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         /**
  44          * When no format parameter is given, this format will be used
  45          */
  46         const API_DEFAULT_FORMAT = 'xmlfm';
  47
  48         /**
  49          * List of available modules: action name => module class
  50          */
  51         private static $Modules = array(
  52                 'login' => 'ApiLogin',
  53                 'logout' => 'ApiLogout',
  54                 'createaccount' => 'ApiCreateAccount',
  55                 'query' => 'ApiQuery',
  56                 'expandtemplates' => 'ApiExpandTemplates',
  57                 'parse' => 'ApiParse',
  58                 'opensearch' => 'ApiOpenSearch',
  59                 'feedcontributions' => 'ApiFeedContributions',
  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         );
  87
  88         /**
  89          * List of available formats: format name => format class
  90          */
  91         private static $Formats = array(
  92                 'json' => 'ApiFormatJson',
  93                 'jsonfm' => 'ApiFormatJson',
  94                 'php' => 'ApiFormatPhp',
  95                 'phpfm' => 'ApiFormatPhp',
  96                 'wddx' => 'ApiFormatWddx',
  97                 'wddxfm' => 'ApiFormatWddx',
  98                 'xml' => 'ApiFormatXml',
  99                 'xmlfm' => 'ApiFormatXml',
 100                 'yaml' => 'ApiFormatYaml',
 101                 'yamlfm' => 'ApiFormatYaml',
 102                 'rawfm' => 'ApiFormatJson',
 103                 'txt' => 'ApiFormatTxt',
 104                 'txtfm' => 'ApiFormatTxt',
 105                 'dbg' => 'ApiFormatDbg',
 106                 'dbgfm' => 'ApiFormatDbg',
 107                 'dump' => 'ApiFormatDump',
 108                 'dumpfm' => 'ApiFormatDump',
 109                 'none' => 'ApiFormatNone',
 110         );
 111
 112         /**
 113          * List of user roles that are specifically relevant to the API.
 114          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 115          *                           'params' => array ( $someVarToSubst ) ),
 116          *                          );
 117          */
 118         private static $mRights = array(
 119                 'writeapi' => array(
 120                         'msg' => 'Use of the write API',
 121                         'params' => array()
 122                 ),
 123                 'apihighlimits' => array(
 124                         '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.',
 125                         'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
 126                 )
 127         );
 128
 129         /**
 130          * @var ApiFormatBase
 131          */
 132         private $mPrinter;
 133
 134         private $mModules, $mModuleNames, $mFormats, $mFormatNames;
 135         private $mResult, $mAction, $mShowVersions, $mEnableWrite;
 136         private $mInternalMode, $mSquidMaxage, $mModule;
 137
 138         private $mCacheMode = 'private';
 139         private $mCacheControl = array();
 140         private $mParamsUsed = array();
 141
 142         /**
 143          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 144          *
 145          * @param $context IContextSource|WebRequest - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 146          * @param $enableWrite bool should be set to true if the api may modify data
 147          */
 148         public function __construct( $context = null, $enableWrite = false ) {
 149                 if ( $context === null ) {
 150                         $context = RequestContext::getMain();
 151                 } elseif ( $context instanceof WebRequest ) {
 152                         // BC for pre-1.19
 153                         $request = $context;
 154                         $context = RequestContext::getMain();
 155                 }
 156                 // We set a derivative context so we can change stuff later
 157                 $this->setContext( new DerivativeContext( $context ) );
 158
 159                 if ( isset( $request ) ) {
 160                         $this->getContext()->setRequest( $request );
 161                 }
 162
 163                 $this->mInternalMode = ( $this->getRequest() instanceof FauxRequest );
 164
 165                 // Special handling for the main module: $parent === $this
 166                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 167
 168                 if ( !$this->mInternalMode ) {
 169                         // Impose module restrictions.
 170                         // If the current user cannot read,
 171                         // Remove all modules other than login
 172                         global $wgUser;
 173
 174                         if ( $this->getVal( 'callback' ) !== null ) {
 175                                 // JSON callback allows cross-site reads.
 176                                 // For safety, strip user credentials.
 177                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 178                                 $wgUser = new User();
 179                                 $this->getContext()->setUser( $wgUser );
 180                         }
 181                 }
 182
 183                 global $wgAPIModules; // extension modules
 184                 $this->mModules = $wgAPIModules + self::$Modules;
 185
 186                 $this->mModuleNames = array_keys( $this->mModules );
 187                 $this->mFormats = self::$Formats;
 188                 $this->mFormatNames = array_keys( $this->mFormats );
 189
 190                 $this->mResult = new ApiResult( $this );
 191                 $this->mShowVersions = false;
 192                 $this->mEnableWrite = $enableWrite;
 193
 194                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 195                 $this->mCommit = false;
 196         }
 197
 198         /**
 199          * Return true if the API was started by other PHP code using FauxRequest
 200          * @return bool
 201          */
 202         public function isInternalMode() {
 203                 return $this->mInternalMode;
 204         }
 205
 206         /**
 207          * Get the ApiResult object associated with current request
 208          *
 209          * @return ApiResult
 210          */
 211         public function getResult() {
 212                 return $this->mResult;
 213         }
 214
 215         /**
 216          * Get the API module object. Only works after executeAction()
 217          *
 218          * @return ApiBase
 219          */
 220         public function getModule() {
 221                 return $this->mModule;
 222         }
 223
 224         /**
 225          * Get the result formatter object. Only works after setupExecuteAction()
 226          *
 227          * @return ApiFormatBase
 228          */
 229         public function getPrinter() {
 230                 return $this->mPrinter;
 231         }
 232
 233         /**
 234          * Set how long the response should be cached.
