 472
 473                 $request = $this->getRequest();
 474                 $response = $request->response();
 475                 // Origin: header is a space-separated list of origins, check all of them
 476                 $originHeader = $request->getHeader( 'Origin' );
 477                 if ( $originHeader === false ) {
 478                         $origins = array();
 479                 } else {
 480                         $origins = explode( ' ', $originHeader );
 481                 }
 482
 483                 if ( !in_array( $originParam, $origins ) ) {
 484                         // origin parameter set but incorrect
 485                         // Send a 403 response
 486                         $message = HttpStatus::getMessage( 403 );
 487                         $response->header( "HTTP/1.1 403 $message", true, 403 );
 488                         $response->header( 'Cache-Control: no-cache' );
 489                         echo "'origin' parameter does not match Origin header\n";
 490
 491                         return false;
 492                 }
 493
 494                 $matchOrigin = self::matchOrigin(
 495                         $originParam,
 496                         $wgCrossSiteAJAXdomains,
 497                         $wgCrossSiteAJAXdomainExceptions
 498                 );
 499
 500                 if ( $matchOrigin ) {
 501                         $response->header( "Access-Control-Allow-Origin: $originParam" );
 502                         $response->header( 'Access-Control-Allow-Credentials: true' );
 503                         $this->getOutput()->addVaryHeader( 'Origin' );
 504                 }
 505
 506                 return true;
 507         }
 508
 509         /**
 510          * Attempt to match an Origin header against a set of rules and a set of exceptions
 511          * @param string $value Origin header
 512          * @param array $rules Set of wildcard rules
 513          * @param array $exceptions Set of wildcard rules
 514          * @return bool True if $value matches a rule in $rules and doesn't match
 515          *    any rules in $exceptions, false otherwise
 516          */
 517         protected static function matchOrigin( $value, $rules, $exceptions ) {
 518                 foreach ( $rules as $rule ) {
 519                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 520                                 // Rule matches, check exceptions
 521                                 foreach ( $exceptions as $exc ) {
 522                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 523                                                 return false;
 524                                         }
 525                                 }
 526
 527                                 return true;
 528                         }
 529                 }
 530
 531                 return false;
 532         }
 533
 534         /**
 535          * Helper function to convert wildcard string into a regex
 536          * '*' => '.*?'
 537          * '?' => '.'
 538          *
 539          * @param string $wildcard String with wildcards
 540          * @return string Regular expression
 541          */
 542         protected static function wildcardToRegex( $wildcard ) {
 543                 $wildcard = preg_quote( $wildcard, '/' );
 544                 $wildcard = str_replace(
 545                         array( '\*', '\?' ),
 546                         array( '.*?', '.' ),
 547                         $wildcard
 548                 );
 549
 550                 return "/https?:\/\/$wildcard/";
 551         }
 552
 553         protected function sendCacheHeaders() {
 554                 global $wgUseXVO, $wgVaryOnXFP;
 555                 $response = $this->getRequest()->response();
 556                 $out = $this->getOutput();
 557
 558                 if ( $wgVaryOnXFP ) {
 559                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 560                 }
 561
 562                 if ( $this->mCacheMode == 'private' ) {
 563                         $response->header( 'Cache-Control: private' );
 564
 565                         return;
 566                 }
 567
 568                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 569                         $out->addVaryHeader( 'Cookie' );
 570                         $response->header( $out->getVaryHeader() );
 571                         if ( $wgUseXVO ) {
 572                                 $response->header( $out->getXVO() );
 573                                 if ( $out->haveCacheVaryCookies() ) {
 574                                         // Logged in, mark this request private
 575                                         $response->header( 'Cache-Control: private' );
 576
 577                                         return;
 578                                 }
 579                                 // Logged out, send normal public headers below
 580                         } elseif ( session_id() != '' ) {
 581                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 582                                 // Mark request private
 583                                 $response->header( 'Cache-Control: private' );
 584
 585                                 return;
 586                         } // else no XVO and anonymous, send public headers below
 587                 }
 588
 589                 // Send public headers
 590                 $response->header( $out->getVaryHeader() );
 591                 if ( $wgUseXVO ) {
 592                         $response->header( $out->getXVO() );
 593                 }
 594
 595                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 596                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 597                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 598                 }
 599                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 600                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 601                 }
 602
 603                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 604                         // Public cache not requested
 605                         // Sending a Vary header in this case is harmless, and protects us
 606                         // against conditional calls of setCacheMaxAge().
