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, $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                                 $out = $this->getOutput();
 420                                 if ( $wgVaryOnXFP ) {
 421                                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 422                                 }
 423                                 $response->header( $out->getXVO() );
 424                                 if ( $out->haveCacheVaryCookies() ) {
 425                                         // Logged in, mark this request private
 426                                         $response->header( 'Cache-Control: private' );
 427                                         return;
 428                                 }
 429                                 // Logged out, send normal public headers below
 430                         } elseif ( session_id() != '' ) {
 431                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 432                                 // Mark request private
 433                                 $response->header( 'Cache-Control: private' );
 434                                 return;
 435                         } // else no XVO and anonymous, send public headers below
 436                 }
 437
 438                 // Send public headers
 439                 if ( $wgVaryOnXFP ) {
 440                         $response->header( 'Vary: Accept-Encoding, X-Forwarded-Proto' );
 441                         if ( $wgUseXVO ) {
 442                                 // Bleeeeegh. Our header setting system sucks
 443                                 $response->header( 'X-Vary-Options: Accept-Encoding;list-contains=gzip, X-Forwarded-Proto' );
 444                         }
 445                 }
 446
 447                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 448                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 449                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 450                 }
 451                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 452                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 453                 }
 454
 455                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 456                         // Public cache not requested
 457                         // Sending a Vary header in this case is harmless, and protects us
 458                         // against conditional calls of setCacheMaxAge().
 459                         $response->header( 'Cache-Control: private' );
 460                         return;
 461                 }
 462
 463                 $this->mCacheControl['public'] = true;
 464
 465                 // Send an Expires header
 466                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 467                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 468                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 469
 470                 // Construct the Cache-Control header
 471                 $ccHeader = '';
 472                 $separator = '';
 473                 foreach ( $this->mCacheControl as $name => $value ) {
 474                         if ( is_bool( $value ) ) {
 475                                 if ( $value ) {
 476                                         $ccHeader .= $separator . $name;
 477                                         $separator = ', ';
 478                                 }
 479                         } else {
 480                                 $ccHeader .= $separator . "$name=$value";
 481                                 $separator = ', ';
 482                         }
 483                 }
 484
 485                 $response->header( "Cache-Control: $ccHeader" );
 486         }
 487
 488         /**
 489          * Replace the result data with the information about an exception.
 490          * Returns the error code
 491          * @param $e Exception
 492          * @return string
 493          */
 494         protected function substituteResultWithError( $e ) {
 495                 global $wgShowHostnames;
 496
 497                 $result = $this->getResult();
 498                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 499                 if ( !isset ( $this->mPrinter ) ) {
 500                         // The printer has not been created yet. Try to manually get formatter value.
 501                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 502                         if ( !in_array( $value, $this->mFormatNames ) ) {
 503                                 $value = self::API_DEFAULT_FORMAT;
 504                         }
 505
 506                         $this->mPrinter = $this->createPrinterByName( $value );
 507                         if ( $this->mPrinter->getNeedsRawData() ) {
 508                                 $result->setRawMode();
 509                         }
 510                 }
 511
 512                 if ( $e instanceof UsageException ) {
 513                         // User entered incorrect parameters - print usage screen
 514                         $errMessage = $e->getMessageArray();
 515
 516                         // Only print the help message when this is for the developer, not runtime
 517                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 518                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 519                         }
 520
 521                 } else {
 522                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 523                         // Something is seriously wrong
 524                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 525                                 $info = 'Database query error';
 526                         } else {
 527                                 $info = "Exception Caught: {$e->getMessage()}";
 528                         }
 529
 530                         $errMessage = array(
 531                                 'code' => 'internal_api_error_' . get_class( $e ),
 532                                 'info' => $info,
 533                         );
 534                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 535                 }
 536
 537                 $result->reset();
 538                 $result->disableSizeCheck();
 539                 // Re-add the id
 540                 $requestid = $this->getParameter( 'requestid' );
 541                 if ( !is_null( $requestid ) ) {
 542                         $result->addValue( null, 'requestid', $requestid );
 543                 }
 544
 545                 if ( $wgShowHostnames ) {
 546                         // servedby is especially useful when debugging errors
 547                         $result->addValue( null, 'servedby', wfHostName() );
 548                 }
 549
 550                 $result->addValue( null, 'error', $errMessage );
 551
 552                 return $errMessage['code'];
 553         }
 554
 555         /**
 556          * Set up for the execution.
