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                 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 Exception $e
 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 ApiBase $module Api module being used
 786          * @param array $params Array an array containing the request parameters.
 787          * @return bool 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 ApiBase $module 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 array $params
 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 ApiBase $module 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          * @param string $s
 957          * return string
 958          */
 959         protected function encodeRequestLogValue( $s ) {
 960                 static $table;
 961                 if ( !$table ) {
 962                         $chars = ';@$!*(),/:';
 963                         $numChars = strlen( $chars );
 964                         for ( $i = 0; $i < $numChars; $i++ ) {
 965                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
 966                         }
 967                 }
 968
 969                 return strtr( rawurlencode( $s ), $table );
 970         }
 971
 972         /**
 973          * Get the request parameters used in the course of the preceding execute() request
 974          * @return array
 975          */
 976         protected function getParamsUsed() {
 977                 return array_keys( $this->mParamsUsed );
 978         }
 979
 980         /**
 981          * Get a request value, and register the fact that it was used, for logging.
 982          * @param string $name
 983          * @param mixed $default
 984          * @return mixed
 985          */
 986         public function getVal( $name, $default = null ) {
 987                 $this->mParamsUsed[$name] = true;
 988
 989                 return $this->getRequest()->getVal( $name, $default );
 990         }
 991
 992         /**
 993          * Get a boolean request value, and register the fact that the parameter
 994          * was used, for logging.
 995          * @param string $name
 996          * @return bool
 997          */
 998         public function getCheck( $name ) {
 999                 $this->mParamsUsed[$name] = true;
1000
1001                 return $this->getRequest()->getCheck( $name );
1002         }
1003
1004         /**
1005          * Get a request upload, and register the fact that it was used, for logging.
1006          *
1007          * @since 1.21
1008          * @param string $name Parameter name
1009          * @return WebRequestUpload
1010          */
1011         public function getUpload( $name ) {
1012                 $this->mParamsUsed[$name] = true;
1013
1014                 return $this->getRequest()->getUpload( $name );
1015         }
1016
1017         /**
1018          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
1019          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
1020          */
1021         protected function reportUnusedParams() {
1022                 $paramsUsed = $this->getParamsUsed();
1023                 $allParams = $this->getRequest()->getValueNames();
1024
1025                 if ( !$this->mInternalMode ) {
1026                         // Printer has not yet executed; don't warn that its parameters are unused
1027                         $printerParams = array_map(
1028                                 array( $this->mPrinter, 'encodeParamName' ),
1029                                 array_keys( $this->mPrinter->getFinalParams() ?: array() )
1030                         );
1031                         $unusedParams = array_diff( $allParams, $paramsUsed, $printerParams );
1032                 } else {
1033                         $unusedParams = array_diff( $allParams, $paramsUsed );
1034                 }
1035
1036                 if ( count( $unusedParams ) ) {
1037                         $s = count( $unusedParams ) > 1 ? 's' : '';
1038                         $this->setWarning( "Unrecognized parameter$s: '" . implode( $unusedParams, "', '" ) . "'" );
1039                 }
1040         }
1041
1042         /**
1043          * Print results using the current printer
1044          *
1045          * @param bool $isError
1046          */
1047         protected function printResult( $isError ) {
1048                 global $wgDebugAPI;
1049                 if ( $wgDebugAPI !== false ) {
1050                         $this->setWarning( 'SECURITY WARNING: $wgDebugAPI is enabled' );
1051                 }
1052
1053                 $this->getResult()->cleanUpUTF8();
1054                 $printer = $this->mPrinter;
1055                 $printer->profileIn();
1056
1057                 /**
1058                  * If the help message is requested in the default (xmlfm) format,
1059                  * tell the printer not to escape ampersands so that our links do
1060                  * not break.
1061                  */
1062                 $isHelp = $isError || $this->mAction == 'help';
1063                 $printer->setUnescapeAmps( $isHelp && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
1064
1065                 $printer->initPrinter( $isHelp );
1066
1067                 $printer->execute();
1068                 $printer->closePrinter();
1069                 $printer->profileOut();
1070         }
1071
1072         /**
1073          * @return bool
1074          */
1075         public function isReadMode() {
1076                 return false;
1077         }
1078
1079         /**
1080          * See ApiBase for description.
