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                 'query' => 'ApiQuery',
  55                 'expandtemplates' => 'ApiExpandTemplates',
  56                 'parse' => 'ApiParse',
  57                 'opensearch' => 'ApiOpenSearch',
  58                 'feedcontributions' => 'ApiFeedContributions',
  59                 'feedwatchlist' => 'ApiFeedWatchlist',
  60                 'help' => 'ApiHelp',
  61                 'paraminfo' => 'ApiParamInfo',
  62                 'rsd' => 'ApiRsd',
  63                 'compare' => 'ApiComparePages',
  64                 'tokens' => 'ApiTokens',
  65
  66                 // Write modules
  67                 'purge' => 'ApiPurge',
  68                 'setnotificationtimestamp' => 'ApiSetNotificationTimestamp',
  69                 'rollback' => 'ApiRollback',
  70                 'delete' => 'ApiDelete',
  71                 'undelete' => 'ApiUndelete',
  72                 'protect' => 'ApiProtect',
  73                 'block' => 'ApiBlock',
  74                 'unblock' => 'ApiUnblock',
  75                 'move' => 'ApiMove',
  76                 'edit' => 'ApiEditPage',
  77                 'upload' => 'ApiUpload',
  78                 'filerevert' => 'ApiFileRevert',
  79                 'emailuser' => 'ApiEmailUser',
  80                 'watch' => 'ApiWatch',
  81                 'patrol' => 'ApiPatrol',
  82                 'import' => 'ApiImport',
  83                 'userrights' => 'ApiUserrights',
  84                 'options' => 'ApiOptions',
  85         );
  86
  87         /**
  88          * List of available formats: format name => format class
  89          */
  90         private static $Formats = array(
  91                 'json' => 'ApiFormatJson',
  92                 'jsonfm' => 'ApiFormatJson',
  93                 'php' => 'ApiFormatPhp',
  94                 'phpfm' => 'ApiFormatPhp',
  95                 'wddx' => 'ApiFormatWddx',
  96                 'wddxfm' => 'ApiFormatWddx',
  97                 'xml' => 'ApiFormatXml',
  98                 'xmlfm' => 'ApiFormatXml',
  99                 'yaml' => 'ApiFormatYaml',
 100                 'yamlfm' => 'ApiFormatYaml',
 101                 'rawfm' => 'ApiFormatJson',
 102                 'txt' => 'ApiFormatTxt',
 103                 'txtfm' => 'ApiFormatTxt',
 104                 'dbg' => 'ApiFormatDbg',
 105                 'dbgfm' => 'ApiFormatDbg',
 106                 'dump' => 'ApiFormatDump',
 107                 'dumpfm' => 'ApiFormatDump',
 108         );
 109
 110         /**
 111          * List of user roles that are specifically relevant to the API.
 112          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 113          *                           'params' => array ( $someVarToSubst ) ),
 114          *                          );
 115          */
 116         private static $mRights = array(
 117                 'writeapi' => array(
 118                         'msg' => 'Use of the write API',
 119                         'params' => array()
 120                 ),
 121                 'apihighlimits' => array(
 122                         '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.',
 123                         'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
 124                 )
 125         );
 126
 127         /**
 128          * @var ApiFormatBase
 129          */
 130         private $mPrinter;
 131
 132         private $mModules, $mModuleNames, $mFormats, $mFormatNames;
 133         private $mResult, $mAction, $mShowVersions, $mEnableWrite;
 134         private $mInternalMode, $mSquidMaxage, $mModule;
 135
 136         private $mCacheMode = 'private';
 137         private $mCacheControl = array();
 138
 139         /**
 140          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 141          *
 142          * @param $context IContextSource|WebRequest - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 143          * @param $enableWrite bool should be set to true if the api may modify data
 144          */
 145         public function __construct( $context = null, $enableWrite = false ) {
 146                 if ( $context === null ) {
 147                         $context = RequestContext::getMain();
 148                 } elseif ( $context instanceof WebRequest ) {
 149                         // BC for pre-1.19
 150                         $request = $context;
 151                         $context = RequestContext::getMain();
 152                 }
 153                 // We set a derivative context so we can change stuff later
 154                 $this->setContext( new DerivativeContext( $context ) );
 155
 156                 if ( isset( $request ) ) {
 157                         $this->getContext()->setRequest( $request );
 158                 }
 159
 160                 $this->mInternalMode = ( $this->getRequest() instanceof FauxRequest );
 161
 162                 // Special handling for the main module: $parent === $this
 163                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 164
 165                 if ( !$this->mInternalMode ) {
 166                         // Impose module restrictions.