 557          * @return array
 558          */
 559         protected function setupExecuteAction() {
 560                 global $wgShowHostnames;
 561
 562                 // First add the id to the top element
 563                 $result = $this->getResult();
 564                 $requestid = $this->getParameter( 'requestid' );
 565                 if ( !is_null( $requestid ) ) {
 566                         $result->addValue( null, 'requestid', $requestid );
 567                 }
 568
 569                 if ( $wgShowHostnames ) {
 570                         $servedby = $this->getParameter( 'servedby' );
 571                         if ( $servedby ) {
 572                                 $result->addValue( null, 'servedby', wfHostName() );
 573                         }
 574                 }
 575
 576                 $params = $this->extractRequestParams();
 577
 578                 $this->mShowVersions = $params['version'];
 579                 $this->mAction = $params['action'];
 580
 581                 if ( !is_string( $this->mAction ) ) {
 582                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 583                 }
 584
 585                 return $params;
 586         }
 587
 588         /**
 589          * Set up the module for response
 590          * @return ApiBase The module that will handle this action
 591          */
 592         protected function setupModule() {
 593                 // Instantiate the module requested by the user
 594                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 595                 $this->mModule = $module;
 596
 597                 $moduleParams = $module->extractRequestParams();
 598
 599                 // Die if token required, but not provided (unless there is a gettoken parameter)
 600                 $salt = $module->getTokenSalt();
 601                 if ( $salt !== false && !isset( $moduleParams['gettoken'] ) ) {
 602                         if ( !isset( $moduleParams['token'] ) ) {
 603                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 604                         } else {
 605                                 if ( !$this->getUser()->matchEditToken( $moduleParams['token'], $salt, $this->getRequest() ) ) {
 606                                         $this->dieUsageMsg( 'sessionfailure' );
 607                                 }
 608                         }
 609                 }
 610                 return $module;
 611         }
 612
 613         /**
 614          * Check the max lag if necessary
 615          * @param $module ApiBase object: Api module being used
 616          * @param $params Array an array containing the request parameters.
 617          * @return boolean True on success, false should exit immediately
 618          */
 619         protected function checkMaxLag( $module, $params ) {
 620                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 621                         // Check for maxlag
 622                         global $wgShowHostnames;
 623                         $maxLag = $params['maxlag'];
 624                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 625                         if ( $lag > $maxLag ) {
 626                                 $response = $this->getRequest()->response();
 627
 628                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 629                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 630
 631                                 if ( $wgShowHostnames ) {
 632                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 633                                 } else {
 634                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 635                                 }
 636                                 return false;
 637                         }
 638                 }
 639                 return true;
 640         }
 641
 642         /**
 643          * Check for sufficient permissions to execute
 644          * @param $module ApiBase An Api module
 645          */
 646         protected function checkExecutePermissions( $module ) {
 647                 $user = $this->getUser();
 648                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 649                         !$user->isAllowed( 'read' ) )
 650                 {
 651                         $this->dieUsageMsg( 'readrequired' );
 652                 }
 653                 if ( $module->isWriteMode() ) {
 654                         if ( !$this->mEnableWrite ) {
 655                                 $this->dieUsageMsg( 'writedisabled' );
 656                         }
 657                         if ( !$user->isAllowed( 'writeapi' ) ) {
 658                                 $this->dieUsageMsg( 'writerequired' );
 659                         }
 660                         if ( wfReadOnly() ) {
 661                                 $this->dieReadOnly();
 662                         }
 663                 }
 664         }
 665
 666         /**
 667          * Check POST for external response and setup result printer
 668          * @param $module ApiBase An Api module
 669          * @param $params Array an array with the request parameters
 670          */
 671         protected function setupExternalResponse( $module, $params ) {
 672                 // Ignore mustBePosted() for internal calls
 673                 if ( $module->mustBePosted() && !$this->getRequest()->wasPosted() ) {
 674                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 675                 }
 676
 677                 // See if custom printer is used
