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                 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 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                 global $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions;
 469
 470                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 471                 if ( $originParam === null ) {
 472                         // No origin parameter, nothing to do
 473                         return true;
 474                 }
 475
 476                 $request = $this->getRequest();
 477                 $response = $request->response();
 478                 // Origin: header is a space-separated list of origins, check all of them
 479                 $originHeader = $request->getHeader( 'Origin' );
 480                 if ( $originHeader === false ) {
 481                         $origins = array();
 482                 } else {
 483                         $origins = explode( ' ', $originHeader );
 484                 }
 485
 486                 if ( !in_array( $originParam, $origins ) ) {
 487                         // origin parameter set but incorrect
 488                         // Send a 403 response
 489                         $message = HttpStatus::getMessage( 403 );
 490                         $response->header( "HTTP/1.1 403 $message", true, 403 );
 491                         $response->header( 'Cache-Control: no-cache' );
 492                         echo "'origin' parameter does not match Origin header\n";
 493
 494                         return false;
 495                 }
 496
 497                 $matchOrigin = self::matchOrigin(
 498                         $originParam,
 499                         $wgCrossSiteAJAXdomains,
 500                         $wgCrossSiteAJAXdomainExceptions
 501                 );
 502
 503                 if ( $matchOrigin ) {
 504                         $response->header( "Access-Control-Allow-Origin: $originParam" );
 505                         $response->header( 'Access-Control-Allow-Credentials: true' );
 506                         $this->getOutput()->addVaryHeader( 'Origin' );
 507                 }
 508
 509                 return true;
 510         }
 511
 512         /**
 513          * Attempt to match an Origin header against a set of rules and a set of exceptions
 514          * @param string $value Origin header
 515          * @param array $rules Set of wildcard rules
 516          * @param array $exceptions Set of wildcard rules
 517          * @return bool True if $value matches a rule in $rules and doesn't match
 518          *    any rules in $exceptions, false otherwise
 519          */
 520         protected static function matchOrigin( $value, $rules, $exceptions ) {
 521                 foreach ( $rules as $rule ) {
 522                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 523                                 // Rule matches, check exceptions
 524                                 foreach ( $exceptions as $exc ) {
 525                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 526                                                 return false;
 527                                         }
 528                                 }
 529
 530                                 return true;
 531                         }
 532                 }
 533
 534                 return false;
 535         }
 536
 537         /**
 538          * Helper function to convert wildcard string into a regex
 539          * '*' => '.*?'
 540          * '?' => '.'
 541          *
 542          * @param string $wildcard String with wildcards
 543          * @return string Regular expression
 544          */
 545         protected static function wildcardToRegex( $wildcard ) {
 546                 $wildcard = preg_quote( $wildcard, '/' );
 547                 $wildcard = str_replace(
 548                         array( '\*', '\?' ),
 549                         array( '.*?', '.' ),
 550                         $wildcard
 551                 );
 552
 553                 return "/https?:\/\/$wildcard/";
 554         }
 555
 556         protected function sendCacheHeaders() {
 557                 global $wgUseXVO, $wgVaryOnXFP;
 558                 $response = $this->getRequest()->response();
 559                 $out = $this->getOutput();
 560
 561                 if ( $wgVaryOnXFP ) {
 562                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 563                 }
 564
 565                 if ( $this->mCacheMode == 'private' ) {
 566                         $response->header( 'Cache-Control: private' );
 567
 568                         return;
 569                 }
 570
 571                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 572                         $out->addVaryHeader( 'Cookie' );
 573                         $response->header( $out->getVaryHeader() );
 574                         if ( $wgUseXVO ) {
 575                                 $response->header( $out->getXVO() );
 576                                 if ( $out->haveCacheVaryCookies() ) {
 577                                         // Logged in, mark this request private
 578                                         $response->header( 'Cache-Control: private' );
 579
 580                                         return;
 581                                 }
 582                                 // Logged out, send normal public headers below
 583                         } elseif ( session_id() != '' ) {
 584                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 585                                 // Mark request private
 586                                 $response->header( 'Cache-Control: private' );
 587
 588                                 return;
 589                         } // else no XVO and anonymous, send public headers below
 590                 }
 591
 592                 // Send public headers
 593                 $response->header( $out->getVaryHeader() );
 594                 if ( $wgUseXVO ) {
 595                         $response->header( $out->getXVO() );
 596                 }
 597
 598                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 599                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 600                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 601                 }
 602                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 603                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 604                 }
 605
 606                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 607                         // Public cache not requested
 608                         // Sending a Vary header in this case is harmless, and protects us
 609                         // against conditional calls of setCacheMaxAge().