 167                         // If the current user cannot read,
 168                         // Remove all modules other than login
 169                         global $wgUser;
 170
 171                         if ( $this->getRequest()->getVal( 'callback' ) !== null ) {
 172                                 // JSON callback allows cross-site reads.
 173                                 // For safety, strip user credentials.
 174                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 175                                 $wgUser = new User();
 176                                 $this->getContext()->setUser( $wgUser );
 177                         }
 178                 }
 179
 180                 global $wgAPIModules; // extension modules
 181                 $this->mModules = $wgAPIModules + self::$Modules;
 182
 183                 $this->mModuleNames = array_keys( $this->mModules );
 184                 $this->mFormats = self::$Formats;
 185                 $this->mFormatNames = array_keys( $this->mFormats );
 186
 187                 $this->mResult = new ApiResult( $this );
 188                 $this->mShowVersions = false;
 189                 $this->mEnableWrite = $enableWrite;
 190
 191                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 192                 $this->mCommit = false;
 193         }
 194
 195         /**
 196          * Return true if the API was started by other PHP code using FauxRequest
 197          * @return bool
 198          */
 199         public function isInternalMode() {
 200                 return $this->mInternalMode;
 201         }
 202
 203         /**
 204          * Get the ApiResult object associated with current request
 205          *
 206          * @return ApiResult
 207          */
 208         public function getResult() {
 209                 return $this->mResult;
 210         }
 211
 212         /**
 213          * Get the API module object. Only works after executeAction()
 214          *
 215          * @return ApiBase
 216          */
 217         public function getModule() {
 218                 return $this->mModule;
 219         }
 220
 221         /**
 222          * Get the result formatter object. Only works after setupExecuteAction()
 223          *
 224          * @return ApiFormatBase
 225          */
 226         public function getPrinter() {
 227                 return $this->mPrinter;
 228         }
 229
 230         /**
 231          * Set how long the response should be cached.
 232          *
 233          * @param $maxage
 234          */
 235         public function setCacheMaxAge( $maxage ) {
 236                 $this->setCacheControl( array(
 237                         'max-age' => $maxage,
 238                         's-maxage' => $maxage
 239                 ) );
 240         }
 241
 242         /**
 243          * Set the type of caching headers which will be sent.
 244          *
 245          * @param $mode String One of:
 246          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 247          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 248          *         not provided by any of these means, the object will be private.
 249          *    - 'private':    Cache this object only in private client-side caches.
 250          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 251          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 252          *         set consistently for a given URL, it cannot be set differently depending on
 253          *         things like the contents of the database, or whether the user is logged in.
 254          *
 255          *  If the wiki does not allow anonymous users to read it, the mode set here
 256          *  will be ignored, and private caching headers will always be sent. In other words,
 257          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 258          *  view.
 259          *
 260          *  For user-dependent data, the private mode should generally be used. The
 261          *  anon-public-user-private mode should only be used where there is a particularly
 262          *  good performance reason for caching the anonymous response, but where the
 263          *  response to logged-in users may differ, or may contain private data.
 264          *
 265          *  If this function is never called, then the default will be the private mode.
 266          */
 267         public function setCacheMode( $mode ) {
 268                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 269                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 270                         // Ignore for forwards-compatibility
 271                         return;
 272                 }
 273
 274                 if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 275                         // Private wiki, only private headers
 276                         if ( $mode !== 'private' ) {
 277                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 278                                 return;
 279                         }
 280                 }
 281
 282                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 283                 $this->mCacheMode = $mode;
 284         }
 285
 286         /**
 287          * @deprecated since 1.17 Private caching is now the default, so there is usually no
 288          * need to call this function. If there is a need, you can use
 289          * $this->setCacheMode('private')
 290          */
 291         public function setCachePrivate() {
 292                 wfDeprecated( __METHOD__, '1.17' );
 293                 $this->setCacheMode( 'private' );
 294         }
 295
 296         /**
 297          * Set directives (key/value pairs) for the Cache-Control header.
 298          * Boolean values will be formatted as such, by including or omitting
 299          * without an equals sign.
 300          *
 301          * Cache control values set here will only be used if the cache mode is not
 302          * private, see setCacheMode().
 303          *
 304          * @param $directives array
 305          */
 306         public function setCacheControl( $directives ) {
 307                 $this->mCacheControl = $directives + $this->mCacheControl;
 308         }
 309
 310         /**
 311          * Make sure Vary: Cookie and friends are set. Use this when the output of a request
 312          * may be cached for anons but may not be cached for logged-in users.
 313          *
 314          * WARNING: This function must be called CONSISTENTLY for a given URL. This means that a
 315          * given URL must either always or never call this function; if it sometimes does and
 316          * sometimes doesn't, stuff will break.