 235          *
 236          * @param $maxage
 237          */
 238         public function setCacheMaxAge( $maxage ) {
 239                 $this->setCacheControl( array(
 240                         'max-age' => $maxage,
 241                         's-maxage' => $maxage
 242                 ) );
 243         }
 244
 245         /**
 246          * Set the type of caching headers which will be sent.
 247          *
 248          * @param $mode String One of:
 249          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 250          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 251          *         not provided by any of these means, the object will be private.
 252          *    - 'private':    Cache this object only in private client-side caches.
 253          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 254          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 255          *         set consistently for a given URL, it cannot be set differently depending on
 256          *         things like the contents of the database, or whether the user is logged in.
 257          *
 258          *  If the wiki does not allow anonymous users to read it, the mode set here
 259          *  will be ignored, and private caching headers will always be sent. In other words,
 260          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 261          *  view.
 262          *
 263          *  For user-dependent data, the private mode should generally be used. The
 264          *  anon-public-user-private mode should only be used where there is a particularly
 265          *  good performance reason for caching the anonymous response, but where the
 266          *  response to logged-in users may differ, or may contain private data.
 267          *
 268          *  If this function is never called, then the default will be the private mode.
 269          */
 270         public function setCacheMode( $mode ) {
 271                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 272                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 273                         // Ignore for forwards-compatibility
 274                         return;
 275                 }
 276
 277                 if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 278                         // Private wiki, only private headers
 279                         if ( $mode !== 'private' ) {
 280                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 281                                 return;
 282                         }
 283                 }
 284
 285                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 286                 $this->mCacheMode = $mode;
 287         }
 288
 289         /**
 290          * @deprecated since 1.17 Private caching is now the default, so there is usually no
 291          * need to call this function. If there is a need, you can use
 292          * $this->setCacheMode('private')
 293          */
 294         public function setCachePrivate() {
 295                 wfDeprecated( __METHOD__, '1.17' );
 296                 $this->setCacheMode( 'private' );
 297         }
 298
 299         /**
 300          * Set directives (key/value pairs) for the Cache-Control header.
 301          * Boolean values will be formatted as such, by including or omitting
 302          * without an equals sign.
 303          *
 304          * Cache control values set here will only be used if the cache mode is not
 305          * private, see setCacheMode().
 306          *
 307          * @param $directives array
 308          */
 309         public function setCacheControl( $directives ) {
 310                 $this->mCacheControl = $directives + $this->mCacheControl;
 311         }
 312
 313         /**
 314          * Make sure Vary: Cookie and friends are set. Use this when the output of a request
 315          * may be cached for anons but may not be cached for logged-in users.
 316          *
 317          * WARNING: This function must be called CONSISTENTLY for a given URL. This means that a
 318          * given URL must either always or never call this function; if it sometimes does and
 319          * sometimes doesn't, stuff will break.
 320          *
 321          * @deprecated since 1.17 Use setCacheMode( 'anon-public-user-private' )
 322          */
 323         public function setVaryCookie() {
 324                 wfDeprecated( __METHOD__, '1.17' );
 325                 $this->setCacheMode( 'anon-public-user-private' );
 326         }
 327
 328         /**
 329          * Create an instance of an output formatter by its name
 330          *
 331          * @param $format string
 332          *
 333          * @return ApiFormatBase
 334          */
 335         public function createPrinterByName( $format ) {
 336                 if ( !isset( $this->mFormats[$format] ) ) {
 337                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 338                 }
 339                 return new $this->mFormats[$format] ( $this, $format );
 340         }
 341
 342         /**
 343          * Execute api request. Any errors will be handled if the API was called by the remote client.
 344          */
 345         public function execute() {
 346                 $this->profileIn();
 347                 if ( $this->mInternalMode ) {
 348                         $this->executeAction();
 349                 } else {
 350                         $this->executeActionWithErrorHandling();
 351                 }
 352
 353                 $this->profileOut();
 354         }
 355
 356         /**
 357          * Execute an action, and in case of an error, erase whatever partial results
 358          * have been accumulated, and replace it with an error message and a help screen.