 607                         $response->header( 'Cache-Control: private' );
 608
 609                         return;
 610                 }
 611
 612                 $this->mCacheControl['public'] = true;
 613
 614                 // Send an Expires header
 615                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 616                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 617                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 618
 619                 // Construct the Cache-Control header
 620                 $ccHeader = '';
 621                 $separator = '';
 622                 foreach ( $this->mCacheControl as $name => $value ) {
 623                         if ( is_bool( $value ) ) {
 624                                 if ( $value ) {
 625                                         $ccHeader .= $separator . $name;
 626                                         $separator = ', ';
 627                                 }
 628                         } else {
 629                                 $ccHeader .= $separator . "$name=$value";
 630                                 $separator = ', ';
 631                         }
 632                 }
 633
 634                 $response->header( "Cache-Control: $ccHeader" );
 635         }
 636
 637         /**
 638          * Replace the result data with the information about an exception.
 639          * Returns the error code
 640          * @param $e Exception
 641          * @return string
 642          */
 643         protected function substituteResultWithError( $e ) {
 644                 global $wgShowHostnames;
 645
 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                 if ( $e instanceof UsageException ) {
 670                         // User entered incorrect parameters - print usage screen
 671                         $errMessage = $e->getMessageArray();
 672
 673                         // Only print the help message when this is for the developer, not runtime
 674                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 675                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 676                         }
 677                 } else {
 678                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 679                         // Something is seriously wrong
 680                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 681                                 $info = 'Database query error';
 682                         } else {
 683                                 $info = "Exception Caught: {$e->getMessage()}";
 684                         }
 685
 686                         $errMessage = array(
 687                                 'code' => 'internal_api_error_' . get_class( $e ),
 688                                 'info' => $info,
 689                         );
 690                         ApiResult::setContent(
 691                                 $errMessage,
 692                                 $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : ''
 693                         );
 694                 }
 695
 696                 // Remember all the warnings to re-add them later
 697                 $oldResult = $result->getData();
 698                 $warnings = isset( $oldResult['warnings'] ) ? $oldResult['warnings'] : null;
 699
 700                 $result->reset();
 701                 $result->disableSizeCheck();
 702                 // Re-add the id
 703                 $requestid = $this->getParameter( 'requestid' );
 704                 if ( !is_null( $requestid ) ) {
 705                         $result->addValue( null, 'requestid', $requestid );
 706                 }
 707                 if ( $wgShowHostnames ) {
 708                         // servedby is especially useful when debugging errors
 709                         $result->addValue( null, 'servedby', wfHostName() );
 710                 }
 711                 if ( $warnings !== null ) {
 712                         $result->addValue( null, 'warnings', $warnings );
 713                 }
 714
 715                 $result->addValue( null, 'error', $errMessage );
 716
 717                 return $errMessage['code'];
 718         }
 719
 720         /**
 721          * Set up for the execution.