1081          *
1082          * @return array
1083          */
1084         public function getAllowedParams() {
1085                 return array(
1086                         'format' => array(
1087                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
1088                                 ApiBase::PARAM_TYPE => $this->mModuleMgr->getNames( 'format' )
1089                         ),
1090                         'action' => array(
1091                                 ApiBase::PARAM_DFLT => 'help',
1092                                 ApiBase::PARAM_TYPE => $this->mModuleMgr->getNames( 'action' )
1093                         ),
1094                         'maxlag' => array(
1095                                 ApiBase::PARAM_TYPE => 'integer'
1096                         ),
1097                         'smaxage' => array(
1098                                 ApiBase::PARAM_TYPE => 'integer',
1099                                 ApiBase::PARAM_DFLT => 0
1100                         ),
1101                         'maxage' => array(
1102                                 ApiBase::PARAM_TYPE => 'integer',
1103                                 ApiBase::PARAM_DFLT => 0
1104                         ),
1105                         'assert' => array(
1106                                 ApiBase::PARAM_TYPE => array( 'user', 'bot' )
1107                         ),
1108                         'requestid' => null,
1109                         'servedby' => false,
1110                         'origin' => null,
1111                 );
1112         }
1113
1114         /**
1115          * See ApiBase for description.
1116          *
1117          * @return array
1118          */
1119         public function getParamDescription() {
1120                 return array(
1121                         'format' => 'The format of the output',
1122                         'action' => 'What action you would like to perform. See below for module help',
1123                         'maxlag' => array(
1124                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
1125                                 'To save actions causing any more site replication lag, this parameter can make the client',
1126                                 'wait until the replication lag is less than the specified value.',
1127                                 'In case of a replag error, error code "maxlag" is returned, with the message like',
1128                                 '"Waiting for $host: $lag seconds lagged\n".',
1129                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
1130                         ),
1131                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
1132                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
1133                         'assert' => 'Verify the user is logged in if set to "user", or has the bot userright if "bot"',
1134                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
1135                         'servedby' => 'Include the hostname that served the request in the ' .
1136                                 'results. Unconditionally shown on error',
1137                         'origin' => array(
1138                                 'When accessing the API using a cross-domain AJAX request (CORS), set this to the',
1139                                 'originating domain. This must be included in any pre-flight request, and',
1140                                 'therefore must be part of the request URI (not the POST body). This must match',
1141                                 'one of the origins in the Origin: header exactly, so it has to be set to ',
1142                                 'something like http://en.wikipedia.org or https://meta.wikimedia.org . If this',
1143                                 'parameter does not match the Origin: header, a 403 response will be returned. If',
1144                                 'this parameter matches the Origin: header and the origin is whitelisted, an',
1145                                 'Access-Control-Allow-Origin header will be set.',
1146                         ),
1147                 );
1148         }
1149
1150         /**
1151          * See ApiBase for description.
1152          *
1153          * @return array
1154          */
1155         public function getDescription() {
1156                 return array(
1157                         '',
1158                         '',
1159                         '**********************************************************************************************',
1160                         '**                                                                                          **',
1161                         '**                This is an auto-generated MediaWiki API documentation page                **',
1162                         '**                                                                                          **',
1163                         '**                               Documentation and Examples:                                **',
1164                         '**                            https://www.mediawiki.org/wiki/API                            **',
1165                         '**                                                                                          **',
1166                         '**********************************************************************************************',
1167                         '',
1168                         'Status:                All features shown on this page should be working, but the API',
1169                         '                       is still in active development, and may change at any time.',
1170                         '                       Make sure to monitor our mailing list for any updates.',
1171                         '',
1172                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
1173                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
1174                         '                       header and the error code sent back will be set to the same value.',
1175                         '',
1176                         '                       In the case of an invalid action being passed, these will have a value',
1177                         '                       of "unknown_action".',
1178                         '',
1179                         '                       For more information see https://www.mediawiki.org' .
1180                                 '/wiki/API:Errors_and_warnings',
1181                         '',
1182                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
1183                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
1184                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
1185                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
1186                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&' .