 359          */
 360         protected function executeActionWithErrorHandling() {
 361                 // Verify the CORS header before executing the action
 362                 if ( !$this->handleCORS() ) {
 363                         // handleCORS() has sent a 403, abort
 364                         return;
 365                 }
 366
 367                 // In case an error occurs during data output,
 368                 // clear the output buffer and print just the error information
 369                 ob_start();
 370
 371                 $t = microtime( true );
 372                 try {
 373                         $this->executeAction();
 374                 } catch ( Exception $e ) {
 375                         // Allow extra cleanup and logging
 376                         wfRunHooks( 'ApiMain::onException', array( $this, $e ) );
 377
 378                         // Log it
 379                         if ( $e instanceof MWException && !( $e instanceof UsageException ) ) {
 380                                 global $wgLogExceptionBacktrace;
 381                                 if ( $wgLogExceptionBacktrace ) {
 382                                         wfDebugLog( 'exception', $e->getLogMessage() . "\n" . $e->getTraceAsString() . "\n" );
 383                                 } else {
 384                                         wfDebugLog( 'exception', $e->getLogMessage() );
 385                                 }
 386                         }
 387
 388                         // Handle any kind of exception by outputing properly formatted error message.
 389                         // If this fails, an unhandled exception should be thrown so that global error
 390                         // handler will process and log it.
 391
 392                         $errCode = $this->substituteResultWithError( $e );
 393
 394                         // Error results should not be cached
 395                         $this->setCacheMode( 'private' );
 396
 397                         $response = $this->getRequest()->response();
 398                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 399                         if ( $e->getCode() === 0 ) {
 400                                 $response->header( $headerStr );
 401                         } else {
 402                                 $response->header( $headerStr, true, $e->getCode() );
 403                         }
 404
 405                         // Reset and print just the error message
 406                         ob_clean();
 407
 408                         // If the error occurred during printing, do a printer->profileOut()
 409                         $this->mPrinter->safeProfileOut();
 410                         $this->printResult( true );
 411                 }
 412
 413                 // Log the request whether or not there was an error
 414                 $this->logRequest( microtime( true ) - $t);
 415
 416                 // Send cache headers after any code which might generate an error, to
 417                 // avoid sending public cache headers for errors.
 418                 $this->sendCacheHeaders();
 419
 420                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 421                         echo wfReportTime();
 422                 }
 423
 424                 ob_end_flush();
 425         }
 426
 427         /**
 428          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 429          *
 430          * If no origin parameter is present, nothing happens.
 431          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 432          * is set and false is returned.
 433          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 434          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 435          * headers are set.
 436          *
 437          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 438          */
 439         protected function handleCORS() {
 440                 global $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions;
 441
 442                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 443                 if ( $originParam === null ) {
 444                         // No origin parameter, nothing to do
 445                         return true;
 446                 }
 447
 448                 $request = $this->getRequest();
 449                 $response = $request->response();
 450                 // Origin: header is a space-separated list of origins, check all of them
 451                 $originHeader = $request->getHeader( 'Origin' );
 452                 if ( $originHeader === false ) {
 453                         $origins = array();
 454                 } else {
 455                         $origins = explode( ' ', $originHeader );
 456                 }
 457                 if ( !in_array( $originParam, $origins ) ) {
 458                         // origin parameter set but incorrect
 459                         // Send a 403 response
 460                         $message = HttpStatus::getMessage( 403 );
 461                         $response->header( "HTTP/1.1 403 $message", true, 403 );
 462                         $response->header( 'Cache-Control: no-cache' );
 463                         echo "'origin' parameter does not match Origin header\n";
 464                         return false;
 465                 }
 466                 if ( self::matchOrigin( $originParam, $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions ) ) {
 467                         $response->header( "Access-Control-Allow-Origin: $originParam" );
 468                         $response->header( 'Access-Control-Allow-Credentials: true' );
 469                         $this->getOutput()->addVaryHeader( 'Origin' );
 470                 }
 471                 return true;
 472         }
 473
 474         /**
 475          * Attempt to match an Origin header against a set of rules and a set of exceptions
 476          * @param $value string Origin header
 477          * @param $rules array Set of wildcard rules
 478          * @param $exceptions array Set of wildcard rules
 479          * @return bool True if $value matches a rule in $rules and doesn't match any rules in $exceptions, false otherwise
 480          */
 481         protected static function matchOrigin( $value, $rules, $exceptions ) {
 482                 foreach ( $rules as $rule ) {
 483                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 484                                 // Rule matches, check exceptions
 485                                 foreach ( $exceptions as $exc ) {
 486                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 487                                                 return false;
 488                                         }
 489                                 }
 490                                 return true;
 491                         }
 492                 }
 493                 return false;
 494         }
 495
 496         /**
 497          * Helper function to convert wildcard string into a regex
 498          * '*' => '.*?'
 499          * '?' => '.'