 722          * @return array
 723          */
 724         protected function setupExecuteAction() {
 725                 global $wgShowHostnames;
 726
 727                 // First add the id to the top element
 728                 $result = $this->getResult();
 729                 $requestid = $this->getParameter( 'requestid' );
 730                 if ( !is_null( $requestid ) ) {
 731                         $result->addValue( null, 'requestid', $requestid );
 732                 }
 733
 734                 if ( $wgShowHostnames ) {
 735                         $servedby = $this->getParameter( 'servedby' );
 736                         if ( $servedby ) {
 737                                 $result->addValue( null, 'servedby', wfHostName() );
 738                         }
 739                 }
 740
 741                 $params = $this->extractRequestParams();
 742
 743                 $this->mAction = $params['action'];
 744
 745                 if ( !is_string( $this->mAction ) ) {
 746                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 747                 }
 748
 749                 return $params;
 750         }
 751
 752         /**
 753          * Set up the module for response
 754          * @return ApiBase The module that will handle this action
 755          */
 756         protected function setupModule() {
 757                 // Instantiate the module requested by the user
 758                 $module = $this->mModuleMgr->getModule( $this->mAction, 'action' );
 759                 if ( $module === null ) {
 760                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 761                 }
 762                 $moduleParams = $module->extractRequestParams();
 763
 764                 // Die if token required, but not provided
 765                 $salt = $module->getTokenSalt();
 766                 if ( $salt !== false ) {
 767                         if ( !isset( $moduleParams['token'] ) ) {
 768                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 769                         }
 770
 771                         if ( !$this->getUser()->matchEditToken(
 772                                 $moduleParams['token'],
 773                                 $salt,
 774                                 $this->getContext()->getRequest() )
 775                         ) {
 776                                 $this->dieUsageMsg( 'sessionfailure' );
 777                         }
 778                 }
 779
 780                 return $module;
 781         }
 782
 783         /**
 784          * Check the max lag if necessary
 785          * @param $module ApiBase object: Api module being used
 786          * @param array $params an array containing the request parameters.
 787          * @return boolean True on success, false should exit immediately
 788          */
 789         protected function checkMaxLag( $module, $params ) {
 790                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 791                         // Check for maxlag
 792                         global $wgShowHostnames;
 793                         $maxLag = $params['maxlag'];
 794                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 795                         if ( $lag > $maxLag ) {
 796                                 $response = $this->getRequest()->response();
 797
 798                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 799                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 800
 801                                 if ( $wgShowHostnames ) {
 802                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 803                                 }
 804
 805                                 $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 806                         }
 807                 }
 808
 809                 return true;
 810         }
 811
 812         /**
 813          * Check for sufficient permissions to execute
 814          * @param $module ApiBase An Api module
 815          */
 816         protected function checkExecutePermissions( $module ) {
 817                 $user = $this->getUser();
 818                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
 819                         !$user->isAllowed( 'read' )
 820                 ) {
 821                         $this->dieUsageMsg( 'readrequired' );
 822                 }
 823                 if ( $module->isWriteMode() ) {
 824                         if ( !$this->mEnableWrite ) {
 825                                 $this->dieUsageMsg( 'writedisabled' );
 826                         }
 827                         if ( !$user->isAllowed( 'writeapi' ) ) {
 828                                 $this->dieUsageMsg( 'writerequired' );
 829                         }
 830                         if ( wfReadOnly() ) {
 831                                 $this->dieReadOnly();
 832                         }
 833                 }
 834
 835                 // Allow extensions to stop execution for arbitrary reasons.
 836                 $message = false;
 837                 if ( !wfRunHooks( 'ApiCheckCanExecute', array( $module, $user, &$message ) ) ) {
 838                         $this->dieUsageMsg( $message );
 839                 }
 840         }
 841
 842         /**
 843          * Check asserts of the user's rights
 844          * @param $params array
 845          */
 846         protected function checkAsserts( $params ) {
 847                 if ( isset( $params['assert'] ) ) {
 848                         $user = $this->getUser();
 849                         switch ( $params['assert'] ) {
 850                                 case 'user':
 851                                         if ( $user->isAnon() ) {
 852                                                 $this->dieUsage( 'Assertion that the user is logged in failed', 'assertuserfailed' );
 853                                         }
 854                                         break;
 855                                 case 'bot':
 856                                         if ( !$user->isAllowed( 'bot' ) ) {
 857                                                 $this->dieUsage( 'Assertion that the user has the bot right failed', 'assertbotfailed' );
 858                                         }
 859                                         break;
 860                         }
 861                 }
 862         }
 863
 864         /**
 865          * Check POST for external response and setup result printer
 866          * @param $module ApiBase An Api module
 867          * @param array $params an array with the request parameters
 868          */
 869         protected function setupExternalResponse( $module, $params ) {
 870                 if ( !$this->getRequest()->wasPosted() && $module->mustBePosted() ) {
 871                         // Module requires POST. GET request might still be allowed
 872                         // if $wgDebugApi is true, otherwise fail.
