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