includes/api/ApiMain.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Sep 4, 2006
   6  *
   7  * Copyright © 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @file
  25  * @defgroup API API
  26  */
  27
  28 /**
  29  * This is the main API class, used for both external and internal processing.
  30  * When executed, it will create the requested formatter object,
  31  * instantiate and execute an object associated with the needed action,
  32  * and use formatter to print results.
  33  * In case of an exception, an error message will be printed using the same formatter.
  34  *
  35  * To use API from another application, run it using FauxRequest object, in which
  36  * case any internal exceptions will not be handled but passed up to the caller.
  37  * After successful execution, use getResult() for the resulting data.
  38  *
  39  * @ingroup API
  40  */
  41 class ApiMain extends ApiBase {
  42
  43         /**
  44          * When no format parameter is given, this format will be used
  45          */
  46         const API_DEFAULT_FORMAT = 'xmlfm';
  47
  48         /**
  49          * List of available modules: action name => module class
  50          */
  51         private static $Modules = array(
  52                 'login' => 'ApiLogin',
  53                 'logout' => 'ApiLogout',
  54                 'query' => 'ApiQuery',
  55                 'expandtemplates' => 'ApiExpandTemplates',
  56                 'parse' => 'ApiParse',
  57                 'opensearch' => 'ApiOpenSearch',
  58                 'feedcontributions' => 'ApiFeedContributions',
  59                 'feedwatchlist' => 'ApiFeedWatchlist',
  60                 'help' => 'ApiHelp',
  61                 'paraminfo' => 'ApiParamInfo',
  62                 'rsd' => 'ApiRsd',
  63                 'compare' => 'ApiComparePages',
  64                 'tokens' => 'ApiTokens',
  65
  66                 // Write modules
  67                 'purge' => 'ApiPurge',
  68                 'rollback' => 'ApiRollback',
  69                 'delete' => 'ApiDelete',
  70                 'undelete' => 'ApiUndelete',
  71                 'protect' => 'ApiProtect',
  72                 'block' => 'ApiBlock',
  73                 'unblock' => 'ApiUnblock',
  74                 'move' => 'ApiMove',
  75                 'edit' => 'ApiEditPage',
  76                 'upload' => 'ApiUpload',
  77                 'filerevert' => 'ApiFileRevert',
  78                 'emailuser' => 'ApiEmailUser',
  79                 'watch' => 'ApiWatch',
  80                 'patrol' => 'ApiPatrol',
  81                 'import' => 'ApiImport',
  82                 'userrights' => 'ApiUserrights',
  83                 'options' => 'ApiOptions',
  84         );
  85
  86         /**
  87          * List of available formats: format name => format class
  88          */
  89         private static $Formats = array(
  90                 'json' => 'ApiFormatJson',
  91                 'jsonfm' => 'ApiFormatJson',
  92                 'php' => 'ApiFormatPhp',
  93                 'phpfm' => 'ApiFormatPhp',
  94                 'wddx' => 'ApiFormatWddx',
  95                 'wddxfm' => 'ApiFormatWddx',
  96                 'xml' => 'ApiFormatXml',
  97                 'xmlfm' => 'ApiFormatXml',
  98                 'yaml' => 'ApiFormatYaml',
  99                 'yamlfm' => 'ApiFormatYaml',
 100                 'rawfm' => 'ApiFormatJson',
 101                 'txt' => 'ApiFormatTxt',
 102                 'txtfm' => 'ApiFormatTxt',
 103                 'dbg' => 'ApiFormatDbg',
 104                 'dbgfm' => 'ApiFormatDbg',
 105                 'dump' => 'ApiFormatDump',
 106                 'dumpfm' => 'ApiFormatDump',
 107                 'none' => 'ApiFormatNone',
 108         );
 109
 110         /**
 111          * List of user roles that are specifically relevant to the API.
