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 if ( !defined( 'MEDIAWIKI' ) ) {
  29         // Eclipse helper - will be ignored in production
  30         require_once( 'ApiBase.php' );
  31 }
  32
  33 /**
  34  * This is the main API class, used for both external and internal processing.
  35  * When executed, it will create the requested formatter object,
  36  * instantiate and execute an object associated with the needed action,
  37  * and use formatter to print results.
  38  * In case of an exception, an error message will be printed using the same formatter.
  39  *
  40  * To use API from another application, run it using FauxRequest object, in which
  41  * case any internal exceptions will not be handled but passed up to the caller.
  42  * After successful execution, use getResult() for the resulting data.
  43  *
  44  * @ingroup API
  45  */
  46 class ApiMain extends ApiBase {
  47
  48         /**
  49          * When no format parameter is given, this format will be used
  50          */
  51         const API_DEFAULT_FORMAT = 'xmlfm';
  52
  53         /**
  54          * List of available modules: action name => module class
  55          */
  56         private static $Modules = array(
  57                 'login' => 'ApiLogin',
  58                 'logout' => 'ApiLogout',
  59                 'query' => 'ApiQuery',
  60                 'expandtemplates' => 'ApiExpandTemplates',
  61                 'parse' => 'ApiParse',
  62                 'opensearch' => 'ApiOpenSearch',
  63                 'feedcontributions' => 'ApiFeedContributions',
  64                 'feedwatchlist' => 'ApiFeedWatchlist',
  65                 'help' => 'ApiHelp',
  66                 'paraminfo' => 'ApiParamInfo',
  67                 'rsd' => 'ApiRsd',
  68                 'compare' => 'ApiComparePages',
  69
  70                 // Write modules
  71                 'purge' => 'ApiPurge',
  72                 'rollback' => 'ApiRollback',
  73                 'delete' => 'ApiDelete',
  74                 'undelete' => 'ApiUndelete',
  75                 'protect' => 'ApiProtect',
  76                 'block' => 'ApiBlock',
  77                 'unblock' => 'ApiUnblock',
  78                 'move' => 'ApiMove',
  79                 'edit' => 'ApiEditPage',
  80                 'upload' => 'ApiUpload',
  81                 'filerevert' => 'ApiFileRevert',
  82                 'emailuser' => 'ApiEmailUser',
  83                 'watch' => 'ApiWatch',
  84                 'patrol' => 'ApiPatrol',
  85                 'import' => 'ApiImport',
  86                 'userrights' => 'ApiUserrights',
  87         );
  88
  89         /**
  90          * List of available formats: format name => format class
  91          */
  92         private static $Formats = array(
  93                 'json' => 'ApiFormatJson',
  94                 'jsonfm' => 'ApiFormatJson',
  95                 'php' => 'ApiFormatPhp',
  96                 'phpfm' => 'ApiFormatPhp',
  97                 'wddx' => 'ApiFormatWddx',
  98                 'wddxfm' => 'ApiFormatWddx',
  99                 'xml' => 'ApiFormatXml',
 100                 'xmlfm' => 'ApiFormatXml',
 101                 'yaml' => 'ApiFormatYaml',
 102                 'yamlfm' => 'ApiFormatYaml',
 103                 'rawfm' => 'ApiFormatJson',
 104                 'txt' => 'ApiFormatTxt',
 105                 'txtfm' => 'ApiFormatTxt',
 106                 'dbg' => 'ApiFormatDbg',
 107                 'dbgfm' => 'ApiFormatDbg',
 108                 'dump' => 'ApiFormatDump',
 109                 'dumpfm' => 'ApiFormatDump',
 110         );
 111
 112         /**
 113          * List of user roles that are specifically relevant to the API.