 873                         $this->dieUsageMsgOrDebug( array( 'mustbeposted', $this->mAction ) );
 874                 }
 875
 876                 // See if custom printer is used
 877                 $this->mPrinter = $module->getCustomPrinter();
 878                 if ( is_null( $this->mPrinter ) ) {
 879                         // Create an appropriate printer
 880                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 881                 }
 882
 883                 if ( $this->mPrinter->getNeedsRawData() ) {
 884                         $this->getResult()->setRawMode();
 885                 }
 886         }
 887
 888         /**
 889          * Execute the actual module, without any error handling
 890          */
 891         protected function executeAction() {
 892                 $params = $this->setupExecuteAction();
 893                 $module = $this->setupModule();
 894                 $this->mModule = $module;
 895
 896                 $this->checkExecutePermissions( $module );
 897
 898                 if ( !$this->checkMaxLag( $module, $params ) ) {
 899                         return;
 900                 }
 901
 902                 if ( !$this->mInternalMode ) {
 903                         $this->setupExternalResponse( $module, $params );
 904                 }
 905
 906                 $this->checkAsserts( $params );
 907
 908                 // Execute
 909                 $module->profileIn();
 910                 $module->execute();
 911                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 912                 $module->profileOut();
 913
 914                 $this->reportUnusedParams();
 915
 916                 if ( !$this->mInternalMode ) {
 917                         //append Debug information
 918                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
 919
 920                         // Print result data
 921                         $this->printResult( false );
 922                 }
 923         }
 924
 925         /**
 926          * Log the preceding request
 927          * @param int $time Time in seconds
 928          */
 929         protected function logRequest( $time ) {
 930                 $request = $this->getRequest();
 931                 $milliseconds = $time === null ? '?' : round( $time * 1000 );
 932                 $s = 'API' .
 933                         ' ' . $request->getMethod() .
 934                         ' ' . wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
 935                         ' ' . $request->getIP() .
 936                         ' T=' . $milliseconds . 'ms';
 937                 foreach ( $this->getParamsUsed() as $name ) {
 938                         $value = $request->getVal( $name );
 939                         if ( $value === null ) {
 940                                 continue;
 941                         }
 942                         $s .= ' ' . $name . '=';
 943                         if ( strlen( $value ) > 256 ) {
 944                                 $encValue = $this->encodeRequestLogValue( substr( $value, 0, 256 ) );
 945                                 $s .= $encValue . '[...]';
 946                         } else {
 947                                 $s .= $this->encodeRequestLogValue( $value );
 948                         }
 949                 }
 950                 $s .= "\n";
 951                 wfDebugLog( 'api', $s, 'private' );
 952         }
 953
 954         /**
 955          * Encode a value in a format suitable for a space-separated log line.
 956          */
 957         protected function encodeRequestLogValue( $s ) {
 958                 static $table;
 959                 if ( !$table ) {
 960                         $chars = ';@$!*(),/:';
 961                         $numChars = strlen( $chars );
 962                         for ( $i = 0; $i < $numChars; $i++ ) {
 963                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
 964                         }
 965                 }
 966
 967                 return strtr( rawurlencode( $s ), $table );
 968         }
 969
 970         /**
 971          * Get the request parameters used in the course of the preceding execute() request
 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          */
 980         public function getVal( $name, $default = null ) {
 981                 $this->mParamsUsed[$name] = true;
 982
 983                 return $this->getRequest()->getVal( $name, $default );
 984         }
 985
 986         /**
 987          * Get a boolean request value, and register the fact that the parameter
 988          * was used, for logging.