 112          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 113          *                           'params' => array ( $someVarToSubst ) ),
 114          *                          );
 115          */
 116         private static $mRights = array(
 117                 'writeapi' => array(
 118                         'msg' => 'Use of the write API',
 119                         'params' => array()
 120                 ),
 121                 'apihighlimits' => array(
 122                         'msg' => 'Use higher limits in API queries (Slow queries: $1 results; Fast queries: $2 results). The limits for slow queries also apply to multivalue parameters.',
 123                         'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
 124                 )
 125         );
 126
 127         /**
 128          * @var ApiFormatBase
 129          */
 130         private $mPrinter;
 131
 132         private $mModules, $mModuleNames, $mFormats, $mFormatNames;
 133         private $mResult, $mAction, $mShowVersions, $mEnableWrite;
 134         private $mInternalMode, $mSquidMaxage, $mModule;
 135
 136         private $mCacheMode = 'private';
 137         private $mCacheControl = array();
 138
 139         /**
 140          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 141          *
 142          * @param $context IContextSource|WebRequest - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 143          * @param $enableWrite bool should be set to true if the api may modify data
 144          */
 145         public function __construct( $context = null, $enableWrite = false ) {
 146                 if ( $context === null ) {
 147                         $context = RequestContext::getMain();
 148                 } elseif ( $context instanceof WebRequest ) {
 149                         // BC for pre-1.19
 150                         $request = $context;
 151                         $context = RequestContext::getMain();
 152                 }
 153                 // We set a derivative context so we can change stuff later
 154                 $this->setContext( new DerivativeContext( $context ) );
 155
 156                 if ( isset( $request ) ) {
 157                         $this->getContext()->setRequest( $request );
 158                 }
 159
 160                 $this->mInternalMode = ( $this->getRequest() instanceof FauxRequest );
 161
 162                 // Special handling for the main module: $parent === $this
 163                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 164
 165                 if ( !$this->mInternalMode ) {
 166                         // Impose module restrictions.
 167                         // If the current user cannot read,
 168                         // Remove all modules other than login
 169                         global $wgUser;
 170
 171                         if ( $this->getRequest()->getVal( 'callback' ) !== null ) {
 172                                 // JSON callback allows cross-site reads.
 173                                 // For safety, strip user credentials.
 174                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 175                                 $wgUser = new User();
 176                                 $this->getContext()->setUser( $wgUser );
 177                         }
 178                 }
 179
 180                 global $wgAPIModules; // extension modules
 181                 $this->mModules = $wgAPIModules + self::$Modules;
 182
 183                 $this->mModuleNames = array_keys( $this->mModules );
 184                 $this->mFormats = self::$Formats;
 185                 $this->mFormatNames = array_keys( $this->mFormats );
 186
 187                 $this->mResult = new ApiResult( $this );
 188                 $this->mShowVersions = false;
 189                 $this->mEnableWrite = $enableWrite;
 190
 191                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 192                 $this->mCommit = false;
 193         }
 194
 195         /**
 196          * Return true if the API was started by other PHP code using FauxRequest
 197          * @return bool
 198          */
 199         public function isInternalMode() {
 200                 return $this->mInternalMode;
 201         }
 202
 203         /**
 204          * Get the ApiResult object associated with current request
 205          *
 206          * @return ApiResult
 207          */
 208         public function getResult() {
 209                 return $this->mResult;
 210         }
 211
 212         /**
 213          * Get the API module object. Only works after executeAction()
 214          *
 215          * @return ApiBase
 216          */
 217         public function getModule() {
 218                 return $this->mModule;
 219         }
 220
 221         /**
 222          * Get the result formatter object. Only works after setupExecuteAction()
 223          *
 224          * @return ApiFormatBase
 225          */
 226         public function getPrinter() {
 227                 return $this->mPrinter;
 228         }
 229
 230         /**
 231          * Set how long the response should be cached.
 232          *
 233          * @param $maxage
 234          */
 235         public function setCacheMaxAge( $maxage ) {
 236                 $this->setCacheControl( array(
 237                         'max-age' => $maxage,
 238                         's-maxage' => $maxage
 239                 ) );
 240         }
 241
 242         /**
 243          * Set the type of caching headers which will be sent.
 244          *
 245          * @param $mode String One of:
 246          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 247          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 248          *         not provided by any of these means, the object will be private.
 249          *    - 'private':    Cache this object only in private client-side caches.
 250          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 251          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 252          *         set consistently for a given URL, it cannot be set differently depending on
 253          *         things like the contents of the database, or whether the user is logged in.
 254          *
 255          *  If the wiki does not allow anonymous users to read it, the mode set here
 256          *  will be ignored, and private caching headers will always be sent. In other words,
 257          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 258          *  view.