 678                 $this->mPrinter = $module->getCustomPrinter();
 679                 if ( is_null( $this->mPrinter ) ) {
 680                         // Create an appropriate printer
 681                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 682                 }
 683
 684                 if ( $this->mPrinter->getNeedsRawData() ) {
 685                         $this->getResult()->setRawMode();
 686                 }
 687         }
 688
 689         /**
 690          * Execute the actual module, without any error handling
 691          */
 692         protected function executeAction() {
 693                 $params = $this->setupExecuteAction();
 694                 $module = $this->setupModule();
 695
 696                 $this->checkExecutePermissions( $module );
 697
 698                 if ( !$this->checkMaxLag( $module, $params ) ) {
 699                         return;
 700                 }
 701
 702                 if ( !$this->mInternalMode ) {
 703                         $this->setupExternalResponse( $module, $params );
 704                 }
 705
 706                 // Execute
 707                 $module->profileIn();
 708                 $module->execute();
 709                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 710                 $module->profileOut();
 711
 712                 if ( !$this->mInternalMode ) {
 713                         // Print result data
 714                         $this->printResult( false );
 715                 }
 716         }
 717
 718         /**
 719          * Print results using the current printer
 720          *
 721          * @param $isError bool
 722          */
 723         protected function printResult( $isError ) {
 724                 $this->getResult()->cleanUpUTF8();
 725                 $printer = $this->mPrinter;
 726                 $printer->profileIn();
 727
 728                 /**
 729                  * If the help message is requested in the default (xmlfm) format,
 730                  * tell the printer not to escape ampersands so that our links do
 731                  * not break.
 732                  */
 733                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 734                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 735
 736                 $printer->initPrinter( $isError );
 737
 738                 $printer->execute();
 739                 $printer->closePrinter();
 740                 $printer->profileOut();
 741         }
 742
 743         /**
 744          * @return bool
 745          */
 746         public function isReadMode() {
 747                 return false;
 748         }
 749
 750         /**
 751          * See ApiBase for description.
 752          *
 753          * @return array
 754          */
 755         public function getAllowedParams() {
 756                 return array(
 757                         'format' => array(
 758                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 759                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 760                         ),
 761                         'action' => array(
 762                                 ApiBase::PARAM_DFLT => 'help',
 763                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 764                         ),
 765                         'version' => false,
 766                         'maxlag'  => array(
 767                                 ApiBase::PARAM_TYPE => 'integer'
 768                         ),
 769                         'smaxage' => array(
 770                                 ApiBase::PARAM_TYPE => 'integer',
 771                                 ApiBase::PARAM_DFLT => 0
 772                         ),
 773                         'maxage' => array(
 774                                 ApiBase::PARAM_TYPE => 'integer',
 775                                 ApiBase::PARAM_DFLT => 0
 776                         ),
 777                         'requestid' => null,
 778                         'servedby'  => false,
 779                 );
 780         }
 781
 782         /**
 783          * See ApiBase for description.
 784          *
 785          * @return array
 786          */
 787         public function getParamDescription() {
 788                 return array(
 789                         'format' => 'The format of the output',
 790                         'action' => 'What action you would like to perform. See below for module help',
 791                         'version' => 'When showing help, include version for each module',
 792                         'maxlag' => array(
 793                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
 794                                 'To save actions causing any more site replication lag, this parameter can make the client',
 795                                 'wait until the replication lag is less than the specified value.',
 796                                 'In case of a replag error, a HTTP 503 error is returned, with the message like',
 797                                 '"Waiting for $host: $lag seconds lagged\n".',
 798                                 'See http://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
 799                         ),
 800                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 801                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 802                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 803                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 804                 );
 805         }
 806
 807         /**
 808          * See ApiBase for description.