 317          *
 318          * @deprecated since 1.17 Use setCacheMode( 'anon-public-user-private' )
 319          */
 320         public function setVaryCookie() {
 321                 wfDeprecated( __METHOD__, '1.17' );
 322                 $this->setCacheMode( 'anon-public-user-private' );
 323         }
 324
 325         /**
 326          * Create an instance of an output formatter by its name
 327          *
 328          * @param $format string
 329          *
 330          * @return ApiFormatBase
 331          */
 332         public function createPrinterByName( $format ) {
 333                 if ( !isset( $this->mFormats[$format] ) ) {
 334                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 335                 }
 336                 return new $this->mFormats[$format] ( $this, $format );
 337         }
 338
 339         /**
 340          * Execute api request. Any errors will be handled if the API was called by the remote client.
 341          */
 342         public function execute() {
 343                 $this->profileIn();
 344                 if ( $this->mInternalMode ) {
 345                         $this->executeAction();
 346                 } else {
 347                         $this->executeActionWithErrorHandling();
 348                 }
 349
 350                 $this->profileOut();
 351         }
 352
 353         /**
 354          * Execute an action, and in case of an error, erase whatever partial results
 355          * have been accumulated, and replace it with an error message and a help screen.
 356          */
 357         protected function executeActionWithErrorHandling() {
 358                 // Verify the CORS header before executing the action
 359                 if ( !$this->handleCORS() ) {
 360                         // handleCORS() has sent a 403, abort
 361                         return;
 362                 }
 363
 364                 // In case an error occurs during data output,
 365                 // clear the output buffer and print just the error information
 366                 ob_start();
 367
 368                 try {
 369                         $this->executeAction();
 370                 } catch ( Exception $e ) {
 371                         // Log it
 372                         if ( !( $e instanceof UsageException ) ) {
 373                                 wfDebugLog( 'exception', $e->getLogMessage() );
 374                         }
 375
 376                         // Handle any kind of exception by outputing properly formatted error message.
 377                         // If this fails, an unhandled exception should be thrown so that global error
 378                         // handler will process and log it.
 379
 380                         $errCode = $this->substituteResultWithError( $e );
 381
 382                         // Error results should not be cached
 383                         $this->setCacheMode( 'private' );
 384
 385                         $response = $this->getRequest()->response();
 386                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 387                         if ( $e->getCode() === 0 ) {
 388                                 $response->header( $headerStr );
 389                         } else {
 390                                 $response->header( $headerStr, true, $e->getCode() );
 391                         }
 392
 393                         // Reset and print just the error message
 394                         ob_clean();
 395
 396                         // If the error occurred during printing, do a printer->profileOut()
 397                         $this->mPrinter->safeProfileOut();
 398                         $this->printResult( true );
 399                 }
 400
 401                 // Send cache headers after any code which might generate an error, to
 402                 // avoid sending public cache headers for errors.
 403                 $this->sendCacheHeaders();
 404
 405                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 406                         echo wfReportTime();
 407                 }
 408
 409                 ob_end_flush();
 410         }
 411
 412         /**
 413          * Check the &origin= query parameter against the Origin: HTTP header and respond appropriately.
 414          *
 415          * If no origin parameter is present, nothing happens.
 416          * If an origin parameter is present but doesn't match the Origin header, a 403 status code
 417          * is set and false is returned.
 418          * If the parameter and the header do match, the header is checked against $wgCrossSiteAJAXdomains
 419          * and $wgCrossSiteAJAXdomainExceptions, and if the origin qualifies, the appropriate CORS
 420          * headers are set.