 259          *
 260          *  For user-dependent data, the private mode should generally be used. The
 261          *  anon-public-user-private mode should only be used where there is a particularly
 262          *  good performance reason for caching the anonymous response, but where the
 263          *  response to logged-in users may differ, or may contain private data.
 264          *
 265          *  If this function is never called, then the default will be the private mode.
 266          */
 267         public function setCacheMode( $mode ) {
 268                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 269                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 270                         // Ignore for forwards-compatibility
 271                         return;
 272                 }
 273
 274                 if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 275                         // Private wiki, only private headers
 276                         if ( $mode !== 'private' ) {
 277                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 278                                 return;
 279                         }
 280                 }
 281
 282                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 283                 $this->mCacheMode = $mode;
 284         }
 285
 286         /**
 287          * @deprecated since 1.17 Private caching is now the default, so there is usually no
 288          * need to call this function. If there is a need, you can use
 289          * $this->setCacheMode('private')
 290          */
 291         public function setCachePrivate() {
 292                 wfDeprecated( __METHOD__, '1.17' );
 293                 $this->setCacheMode( 'private' );
 294         }
 295
 296         /**
 297          * Set directives (key/value pairs) for the Cache-Control header.
 298          * Boolean values will be formatted as such, by including or omitting
 299          * without an equals sign.
 300          *
 301          * Cache control values set here will only be used if the cache mode is not
 302          * private, see setCacheMode().
 303          *
 304          * @param $directives array
 305          */
 306         public function setCacheControl( $directives ) {
 307                 $this->mCacheControl = $directives + $this->mCacheControl;
 308         }
 309
 310         /**
 311          * Make sure Vary: Cookie and friends are set. Use this when the output of a request
 312          * may be cached for anons but may not be cached for logged-in users.
 313          *
 314          * WARNING: This function must be called CONSISTENTLY for a given URL. This means that a
 315          * given URL must either always or never call this function; if it sometimes does and
 316          * sometimes doesn't, stuff will break.
 317          *
 318          * @deprecated since 1.17 Use setCacheMode( 'anon-public-user-private' )
 319          */
 320         public function setVaryCookie() {
 321                 wfDeprecated( __METHOD__, '1.17' );
 322                 $this->setCacheMode( 'anon-public-user-private' );
 323         }
 324
 325         /**
 326          * Create an instance of an output formatter by its name
 327          *
 328          * @param $format string
 329          *
 330          * @return ApiFormatBase
 331          */
 332         public function createPrinterByName( $format ) {
 333                 if ( !isset( $this->mFormats[$format] ) ) {
 334                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 335                 }
 336                 return new $this->mFormats[$format] ( $this, $format );
 337         }
 338
 339         /**
 340          * Execute api request. Any errors will be handled if the API was called by the remote client.
 341          */
 342         public function execute() {
 343                 $this->profileIn();
 344                 if ( $this->mInternalMode ) {
 345                         $this->executeAction();
 346                 } else {
 347                         $this->executeActionWithErrorHandling();
 348                 }
 349
 350                 $this->profileOut();
 351         }
 352
 353         /**
 354          * Execute an action, and in case of an error, erase whatever partial results
 355          * have been accumulated, and replace it with an error message and a help screen.
 356          */
 357         protected function executeActionWithErrorHandling() {
 358                 // 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 UsageException ) ) {
 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                 if ( isset( $moduleParams['gettoken'] ) ) {
 601                         $gettoken = $moduleParams['gettoken'];
 602                 } else {
 603                         $gettoken = false;
 604                 }
 605
 606                 $salt = $module->getTokenSalt();
 607                 if ( $salt !== false && !$gettoken ) {
 608                         if ( !isset( $moduleParams['token'] ) ) {
 609                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 610                         } else {
 611                                 if ( !$this->getUser()->matchEditToken( $moduleParams['token'], $salt ) ) {
 612                                         $this->dieUsageMsg( 'sessionfailure' );
 613                                 }
 614                         }
 615                 }
 616                 return $module;
 617         }
 618
 619         /**
 620          * Check the max lag if necessary
 621          * @param $module ApiBase object: Api module being used
 622          * @param $params Array an array containing the request parameters.