 610                         $response->header( 'Cache-Control: private' );
 611
 612                         return;
 613                 }
 614
 615                 $this->mCacheControl['public'] = true;
 616
 617                 // Send an Expires header
 618                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 619                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 620                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 621
 622                 // Construct the Cache-Control header
 623                 $ccHeader = '';
 624                 $separator = '';
 625                 foreach ( $this->mCacheControl as $name => $value ) {
 626                         if ( is_bool( $value ) ) {
 627                                 if ( $value ) {
 628                                         $ccHeader .= $separator . $name;
 629                                         $separator = ', ';
 630                                 }
 631                         } else {
 632                                 $ccHeader .= $separator . "$name=$value";
 633                                 $separator = ', ';
 634                         }
 635                 }
 636
 637                 $response->header( "Cache-Control: $ccHeader" );
 638         }
 639
 640         /**
 641          * Replace the result data with the information about an exception.
 642          * Returns the error code
 643          * @param Exception $e
 644          * @return string
 645          */
 646         protected function substituteResultWithError( $e ) {
 647                 global $wgShowHostnames;
 648
 649                 $result = $this->getResult();
 650
 651                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 652                 if ( !isset( $this->mPrinter ) ) {
 653                         // The printer has not been created yet. Try to manually get formatter value.
 654                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 655                         if ( !$this->mModuleMgr->isDefined( $value, 'format' ) ) {
 656                                 $value = self::API_DEFAULT_FORMAT;
 657                         }
 658
 659                         $this->mPrinter = $this->createPrinterByName( $value );
 660                 }
 661
 662                 // Printer may not be able to handle errors. This is particularly
 663                 // likely if the module returns something for getCustomPrinter().
 664                 if ( !$this->mPrinter->canPrintErrors() ) {
 665                         $this->mPrinter->safeProfileOut();
 666                         $this->mPrinter = $this->createPrinterByName( self::API_DEFAULT_FORMAT );
 667                 }
 668
 669                 // Update raw mode flag for the selected printer.
 670                 $result->setRawMode( $this->mPrinter->getNeedsRawData() );
 671
 672                 if ( $e instanceof UsageException ) {
 673                         // User entered incorrect parameters - print usage screen
 674                         $errMessage = $e->getMessageArray();
 675
 676                         // Only print the help message when this is for the developer, not runtime
 677                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 678                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 679                         }
 680                 } else {
 681                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 682                         // Something is seriously wrong
 683                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 684                                 $info = 'Database query error';
 685                         } else {
 686                                 $info = "Exception Caught: {$e->getMessage()}";
 687                         }
 688
 689                         $errMessage = array(
 690                                 'code' => 'internal_api_error_' . get_class( $e ),
 691                                 'info' => $info,
 692                         );
 693                         ApiResult::setContent(
 694                                 $errMessage,
 695                                 $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : ''
 696                         );
 697                 }
 698
 699                 // Remember all the warnings to re-add them later
 700                 $oldResult = $result->getData();
 701                 $warnings = isset( $oldResult['warnings'] ) ? $oldResult['warnings'] : null;
 702
 703                 $result->reset();
 704                 $result->disableSizeCheck();
 705                 // Re-add the id
 706                 $requestid = $this->getParameter( 'requestid' );
 707                 if ( !is_null( $requestid ) ) {
 708                         $result->addValue( null, 'requestid', $requestid );
 709                 }
 710                 if ( $wgShowHostnames ) {
 711                         // servedby is especially useful when debugging errors
 712                         $result->addValue( null, 'servedby', wfHostName() );
 713                 }
 714                 if ( $warnings !== null ) {
 715                         $result->addValue( null, 'warnings', $warnings );
 716                 }
 717
 718                 $result->addValue( null, 'error', $errMessage );
 719
 720                 return $errMessage['code'];
 721         }
 722
 723         /**
 724          * Set up for the execution.