 989          */
 990         public function getCheck( $name ) {
 991                 $this->mParamsUsed[$name] = true;
 992
 993                 return $this->getRequest()->getCheck( $name );
 994         }
 995
 996         /**
 997          * Get a request upload, and register the fact that it was used, for logging.
 998          *
 999          * @since 1.21
1000          * @param string $name Parameter name
1001          * @return WebRequestUpload
1002          */
1003         public function getUpload( $name ) {
1004                 $this->mParamsUsed[$name] = true;
1005
1006                 return $this->getRequest()->getUpload( $name );
1007         }
1008
1009         /**
1010          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1011          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1012          */
1013         protected function reportUnusedParams() {
1014                 $paramsUsed = $this->getParamsUsed();
1015                 $allParams = $this->getRequest()->getValueNames();
1016
1017                 if ( !$this->mInternalMode ) {
1018                         // Printer has not yet executed; don't warn that its parameters are unused
1019                         $printerParams = array_map(
1020                                 array( $this->mPrinter, 'encodeParamName' ),
1021                                 array_keys( $this->mPrinter->getFinalParams() ?: array() )
1022                         );
1023                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1024                 } else {
1025                         $unusedParams = array_diff( $allParams, $paramsUsed );
1026                 }
1027
1028                 if ( count( $unusedParams ) ) {
1029                         $s = count( $unusedParams ) > 1 ? 's' : '';
1030                         $this->setWarning( "Unrecognized parameter$s: '" . implode( $unusedParams, "', '" ) . "'" );
1031                 }
1032         }
1033
1034         /**
1035          * Print results using the current printer
1036          *
1037          * @param $isError bool
1038          */
1039         protected function printResult( $isError ) {
1040                 global $wgDebugAPI;
1041                 if ( $wgDebugAPI !== false ) {
1042                         $this->setWarning( 'SECURITY WARNING: $wgDebugAPI is enabled' );
1043                 }
1044
1045                 $this->getResult()->cleanUpUTF8();
1046                 $printer = $this->mPrinter;
1047                 $printer->profileIn();
1048
1049                 /**
1050                  * If the help message is requested in the default (xmlfm) format,
1051                  * tell the printer not to escape ampersands so that our links do
1052                  * not break.
1053                  */
1054                 $isHelp = $isError || $this->mAction == 'help';
1055                 $printer->setUnescapeAmps( $isHelp && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
1056
1057                 $printer->initPrinter( $isHelp );
1058
1059                 $printer->execute();
1060                 $printer->closePrinter();
1061                 $printer->profileOut();
1062         }
1063
1064         /**
1065          * @return bool
1066          */
1067         public function isReadMode() {
1068                 return false;
1069         }
1070
1071         /**
1072          * See ApiBase for description.
1073          *
1074          * @return array
1075          */
1076         public function getAllowedParams() {
1077                 return array(
1078                         'format' => array(
1079                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1080                                 ApiBase::PARAM_TYPE => $this->mModuleMgr->getNames( 'format' )
1081                         ),
1082                         'action' => array(
1083                                 ApiBase::PARAM_DFLT => 'help',
1084                                 ApiBase::PARAM_TYPE => $this->mModuleMgr->getNames( 'action' )
1085                         ),
1086                         'maxlag' => array(
1087                                 ApiBase::PARAM_TYPE => 'integer'
1088                         ),
1089                         'smaxage' => array(
1090                                 ApiBase::PARAM_TYPE => 'integer',
1091                                 ApiBase::PARAM_DFLT => 0
1092                         ),
1093                         'maxage' => array(
1094                                 ApiBase::PARAM_TYPE => 'integer',
1095                                 ApiBase::PARAM_DFLT => 0
1096                         ),
1097                         'assert' => array(
1098                                 ApiBase::PARAM_TYPE => array( 'user', 'bot' )
1099                         ),
1100                         'requestid' => null,
1101                         'servedby' => false,
1102                         'origin' => null,
1103                 );
1104         }
1105
1106         /**
1107          * See ApiBase for description.