 623          * @return boolean True on success, false should exit immediately
 624          */
 625         protected function checkMaxLag( $module, $params ) {
 626                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 627                         // Check for maxlag
 628                         global $wgShowHostnames;
 629                         $maxLag = $params['maxlag'];
 630                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 631                         if ( $lag > $maxLag ) {
 632                                 $response = $this->getRequest()->response();
 633
 634                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 635                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 636
 637                                 if ( $wgShowHostnames ) {
 638                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 639                                 } else {
 640                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 641                                 }
 642                                 return false;
 643                         }
 644                 }
 645                 return true;
 646         }
 647
 648         /**
 649          * Check for sufficient permissions to execute
 650          * @param $module ApiBase An Api module
 651          */
 652         protected function checkExecutePermissions( $module ) {
 653                 $user = $this->getUser();
 654                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 655                         !$user->isAllowed( 'read' ) )
 656                 {
 657                         $this->dieUsageMsg( 'readrequired' );
 658                 }
 659                 if ( $module->isWriteMode() ) {
 660                         if ( !$this->mEnableWrite ) {
 661                                 $this->dieUsageMsg( 'writedisabled' );
 662                         }
 663                         if ( !$user->isAllowed( 'writeapi' ) ) {
 664                                 $this->dieUsageMsg( 'writerequired' );
 665                         }
 666                         if ( wfReadOnly() ) {
 667                                 $this->dieReadOnly();
 668                         }
 669                 }
 670         }
 671
 672         /**
 673          * Check POST for external response and setup result printer
 674          * @param $module ApiBase An Api module
 675          * @param $params Array an array with the request parameters
 676          */
 677         protected function setupExternalResponse( $module, $params ) {
 678                 // Ignore mustBePosted() for internal calls
 679                 if ( $module->mustBePosted() && !$this->getRequest()->wasPosted() ) {
 680                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 681                 }
 682
 683                 // See if custom printer is used
 684                 $this->mPrinter = $module->getCustomPrinter();
 685                 if ( is_null( $this->mPrinter ) ) {
 686                         // Create an appropriate printer
 687                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 688                 }
 689
 690                 if ( $this->mPrinter->getNeedsRawData() ) {
 691                         $this->getResult()->setRawMode();
 692                 }
 693         }
 694
 695         /**
 696          * Execute the actual module, without any error handling
 697          */
 698         protected function executeAction() {
 699                 $params = $this->setupExecuteAction();
 700                 $module = $this->setupModule();
 701
 702                 $this->checkExecutePermissions( $module );
 703
 704                 if ( !$this->checkMaxLag( $module, $params ) ) {
 705                         return;
 706                 }
 707
 708                 if ( !$this->mInternalMode ) {
 709                         $this->setupExternalResponse( $module, $params );
 710                 }
 711
 712                 // Execute
 713                 $module->profileIn();
 714                 $module->execute();
 715                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 716                 $module->profileOut();
 717
 718                 if ( !$this->mInternalMode ) {
 719                         //append Debug information
 720                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
 721
 722                         // Print result data
 723                         $this->printResult( false );
 724                 }
 725         }
 726
 727         /**
 728          * Print results using the current printer
 729          *
 730          * @param $isError bool
 731          */
 732         protected function printResult( $isError ) {
 733                 $this->getResult()->cleanUpUTF8();
 734                 $printer = $this->mPrinter;
 735                 $printer->profileIn();
 736
 737                 /**
 738                  * If the help message is requested in the default (xmlfm) format,
 739                  * tell the printer not to escape ampersands so that our links do
 740                  * not break.
 741                  */
 742                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 743                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 744
 745                 $printer->initPrinter( $isError );
 746
 747                 $printer->execute();
 748                 $printer->closePrinter();
 749                 $printer->profileOut();
 750         }
 751
 752         /**
 753          * @return bool
 754          */
 755         public function isReadMode() {
 756                 return false;
 757         }
 758
 759         /**
 760          * See ApiBase for description.