 421          *
 422          * @return bool False if the caller should abort (403 case), true otherwise (all other cases)
 423          */
 424         protected function handleCORS() {
 425                 global $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions;
 426
 427                 $originParam = $this->getParameter( 'origin' ); // defaults to null
 428                 if ( $originParam === null ) {
 429                         // No origin parameter, nothing to do
 430                         return true;
 431                 }
 432
 433                 $request = $this->getRequest();
 434                 $response = $request->response();
 435                 // Origin: header is a space-separated list of origins, check all of them
 436                 $originHeader = $request->getHeader( 'Origin' );
 437                 if ( $originHeader === false ) {
 438                         $origins = array();
 439                 } else {
 440                         $origins = explode( ' ', $originHeader );
 441                 }
 442                 if ( !in_array( $originParam, $origins ) ) {
 443                         // origin parameter set but incorrect
 444                         // Send a 403 response
 445                         $message = HttpStatus::getMessage( 403 );
 446                         $response->header( "HTTP/1.1 403 $message", true, 403 );
 447                         $response->header( 'Cache-Control: no-cache' );
 448                         echo "'origin' parameter does not match Origin header\n";
 449                         return false;
 450                 }
 451                 if ( self::matchOrigin( $originParam, $wgCrossSiteAJAXdomains, $wgCrossSiteAJAXdomainExceptions ) ) {
 452                         $response->header( "Access-Control-Allow-Origin: $originParam" );
 453                         $response->header( 'Access-Control-Allow-Credentials: true' );
 454                         $this->getOutput()->addVaryHeader( 'Origin' );
 455                 }
 456                 return true;
 457         }
 458
 459         /**
 460          * Attempt to match an Origin header against a set of rules and a set of exceptions
 461          * @param $value string Origin header
 462          * @param $rules array Set of wildcard rules
 463          * @param $exceptions array Set of wildcard rules
 464          * @return bool True if $value matches a rule in $rules and doesn't match any rules in $exceptions, false otherwise
 465          */
 466         protected static function matchOrigin( $value, $rules, $exceptions ) {
 467                 foreach ( $rules as $rule ) {
 468                         if ( preg_match( self::wildcardToRegex( $rule ), $value ) ) {
 469                                 // Rule matches, check exceptions
 470                                 foreach ( $exceptions as $exc ) {
 471                                         if ( preg_match( self::wildcardToRegex( $exc ), $value ) ) {
 472                                                 return false;
 473                                         }
 474                                 }
 475                                 return true;
 476                         }
 477                 }
 478                 return false;
 479         }
 480
 481         /**
 482          * Helper function to convert wildcard string into a regex
 483          * '*' => '.*?'
 484          * '?' => '.'
 485          *
 486          * @param $wildcard string String with wildcards
 487          * @return string Regular expression
 488          */
 489         protected static function wildcardToRegex( $wildcard ) {
 490                 $wildcard = preg_quote( $wildcard, '/' );
 491                 $wildcard = str_replace(
 492                         array( '\*', '\?' ),
 493                         array( '.*?', '.' ),
 494                         $wildcard
 495                 );
 496                 return "/https?:\/\/$wildcard/";
 497         }
 498
 499         protected function sendCacheHeaders() {
 500                 global $wgUseXVO, $wgVaryOnXFP;
 501                 $response = $this->getRequest()->response();
 502                 $out = $this->getOutput();
 503
 504                 if ( $wgVaryOnXFP ) {
 505                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 506                 }
 507
 508                 if ( $this->mCacheMode == 'private' ) {
 509                         $response->header( 'Cache-Control: private' );
 510                         return;
 511                 }
 512
 513                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 514                         $out->addVaryHeader( 'Cookie' );
 515                         $response->header( $out->getVaryHeader() );
 516                         if ( $wgUseXVO ) {
 517                                 $response->header( $out->getXVO() );
 518                                 if ( $out->haveCacheVaryCookies() ) {
 519                                         // Logged in, mark this request private
 520                                         $response->header( 'Cache-Control: private' );
 521                                         return;
 522                                 }
 523                                 // Logged out, send normal public headers below
 524                         } elseif ( session_id() != '' ) {
 525                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 526                                 // Mark request private
 527                                 $response->header( 'Cache-Control: private' );
 528                                 return;
 529                         } // else no XVO and anonymous, send public headers below
 530                 }
 531
 532                 // Send public headers
 533                 $response->header( $out->getVaryHeader() );
 534                 if ( $wgUseXVO ) {
 535                         $response->header( $out->getXVO() );
 536                 }
 537
 538                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 539                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 540                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 541                 }
 542                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 543                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 544                 }
 545
 546                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 547                         // Public cache not requested
 548                         // Sending a Vary header in this case is harmless, and protects us
 549                         // against conditional calls of setCacheMaxAge().
 550                         $response->header( 'Cache-Control: private' );
 551                         return;
 552                 }
 553
 554                 $this->mCacheControl['public'] = true;
 555
 556                 // Send an Expires header
 557                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 558                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 559                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 560
 561                 // Construct the Cache-Control header
 562                 $ccHeader = '';
 563                 $separator = '';
 564                 foreach ( $this->mCacheControl as $name => $value ) {
 565                         if ( is_bool( $value ) ) {
 566                                 if ( $value ) {
 567                                         $ccHeader .= $separator . $name;
 568                                         $separator = ', ';
 569                                 }
 570                         } else {
 571                                 $ccHeader .= $separator . "$name=$value";
 572                                 $separator = ', ';
 573                         }
 574                 }
 575
 576                 $response->header( "Cache-Control: $ccHeader" );
 577         }
 578
 579         /**
 580          * Replace the result data with the information about an exception.
 581          * Returns the error code
 582          * @param $e Exception
 583          * @return string
 584          */
 585         protected function substituteResultWithError( $e ) {
 586                 global $wgShowHostnames;
 587
 588                 $result = $this->getResult();
 589                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 590                 if ( !isset ( $this->mPrinter ) ) {
 591                         // The printer has not been created yet. Try to manually get formatter value.