 114          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 115          *                           'params' => array ( $someVarToSubst ) ),
 116          *                          );
 117          */
 118         private static $mRights = array(
 119                 'writeapi' => array(
 120                         'msg' => 'Use of the write API',
 121                         'params' => array()
 122                 ),
 123                 'apihighlimits' => array(
 124                         'msg' => 'Use higher limits in API queries (Slow queries: $1 results; Fast queries: $2 results). The limits for slow queries also apply to multivalue parameters.',
 125                         'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
 126                 )
 127         );
 128
 129         /**
 130          * @var ApiFormatBase
 131          */
 132         private $mPrinter;
 133
 134         private $mModules, $mModuleNames, $mFormats, $mFormatNames;
 135         private $mResult, $mAction, $mShowVersions, $mEnableWrite/*, $mRequest*/;
 136         private $mInternalMode, $mSquidMaxage, $mModule;
 137
 138         private $mCacheMode = 'private';
 139         private $mCacheControl = array();
 140
 141         /**
 142          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 143          *
 144          * @param $context IContextSource|WebRequest - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 145          * @param $enableWrite bool should be set to true if the api may modify data
 146          */
 147         public function __construct( $context = null, $enableWrite = false ) {
 148                 if ( $context === null ) {
 149                         $context = RequestContext::getMain();
 150                 } elseif ( $context instanceof WebRequest ) {
 151                         // BC for pre-1.19
 152                         $request = $context;
 153                         $context = RequestContext::getMain();
 154                 }
 155                 // We set a derivative context so we can change stuff later
 156                 $this->setContext( new DerivativeContext( $context ) );
 157
 158                 if ( isset( $request ) ) {
 159                         $this->getContext()->setRequest( $request );
 160                 }
 161
 162                 $this->mInternalMode = ( $this->getRequest() instanceof FauxRequest );
 163
 164                 // Special handling for the main module: $parent === $this
 165                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 166
 167                 if ( !$this->mInternalMode ) {
 168                         // Impose module restrictions.
 169                         // If the current user cannot read,
 170                         // Remove all modules other than login
 171                         global $wgUser;
 172
 173                         if ( $this->getRequest()->getVal( 'callback' ) !== null ) {
 174                                 // JSON callback allows cross-site reads.
 175                                 // For safety, strip user credentials.
 176                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 177                                 $wgUser = new User();
 178                                 $this->getContext()->setUser( $wgUser );
 179                         }
 180                 }
 181
 182                 global $wgAPIModules; // extension modules
 183                 $this->mModules = $wgAPIModules + self::$Modules;
 184
 185                 $this->mModuleNames = array_keys( $this->mModules );
 186                 $this->mFormats = self::$Formats;
 187                 $this->mFormatNames = array_keys( $this->mFormats );
 188
 189                 $this->mResult = new ApiResult( $this );
 190                 $this->mShowVersions = false;
 191                 $this->mEnableWrite = $enableWrite;
 192
 193                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 194                 $this->mCommit = false;
 195         }
 196
 197         /**
 198          * Return true if the API was started by other PHP code using FauxRequest
 199          * @return bool
 200          */
 201         public function isInternalMode() {
 202                 return $this->mInternalMode;
 203         }
 204
 205         /**
 206          * Get the ApiResult object associated with current request
 207          *
 208          * @return ApiResult
 209          */
 210         public function getResult() {
 211                 return $this->mResult;
 212         }
 213
 214         /**
 215          * Get the API module object. Only works after executeAction()
 216          *
 217          * @return ApiBase
 218          */
 219         public function getModule() {
 220                 return $this->mModule;
 221         }
 222
 223         /**
 224          * Get the result formatter object. Only works after setupExecuteAction()
 225          *
 226          * @return ApiFormatBase
 227          */
 228         public function getPrinter() {
 229                 return $this->mPrinter;
 230         }
 231
 232         /**
 233          * Set how long the response should be cached.
 234          *
 235          * @param $maxage
 236          */
 237         public function setCacheMaxAge( $maxage ) {
 238                 $this->setCacheControl( array(
 239                         'max-age' => $maxage,
 240                         's-maxage' => $maxage
 241                 ) );
 242         }
 243
 244         /**
 245          * Set the type of caching headers which will be sent.
 246          *
 247          * @param $mode String One of:
 248          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 249          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 250          *         not provided by any of these means, the object will be private.