1108          *
1109          * @return array
1110          */
1111         public function getParamDescription() {
1112                 return array(
1113                         'format' => 'The format of the output',
1114                         'action' => 'What action you would like to perform. See below for module help',
1115                         'maxlag' => array(
1116                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
1117                                 'To save actions causing any more site replication lag, this parameter can make the client',
1118                                 'wait until the replication lag is less than the specified value.',
1119                                 'In case of a replag error, error code "maxlag" is returned, with the message like',
1120                                 '"Waiting for $host: $lag seconds lagged\n".',
1121                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
1122                         ),
1123                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
1124                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
1125                         'assert' => 'Verify the user is logged in if set to "user", or has the bot userright if "bot"',
1126                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
1127                         'servedby' => 'Include the hostname that served the request in the ' .
1128                                 'results. Unconditionally shown on error',
1129                         'origin' => array(
1130                                 'When accessing the API using a cross-domain AJAX request (CORS), set this to the',
1131                                 'originating domain. This must be included in any pre-flight request, and',
1132                                 'therefore must be part of the request URI (not the POST body). This must match',
1133                                 'one of the origins in the Origin: header exactly, so it has to be set to ',
1134                                 'something like http://en.wikipedia.org or https://meta.wikimedia.org . If this',
1135                                 'parameter does not match the Origin: header, a 403 response will be returned. If',
1136                                 'this parameter matches the Origin: header and the origin is whitelisted, an',
1137                                 'Access-Control-Allow-Origin header will be set.',
1138                         ),
1139                 );
1140         }
1141
1142         /**
1143          * See ApiBase for description.
1144          *
1145          * @return array
1146          */
1147         public function getDescription() {
1148                 return array(
1149                         '',
1150                         '',
1151                         '**********************************************************************************************',
1152                         '**                                                                                          **',
1153                         '**                This is an auto-generated MediaWiki API documentation page                **',
1154                         '**                                                                                          **',
1155                         '**                               Documentation and Examples:                                **',
1156                         '**                            https://www.mediawiki.org/wiki/API                            **',
1157                         '**                                                                                          **',
1158                         '**********************************************************************************************',
1159                         '',
1160                         'Status:                All features shown on this page should be working, but the API',
1161                         '                       is still in active development, and may change at any time.',
1162                         '                       Make sure to monitor our mailing list for any updates.',
1163                         '',
1164                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
1165                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
1166                         '                       header and the error code sent back will be set to the same value.',
1167                         '',
1168                         '                       In the case of an invalid action being passed, these will have a value',
1169                         '                       of "unknown_action".',
1170                         '',
1171                         '                       For more information see https://www.mediawiki.org' .
1172                                 '/wiki/API:Errors_and_warnings',
1173                         '',
1174                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
1175                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
1176                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
1177                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
1178                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&' .