 500          *
 501          * @param $wildcard string String with wildcards
 502          * @return string Regular expression
 503          */
 504         protected static function wildcardToRegex( $wildcard ) {
 505                 $wildcard = preg_quote( $wildcard, '/' );
 506                 $wildcard = str_replace(
 507                         array( '\*', '\?' ),
 508                         array( '.*?', '.' ),
 509                         $wildcard
 510                 );
 511                 return "/https?:\/\/$wildcard/";
 512         }
 513
 514         protected function sendCacheHeaders() {
 515                 global $wgUseXVO, $wgVaryOnXFP;
 516                 $response = $this->getRequest()->response();
 517                 $out = $this->getOutput();
 518
 519                 if ( $wgVaryOnXFP ) {
 520                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 521                 }
 522
 523                 if ( $this->mCacheMode == 'private' ) {
 524                         $response->header( 'Cache-Control: private' );
 525                         return;
 526                 }
 527
 528                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 529                         $out->addVaryHeader( 'Cookie' );
 530                         $response->header( $out->getVaryHeader() );
 531                         if ( $wgUseXVO ) {
 532                                 $response->header( $out->getXVO() );
 533                                 if ( $out->haveCacheVaryCookies() ) {
 534                                         // Logged in, mark this request private
 535                                         $response->header( 'Cache-Control: private' );
 536                                         return;
 537                                 }
 538                                 // Logged out, send normal public headers below
 539                         } elseif ( session_id() != '' ) {
 540                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 541                                 // Mark request private
 542                                 $response->header( 'Cache-Control: private' );
 543                                 return;
 544                         } // else no XVO and anonymous, send public headers below
 545                 }
 546
 547                 // Send public headers
 548                 $response->header( $out->getVaryHeader() );
 549                 if ( $wgUseXVO ) {
 550                         $response->header( $out->getXVO() );
 551                 }
 552
 553                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 554                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 555                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 556                 }
 557                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 558                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 559                 }
 560
 561                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 562                         // Public cache not requested
 563                         // Sending a Vary header in this case is harmless, and protects us
 564                         // against conditional calls of setCacheMaxAge().
 565                         $response->header( 'Cache-Control: private' );
 566                         return;
 567                 }
 568
 569                 $this->mCacheControl['public'] = true;
 570
 571                 // Send an Expires header
 572                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 573                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 574                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 575
 576                 // Construct the Cache-Control header
 577                 $ccHeader = '';
 578                 $separator = '';
 579                 foreach ( $this->mCacheControl as $name => $value ) {
 580                         if ( is_bool( $value ) ) {
 581                                 if ( $value ) {
 582                                         $ccHeader .= $separator . $name;
 583                                         $separator = ', ';
 584                                 }
 585                         } else {
 586                                 $ccHeader .= $separator . "$name=$value";
 587                                 $separator = ', ';
 588                         }
 589                 }
 590
 591                 $response->header( "Cache-Control: $ccHeader" );
 592         }
 593
 594         /**
 595          * Replace the result data with the information about an exception.
 596          * Returns the error code
 597          * @param $e Exception
 598          * @return string
 599          */
 600         protected function substituteResultWithError( $e ) {
 601                 global $wgShowHostnames;
 602
 603                 $result = $this->getResult();
 604                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 605                 if ( !isset ( $this->mPrinter ) ) {
 606                         // The printer has not been created yet. Try to manually get formatter value.
 607                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 608                         if ( !in_array( $value, $this->mFormatNames ) ) {
 609                                 $value = self::API_DEFAULT_FORMAT;
 610                         }
 611
 612                         $this->mPrinter = $this->createPrinterByName( $value );
 613                         if ( $this->mPrinter->getNeedsRawData() ) {
 614                                 $result->setRawMode();
 615                         }
 616                 }
 617
 618                 if ( $e instanceof UsageException ) {
 619                         // User entered incorrect parameters - print usage screen
 620                         $errMessage = $e->getMessageArray();
 621
 622                         // Only print the help message when this is for the developer, not runtime
 623                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 624                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 625                         }
 626
 627                 } else {
 628                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 629                         // Something is seriously wrong
 630                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 631                                 $info = 'Database query error';
 632                         } else {
 633                                 $info = "Exception Caught: {$e->getMessage()}";
 634                         }
 635
 636                         $errMessage = array(
 637                                 'code' => 'internal_api_error_' . get_class( $e ),
 638                                 'info' => $info,
 639                         );
 640                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 641                 }
 642
 643                 $result->reset();
 644                 $result->disableSizeCheck();
 645                 // Re-add the id
 646                 $requestid = $this->getParameter( 'requestid' );
 647                 if ( !is_null( $requestid ) ) {
 648                         $result->addValue( null, 'requestid', $requestid );
 649                 }
 650
 651                 if ( $wgShowHostnames ) {
 652                         // servedby is especially useful when debugging errors
 653                         $result->addValue( null, 'servedby', wfHostName() );
 654                 }
 655
 656                 $result->addValue( null, 'error', $errMessage );
 657
 658                 return $errMessage['code'];
 659         }
 660
 661         /**
 662          * Set up for the execution.