 251          *    - 'private':    Cache this object only in private client-side caches.
 252          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 253          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 254          *         set consistently for a given URL, it cannot be set differently depending on
 255          *         things like the contents of the database, or whether the user is logged in.
 256          *
 257          *  If the wiki does not allow anonymous users to read it, the mode set here
 258          *  will be ignored, and private caching headers will always be sent. In other words,
 259          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 260          *  view.
 261          *
 262          *  For user-dependent data, the private mode should generally be used. The
 263          *  anon-public-user-private mode should only be used where there is a particularly
 264          *  good performance reason for caching the anonymous response, but where the
 265          *  response to logged-in users may differ, or may contain private data.
 266          *
 267          *  If this function is never called, then the default will be the private mode.
 268          */
 269         public function setCacheMode( $mode ) {
 270                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 271                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 272                         // Ignore for forwards-compatibility
 273                         return;
 274                 }
 275
 276                 if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 277                         // Private wiki, only private headers
 278                         if ( $mode !== 'private' ) {
 279                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 280                                 return;
 281                         }
 282                 }
 283
 284                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 285                 $this->mCacheMode = $mode;
 286         }
 287
 288         /**
 289          * @deprecated since 1.17 Private caching is now the default, so there is usually no
 290          * need to call this function. If there is a need, you can use
 291          * $this->setCacheMode('private')
 292          */
 293         public function setCachePrivate() {
 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                 $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                 // In case an error occurs during data output,
 359                 // clear the output buffer and print just the error information
 360                 ob_start();
 361
 362                 try {
 363                         $this->executeAction();
 364                 } catch ( Exception $e ) {
 365                         // Log it
 366                         if ( $e instanceof MWException ) {
 367                                 wfDebugLog( 'exception', $e->getLogMessage() );
 368                         }
 369
 370                         // Handle any kind of exception by outputing properly formatted error message.
 371                         // If this fails, an unhandled exception should be thrown so that global error
 372                         // handler will process and log it.
 373
 374                         $errCode = $this->substituteResultWithError( $e );
 375
 376                         // Error results should not be cached
 377                         $this->setCacheMode( 'private' );
 378
 379                         $response = $this->getRequest()->response();
 380                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 381                         if ( $e->getCode() === 0 ) {
 382                                 $response->header( $headerStr );
 383                         } else {
 384                                 $response->header( $headerStr, true, $e->getCode() );
 385                         }
 386
 387                         // Reset and print just the error message
 388                         ob_clean();
 389
 390                         // If the error occured during printing, do a printer->profileOut()
 391                         $this->mPrinter->safeProfileOut();
 392                         $this->printResult( true );
 393                 }
 394
 395                 // Send cache headers after any code which might generate an error, to
 396                 // avoid sending public cache headers for errors.
 397                 $this->sendCacheHeaders();
 398
 399                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 400                         echo wfReportTime();
 401                 }
 402
 403                 ob_end_flush();
 404         }
 405
 406         protected function sendCacheHeaders() {
 407                 global $wgUseXVO, $wgOut, $wgVaryOnXFP;
 408                 $response = $this->getRequest()->response();
 409
 410                 if ( $this->mCacheMode == 'private' ) {
 411                         $response->header( 'Cache-Control: private' );
 412                         return;
 413                 }
 414
 415                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 416                         $xfp = $wgVaryOnXFP ? ', X-Forwarded-Proto' : '';
 417                         $response->header( 'Vary: Accept-Encoding, Cookie' . $xfp );
 418                         if ( $wgUseXVO ) {
 419                                 if ( $wgVaryOnXFP ) {
 420                                         $wgOut->addVaryHeader( 'X-Forwarded-Proto' );
 421                                 }
 422                                 $response->header( $wgOut->getXVO() );
 423                                 if ( $wgOut->haveCacheVaryCookies() ) {
 424                                         // Logged in, mark this request private
 425                                         $response->header( 'Cache-Control: private' );
 426                                         return;
 427                                 }
 428                                 // Logged out, send normal public headers below
 429                         } elseif ( session_id() != '' ) {
 430                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 431                                 // Mark request private
 432                                 $response->header( 'Cache-Control: private' );
 433                                 return;
 434                         } // else no XVO and anonymous, send public headers below
 435                 }
 436
 437                 // Send public headers
 438                 if ( $wgVaryOnXFP ) {
 439                         $response->header( 'Vary: Accept-Encoding, X-Forwarded-Proto' );
 440                         if ( $wgUseXVO ) {
 441                                 // Bleeeeegh. Our header setting system sucks
 442                                 $response->header( 'X-Vary-Options: Accept-Encoding;list-contains=gzip, X-Forwarded-Proto' );
 443                         }
 444                 }
 445
 446                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 447                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 448                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 449                 }
 450                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 451                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 452                 }
 453
 454                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 455                         // Public cache not requested
 456                         // Sending a Vary header in this case is harmless, and protects us
 457                         // against conditional calls of setCacheMaxAge().