1187                                 'bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
1188                         '',
1189                         '',
1190                         '',
1191                         '',
1192                         '',
1193                 );
1194         }
1195
1196         /**
1197          * @return array
1198          */
1199         public function getPossibleErrors() {
1200                 return array_merge( parent::getPossibleErrors(), array(
1201                         array( 'readonlytext' ),
1202                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
1203                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
1204                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
1205                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
1206                         array( 'code' => 'assertuserfailed', 'info' => 'Assertion that the user is logged in failed' ),
1207                         array(
1208                                 'code' => 'assertbotfailed',
1209                                 'info' => 'Assertion that the user has the bot right failed'
1210                         ),
1211                 ) );
1212         }
1213
1214         /**
1215          * Returns an array of strings with credits for the API
1216          * @return array
1217          */
1218         protected function getCredits() {
1219                 return array(
1220                         'API developers:',
1221                         '    Roan Kattouw (lead developer Sep 2007-2009)',
1222                         '    Victor Vasiliev',
1223                         '    Bryan Tong Minh',
1224                         '    Sam Reed',
1225                         '    Yuri Astrakhan (creator, lead developer Sep 2006-Sep 2007, 2012-present)',
1226                         '',
1227                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
1228                         'or file a bug report at https://bugzilla.wikimedia.org/'
1229                 );
1230         }
1231
1232         /**
1233          * Sets whether the pretty-printer should format *bold* and $italics$
1234          *
1235          * @param bool $help
1236          */
1237         public function setHelp( $help = true ) {
1238                 $this->mPrinter->setHelp( $help );
1239         }
1240
1241         /**
1242          * Override the parent to generate help messages for all available modules.
1243          *
1244          * @return string
1245          */
1246         public function makeHelpMsg() {
1247                 global $wgMemc, $wgAPICacheHelpTimeout;
1248                 $this->setHelp();
1249                 // Get help text from cache if present
1250                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
1251                         str_replace( ' ', '_', SpecialVersion::getVersion( 'nodb' ) ) );
1252                 if ( $wgAPICacheHelpTimeout > 0 ) {
1253                         $cached = $wgMemc->get( $key );
1254                         if ( $cached ) {
1255                                 return $cached;
1256                         }
1257                 }
1258                 $retval = $this->reallyMakeHelpMsg();
1259                 if ( $wgAPICacheHelpTimeout > 0 ) {
1260                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
1261                 }
1262
1263                 return $retval;
1264         }
1265
1266         /**
1267          * @return mixed|string
1268          */
1269         public function reallyMakeHelpMsg() {
1270                 $this->setHelp();
1271
1272                 // Use parent to make default message for the main module
1273                 $msg = parent::makeHelpMsg();
1274
1275                 $astriks = str_repeat( '*** ', 14 );
1276                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
1277
1278                 foreach ( $this->mModuleMgr->getNames( 'action' ) as $name ) {
1279                         $module = $this->mModuleMgr->getModule( $name );
1280                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1281
1282                         $msg2 = $module->makeHelpMsg();
1283                         if ( $msg2 !== false ) {
1284                                 $msg .= $msg2;
1285                         }
1286                         $msg .= "\n";
1287                 }
1288
1289                 $msg .= "\n$astriks Permissions $astriks\n\n";
1290                 foreach ( self::$mRights as $right => $rightMsg ) {
1291                         $groups = User::getGroupsWithPermission( $right );
1292                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg['msg'], $rightMsg['params'] ) .