 592                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 593                         if ( !in_array( $value, $this->mFormatNames ) ) {
 594                                 $value = self::API_DEFAULT_FORMAT;
 595                         }
 596
 597                         $this->mPrinter = $this->createPrinterByName( $value );
 598                         if ( $this->mPrinter->getNeedsRawData() ) {
 599                                 $result->setRawMode();
 600                         }
 601                 }
 602
 603                 if ( $e instanceof UsageException ) {
 604                         // User entered incorrect parameters - print usage screen
 605                         $errMessage = $e->getMessageArray();
 606
 607                         // Only print the help message when this is for the developer, not runtime
 608                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 609                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 610                         }
 611
 612                 } else {
 613                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 614                         // Something is seriously wrong
 615                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 616                                 $info = 'Database query error';
 617                         } else {
 618                                 $info = "Exception Caught: {$e->getMessage()}";
 619                         }
 620
 621                         $errMessage = array(
 622                                 'code' => 'internal_api_error_' . get_class( $e ),
 623                                 'info' => $info,
 624                         );
 625                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 626                 }
 627
 628                 $result->reset();
 629                 $result->disableSizeCheck();
 630                 // Re-add the id
 631                 $requestid = $this->getParameter( 'requestid' );
 632                 if ( !is_null( $requestid ) ) {
 633                         $result->addValue( null, 'requestid', $requestid );
 634                 }
 635
 636                 if ( $wgShowHostnames ) {
 637                         // servedby is especially useful when debugging errors
 638                         $result->addValue( null, 'servedby', wfHostName() );
 639                 }
 640
 641                 $result->addValue( null, 'error', $errMessage );
 642
 643                 return $errMessage['code'];
 644         }
 645
 646         /**
 647          * Set up for the execution.
 648          * @return array
 649          */
 650         protected function setupExecuteAction() {
 651                 global $wgShowHostnames;
 652
 653                 // First add the id to the top element
 654                 $result = $this->getResult();
 655                 $requestid = $this->getParameter( 'requestid' );
 656                 if ( !is_null( $requestid ) ) {
 657                         $result->addValue( null, 'requestid', $requestid );
 658                 }
 659
 660                 if ( $wgShowHostnames ) {
 661                         $servedby = $this->getParameter( 'servedby' );
 662                         if ( $servedby ) {
 663                                 $result->addValue( null, 'servedby', wfHostName() );
 664                         }
 665                 }
 666
 667                 $params = $this->extractRequestParams();
 668
 669                 $this->mShowVersions = $params['version'];
 670                 $this->mAction = $params['action'];
 671
 672                 if ( !is_string( $this->mAction ) ) {
 673                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 674                 }
 675
 676                 return $params;
 677         }
 678
 679         /**
 680          * Set up the module for response
 681          * @return ApiBase The module that will handle this action
 682          */
 683         protected function setupModule() {
 684                 // Instantiate the module requested by the user
 685                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 686                 $this->mModule = $module;
 687
 688                 $moduleParams = $module->extractRequestParams();
 689
 690                 // Die if token required, but not provided (unless there is a gettoken parameter)
 691                 if ( isset( $moduleParams['gettoken'] ) ) {
 692                         $gettoken = $moduleParams['gettoken'];
 693                 } else {
 694                         $gettoken = false;
 695                 }
 696
 697                 $salt = $module->getTokenSalt();
 698                 if ( $salt !== false && !$gettoken ) {
 699                         if ( !isset( $moduleParams['token'] ) ) {
 700                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 701                         } else {
 702                                 if ( !$this->getUser()->matchEditToken( $moduleParams['token'], $salt, $this->getContext()->getRequest() ) ) {
 703                                         $this->dieUsageMsg( 'sessionfailure' );
 704                                 }
 705                         }
 706                 }
 707                 return $module;
 708         }
 709
 710         /**
 711          * Check the max lag if necessary
 712          * @param $module ApiBase object: Api module being used
 713          * @param $params Array an array containing the request parameters.