 725          * @return array
 726          */
 727         protected function setupExecuteAction() {
 728                 global $wgShowHostnames;
 729
 730                 // First add the id to the top element
 731                 $result = $this->getResult();
 732                 $requestid = $this->getParameter( 'requestid' );
 733                 if ( !is_null( $requestid ) ) {
 734                         $result->addValue( null, 'requestid', $requestid );
 735                 }
 736
 737                 if ( $wgShowHostnames ) {
 738                         $servedby = $this->getParameter( 'servedby' );
 739                         if ( $servedby ) {
 740                                 $result->addValue( null, 'servedby', wfHostName() );
 741                         }
 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                 // Die if token required, but not provided
 768                 $salt = $module->getTokenSalt();
 769                 if ( $salt !== false ) {
 770                         if ( !isset( $moduleParams['token'] ) ) {
 771                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 772                         }
 773
 774                         if ( !$this->getUser()->matchEditToken(
 775                                 $moduleParams['token'],
 776                                 $salt,
 777                                 $this->getContext()->getRequest() )
 778                         ) {
 779                                 $this->dieUsageMsg( 'sessionfailure' );
 780                         }
 781                 }
 782
 783                 return $module;
 784         }
 785
 786         /**
 787          * Check the max lag if necessary
 788          * @param ApiBase $module Api module being used
 789          * @param array $params Array an array containing the request parameters.
 790          * @return bool True on success, false should exit immediately
 791          */
 792         protected function checkMaxLag( $module, $params ) {
 793                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 794                         // Check for maxlag
 795                         global $wgShowHostnames;
 796                         $maxLag = $params['maxlag'];
 797                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 798                         if ( $lag > $maxLag ) {
 799                                 $response = $this->getRequest()->response();
 800
 801                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 802                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 803
 804                                 if ( $wgShowHostnames ) {
 805                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 806                                 }
 807
 808                                 $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 809                         }
 810                 }
 811
 812                 return true;
 813         }
 814
 815         /**
 816          * Check for sufficient permissions to execute
 817          * @param ApiBase $module An Api module
 818          */
 819         protected function checkExecutePermissions( $module ) {
 820                 $user = $this->getUser();
 821                 if ( $module->isReadMode() && !User::isEveryoneAllowed( 'read' ) &&
 822                         !$user->isAllowed( 'read' )
 823                 ) {
 824                         $this->dieUsageMsg( 'readrequired' );
 825                 }
 826                 if ( $module->isWriteMode() ) {
 827                         if ( !$this->mEnableWrite ) {
 828                                 $this->dieUsageMsg( 'writedisabled' );
 829                         }
 830                         if ( !$user->isAllowed( 'writeapi' ) ) {
 831                                 $this->dieUsageMsg( 'writerequired' );
 832                         }
 833                         if ( wfReadOnly() ) {
 834                                 $this->dieReadOnly();
 835                         }
 836                 }
 837
 838                 // Allow extensions to stop execution for arbitrary reasons.