 458                         $response->header( 'Cache-Control: private' );
 459                         return;
 460                 }
 461
 462                 $this->mCacheControl['public'] = true;
 463
 464                 // Send an Expires header
 465                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 466                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 467                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 468
 469                 // Construct the Cache-Control header
 470                 $ccHeader = '';
 471                 $separator = '';
 472                 foreach ( $this->mCacheControl as $name => $value ) {
 473                         if ( is_bool( $value ) ) {
 474                                 if ( $value ) {
 475                                         $ccHeader .= $separator . $name;
 476                                         $separator = ', ';
 477                                 }
 478                         } else {
 479                                 $ccHeader .= $separator . "$name=$value";
 480                                 $separator = ', ';
 481                         }
 482                 }
 483
 484                 $response->header( "Cache-Control: $ccHeader" );
 485         }
 486
 487         /**
 488          * Replace the result data with the information about an exception.
 489          * Returns the error code
 490          * @param $e Exception
 491          * @return string
 492          */
 493         protected function substituteResultWithError( $e ) {
 494                 global $wgShowHostnames;
 495
 496                 $result = $this->getResult();
 497                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 498                 if ( !isset ( $this->mPrinter ) ) {
 499                         // The printer has not been created yet. Try to manually get formatter value.
 500                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 501                         if ( !in_array( $value, $this->mFormatNames ) ) {
 502                                 $value = self::API_DEFAULT_FORMAT;
 503                         }
 504
 505                         $this->mPrinter = $this->createPrinterByName( $value );
 506                         if ( $this->mPrinter->getNeedsRawData() ) {
 507                                 $result->setRawMode();
 508                         }
 509                 }
 510
 511                 if ( $e instanceof UsageException ) {
 512                         // User entered incorrect parameters - print usage screen
 513                         $errMessage = $e->getMessageArray();
 514
 515                         // Only print the help message when this is for the developer, not runtime
 516                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 517                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 518                         }
 519
 520                 } else {
 521                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 522                         // Something is seriously wrong
 523                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 524                                 $info = 'Database query error';
 525                         } else {
 526                                 $info = "Exception Caught: {$e->getMessage()}";
 527                         }
 528
 529                         $errMessage = array(
 530                                 'code' => 'internal_api_error_' . get_class( $e ),
 531                                 'info' => $info,
 532                         );
 533                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 534                 }
 535
 536                 $result->reset();
 537                 $result->disableSizeCheck();
 538                 // Re-add the id
 539                 $requestid = $this->getParameter( 'requestid' );
 540                 if ( !is_null( $requestid ) ) {
 541                         $result->addValue( null, 'requestid', $requestid );
 542                 }
 543
 544                 if ( $wgShowHostnames ) {
 545                         // servedby is especially useful when debugging errors
 546                         $result->addValue( null, 'servedby', wfHostName() );
 547                 }
 548
 549                 $result->addValue( null, 'error', $errMessage );
 550
 551                 return $errMessage['code'];
 552         }
 553
 554         /**
 555          * Set up for the execution.