1293                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1294                 }
1295
1296                 $msg .= "\n$astriks Formats  $astriks\n\n";
1297                 foreach ( $this->mModuleMgr->getNames( 'format' ) as $name ) {
1298                         $module = $this->mModuleMgr->getModule( $name );
1299                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1300                         $msg2 = $module->makeHelpMsg();
1301                         if ( $msg2 !== false ) {
1302                                 $msg .= $msg2;
1303                         }
1304                         $msg .= "\n";
1305                 }
1306
1307                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
1308
1309                 return $msg;
1310         }
1311
1312         /**
1313          * @param ApiBase $module
1314          * @param string $paramName What type of request is this? e.g. action,
1315          *    query, list, prop, meta, format
1316          * @return string
1317          */
1318         public static function makeHelpMsgHeader( $module, $paramName ) {
1319                 $modulePrefix = $module->getModulePrefix();
1320                 if ( strval( $modulePrefix ) !== '' ) {
1321                         $modulePrefix = "($modulePrefix) ";
1322                 }
1323
1324                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1325         }
1326
1327         private $mCanApiHighLimits = null;
1328
1329         /**
1330          * Check whether the current user is allowed to use high limits
1331          * @return bool
1332          */
1333         public function canApiHighLimits() {
1334                 if ( !isset( $this->mCanApiHighLimits ) ) {
1335                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1336                 }
1337
1338                 return $this->mCanApiHighLimits;
1339         }
1340
1341         /**
1342          * Check whether the user wants us to show version information in the API help
1343          * @return bool
1344          * @deprecated since 1.21, always returns false
1345          */
1346         public function getShowVersions() {
1347                 wfDeprecated( __METHOD__, '1.21' );
1348
1349                 return false;
1350         }
1351
1352         /**
1353          * Overrides to return this instance's module manager.
1354          * @return ApiModuleManager
1355          */
1356         public function getModuleManager() {
1357                 return $this->mModuleMgr;
1358         }
1359
1360         /**
1361          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1362          * classes who wish to add their own modules to their lexicon or override the
1363          * behavior of inherent ones.
1364          *
1365          * @deprecated since 1.21, Use getModuleManager()->addModule() instead.
1366          * @param string $name The identifier for this module.
1367          * @param ApiBase $class The class where this module is implemented.
1368          */
1369         protected function addModule( $name, $class ) {
1370                 $this->getModuleManager()->addModule( $name, 'action', $class );
1371         }
1372
1373         /**
1374          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1375          * classes who wish to add to or modify current formatters.
1376          *
1377          * @deprecated since 1.21, Use getModuleManager()->addModule() instead.
1378          * @param string $name The identifier for this format.
1379          * @param ApiFormatBase $class The class implementing this format.
1380          */
1381         protected function addFormat( $name, $class ) {
1382                 $this->getModuleManager()->addModule( $name, 'format', $class );
1383         }
1384
1385         /**
1386          * Get the array mapping module names to class names
1387          * @deprecated since 1.21, Use getModuleManager()'s methods instead.
1388          * @return array
1389          */
1390         function getModules() {
1391                 return $this->getModuleManager()->getNamesWithClasses( 'action' );
1392         }
1393
1394         /**
1395          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1396          *
1397          * @since 1.18
1398          * @deprecated since 1.21, Use getModuleManager()'s methods instead.
1399          * @return array
1400          */
1401         public function getFormats() {
1402                 return $this->getModuleManager()->getNamesWithClasses( 'format' );
1403         }
1404 }
1405
1406 /**
1407  * This exception will be thrown when dieUsage is called to stop module execution.
1408  * The exception handling code will print a help screen explaining how this API may be used.
1409  *
1410  * @ingroup API
1411  */
1412 class UsageException extends MWException {
1413
1414         private $mCodestr;
1415
1416         /**
1417          * @var null|array
1418          */
1419         private $mExtraData;
1420
1421         /**
1422          * @param string $message
1423          * @param string $codestr
1424          * @param int $code
1425          * @param array|null $extradata
1426          */
1427         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1428                 parent::__construct( $message, $code );
1429                 $this->mCodestr = $codestr;
1430                 $this->mExtraData = $extradata;
1431         }
1432
1433         /**
1434          * @return string
1435          */
1436         public function getCodeString() {
1437                 return $this->mCodestr;
1438         }
1439
1440         /**
1441          * @return array
1442          */
1443         public function getMessageArray() {
1444                 $result = array(
1445                         'code' => $this->mCodestr,
1446                         'info' => $this->getMessage()
1447                 );
1448                 if ( is_array( $this->mExtraData ) ) {
1449                         $result = array_merge( $result, $this->mExtraData );
1450                 }
1451
1452                 return $result;
1453         }
1454
1455         /**
1456          * @return string
1457          */
1458         public function __toString() {
1459                 return "{$this->getCodeString()}: {$this->getMessage()}";
1460         }
1461 }