 839                 $message = false;
 840                 if ( !wfRunHooks( 'ApiCheckCanExecute', array( $module, $user, &$message ) ) ) {
 841                         $this->dieUsageMsg( $message );
 842                 }
 843         }
 844
 845         /**
 846          * Check asserts of the user's rights
 847          * @param array $params
 848          */
 849         protected function checkAsserts( $params ) {
 850                 if ( isset( $params['assert'] ) ) {
 851                         $user = $this->getUser();
 852                         switch ( $params['assert'] ) {
 853                                 case 'user':
 854                                         if ( $user->isAnon() ) {
 855                                                 $this->dieUsage( 'Assertion that the user is logged in failed', 'assertuserfailed' );
 856                                         }
 857                                         break;
 858                                 case 'bot':
 859                                         if ( !$user->isAllowed( 'bot' ) ) {
 860                                                 $this->dieUsage( 'Assertion that the user has the bot right failed', 'assertbotfailed' );
 861                                         }
 862                                         break;
 863                         }
 864                 }
 865         }
 866
 867         /**
 868          * Check POST for external response and setup result printer
 869          * @param ApiBase $module An Api module
 870          * @param array $params an array with the request parameters
 871          */
 872         protected function setupExternalResponse( $module, $params ) {
 873                 if ( !$this->getRequest()->wasPosted() && $module->mustBePosted() ) {
 874                         // Module requires POST. GET request might still be allowed
 875                         // if $wgDebugApi is true, otherwise fail.
 876                         $this->dieUsageMsgOrDebug( array( 'mustbeposted', $this->mAction ) );
 877                 }
 878
 879                 // See if custom printer is used
 880                 $this->mPrinter = $module->getCustomPrinter();
 881                 if ( is_null( $this->mPrinter ) ) {
 882                         // Create an appropriate printer
 883                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 884                 }
 885
 886                 if ( $this->mPrinter->getNeedsRawData() ) {
 887                         $this->getResult()->setRawMode();
 888                 }
 889         }
 890
 891         /**
 892          * Execute the actual module, without any error handling
 893          */
 894         protected function executeAction() {
 895                 $params = $this->setupExecuteAction();
 896                 $module = $this->setupModule();
 897                 $this->mModule = $module;
 898
 899                 $this->checkExecutePermissions( $module );
 900
 901                 if ( !$this->checkMaxLag( $module, $params ) ) {
 902                         return;
 903                 }
 904
 905                 if ( !$this->mInternalMode ) {
 906                         $this->setupExternalResponse( $module, $params );
 907                 }
 908
 909                 $this->checkAsserts( $params );
 910
 911                 // Execute
 912                 $module->profileIn();
 913                 $module->execute();
 914                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 915                 $module->profileOut();
 916
 917                 $this->reportUnusedParams();
 918
 919                 if ( !$this->mInternalMode ) {
 920                         //append Debug information
 921                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
 922
 923                         // Print result data
 924                         $this->printResult( false );
 925                 }
 926         }
 927
 928         /**
 929          * Log the preceding request
 930          * @param int $time Time in seconds
 931          */
 932         protected function logRequest( $time ) {
 933                 $request = $this->getRequest();
 934                 $milliseconds = $time === null ? '?' : round( $time * 1000 );
 935                 $s = 'API' .
 936                         ' ' . $request->getMethod() .
 937                         ' ' . wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
 938                         ' ' . $request->getIP() .
 939                         ' T=' . $milliseconds . 'ms';
 940                 foreach ( $this->getParamsUsed() as $name ) {
 941                         $value = $request->getVal( $name );
 942                         if ( $value === null ) {
 943                                 continue;
 944                         }
 945                         $s .= ' ' . $name . '=';
 946                         if ( strlen( $value ) > 256 ) {
 947                                 $encValue = $this->encodeRequestLogValue( substr( $value, 0, 256 ) );
 948                                 $s .= $encValue . '[...]';
 949                         } else {
 950                                 $s .= $this->encodeRequestLogValue( $value );
 951                         }
 952                 }
 953                 $s .= "\n";
 954                 wfDebugLog( 'api', $s, 'private' );
 955         }
 956
 957         /**
 958          * Encode a value in a format suitable for a space-separated log line.
 959          * @param string $s
 960          * @return string
 961          */
 962         protected function encodeRequestLogValue( $s ) {
 963                 static $table;
 964                 if ( !$table ) {
 965                         $chars = ';@$!*(),/:';
 966                         $numChars = strlen( $chars );
 967                         for ( $i = 0; $i < $numChars; $i++ ) {
 968                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
 969                         }
 970                 }
 971
 972                 return strtr( rawurlencode( $s ), $table );
 973         }
 974
 975         /**
 976          * Get the request parameters used in the course of the preceding execute() request
 977          * @return array
 978          */
 979         protected function getParamsUsed() {
 980                 return array_keys( $this->mParamsUsed );
 981         }
 982
 983         /**
 984          * Get a request value, and register the fact that it was used, for logging.