 556          * @return array
 557          */
 558         protected function setupExecuteAction() {
 559                 global $wgShowHostnames;
 560
 561                 // First add the id to the top element
 562                 $result = $this->getResult();
 563                 $requestid = $this->getParameter( 'requestid' );
 564                 if ( !is_null( $requestid ) ) {
 565                         $result->addValue( null, 'requestid', $requestid );
 566                 }
 567
 568                 if ( $wgShowHostnames ) {
 569                         $servedby = $this->getParameter( 'servedby' );
 570                         if ( $servedby ) {
 571                                 $result->addValue( null, 'servedby', wfHostName() );
 572                         }
 573                 }
 574
 575                 $params = $this->extractRequestParams();
 576
 577                 $this->mShowVersions = $params['version'];
 578                 $this->mAction = $params['action'];
 579
 580                 if ( !is_string( $this->mAction ) ) {
 581                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 582                 }
 583
 584                 return $params;
 585         }
 586
 587         /**
 588          * Set up the module for response
 589          * @return ApiBase The module that will handle this action
 590          */
 591         protected function setupModule() {
 592                 // Instantiate the module requested by the user
 593                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 594                 $this->mModule = $module;
 595
 596                 $moduleParams = $module->extractRequestParams();
 597
 598                 // Die if token required, but not provided (unless there is a gettoken parameter)
 599                 $salt = $module->getTokenSalt();
 600                 if ( $salt !== false && !isset( $moduleParams['gettoken'] ) ) {
 601                         if ( !isset( $moduleParams['token'] ) ) {
 602                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 603                         } else {
 604                                 if ( !$this->getUser()->matchEditToken( $moduleParams['token'], $salt, $this->getRequest() ) ) {
 605                                         $this->dieUsageMsg( 'sessionfailure' );
 606                                 }
 607                         }
 608                 }
 609                 return $module;
 610         }
 611
 612         /**
 613          * Check the max lag if necessary
 614          * @param $module ApiBase object: Api module being used
 615          * @param $params Array an array containing the request parameters.
 616          * @return boolean True on success, false should exit immediately
 617          */
 618         protected function checkMaxLag( $module, $params ) {
 619                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 620                         // Check for maxlag
 621                         global $wgShowHostnames;
 622                         $maxLag = $params['maxlag'];
 623                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 624                         if ( $lag > $maxLag ) {
 625                                 $response = $this->getRequest()->response();
 626
 627                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 628                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 629
 630                                 if ( $wgShowHostnames ) {
 631                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 632                                 } else {
 633                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 634                                 }
 635                                 return false;
 636                         }
 637                 }
 638                 return true;
 639         }
 640
 641         /**
 642          * Check for sufficient permissions to execute
 643          * @param $module ApiBase An Api module
 644          */
 645         protected function checkExecutePermissions( $module ) {
 646                 $user = $this->getUser();
 647                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 648                         !$user->isAllowed( 'read' ) )
 649                 {
 650                         $this->dieUsageMsg( 'readrequired' );
 651                 }
 652                 if ( $module->isWriteMode() ) {
 653                         if ( !$this->mEnableWrite ) {
 654                                 $this->dieUsageMsg( 'writedisabled' );
 655                         }
 656                         if ( !$user->isAllowed( 'writeapi' ) ) {
 657                                 $this->dieUsageMsg( 'writerequired' );
 658                         }
 659                         if ( wfReadOnly() ) {
 660                                 $this->dieReadOnly();
 661                         }
 662                 }
 663         }
 664
 665         /**
 666          * Check POST for external response and setup result printer
 667          * @param $module ApiBase An Api module
 668          * @param $params Array an array with the request parameters
 669          */
 670         protected function setupExternalResponse( $module, $params ) {
 671                 // Ignore mustBePosted() for internal calls
 672                 if ( $module->mustBePosted() && !$this->getRequest()->wasPosted() ) {
 673                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 674                 }
 675
 676                 // See if custom printer is used