 809          *
 810          * @return array
 811          */
 812         public function getDescription() {
 813                 return array(
 814                         '',
 815                         '',
 816                         '**********************************************************************************************************',
 817                         '**                                                                                                      **',
 818                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 819                         '**                                                                                                      **',
 820                         '**                                    Documentation and Examples:                                       **',
 821                         '**                                 http://www.mediawiki.org/wiki/API                                    **',
 822                         '**                                                                                                      **',
 823                         '**********************************************************************************************************',
 824                         '',
 825                         'Status:                All features shown on this page should be working, but the API',
 826                         '                       is still in active development, and may change at any time.',
 827                         '                       Make sure to monitor our mailing list for any updates',
 828                         '',
 829                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
 830                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
 831                         '                       header and the error code sent back will be set to the same value',
 832                         '',
 833                         '                       In the case of an invalid action being passed, these will have a value',
 834                         '                       of "unknown_action"',
 835                         '',
 836                         '                       For more information see http://www.mediawiki.org/wiki/API:Errors_and_warnings',
 837                         '',
 838                         'Documentation:         http://www.mediawiki.org/wiki/API:Main_page',
 839                         'FAQ                    http://www.mediawiki.org/wiki/API:FAQ',
 840                         'Mailing list:          http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 841                         'Api Announcements:     http://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 842                         'Bugs & Requests:       http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 843                         '',
 844                         '',
 845                         '',
 846                         '',
 847                         '',
 848                 );
 849         }
 850
 851         /**
 852          * @return array
 853          */
 854         public function getPossibleErrors() {
 855                 return array_merge( parent::getPossibleErrors(), array(
 856                         array( 'readonlytext' ),
 857                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 858                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 859                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 860                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 861                 ) );
 862         }
 863
 864         /**
 865          * Returns an array of strings with credits for the API
 866          * @return array
 867          */
 868         protected function getCredits() {
 869                 return array(
 870                         'API developers:',
 871                         '    Roan Kattouw <Firstname>.<Lastname>@gmail.com (lead developer Sep 2007-present)',
 872                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 873                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 874                         '    Sam Reed - sam @ reedyboy . net',
 875                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 876                         '',
 877                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 878                         'or file a bug report at http://bugzilla.wikimedia.org/'
 879                 );
 880         }
 881
 882         /**
 883          * Sets whether the pretty-printer should format *bold* and $italics$
 884          *
 885          * @param $help bool
 886          */
 887         public function setHelp( $help = true ) {
 888                 $this->mPrinter->setHelp( $help );
 889         }
 890
 891         /**
 892          * Override the parent to generate help messages for all available modules.
 893          *
 894          * @return string
 895          */
 896         public function makeHelpMsg() {
 897                 global $wgMemc, $wgAPICacheHelpTimeout;
 898                 $this->setHelp();
 899                 // Get help text from cache if present
 900                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
 901                         SpecialVersion::getVersion( 'nodb' ) .
 902                         $this->getShowVersions() );
 903                 if ( $wgAPICacheHelpTimeout > 0 ) {
 904                         $cached = $wgMemc->get( $key );
 905                         if ( $cached ) {
 906                                 return $cached;
 907                         }
 908                 }
 909                 $retval = $this->reallyMakeHelpMsg();
 910                 if ( $wgAPICacheHelpTimeout > 0 ) {
 911                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
 912                 }
 913                 return $retval;
 914         }
 915
 916         /**
 917          * @return mixed|string
 918          */
 919         public function reallyMakeHelpMsg() {
 920                 $this->setHelp();
 921
 922                 // Use parent to make default message for the main module
 923                 $msg = parent::makeHelpMsg();
 924
 925                 $astriks = str_repeat( '*** ', 14 );
 926                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 927                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
 928                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