 985          * @param string $name
 986          * @param mixed $default
 987          * @return mixed
 988          */
 989         public function getVal( $name, $default = null ) {
 990                 $this->mParamsUsed[$name] = true;
 991
 992                 $ret = $this->getRequest()->getVal( $name );
 993                 if ( $ret === null ) {
 994                         if ( $this->getRequest()->getArray( $name ) !== null ) {
 995                                 // See bug 10262 for why we don't just join( '|', ... ) the
 996                                 // array.
 997                                 $this->setWarning(
 998                                         "Parameter '$name' uses unsupported PHP array syntax"
 999                                 );
1000                         }
1001                         $ret = $default;
1002                 }
1003                 return $ret;
1004         }
1005
1006         /**
1007          * Get a boolean request value, and register the fact that the parameter
1008          * was used, for logging.
1009          * @param string $name
1010          * @return bool
1011          */
1012         public function getCheck( $name ) {
1013                 return $this->getVal( $name, null ) !== null;
1014         }
1015
1016         /**
1017          * Get a request upload, and register the fact that it was used, for logging.
1018          *
1019          * @since 1.21
1020          * @param string $name Parameter name
1021          * @return WebRequestUpload
1022          */
1023         public function getUpload( $name ) {
1024                 $this->mParamsUsed[$name] = true;
1025
1026                 return $this->getRequest()->getUpload( $name );
1027         }
1028
1029         /**
1030          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1031          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1032          */
1033         protected function reportUnusedParams() {
1034                 $paramsUsed = $this->getParamsUsed();
1035                 $allParams = $this->getRequest()->getValueNames();
1036
1037                 if ( !$this->mInternalMode ) {
1038                         // Printer has not yet executed; don't warn that its parameters are unused
1039                         $printerParams = array_map(
1040                                 array( $this->mPrinter, 'encodeParamName' ),
1041                                 array_keys( $this->mPrinter->getFinalParams() ?: array() )
1042                         );
1043                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1044                 } else {
1045                         $unusedParams = array_diff( $allParams, $paramsUsed );
1046                 }
1047
1048                 if ( count( $unusedParams ) ) {
1049                         $s = count( $unusedParams ) > 1 ? 's' : '';
1050                         $this->setWarning( "Unrecognized parameter$s: '" . implode( $unusedParams, "', '" ) . "'" );
1051                 }
1052         }
1053
1054         /**
1055          * Print results using the current printer
1056          *
1057          * @param bool $isError
1058          */
1059         protected function printResult( $isError ) {
1060                 global $wgDebugAPI;
1061                 if ( $wgDebugAPI !== false ) {
1062                         $this->setWarning( 'SECURITY WARNING: $wgDebugAPI is enabled' );
1063                 }
1064
1065                 $this->getResult()->cleanUpUTF8();
1066                 $printer = $this->mPrinter;
1067                 $printer->profileIn();
1068
1069                 /**
1070                  * If the help message is requested in the default (xmlfm) format,
1071                  * tell the printer not to escape ampersands so that our links do
1072                  * not break.
1073                  */
1074                 $isHelp = $isError || $this->mAction == 'help';
1075                 $printer->setUnescapeAmps( $isHelp && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
1076
1077                 $printer->initPrinter( $isHelp );
1078
1079                 $printer->execute();
1080                 $printer->closePrinter();
1081                 $printer->profileOut();
1082         }
1083
1084         /**
1085          * @return bool
1086          */
1087         public function isReadMode() {
1088                 return false;
1089         }
1090
1091         /**
1092          * See ApiBase for description.