 714          * @return boolean True on success, false should exit immediately
 715          */
 716         protected function checkMaxLag( $module, $params ) {
 717                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 718                         // Check for maxlag
 719                         global $wgShowHostnames;
 720                         $maxLag = $params['maxlag'];
 721                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 722                         if ( $lag > $maxLag ) {
 723                                 $response = $this->getRequest()->response();
 724
 725                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 726                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 727
 728                                 if ( $wgShowHostnames ) {
 729                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 730                                 } else {
 731                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 732                                 }
 733                                 return false;
 734                         }
 735                 }
 736                 return true;
 737         }
 738
 739         /**
 740          * Check for sufficient permissions to execute
 741          * @param $module ApiBase An Api module
 742          */
 743         protected function checkExecutePermissions( $module ) {
 744                 $user = $this->getUser();
 745                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 746                         !$user->isAllowed( 'read' ) )
 747                 {
 748                         $this->dieUsageMsg( 'readrequired' );
 749                 }
 750                 if ( $module->isWriteMode() ) {
 751                         if ( !$this->mEnableWrite ) {
 752                                 $this->dieUsageMsg( 'writedisabled' );
 753                         }
 754                         if ( !$user->isAllowed( 'writeapi' ) ) {
 755                                 $this->dieUsageMsg( 'writerequired' );
 756                         }
 757                         if ( wfReadOnly() ) {
 758                                 $this->dieReadOnly();
 759                         }
 760                 }
 761         }
 762
 763         /**
 764          * Check POST for external response and setup result printer
 765          * @param $module ApiBase An Api module
 766          * @param $params Array an array with the request parameters
 767          */
 768         protected function setupExternalResponse( $module, $params ) {
 769                 // Ignore mustBePosted() for internal calls
 770                 if ( $module->mustBePosted() && !$this->getRequest()->wasPosted() ) {
 771                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 772                 }
 773
 774                 // See if custom printer is used
 775                 $this->mPrinter = $module->getCustomPrinter();
 776                 if ( is_null( $this->mPrinter ) ) {
 777                         // Create an appropriate printer
 778                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 779                 }
 780
 781                 if ( $this->mPrinter->getNeedsRawData() ) {
 782                         $this->getResult()->setRawMode();
 783                 }
 784         }
 785
 786         /**
 787          * Execute the actual module, without any error handling
 788          */
 789         protected function executeAction() {
 790                 $params = $this->setupExecuteAction();
 791                 $module = $this->setupModule();
 792
 793                 $this->checkExecutePermissions( $module );
 794
 795                 if ( !$this->checkMaxLag( $module, $params ) ) {
 796                         return;
 797                 }
 798
 799                 if ( !$this->mInternalMode ) {
 800                         $this->setupExternalResponse( $module, $params );
 801                 }
 802
 803                 // Execute
 804                 $module->profileIn();
 805                 $module->execute();
 806                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 807                 $module->profileOut();
 808
 809                 if ( !$this->mInternalMode ) {
 810                         //append Debug information
 811                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
 812
 813                         // Print result data
 814                         $this->printResult( false );
 815                 }
 816         }
 817
 818         /**
 819          * Print results using the current printer
 820          *
 821          * @param $isError bool
 822          */
 823         protected function printResult( $isError ) {
 824                 $this->getResult()->cleanUpUTF8();
 825                 $printer = $this->mPrinter;
 826                 $printer->profileIn();
 827
 828                 /**
 829                  * If the help message is requested in the default (xmlfm) format,
 830                  * tell the printer not to escape ampersands so that our links do
 831                  * not break.
 832                  */
 833                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 834                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 835
 836                 $printer->initPrinter( $isError );
 837
 838                 $printer->execute();
 839                 $printer->closePrinter();
 840                 $printer->profileOut();
 841         }
 842
 843         /**
 844          * @return bool
 845          */
 846         public function isReadMode() {
 847                 return false;
 848         }
 849
 850         /**
 851          * See ApiBase for description.
 852          *
 853          * @return array
 854          */
 855         public function getAllowedParams() {
 856                 return array(
 857                         'format' => array(
 858                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 859                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 860                         ),
 861                         'action' => array(
 862                                 ApiBase::PARAM_DFLT => 'help',
 863                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 864                         ),
 865                         'version' => false,
 866                         'maxlag'  => array(
 867                                 ApiBase::PARAM_TYPE => 'integer'
 868                         ),
 869                         'smaxage' => array(
 870                                 ApiBase::PARAM_TYPE => 'integer',
 871                                 ApiBase::PARAM_DFLT => 0
 872                         ),
 873                         'maxage' => array(
 874                                 ApiBase::PARAM_TYPE => 'integer',
 875                                 ApiBase::PARAM_DFLT => 0
 876                         ),
 877                         'requestid' => null,
 878                         'servedby'  => false,
 879                         'origin' => null,
 880                 );
 881         }
 882
 883         /**
 884          * See ApiBase for description.