 677                 $this->mPrinter = $module->getCustomPrinter();
 678                 if ( is_null( $this->mPrinter ) ) {
 679                         // Create an appropriate printer
 680                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 681                 }
 682
 683                 if ( $this->mPrinter->getNeedsRawData() ) {
 684                         $this->getResult()->setRawMode();
 685                 }
 686         }
 687
 688         /**
 689          * Execute the actual module, without any error handling
 690          */
 691         protected function executeAction() {
 692                 $params = $this->setupExecuteAction();
 693                 $module = $this->setupModule();
 694
 695                 $this->checkExecutePermissions( $module );
 696
 697                 if ( !$this->checkMaxLag( $module, $params ) ) {
 698                         return;
 699                 }
 700
 701                 if ( !$this->mInternalMode ) {
 702                         $this->setupExternalResponse( $module, $params );
 703                 }
 704
 705                 // Execute
 706                 $module->profileIn();
 707                 $module->execute();
 708                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 709                 $module->profileOut();
 710
 711                 if ( !$this->mInternalMode ) {
 712                         // Print result data
 713                         $this->printResult( false );
 714                 }
 715         }
 716
 717         /**
 718          * Print results using the current printer
 719          *
 720          * @param $isError bool
 721          */
 722         protected function printResult( $isError ) {
 723                 $this->getResult()->cleanUpUTF8();
 724                 $printer = $this->mPrinter;
 725                 $printer->profileIn();
 726
 727                 /**
 728                  * If the help message is requested in the default (xmlfm) format,
 729                  * tell the printer not to escape ampersands so that our links do
 730                  * not break.
 731                  */
 732                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 733                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 734
 735                 $printer->initPrinter( $isError );
 736
 737                 $printer->execute();
 738                 $printer->closePrinter();
 739                 $printer->profileOut();
 740         }
 741
 742         /**
 743          * @return bool
 744          */
 745         public function isReadMode() {
 746                 return false;
 747         }
 748
 749         /**
 750          * See ApiBase for description.
 751          *
 752          * @return array
 753          */
 754         public function getAllowedParams() {
 755                 return array(
 756                         'format' => array(
 757                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 758                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 759                         ),
 760                         'action' => array(
 761                                 ApiBase::PARAM_DFLT => 'help',
 762                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 763                         ),
 764                         'version' => false,
 765                         'maxlag'  => array(
 766                                 ApiBase::PARAM_TYPE => 'integer'
 767                         ),
 768                         'smaxage' => array(
 769                                 ApiBase::PARAM_TYPE => 'integer',
 770                                 ApiBase::PARAM_DFLT => 0
 771                         ),
 772                         'maxage' => array(
 773                                 ApiBase::PARAM_TYPE => 'integer',
 774                                 ApiBase::PARAM_DFLT => 0
 775                         ),
 776                         'requestid' => null,
 777                         'servedby'  => false,
 778                 );
 779         }
 780
 781         /**
 782          * See ApiBase for description.
 783          *
 784          * @return array
 785          */
 786         public function getParamDescription() {
 787                 return array(
 788                         'format' => 'The format of the output',
 789                         'action' => 'What action you would like to perform. See below for module help',
 790                         'version' => 'When showing help, include version for each module',
 791                         'maxlag' => array(
 792                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
 793                                 'To save actions causing any more site replication lag, this parameter can make the client',
 794                                 'wait until the replication lag is less than the specified value.',
 795                                 'In case of a replag error, a HTTP 503 error is returned, with the message like',
 796                                 '"Waiting for $host: $lag seconds lagged\n".',
 797                                 'See http://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
 798                         ),
 799                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 800                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 801                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 802                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 803                 );
 804         }
 805
 806         /**
 807          * See ApiBase for description.