1093          *
1094          * @return array
1095          */
1096         public function getAllowedParams() {
1097                 return array(
1098                         'format' => array(
1099                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1100                                 ApiBase::PARAM_TYPE => $this->mModuleMgr->getNames( 'format' )
1101                         ),
1102                         'action' => array(
1103                                 ApiBase::PARAM_DFLT => 'help',
1104                                 ApiBase::PARAM_TYPE => $this->mModuleMgr->getNames( 'action' )
1105                         ),
1106                         'maxlag' => array(
1107                                 ApiBase::PARAM_TYPE => 'integer'
1108                         ),
1109                         'smaxage' => array(
1110                                 ApiBase::PARAM_TYPE => 'integer',
1111                                 ApiBase::PARAM_DFLT => 0
1112                         ),
1113                         'maxage' => array(
1114                                 ApiBase::PARAM_TYPE => 'integer',
1115                                 ApiBase::PARAM_DFLT => 0
1116                         ),
1117                         'assert' => array(
1118                                 ApiBase::PARAM_TYPE => array( 'user', 'bot' )
1119                         ),
1120                         'requestid' => null,
1121                         'servedby' => false,
1122                         'origin' => null,
1123                 );
1124         }
1125
1126         /**
1127          * See ApiBase for description.
1128          *
1129          * @return array
1130          */
1131         public function getParamDescription() {
1132                 return array(
1133                         'format' => 'The format of the output',
1134                         'action' => 'What action you would like to perform. See below for module help',
1135                         'maxlag' => array(
1136                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
1137                                 'To save actions causing any more site replication lag, this parameter can make the client',
1138                                 'wait until the replication lag is less than the specified value.',
1139                                 'In case of a replag error, error code "maxlag" is returned, with the message like',
1140                                 '"Waiting for $host: $lag seconds lagged\n".',
1141                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
1142                         ),
1143                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
1144                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
1145                         'assert' => 'Verify the user is logged in if set to "user", or has the bot userright if "bot"',
1146                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
1147                         'servedby' => 'Include the hostname that served the request in the ' .
1148                                 'results. Unconditionally shown on error',
1149                         'origin' => array(
1150                                 'When accessing the API using a cross-domain AJAX request (CORS), set this to the',
1151                                 'originating domain. This must be included in any pre-flight request, and',
1152                                 'therefore must be part of the request URI (not the POST body). This must match',
1153                                 'one of the origins in the Origin: header exactly, so it has to be set to ',
1154                                 'something like http://en.wikipedia.org or https://meta.wikimedia.org . If this',
1155                                 'parameter does not match the Origin: header, a 403 response will be returned. If',
1156                                 'this parameter matches the Origin: header and the origin is whitelisted, an',
1157                                 'Access-Control-Allow-Origin header will be set.',
1158                         ),
1159                 );
1160         }
1161
1162         /**
1163          * See ApiBase for description.
1164          *
1165          * @return array
1166          */
1167         public function getDescription() {
1168                 return array(
1169                         '',
1170                         '',
1171                         '**********************************************************************************************',
1172                         '**                                                                                          **',
1173                         '**                This is an auto-generated MediaWiki API documentation page                **',
1174                         '**                                                                                          **',
1175                         '**                               Documentation and Examples:                                **',
1176                         '**                            https://www.mediawiki.org/wiki/API                            **',
1177                         '**                                                                                          **',
1178                         '**********************************************************************************************',
1179                         '',
1180                         'Status:                All features shown on this page should be working, but the API',
1181                         '                       is still in active development, and may change at any time.',
1182                         '                       Make sure to monitor our mailing list for any updates.',
1183                         '',
1184                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
1185                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
1186                         '                       header and the error code sent back will be set to the same value.',
1187                         '',
1188                         '                       In the case of an invalid action being passed, these will have a value',
1189                         '                       of "unknown_action".',
1190                         '',
1191                         '                       For more information see https://www.mediawiki.org' .
1192                                 '/wiki/API:Errors_and_warnings',
1193                         '',
1194                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
1195                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
1196                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
1197                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
1198                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&' .