 663          * @return array
 664          */
 665         protected function setupExecuteAction() {
 666                 global $wgShowHostnames;
 667
 668                 // First add the id to the top element
 669                 $result = $this->getResult();
 670                 $requestid = $this->getParameter( 'requestid' );
 671                 if ( !is_null( $requestid ) ) {
 672                         $result->addValue( null, 'requestid', $requestid );
 673                 }
 674
 675                 if ( $wgShowHostnames ) {
 676                         $servedby = $this->getParameter( 'servedby' );
 677                         if ( $servedby ) {
 678                                 $result->addValue( null, 'servedby', wfHostName() );
 679                         }
 680                 }
 681
 682                 $params = $this->extractRequestParams();
 683
 684                 $this->mShowVersions = $params['version'];
 685                 $this->mAction = $params['action'];
 686
 687                 if ( !is_string( $this->mAction ) ) {
 688                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 689                 }
 690
 691                 return $params;
 692         }
 693
 694         /**
 695          * Set up the module for response
 696          * @return ApiBase The module that will handle this action
 697          */
 698         protected function setupModule() {
 699                 // Instantiate the module requested by the user
 700                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 701                 $this->mModule = $module;
 702
 703                 $moduleParams = $module->extractRequestParams();
 704
 705                 // Die if token required, but not provided (unless there is a gettoken parameter)
 706                 if ( isset( $moduleParams['gettoken'] ) ) {
 707                         $gettoken = $moduleParams['gettoken'];
 708                 } else {
 709                         $gettoken = false;
 710                 }
 711
 712                 $salt = $module->getTokenSalt();
 713                 if ( $salt !== false && !$gettoken ) {
 714                         if ( !isset( $moduleParams['token'] ) ) {
 715                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 716                         } else {
 717                                 if ( !$this->getUser()->matchEditToken( $moduleParams['token'], $salt, $this->getContext()->getRequest() ) ) {
 718                                         $this->dieUsageMsg( 'sessionfailure' );
 719                                 }
 720                         }
 721                 }
 722                 return $module;
 723         }
 724
 725         /**
 726          * Check the max lag if necessary
 727          * @param $module ApiBase object: Api module being used
 728          * @param $params Array an array containing the request parameters.
 729          * @return boolean True on success, false should exit immediately
 730          */
 731         protected function checkMaxLag( $module, $params ) {
 732                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 733                         // Check for maxlag
 734                         global $wgShowHostnames;
 735                         $maxLag = $params['maxlag'];
 736                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 737                         if ( $lag > $maxLag ) {
 738                                 $response = $this->getRequest()->response();
 739
 740                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 741                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 742
 743                                 if ( $wgShowHostnames ) {
 744                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 745                                 } else {
 746                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 747                                 }
 748                                 return false;
 749                         }
 750                 }
 751                 return true;
 752         }
 753
 754         /**
 755          * Check for sufficient permissions to execute
 756          * @param $module ApiBase An Api module
 757          */
 758         protected function checkExecutePermissions( $module ) {
 759                 $user = $this->getUser();
 760                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 761                         !$user->isAllowed( 'read' ) )
 762                 {
 763                         $this->dieUsageMsg( 'readrequired' );
 764                 }
 765                 if ( $module->isWriteMode() ) {
 766                         if ( !$this->mEnableWrite ) {
 767                                 $this->dieUsageMsg( 'writedisabled' );
 768                         }
 769                         if ( !$user->isAllowed( 'writeapi' ) ) {
 770                                 $this->dieUsageMsg( 'writerequired' );
 771                         }
 772                         if ( wfReadOnly() ) {
 773                                 $this->dieReadOnly();
 774                         }
 775                 }
 776
 777                 // Allow extensions to stop execution for arbitrary reasons.
 778                 $message = false;
 779                 if( !wfRunHooks( 'ApiCheckCanExecute', array( $module, $user, &$message ) ) ) {
 780                         $this->dieUsageMsg( $message );
 781                 }
 782         }
 783
 784         /**
 785          * Check POST for external response and setup result printer
 786          * @param $module ApiBase An Api module
 787          * @param $params Array an array with the request parameters
 788          */
 789         protected function setupExternalResponse( $module, $params ) {
 790                 // Ignore mustBePosted() for internal calls
 791                 if ( $module->mustBePosted() && !$this->getRequest()->wasPosted() ) {
 792                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 793                 }
 794
 795                 // See if custom printer is used
 796                 $this->mPrinter = $module->getCustomPrinter();
 797                 if ( is_null( $this->mPrinter ) ) {
 798                         // Create an appropriate printer
 799                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 800                 }
 801
 802                 if ( $this->mPrinter->getNeedsRawData() ) {
 803                         $this->getResult()->setRawMode();
 804                 }
 805         }
 806
 807         /**
 808          * Execute the actual module, without any error handling
 809          */
 810         protected function executeAction() {
 811                 $params = $this->setupExecuteAction();
 812                 $module = $this->setupModule();
 813
 814                 $this->checkExecutePermissions( $module );
 815
 816                 if ( !$this->checkMaxLag( $module, $params ) ) {
 817                         return;
 818                 }
 819
 820                 if ( !$this->mInternalMode ) {
 821                         $this->setupExternalResponse( $module, $params );
 822                 }
 823
 824                 // Execute
 825                 $module->profileIn();
 826                 $module->execute();
 827                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 828                 $module->profileOut();
 829
 830                 if ( !$this->mInternalMode ) {
 831                         // Report unused params
 832                         $this->reportUnusedParams();
 833
 834                         //append Debug information
 835                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
 836
 837                         // Print result data
 838                         $this->printResult( false );
 839                 }
 840         }
 841
 842         /**
 843          * Log the preceding request
 844          * @param $time Time in seconds
 845          */
 846         protected function logRequest( $time ) {
 847                 $request = $this->getRequest();
 848                 $milliseconds = $time === null ? '?' : round( $time * 1000 );
 849                 $s = 'API' .