 885          *
 886          * @return array
 887          */
 888         public function getParamDescription() {
 889                 return array(
 890                         'format' => 'The format of the output',
 891                         'action' => 'What action you would like to perform. See below for module help',
 892                         'version' => 'When showing help, include version for each module',
 893                         'maxlag' => array(
 894                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
 895                                 'To save actions causing any more site replication lag, this parameter can make the client',
 896                                 'wait until the replication lag is less than the specified value.',
 897                                 'In case of a replag error, a HTTP 503 error is returned, with the message like',
 898                                 '"Waiting for $host: $lag seconds lagged\n".',
 899                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
 900                         ),
 901                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 902                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 903                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 904                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 905                         'origin' => array(
 906                                 'When accessing the API using a cross-domain AJAX request (CORS), set this to the originating domain.',
 907                                 '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 .',
 908                                 'If this parameter does not match the Origin: header, a 403 response will be returned.',
 909                                 'If this parameter matches the Origin: header and the origin is whitelisted, an Access-Control-Allow-Origin header will be set.',
 910                         ),
 911                 );
 912         }
 913
 914         /**
 915          * See ApiBase for description.
 916          *
 917          * @return array
 918          */
 919         public function getDescription() {
 920                 return array(
 921                         '',
 922                         '',
 923                         '**********************************************************************************************************',
 924                         '**                                                                                                      **',
 925                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 926                         '**                                                                                                      **',
 927                         '**                                     Documentation and Examples:                                      **',
 928                         '**                                  https://www.mediawiki.org/wiki/API                                  **',
 929                         '**                                                                                                      **',
 930                         '**********************************************************************************************************',
 931                         '',
 932                         'Status:                All features shown on this page should be working, but the API',
 933                         '                       is still in active development, and may change at any time.',
 934                         '                       Make sure to monitor our mailing list for any updates',
 935                         '',
 936                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
 937                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
 938                         '                       header and the error code sent back will be set to the same value',
 939                         '',
 940                         '                       In the case of an invalid action being passed, these will have a value',
 941                         '                       of "unknown_action"',
 942                         '',
 943                         '                       For more information see https://www.mediawiki.org/wiki/API:Errors_and_warnings',
 944                         '',
 945                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
 946                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
 947                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 948                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 949                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 950                         '',
 951                         '',
 952                         '',
 953                         '',
 954                         '',
 955                 );
 956         }
 957
 958         /**
 959          * @return array
 960          */
 961         public function getPossibleErrors() {
 962                 return array_merge( parent::getPossibleErrors(), array(
 963                         array( 'readonlytext' ),
 964                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 965                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 966                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 967                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 968                 ) );
 969         }
 970
 971         /**
 972          * Returns an array of strings with credits for the API
 973          * @return array
 974          */
 975         protected function getCredits() {
 976                 return array(
 977                         'API developers:',
 978                         '    Roan Kattouw "<Firstname>.<Lastname>@gmail.com" (lead developer Sep 2007-present)',
 979                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 980                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 981                         '    Sam Reed - sam @ reedyboy . net',
 982                         '    Yuri Astrakhan "<Firstname><Lastname>@gmail.com" (creator, lead developer Sep 2006-Sep 2007)',
 983                         '',
 984                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 985                         'or file a bug report at https://bugzilla.wikimedia.org/'
 986                 );
 987         }
 988
 989         /**
 990          * Sets whether the pretty-printer should format *bold* and $italics$
 991          *
 992          * @param $help bool
 993          */
 994         public function setHelp( $help = true ) {
 995                 $this->mPrinter->setHelp( $help );
 996         }
 997
 998         /**
 999          * Override the parent to generate help messages for all available modules.
1000          *
1001          * @return string
1002          */
1003         public function makeHelpMsg() {
1004                 global $wgMemc, $wgAPICacheHelpTimeout;
1005                 $this->setHelp();