1199                                 'bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
1200                         '',
1201                         '',
1202                         '',
1203                         '',
1204                         '',
1205                 );
1206         }
1207
1208         /**
1209          * @return array
1210          */
1211         public function getPossibleErrors() {
1212                 return array_merge( parent::getPossibleErrors(), array(
1213                         array( 'readonlytext' ),
1214                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
1215                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
1216                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
1217                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
1218                         array( 'code' => 'assertuserfailed', 'info' => 'Assertion that the user is logged in failed' ),
1219                         array(
1220                                 'code' => 'assertbotfailed',
1221                                 'info' => 'Assertion that the user has the bot right failed'
1222                         ),
1223                 ) );
1224         }
1225
1226         /**
1227          * Returns an array of strings with credits for the API
1228          * @return array
1229          */
1230         protected function getCredits() {
1231                 return array(
1232                         'API developers:',
1233                         '    Roan Kattouw (lead developer Sep 2007-2009)',
1234                         '    Victor Vasiliev',
1235                         '    Bryan Tong Minh',
1236                         '    Sam Reed',
1237                         '    Yuri Astrakhan (creator, lead developer Sep 2006-Sep 2007, 2012-2013)',
1238                         '    Brad Jorsch (lead developer 2013-now)',
1239                         '',
1240                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
1241                         'or file a bug report at https://bugzilla.wikimedia.org/'
1242                 );
1243         }
1244
1245         /**
1246          * Sets whether the pretty-printer should format *bold* and $italics$
1247          *
1248          * @param bool $help
1249          */
1250         public function setHelp( $help = true ) {
1251                 $this->mPrinter->setHelp( $help );
1252         }
1253
1254         /**
1255          * Override the parent to generate help messages for all available modules.
1256          *
1257          * @return string
1258          */
1259         public function makeHelpMsg() {
1260                 global $wgMemc, $wgAPICacheHelpTimeout;
1261                 $this->setHelp();
1262                 // Get help text from cache if present
1263                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
1264                         str_replace( ' ', '_', SpecialVersion::getVersion( 'nodb' ) ) );
1265                 if ( $wgAPICacheHelpTimeout > 0 ) {
1266                         $cached = $wgMemc->get( $key );
1267                         if ( $cached ) {
1268                                 return $cached;
1269                         }
1270                 }
1271                 $retval = $this->reallyMakeHelpMsg();
1272                 if ( $wgAPICacheHelpTimeout > 0 ) {
1273                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
1274                 }
1275
1276                 return $retval;
1277         }
1278
1279         /**
1280          * @return mixed|string
1281          */
1282         public function reallyMakeHelpMsg() {
1283                 $this->setHelp();
1284
1285                 // Use parent to make default message for the main module
1286                 $msg = parent::makeHelpMsg();
1287
1288                 $astriks = str_repeat( '*** ', 14 );
1289                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
1290
1291                 foreach ( $this->mModuleMgr->getNames( 'action' ) as $name ) {
1292                         $module = $this->mModuleMgr->getModule( $name );
1293                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1294
1295                         $msg2 = $module->makeHelpMsg();
1296                         if ( $msg2 !== false ) {
1297                                 $msg .= $msg2;
1298                         }
1299                         $msg .= "\n";
1300                 }
1301
1302                 $msg .= "\n$astriks Permissions $astriks\n\n";
1303                 foreach ( self::$mRights as $right => $rightMsg ) {
1304                         $groups = User::getGroupsWithPermission( $right );
1305                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg['msg'], $rightMsg['params'] ) .