 850                         ' ' . $request->getMethod() .
 851                         ' ' . wfUrlencode( str_replace( ' ', '_', $this->getUser()->getName() ) ) .
 852                         ' ' . $request->getIP() .
 853                         ' T=' . $milliseconds .'ms';
 854                 foreach ( $this->getParamsUsed() as $name ) {
 855                         $value = $request->getVal( $name );
 856                         if ( $value === null ) {
 857                                 continue;
 858                         }
 859                         $s .= ' ' . $name . '=';
 860                         if ( strlen( $value ) > 256 ) {
 861                                 $encValue = $this->encodeRequestLogValue( substr( $value, 0, 256 ) );
 862                                 $s .= $encValue . '[...]';
 863                         } else {
 864                                 $s .= $this->encodeRequestLogValue( $value );
 865                         }
 866                 }
 867                 $s .= "\n";
 868                 wfDebugLog( 'api', $s, false );
 869         }
 870
 871         /**
 872          * Encode a value in a format suitable for a space-separated log line.
 873          */
 874         protected function encodeRequestLogValue( $s ) {
 875                 static $table;
 876                 if ( !$table ) {
 877                         $chars = ';@$!*(),/:';
 878                         for ( $i = 0; $i < strlen( $chars ); $i++ ) {
 879                                 $table[rawurlencode( $chars[$i] )] = $chars[$i];
 880                         }
 881                 }
 882                 return strtr( rawurlencode( $s ), $table );
 883         }
 884
 885         /**
 886          * Get the request parameters used in the course of the preceding execute() request
 887          */
 888         protected function getParamsUsed() {
 889                 return array_keys( $this->mParamsUsed );
 890         }
 891
 892         /**
 893          * Get a request value, and register the fact that it was used, for logging.
 894          */
 895         public function getVal( $name, $default = null ) {
 896                 $this->mParamsUsed[$name] = true;
 897                 return $this->getRequest()->getVal( $name, $default );
 898         }
 899
 900         /**
 901          * Get a boolean request value, and register the fact that the parameter
 902          * was used, for logging.
 903          */
 904         public function getCheck( $name ) {
 905                 $this->mParamsUsed[$name] = true;
 906                 return $this->getRequest()->getCheck( $name );
 907         }
 908
 909         /**
 910          * Report unused parameters, so the client gets a hint in case it gave us parameters we don't know,
 911          * for example in case of spelling mistakes or a missing 'g' prefix for generators.
 912          */
 913         protected function reportUnusedParams() {
 914                 $paramsUsed = $this->getParamsUsed();
 915                 $allParams = $this->getRequest()->getValueNames();
 916
 917                 $unusedParams = array_diff( $allParams, $paramsUsed );
 918                 if( count( $unusedParams ) ) {
 919                         $s = count( $unusedParams ) > 1 ? 's' : '';
 920                         $this->setWarning( "Unrecognized parameter$s: '" . implode( $unusedParams, "', '" ) . "'" );
 921                 }
 922         }
 923
 924         /**
 925          * Print results using the current printer
 926          *
 927          * @param $isError bool
 928          */
 929         protected function printResult( $isError ) {
 930                 $this->getResult()->cleanUpUTF8();
 931                 $printer = $this->mPrinter;
 932                 $printer->profileIn();
 933
 934                 /**
 935                  * If the help message is requested in the default (xmlfm) format,
 936                  * tell the printer not to escape ampersands so that our links do
 937                  * not break.
 938                  */
 939                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 940                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 941
 942                 $printer->initPrinter( $isError );
 943
 944                 $printer->execute();
 945                 $printer->closePrinter();
 946                 $printer->profileOut();
 947         }
 948
 949         /**
 950          * @return bool
 951          */
 952         public function isReadMode() {
 953                 return false;
 954         }
 955
 956         /**
 957          * See ApiBase for description.
 958          *
 959          * @return array
 960          */
 961         public function getAllowedParams() {
 962                 return array(
 963                         'format' => array(
 964                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 965                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 966                         ),
 967                         'action' => array(
 968                                 ApiBase::PARAM_DFLT => 'help',
 969                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 970                         ),
 971                         'version' => false,
 972                         'maxlag'  => array(
 973                                 ApiBase::PARAM_TYPE => 'integer'
 974                         ),
 975                         'smaxage' => array(
 976                                 ApiBase::PARAM_TYPE => 'integer',
 977                                 ApiBase::PARAM_DFLT => 0
 978                         ),
 979                         'maxage' => array(
 980                                 ApiBase::PARAM_TYPE => 'integer',
 981                                 ApiBase::PARAM_DFLT => 0
 982                         ),
 983                         'requestid' => null,
 984                         'servedby'  => false,
 985                         'origin' => null,
 986                 );
 987         }
 988
 989         /**
 990          * See ApiBase for description.