1179                                 'bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
1180                         '',
1181                         '',
1182                         '',
1183                         '',
1184                         '',
1185                 );
1186         }
1187
1188         /**
1189          * @return array
1190          */
1191         public function getPossibleErrors() {
1192                 return array_merge( parent::getPossibleErrors(), array(
1193                         array( 'readonlytext' ),
1194                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
1195                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
1196                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
1197                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
1198                         array( 'code' => 'assertuserfailed', 'info' => 'Assertion that the user is logged in failed' ),
1199                         array(
1200                                 'code' => 'assertbotfailed',
1201                                 'info' => 'Assertion that the user has the bot right failed'
1202                         ),
1203                 ) );
1204         }
1205
1206         /**
1207          * Returns an array of strings with credits for the API
1208          * @return array
1209          */
1210         protected function getCredits() {
1211                 return array(
1212                         'API developers:',
1213                         '    Roan Kattouw (lead developer Sep 2007-2009)',
1214                         '    Victor Vasiliev',
1215                         '    Bryan Tong Minh',
1216                         '    Sam Reed',
1217                         '    Yuri Astrakhan (creator, lead developer Sep 2006-Sep 2007, 2012-present)',
1218                         '',
1219                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
1220                         'or file a bug report at https://bugzilla.wikimedia.org/'
1221                 );
1222         }
1223
1224         /**
1225          * Sets whether the pretty-printer should format *bold* and $italics$
1226          *
1227          * @param $help bool
1228          */
1229         public function setHelp( $help = true ) {
1230                 $this->mPrinter->setHelp( $help );
1231         }
1232
1233         /**
1234          * Override the parent to generate help messages for all available modules.
1235          *
1236          * @return string
1237          */
1238         public function makeHelpMsg() {
1239                 global $wgMemc, $wgAPICacheHelpTimeout;
1240                 $this->setHelp();
1241                 // Get help text from cache if present
1242                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
1243                         str_replace( ' ', '_', SpecialVersion::getVersion( 'nodb' ) ) );
1244                 if ( $wgAPICacheHelpTimeout > 0 ) {
1245                         $cached = $wgMemc->get( $key );
1246                         if ( $cached ) {
1247                                 return $cached;
1248                         }
1249                 }
1250                 $retval = $this->reallyMakeHelpMsg();
1251                 if ( $wgAPICacheHelpTimeout > 0 ) {
1252                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
1253                 }
1254
1255                 return $retval;
1256         }
1257
1258         /**
1259          * @return mixed|string
1260          */
1261         public function reallyMakeHelpMsg() {
1262                 $this->setHelp();
1263
1264                 // Use parent to make default message for the main module
1265                 $msg = parent::makeHelpMsg();
1266
1267                 $astriks = str_repeat( '*** ', 14 );
1268                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
1269
1270                 foreach ( $this->mModuleMgr->getNames( 'action' ) as $name ) {
1271                         $module = $this->mModuleMgr->getModule( $name );
1272                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1273
1274                         $msg2 = $module->makeHelpMsg();
1275                         if ( $msg2 !== false ) {
1276                                 $msg .= $msg2;
1277                         }
1278                         $msg .= "\n";
1279                 }
1280
1281                 $msg .= "\n$astriks Permissions $astriks\n\n";
1282                 foreach ( self::$mRights as $right => $rightMsg ) {
1283                         $groups = User::getGroupsWithPermission( $right );
1284                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg['msg'], $rightMsg['params'] ) .
1285                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1286                 }
1287
1288                 $msg .= "\n$astriks Formats  $astriks\n\n";
1289                 foreach ( $this->mModuleMgr->getNames( 'format' ) as $name ) {
1290                         $module = $this->mModuleMgr->getModule( $name );
1291                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1292                         $msg2 = $module->makeHelpMsg();
1293                         if ( $msg2 !== false ) {
1294                                 $msg .= $msg2;
1295                         }
1296                         $msg .= "\n";
1297                 }
1298
1299                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
1300
1301                 return $msg;
1302         }
1303
1304         /**
1305          * @param $module ApiBase
1306          * @param string $paramName What type of request is this? e.g. action,
1307          *    query, list, prop, meta, format
1308          * @return string
1309          */
1310         public static function makeHelpMsgHeader( $module, $paramName ) {
1311                 $modulePrefix = $module->getModulePrefix();
1312                 if ( strval( $modulePrefix ) !== '' ) {
1313                         $modulePrefix = "($modulePrefix) ";
1314                 }
1315
1316                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1317         }
1318
1319         private $mCanApiHighLimits = null;
1320
1321         /**
1322          * Check whether the current user is allowed to use high limits
1323          * @return bool
1324          */
1325         public function canApiHighLimits() {
1326                 if ( !isset( $this->mCanApiHighLimits ) ) {
1327                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1328                 }
1329
1330                 return $this->mCanApiHighLimits;
1331         }
1332
1333         /**
1334          * Check whether the user wants us to show version information in the API help
1335          * @return bool
1336          * @deprecated since 1.21, always returns false
1337          */
1338         public function getShowVersions() {
1339                 wfDeprecated( __METHOD__, '1.21' );
1340
1341                 return false;
1342         }
1343
1344         /**
1345          * Overrides to return this instance's module manager.