1306                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1307                 }
1308
1309                 $msg .= "\n$astriks Formats  $astriks\n\n";
1310                 foreach ( $this->mModuleMgr->getNames( 'format' ) as $name ) {
1311                         $module = $this->mModuleMgr->getModule( $name );
1312                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1313                         $msg2 = $module->makeHelpMsg();
1314                         if ( $msg2 !== false ) {
1315                                 $msg .= $msg2;
1316                         }
1317                         $msg .= "\n";
1318                 }
1319
1320                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
1321
1322                 return $msg;
1323         }
1324
1325         /**
1326          * @param ApiBase $module
1327          * @param string $paramName What type of request is this? e.g. action,
1328          *    query, list, prop, meta, format
1329          * @return string
1330          */
1331         public static function makeHelpMsgHeader( $module, $paramName ) {
1332                 $modulePrefix = $module->getModulePrefix();
1333                 if ( strval( $modulePrefix ) !== '' ) {
1334                         $modulePrefix = "($modulePrefix) ";
1335                 }
1336
1337                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1338         }
1339
1340         private $mCanApiHighLimits = null;
1341
1342         /**
1343          * Check whether the current user is allowed to use high limits
1344          * @return bool
1345          */
1346         public function canApiHighLimits() {
1347                 if ( !isset( $this->mCanApiHighLimits ) ) {
1348                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1349                 }
1350
1351                 return $this->mCanApiHighLimits;
1352         }
1353
1354         /**
1355          * Check whether the user wants us to show version information in the API help
1356          * @return bool
1357          * @deprecated since 1.21, always returns false
1358          */
1359         public function getShowVersions() {
1360                 wfDeprecated( __METHOD__, '1.21' );
1361
1362                 return false;
1363         }
1364
1365         /**
1366          * Overrides to return this instance's module manager.
1367          * @return ApiModuleManager
1368          */
1369         public function getModuleManager() {
1370                 return $this->mModuleMgr;
1371         }
1372
1373         /**
1374          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1375          * classes who wish to add their own modules to their lexicon or override the
1376          * behavior of inherent ones.
1377          *
1378          * @deprecated since 1.21, Use getModuleManager()->addModule() instead.
1379          * @param string $name The identifier for this module.
1380          * @param ApiBase $class The class where this module is implemented.
1381          */
1382         protected function addModule( $name, $class ) {
1383                 $this->getModuleManager()->addModule( $name, 'action', $class );
1384         }
1385
1386         /**
1387          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1388          * classes who wish to add to or modify current formatters.
1389          *
1390          * @deprecated since 1.21, Use getModuleManager()->addModule() instead.
1391          * @param string $name The identifier for this format.
1392          * @param ApiFormatBase $class The class implementing this format.
1393          */
1394         protected function addFormat( $name, $class ) {
1395                 $this->getModuleManager()->addModule( $name, 'format', $class );
1396         }
1397
1398         /**
1399          * Get the array mapping module names to class names
1400          * @deprecated since 1.21, Use getModuleManager()'s methods instead.
1401          * @return array
1402          */
1403         function getModules() {
1404                 return $this->getModuleManager()->getNamesWithClasses( 'action' );
1405         }
1406
1407         /**
1408          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1409          *
1410          * @since 1.18
1411          * @deprecated since 1.21, Use getModuleManager()'s methods instead.
1412          * @return array
1413          */
1414         public function getFormats() {
1415                 return $this->getModuleManager()->getNamesWithClasses( 'format' );
1416         }
1417 }
1418
1419 /**
1420  * This exception will be thrown when dieUsage is called to stop module execution.
1421  * The exception handling code will print a help screen explaining how this API may be used.
1422  *
1423  * @ingroup API
1424  */
1425 class UsageException extends MWException {
1426
1427         private $mCodestr;
1428
1429         /**
1430          * @var null|array
1431          */
1432         private $mExtraData;
1433
1434         /**
1435          * @param string $message
1436          * @param string $codestr
1437          * @param int $code
1438          * @param array|null $extradata
1439          */
1440         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1441                 parent::__construct( $message, $code );
1442                 $this->mCodestr = $codestr;
1443                 $this->mExtraData = $extradata;
1444         }
1445
1446         /**
1447          * @return string
1448          */
1449         public function getCodeString() {
1450                 return $this->mCodestr;
1451         }
1452
1453         /**
1454          * @return array
1455          */
1456         public function getMessageArray() {
1457                 $result = array(
1458                         'code' => $this->mCodestr,
1459                         'info' => $this->getMessage()
1460                 );
1461                 if ( is_array( $this->mExtraData ) ) {
1462                         $result = array_merge( $result, $this->mExtraData );
1463                 }
1464
1465                 return $result;
1466         }
1467
1468         /**
1469          * @return string
1470          */
1471         public function __toString() {
1472                 return "{$this->getCodeString()}: {$this->getMessage()}";
1473         }
1474 }