 991          *
 992          * @return array
 993          */
 994         public function getParamDescription() {
 995                 return array(
 996                         'format' => 'The format of the output',
 997                         'action' => 'What action you would like to perform. See below for module help',
 998                         'version' => 'When showing help, include version for each module',
 999                         'maxlag' => array(
1000                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
1001                                 'To save actions causing any more site replication lag, this parameter can make the client',
1002                                 'wait until the replication lag is less than the specified value.',
1003                                 'In case of a replag error, error code "maxlag" is returned, with the message like',
1004                                 '"Waiting for $host: $lag seconds lagged\n".',
1005                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
1006                         ),
1007                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
1008                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
1009                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
1010                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
1011                         'origin' => array(
1012                                 'When accessing the API using a cross-domain AJAX request (CORS), set this to the originating domain.',
1013                                 'This must match one of the origins in the Origin: header exactly, so it has to be set to something like http://en.wikipedia.org or https://meta.wikimedia.org .',
1014                                 'If this parameter does not match the Origin: header, a 403 response will be returned.',
1015                                 'If this parameter matches the Origin: header and the origin is whitelisted, an Access-Control-Allow-Origin header will be set.',
1016                         ),
1017                 );
1018         }
1019
1020         /**
1021          * See ApiBase for description.
1022          *
1023          * @return array
1024          */
1025         public function getDescription() {
1026                 return array(
1027                         '',
1028                         '',
1029                         '**********************************************************************************************************',
1030                         '**                                                                                                      **',
1031                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
1032                         '**                                                                                                      **',
1033                         '**                                     Documentation and Examples:                                      **',
1034                         '**                                  https://www.mediawiki.org/wiki/API                                  **',
1035                         '**                                                                                                      **',
1036                         '**********************************************************************************************************',
1037                         '',
1038                         'Status:                All features shown on this page should be working, but the API',
1039                         '                       is still in active development, and may change at any time.',
1040                         '                       Make sure to monitor our mailing list for any updates',
1041                         '',
1042                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
1043                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
1044                         '                       header and the error code sent back will be set to the same value',
1045                         '',
1046                         '                       In the case of an invalid action being passed, these will have a value',
1047                         '                       of "unknown_action"',
1048                         '',
1049                         '                       For more information see https://www.mediawiki.org/wiki/API:Errors_and_warnings',
1050                         '',
1051                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
1052                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
1053                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
1054                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
1055                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
1056                         '',
1057                         '',
1058                         '',
1059                         '',
1060                         '',
1061                 );
1062         }
1063
1064         /**
1065          * @return array
1066          */
1067         public function getPossibleErrors() {
1068                 return array_merge( parent::getPossibleErrors(), array(
1069                         array( 'readonlytext' ),
1070                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
1071                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
1072                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
1073                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
1074                 ) );
1075         }
1076
1077         /**
1078          * Returns an array of strings with credits for the API
1079          * @return array
1080          */
1081         protected function getCredits() {
1082                 return array(
1083                         'API developers:',
1084                         '    Roan Kattouw "<Firstname>.<Lastname>@gmail.com" (lead developer Sep 2007-present)',
1085                         '    Victor Vasiliev - vasilvv at gee mail dot com',
1086                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
1087                         '    Sam Reed - sam @ reedyboy . net',
1088                         '    Yuri Astrakhan "<Firstname><Lastname>@gmail.com" (creator, lead developer Sep 2006-Sep 2007)',
1089                         '',
1090                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
1091                         'or file a bug report at https://bugzilla.wikimedia.org/'
1092                 );
1093         }
1094
1095         /**
1096          * Sets whether the pretty-printer should format *bold* and $italics$
1097          *
1098          * @param $help bool
1099          */
1100         public function setHelp( $help = true ) {
1101                 $this->mPrinter->setHelp( $help );
1102         }
1103
1104         /**
1105          * Override the parent to generate help messages for all available modules.
1106          *
1107          * @return string
1108          */
1109         public function makeHelpMsg() {
1110                 global $wgMemc, $wgAPICacheHelpTimeout;
1111                 $this->setHelp();
1112                 // Get help text from cache if present
1113                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
1114                         SpecialVersion::getVersion( 'nodb' ) .
1115                         $this->getShowVersions() );
1116                 if ( $wgAPICacheHelpTimeout > 0 ) {
1117                         $cached = $wgMemc->get( $key );
1118                         if ( $cached ) {
1119                                 return $cached;
1120                         }
1121                 }
1122                 $retval = $this->reallyMakeHelpMsg();
1123                 if ( $wgAPICacheHelpTimeout > 0 ) {
1124                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
1125                 }
1126                 return $retval;
1127         }
1128
1129         /**
1130          * @return mixed|string
1131          */
1132         public function reallyMakeHelpMsg() {
1133                 $this->setHelp();
1134
1135                 // Use parent to make default message for the main module
1136                 $msg = parent::makeHelpMsg();
1137
1138                 $astriks = str_repeat( '*** ', 14 );
1139                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
1140                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
1141                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
1142                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1143
1144                         $msg2 = $module->makeHelpMsg();
1145                         if ( $msg2 !== false ) {
1146                                 $msg .= $msg2;
1147                         }
1148                         $msg .= "\n";
1149                 }
1150
1151                 $msg .= "\n$astriks Permissions $astriks\n\n";
1152                 foreach ( self::$mRights as $right => $rightMsg ) {
1153                         $groups = User::getGroupsWithPermission( $right );
1154                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg['msg'], $rightMsg['params'] ) .