1006                 // Get help text from cache if present
1007                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
1008                         SpecialVersion::getVersion( 'nodb' ) .
1009                         $this->getShowVersions() );
1010                 if ( $wgAPICacheHelpTimeout > 0 ) {
1011                         $cached = $wgMemc->get( $key );
1012                         if ( $cached ) {
1013                                 return $cached;
1014                         }
1015                 }
1016                 $retval = $this->reallyMakeHelpMsg();
1017                 if ( $wgAPICacheHelpTimeout > 0 ) {
1018                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
1019                 }
1020                 return $retval;
1021         }
1022
1023         /**
1024          * @return mixed|string
1025          */
1026         public function reallyMakeHelpMsg() {
1027                 $this->setHelp();
1028
1029                 // Use parent to make default message for the main module
1030                 $msg = parent::makeHelpMsg();
1031
1032                 $astriks = str_repeat( '*** ', 14 );
1033                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
1034                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
1035                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
1036                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
1037                         $msg2 = $module->makeHelpMsg();
1038                         if ( $msg2 !== false ) {
1039                                 $msg .= $msg2;
1040                         }
1041                         $msg .= "\n";
1042                 }
1043
1044                 $msg .= "\n$astriks Permissions $astriks\n\n";
1045                 foreach ( self::$mRights as $right => $rightMsg ) {
1046                         $groups = User::getGroupsWithPermission( $right );
1047                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
1048                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
1049
1050                 }
1051
1052                 $msg .= "\n$astriks Formats  $astriks\n\n";
1053                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
1054                         $module = $this->createPrinterByName( $formatName );
1055                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
1056                         $msg2 = $module->makeHelpMsg();
1057                         if ( $msg2 !== false ) {
1058                                 $msg .= $msg2;
1059                         }
1060                         $msg .= "\n";
1061                 }
1062
1063                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
1064
1065                 return $msg;
1066         }
1067
1068         /**
1069          * @param $module ApiBase
1070          * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
1071          * @return string
1072          */
1073         public static function makeHelpMsgHeader( $module, $paramName ) {
1074                 $modulePrefix = $module->getModulePrefix();
1075                 if ( strval( $modulePrefix ) !== '' ) {
1076                         $modulePrefix = "($modulePrefix) ";
1077                 }
1078
1079                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
1080         }
1081
1082         private $mCanApiHighLimits = null;
1083
1084         /**
1085          * Check whether the current user is allowed to use high limits
1086          * @return bool
1087          */
1088         public function canApiHighLimits() {
1089                 if ( !isset( $this->mCanApiHighLimits ) ) {
1090                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
1091                 }
1092
1093                 return $this->mCanApiHighLimits;
1094         }
1095
1096         /**
1097          * Check whether the user wants us to show version information in the API help
1098          * @return bool
1099          */
1100         public function getShowVersions() {
1101                 return $this->mShowVersions;
1102         }
1103
1104         /**
1105          * Returns the version information of this file, plus it includes
1106          * the versions for all files that are not callable proper API modules
1107          *
1108          * @return array
1109          */
1110         public function getVersion() {
1111                 $vers = array();
1112                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    https://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
1113                 $vers[] = __CLASS__ . ': $Id$';
1114                 $vers[] = ApiBase::getBaseVersion();
1115                 $vers[] = ApiFormatBase::getBaseVersion();
1116                 $vers[] = ApiQueryBase::getBaseVersion();
1117                 return $vers;
1118         }
1119
1120         /**
1121          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1122          * classes who wish to add their own modules to their lexicon or override the
1123          * behavior of inherent ones.
1124          *
1125          * @param $mdlName String The identifier for this module.
1126          * @param $mdlClass String The class where this module is implemented.
1127          */
1128         protected function addModule( $mdlName, $mdlClass ) {
1129                 $this->mModules[$mdlName] = $mdlClass;
1130         }
1131
1132         /**
1133          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1134          * classes who wish to add to or modify current formatters.
1135          *
1136          * @param $fmtName string The identifier for this format.
1137          * @param $fmtClass ApiFormatBase The class implementing this format.
1138          */
1139         protected function addFormat( $fmtName, $fmtClass ) {
1140                 $this->mFormats[$fmtName] = $fmtClass;
1141         }
1142
1143         /**
1144          * Get the array mapping module names to class names
1145          * @return array
1146          */
1147         function getModules() {
1148                 return $this->mModules;
1149         }
1150
1151         /**
1152          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1153          *
1154          * @since 1.18
1155          * @return array
1156          */
1157         public function getFormats() {
1158                 return $this->mFormats;
1159         }
1160 }
1161
1162 /**
1163  * This exception will be thrown when dieUsage is called to stop module execution.
1164  * The exception handling code will print a help screen explaining how this API may be used.
1165  *
1166  * @ingroup API
1167  */
1168 class UsageException extends MWException {
1169
1170         private $mCodestr;
1171
1172         /**
1173          * @var null|array
1174          */
1175         private $mExtraData;
1176
1177         /**
1178          * @param $message string
1179          * @param $codestr string
1180          * @param $code int
1181          * @param $extradata array|null
1182          */
1183         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1184                 parent::__construct( $message, $code );
1185                 $this->mCodestr = $codestr;
1186                 $this->mExtraData = $extradata;
1187         }
1188
1189         /**
1190          * @return string
1191          */
1192         public function getCodeString() {
1193                 return $this->mCodestr;
1194         }
1195
1196         /**
1197          * @return array
1198          */
1199         public function getMessageArray() {
1200                 $result = array(
1201                         'code' => $this->mCodestr,
1202                         'info' => $this->getMessage()
1203                 );
1204                 if ( is_array( $this->mExtraData ) ) {
1205                         $result = array_merge( $result, $this->mExtraData );
1206                 }
1207                 return $result;
1208         }
1209
1210         /**
1211          * @return string
1212          */
1213         public function __toString() {
1214                 return "{$this->getCodeString()}: {$this->getMessage()}";
1215         }
1216 }