 929                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
 930                         $msg2 = $module->makeHelpMsg();
 931                         if ( $msg2 !== false ) {
 932                                 $msg .= $msg2;
 933                         }
 934                         $msg .= "\n";
 935                 }
 936
 937                 $msg .= "\n$astriks Permissions $astriks\n\n";
 938                 foreach ( self::$mRights as $right => $rightMsg ) {
 939                         $groups = User::getGroupsWithPermission( $right );
 940                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
 941                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
 942
 943                 }
 944
 945                 $msg .= "\n$astriks Formats  $astriks\n\n";
 946                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
 947                         $module = $this->createPrinterByName( $formatName );
 948                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
 949                         $msg2 = $module->makeHelpMsg();
 950                         if ( $msg2 !== false ) {
 951                                 $msg .= $msg2;
 952                         }
 953                         $msg .= "\n";
 954                 }
 955
 956                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
 957
 958                 return $msg;
 959         }
 960
 961         /**
 962          * @param $module ApiBase
 963          * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
 964          * @return string
 965          */
 966         public static function makeHelpMsgHeader( $module, $paramName ) {
 967                 $modulePrefix = $module->getModulePrefix();
 968                 if ( strval( $modulePrefix ) !== '' ) {
 969                         $modulePrefix = "($modulePrefix) ";
 970                 }
 971
 972                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 973         }
 974
 975         private $mCanApiHighLimits = null;
 976
 977         /**
 978          * Check whether the current user is allowed to use high limits
 979          * @return bool
 980          */
 981         public function canApiHighLimits() {
 982                 if ( !isset( $this->mCanApiHighLimits ) ) {
 983                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
 984                 }
 985
 986                 return $this->mCanApiHighLimits;
 987         }
 988
 989         /**
 990          * Check whether the user wants us to show version information in the API help
 991          * @return bool
 992          */
 993         public function getShowVersions() {
 994                 return $this->mShowVersions;
 995         }
 996
 997         /**
 998          * Returns the version information of this file, plus it includes
 999          * the versions for all files that are not callable proper API modules
1000          *
1001          * @return array
1002          */
1003         public function getVersion() {
1004                 $vers = array();
1005                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    http://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
1006                 $vers[] = __CLASS__ . ': $Id$';
1007                 $vers[] = ApiBase::getBaseVersion();
1008                 $vers[] = ApiFormatBase::getBaseVersion();
1009                 $vers[] = ApiQueryBase::getBaseVersion();
1010                 return $vers;
1011         }
1012
1013         /**
1014          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1015          * classes who wish to add their own modules to their lexicon or override the
1016          * behavior of inherent ones.
1017          *
1018          * @param $mdlName String The identifier for this module.
1019          * @param $mdlClass String The class where this module is implemented.
1020          */
1021         protected function addModule( $mdlName, $mdlClass ) {
1022                 $this->mModules[$mdlName] = $mdlClass;
1023         }
1024
1025         /**
1026          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1027          * classes who wish to add to or modify current formatters.
1028          *
1029          * @param $fmtName string The identifier for this format.
1030          * @param $fmtClass ApiFormatBase The class implementing this format.
1031          */
1032         protected function addFormat( $fmtName, $fmtClass ) {
1033                 $this->mFormats[$fmtName] = $fmtClass;
1034         }
1035
1036         /**
1037          * Get the array mapping module names to class names
1038          * @return array
1039          */
1040         function getModules() {
1041                 return $this->mModules;
1042         }
1043
1044         /**
1045          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1046          *
1047          * @since 1.18
1048          * @return array
1049          */
1050         public function getFormats() {
1051                 return $this->mFormats;
1052         }
1053 }
1054
1055 /**
1056  * This exception will be thrown when dieUsage is called to stop module execution.
1057  * The exception handling code will print a help screen explaining how this API may be used.
1058  *
1059  * @ingroup API
1060  */
1061 class UsageException extends Exception {
1062
1063         private $mCodestr;
1064         private $mExtraData;
1065
1066         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1067                 parent::__construct( $message, $code );
1068                 $this->mCodestr = $codestr;
1069                 $this->mExtraData = $extradata;
1070         }
1071
1072         /**
1073          * @return string
1074          */
1075         public function getCodeString() {
1076                 return $this->mCodestr;
1077         }
1078
1079         /**
1080          * @return array
1081          */
1082         public function getMessageArray() {
1083                 $result = array(
1084                         'code' => $this->mCodestr,
1085                         'info' => $this->getMessage()
1086                 );
1087                 if ( is_array( $this->mExtraData ) ) {
1088                         $result = array_merge( $result, $this->mExtraData );
1089                 }
1090                 return $result;
1091         }
1092
1093         /**
1094          * @return string
1095          */
1096         public function __toString() {
1097                 return "{$this->getCodeString()}: {$this->getMessage()}";
1098         }
1099 }