 808          *
 809          * @return array
 810          */
 811         public function getDescription() {
 812                 return array(
 813                         '',
 814                         '',
 815                         '**********************************************************************************************************',
 816                         '**                                                                                                      **',
 817                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 818                         '**                                                                                                      **',
 819                         '**                                    Documentation and Examples:                                       **',
 820                         '**                                 http://www.mediawiki.org/wiki/API                                    **',
 821                         '**                                                                                                      **',
 822                         '**********************************************************************************************************',
 823                         '',
 824                         'Status:                All features shown on this page should be working, but the API',
 825                         '                       is still in active development, and may change at any time.',
 826                         '                       Make sure to monitor our mailing list for any updates',
 827                         '',
 828                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
 829                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
 830                         '                       header and the error code sent back will be set to the same value',
 831                         '',
 832                         '                       In the case of an invalid action being passed, these will have a value',
 833                         '                       of "unknown_action"',
 834                         '',
 835                         '                       For more information see http://www.mediawiki.org/wiki/API:Errors_and_warnings',
 836                         '',
 837                         'Documentation:         http://www.mediawiki.org/wiki/API:Main_page',
 838                         'FAQ                    http://www.mediawiki.org/wiki/API:FAQ',
 839                         'Mailing list:          http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 840                         'Api Announcements:     http://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 841                         'Bugs & Requests:       http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 842                         '',
 843                         '',
 844                         '',
 845                         '',
 846                         '',
 847                 );
 848         }
 849
 850         /**
 851          * @return array
 852          */
 853         public function getPossibleErrors() {
 854                 return array_merge( parent::getPossibleErrors(), array(
 855                         array( 'readonlytext' ),
 856                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 857                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 858                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 859                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 860                 ) );
 861         }
 862
 863         /**
 864          * Returns an array of strings with credits for the API
 865          * @return array
 866          */
 867         protected function getCredits() {
 868                 return array(
 869                         'API developers:',
 870                         '    Roan Kattouw <Firstname>.<Lastname>@gmail.com (lead developer Sep 2007-present)',
 871                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 872                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 873                         '    Sam Reed - sam @ reedyboy . net',
 874                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 875                         '',
 876                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 877                         'or file a bug report at http://bugzilla.wikimedia.org/'
 878                 );
 879         }
 880
 881         /**
 882          * Sets whether the pretty-printer should format *bold* and $italics$
 883          *
 884          * @param $help bool
 885          */
 886         public function setHelp( $help = true ) {
 887                 $this->mPrinter->setHelp( $help );
 888         }
 889
 890         /**
 891          * Override the parent to generate help messages for all available modules.
 892          *
 893          * @return string
 894          */
 895         public function makeHelpMsg() {
 896                 global $wgMemc, $wgAPICacheHelpTimeout;
 897                 $this->setHelp();
 898                 // Get help text from cache if present
 899                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
 900                         SpecialVersion::getVersion( 'nodb' ) .
 901                         $this->getShowVersions() );
 902                 if ( $wgAPICacheHelpTimeout > 0 ) {
 903                         $cached = $wgMemc->get( $key );
 904                         if ( $cached ) {
 905                                 return $cached;
 906                         }
 907                 }
 908                 $retval = $this->reallyMakeHelpMsg();
 909                 if ( $wgAPICacheHelpTimeout > 0 ) {
 910                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
 911                 }
 912                 return $retval;
 913         }
 914
 915         /**
 916          * @return mixed|string
 917          */
 918         public function reallyMakeHelpMsg() {
 919                 $this->setHelp();
 920
 921                 // Use parent to make default message for the main module
 922                 $msg = parent::makeHelpMsg();
 923
 924                 $astriks = str_repeat( '*** ', 14 );
 925                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 926                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
 927                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