1155                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1156                 }
1157
1158                 $msg .= "\n$astriks Formats  $astriks\n\n";
1159                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
1160                         $module = $this->createPrinterByName( $formatName );
1161                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1162                         $msg2 = $module->makeHelpMsg();
1163                         if ( $msg2 !== false ) {
1164                                 $msg .= $msg2;
1165                         }
1166                         $msg .= "\n";
1167                 }
1168
1169                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
1170
1171                 return $msg;
1172         }
1173
1174         /**
1175          * @param $module ApiBase
1176          * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
1177          * @return string
1178          */
1179         public static function makeHelpMsgHeader( $module, $paramName ) {
1180                 $modulePrefix = $module->getModulePrefix();
1181                 if ( strval( $modulePrefix ) !== '' ) {
1182                         $modulePrefix = "($modulePrefix) ";
1183                 }
1184
1185                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1186         }
1187
1188         private $mCanApiHighLimits = null;
1189
1190         /**
1191          * Check whether the current user is allowed to use high limits
1192          * @return bool
1193          */
1194         public function canApiHighLimits() {
1195                 if ( !isset( $this->mCanApiHighLimits ) ) {
1196                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1197                 }
1198
1199                 return $this->mCanApiHighLimits;
1200         }
1201
1202         /**
1203          * Check whether the user wants us to show version information in the API help
1204          * @return bool
1205          */
1206         public function getShowVersions() {
1207                 return $this->mShowVersions;
1208         }
1209
1210         /**
1211          * Returns the version information of this file, plus it includes
1212          * the versions for all files that are not callable proper API modules
1213          *
1214          * @return array
1215          */
1216         public function getVersion() {
1217                 $vers = array();
1218                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    https://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
1219                 $vers[] = __CLASS__ . ': $Id$';
1220                 $vers[] = ApiBase::getBaseVersion();
1221                 $vers[] = ApiFormatBase::getBaseVersion();
1222                 $vers[] = ApiQueryBase::getBaseVersion();
1223                 return $vers;
1224         }
1225
1226         /**
1227          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1228          * classes who wish to add their own modules to their lexicon or override the
1229          * behavior of inherent ones.
1230          *
1231          * @param $mdlName String The identifier for this module.
1232          * @param $mdlClass String The class where this module is implemented.
1233          */
1234         protected function addModule( $mdlName, $mdlClass ) {
1235                 $this->mModules[$mdlName] = $mdlClass;
1236         }
1237
1238         /**
1239          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1240          * classes who wish to add to or modify current formatters.
1241          *
1242          * @param $fmtName string The identifier for this format.
1243          * @param $fmtClass ApiFormatBase The class implementing this format.
1244          */
1245         protected function addFormat( $fmtName, $fmtClass ) {
1246                 $this->mFormats[$fmtName] = $fmtClass;
1247         }
1248
1249         /**
1250          * Get the array mapping module names to class names
1251          * @return array
1252          */
1253         function getModules() {
1254                 return $this->mModules;
1255         }
1256
1257         /**
1258          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1259          *
1260          * @since 1.18
1261          * @return array
1262          */
1263         public function getFormats() {
1264                 return $this->mFormats;
1265         }
1266 }
1267
1268 /**
1269  * This exception will be thrown when dieUsage is called to stop module execution.
1270  * The exception handling code will print a help screen explaining how this API may be used.
1271  *
1272  * @ingroup API
1273  */
1274 class UsageException extends MWException {
1275
1276         private $mCodestr;
1277
1278         /**
1279          * @var null|array
1280          */
1281         private $mExtraData;
1282
1283         /**
1284          * @param $message string
1285          * @param $codestr string
1286          * @param $code int
1287          * @param $extradata array|null
1288          */
1289         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1290                 parent::__construct( $message, $code );
1291                 $this->mCodestr = $codestr;
1292                 $this->mExtraData = $extradata;
1293         }
1294
1295         /**
1296          * @return string
1297          */
1298         public function getCodeString() {
1299                 return $this->mCodestr;
1300         }
1301
1302         /**
1303          * @return array
1304          */
1305         public function getMessageArray() {
1306                 $result = array(
1307                         'code' => $this->mCodestr,
1308                         'info' => $this->getMessage()
1309                 );
1310                 if ( is_array( $this->mExtraData ) ) {
1311                         $result = array_merge( $result, $this->mExtraData );
1312                 }
1313                 return $result;
1314         }
1315
1316         /**
1317          * @return string
1318          */
1319         public function __toString() {
1320                 return "{$this->getCodeString()}: {$this->getMessage()}";
1321         }
1322 }