1346          * @return ApiModuleManager
1347          */
1348         public function getModuleManager() {
1349                 return $this->mModuleMgr;
1350         }
1351
1352         /**
1353          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1354          * classes who wish to add their own modules to their lexicon or override the
1355          * behavior of inherent ones.
1356          *
1357          * @deprecated since 1.21, Use getModuleManager()->addModule() instead.
1358          * @param string $name The identifier for this module.
1359          * @param $class ApiBase The class where this module is implemented.
1360          */
1361         protected function addModule( $name, $class ) {
1362                 $this->getModuleManager()->addModule( $name, 'action', $class );
1363         }
1364
1365         /**
1366          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1367          * classes who wish to add to or modify current formatters.
1368          *
1369          * @deprecated since 1.21, Use getModuleManager()->addModule() instead.
1370          * @param string $name The identifier for this format.
1371          * @param $class ApiFormatBase The class implementing this format.
1372          */
1373         protected function addFormat( $name, $class ) {
1374                 $this->getModuleManager()->addModule( $name, 'format', $class );
1375         }
1376
1377         /**
1378          * Get the array mapping module names to class names
1379          * @deprecated since 1.21, Use getModuleManager()'s methods instead.
1380          * @return array
1381          */
1382         function getModules() {
1383                 return $this->getModuleManager()->getNamesWithClasses( 'action' );
1384         }
1385
1386         /**
1387          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1388          *
1389          * @since 1.18
1390          * @deprecated since 1.21, Use getModuleManager()'s methods instead.
1391          * @return array
1392          */
1393         public function getFormats() {
1394                 return $this->getModuleManager()->getNamesWithClasses( 'format' );
1395         }
1396 }
1397
1398 /**
1399  * This exception will be thrown when dieUsage is called to stop module execution.
1400  * The exception handling code will print a help screen explaining how this API may be used.
1401  *
1402  * @ingroup API
1403  */
1404 class UsageException extends MWException {
1405
1406         private $mCodestr;
1407
1408         /**
1409          * @var null|array
1410          */
1411         private $mExtraData;
1412
1413         /**
1414          * @param $message string
1415          * @param $codestr string
1416          * @param $code int
1417          * @param $extradata array|null
1418          */
1419         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1420                 parent::__construct( $message, $code );
1421                 $this->mCodestr = $codestr;
1422                 $this->mExtraData = $extradata;
1423         }
1424
1425         /**
1426          * @return string
1427          */
1428         public function getCodeString() {
1429                 return $this->mCodestr;
1430         }
1431
1432         /**
1433          * @return array
1434          */
1435         public function getMessageArray() {
1436                 $result = array(
1437                         'code' => $this->mCodestr,
1438                         'info' => $this->getMessage()
1439                 );
1440                 if ( is_array( $this->mExtraData ) ) {
1441                         $result = array_merge( $result, $this->mExtraData );
1442                 }
1443
1444                 return $result;
1445         }
1446
1447         /**
1448          * @return string
1449          */
1450         public function __toString() {
1451                 return "{$this->getCodeString()}: {$this->getMessage()}";
1452         }
1453 }