 928                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
 929                         $msg2 = $module->makeHelpMsg();
 930                         if ( $msg2 !== false ) {
 931                                 $msg .= $msg2;
 932                         }
 933                         $msg .= "\n";
 934                 }
 935
 936                 $msg .= "\n$astriks Permissions $astriks\n\n";
 937                 foreach ( self::$mRights as $right => $rightMsg ) {
 938                         $groups = User::getGroupsWithPermission( $right );
 939                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
 940                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
 941
 942                 }
 943
 944                 $msg .= "\n$astriks Formats  $astriks\n\n";
 945                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
 946                         $module = $this->createPrinterByName( $formatName );
 947                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
 948                         $msg2 = $module->makeHelpMsg();
 949                         if ( $msg2 !== false ) {
 950                                 $msg .= $msg2;
 951                         }
 952                         $msg .= "\n";
 953                 }
 954
 955                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
 956
 957                 return $msg;
 958         }
 959
 960         /**
 961          * @param $module ApiBase
 962          * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
 963          * @return string
 964          */
 965         public static function makeHelpMsgHeader( $module, $paramName ) {
 966                 $modulePrefix = $module->getModulePrefix();
 967                 if ( strval( $modulePrefix ) !== '' ) {
 968                         $modulePrefix = "($modulePrefix) ";
 969                 }
 970
 971                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 972         }
 973
 974         private $mCanApiHighLimits = null;
 975
 976         /**
 977          * Check whether the current user is allowed to use high limits
 978          * @return bool
 979          */
 980         public function canApiHighLimits() {
 981                 if ( !isset( $this->mCanApiHighLimits ) ) {
 982                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
 983                 }
 984
 985                 return $this->mCanApiHighLimits;
 986         }
 987
 988         /**
 989          * Check whether the user wants us to show version information in the API help
 990          * @return bool
 991          */
 992         public function getShowVersions() {
 993                 return $this->mShowVersions;
 994         }
 995
 996         /**
 997          * Returns the version information of this file, plus it includes
 998          * the versions for all files that are not callable proper API modules
 999          *
1000          * @return array
1001          */
1002         public function getVersion() {
1003                 $vers = array();
1004                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    http://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
1005                 $vers[] = __CLASS__ . ': $Id$';
1006                 $vers[] = ApiBase::getBaseVersion();
1007                 $vers[] = ApiFormatBase::getBaseVersion();
1008                 $vers[] = ApiQueryBase::getBaseVersion();
1009                 return $vers;
1010         }
1011
1012         /**
1013          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1014          * classes who wish to add their own modules to their lexicon or override the
1015          * behavior of inherent ones.
1016          *
1017          * @param $mdlName String The identifier for this module.
1018          * @param $mdlClass String The class where this module is implemented.
1019          */
1020         protected function addModule( $mdlName, $mdlClass ) {
1021                 $this->mModules[$mdlName] = $mdlClass;
1022         }
1023
1024         /**
1025          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1026          * classes who wish to add to or modify current formatters.
1027          *
1028          * @param $fmtName string The identifier for this format.
1029          * @param $fmtClass ApiFormatBase The class implementing this format.
1030          */
1031         protected function addFormat( $fmtName, $fmtClass ) {
1032                 $this->mFormats[$fmtName] = $fmtClass;
1033         }
1034
1035         /**
1036          * Get the array mapping module names to class names
1037          * @return array
1038          */
1039         function getModules() {
1040                 return $this->mModules;
1041         }
1042
1043         /**
1044          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1045          *
1046          * @since 1.18
1047          * @return array
1048          */
1049         public function getFormats() {
1050                 return $this->mFormats;
1051         }
1052 }
1053
1054 /**
1055  * This exception will be thrown when dieUsage is called to stop module execution.
1056  * The exception handling code will print a help screen explaining how this API may be used.
1057  *
1058  * @ingroup API
1059  */
1060 class UsageException extends Exception {
1061
1062         private $mCodestr;
1063         private $mExtraData;
1064
1065         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1066                 parent::__construct( $message, $code );
1067                 $this->mCodestr = $codestr;
1068                 $this->mExtraData = $extradata;
1069         }
1070
1071         /**
1072          * @return string
1073          */
1074         public function getCodeString() {
1075                 return $this->mCodestr;
1076         }
1077
1078         /**
1079          * @return array
1080          */
1081         public function getMessageArray() {
1082                 $result = array(
1083                         'code' => $this->mCodestr,
1084                         'info' => $this->getMessage()
1085                 );
1086                 if ( is_array( $this->mExtraData ) ) {
1087                         $result = array_merge( $result, $this->mExtraData );
1088                 }
1089                 return $result;
1090         }
1091
1092         /**
1093          * @return string
1094          */
1095         public function __toString() {
1096                 return "{$this->getCodeString()}: {$this->getMessage()}";
1097         }
1098 }