 761          *
 762          * @return array
 763          */
 764         public function getAllowedParams() {
 765                 return array(
 766                         'format' => array(
 767                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 768                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 769                         ),
 770                         'action' => array(
 771                                 ApiBase::PARAM_DFLT => 'help',
 772                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 773                         ),
 774                         'version' => false,
 775                         'maxlag'  => array(
 776                                 ApiBase::PARAM_TYPE => 'integer'
 777                         ),
 778                         'smaxage' => array(
 779                                 ApiBase::PARAM_TYPE => 'integer',
 780                                 ApiBase::PARAM_DFLT => 0
 781                         ),
 782                         'maxage' => array(
 783                                 ApiBase::PARAM_TYPE => 'integer',
 784                                 ApiBase::PARAM_DFLT => 0
 785                         ),
 786                         'requestid' => null,
 787                         'servedby'  => false,
 788                 );
 789         }
 790
 791         /**
 792          * See ApiBase for description.
 793          *
 794          * @return array
 795          */
 796         public function getParamDescription() {
 797                 return array(
 798                         'format' => 'The format of the output',
 799                         'action' => 'What action you would like to perform. See below for module help',
 800                         'version' => 'When showing help, include version for each module',
 801                         'maxlag' => array(
 802                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
 803                                 'To save actions causing any more site replication lag, this parameter can make the client',
 804                                 'wait until the replication lag is less than the specified value.',
 805                                 'In case of a replag error, a HTTP 503 error is returned, with the message like',
 806                                 '"Waiting for $host: $lag seconds lagged\n".',
 807                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
 808                         ),
 809                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 810                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 811                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 812                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 813                 );
 814         }
 815
 816         /**
 817          * See ApiBase for description.
 818          *
 819          * @return array
 820          */
 821         public function getDescription() {
 822                 return array(
 823                         '',
 824                         '',
 825                         '**********************************************************************************************************',
 826                         '**                                                                                                      **',
 827                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 828                         '**                                                                                                      **',
 829                         '**                                     Documentation and Examples:                                      **',
 830                         '**                                  https://www.mediawiki.org/wiki/API                                  **',
 831                         '**                                                                                                      **',
 832                         '**********************************************************************************************************',
 833                         '',
 834                         'Status:                All features shown on this page should be working, but the API',
 835                         '                       is still in active development, and may change at any time.',
 836                         '                       Make sure to monitor our mailing list for any updates',
 837                         '',
 838                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
 839                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
 840                         '                       header and the error code sent back will be set to the same value',
 841                         '',
 842                         '                       In the case of an invalid action being passed, these will have a value',
 843                         '                       of "unknown_action"',
 844                         '',
 845                         '                       For more information see https://www.mediawiki.org/wiki/API:Errors_and_warnings',
 846                         '',
 847                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
 848                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
 849                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 850                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 851                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 852                         '',
 853                         '',
 854                         '',
 855                         '',
 856                         '',
 857                 );
 858         }
 859
 860         /**
 861          * @return array
 862          */
 863         public function getPossibleErrors() {
 864                 return array_merge( parent::getPossibleErrors(), array(
 865                         array( 'readonlytext' ),
 866                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 867                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 868                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 869                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 870                 ) );
 871         }
 872
 873         /**
 874          * Returns an array of strings with credits for the API
 875          * @return array
 876          */
 877         protected function getCredits() {
 878                 return array(
 879                         'API developers:',
 880                         '    Roan Kattouw <Firstname>.<Lastname>@gmail.com (lead developer Sep 2007-present)',
 881                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 882                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 883                         '    Sam Reed - sam @ reedyboy . net',
 884                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 885                         '',
 886                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 887                         'or file a bug report at https://bugzilla.wikimedia.org/'
 888                 );
 889         }
 890
 891         /**
 892          * Sets whether the pretty-printer should format *bold* and $italics$
 893          *
 894          * @param $help bool
 895          */
 896         public function setHelp( $help = true ) {
 897                 $this->mPrinter->setHelp( $help );
 898         }
 899
 900         /**
 901          * Override the parent to generate help messages for all available modules.
 902          *
 903          * @return string
 904          */
 905         public function makeHelpMsg() {
 906                 global $wgMemc, $wgAPICacheHelpTimeout;
 907                 $this->setHelp();
 908                 // Get help text from cache if present
 909                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
 910                         SpecialVersion::getVersion( 'nodb' ) .
 911                         $this->getShowVersions() );
 912                 if ( $wgAPICacheHelpTimeout > 0 ) {
 913                         $cached = $wgMemc->get( $key );
 914                         if ( $cached ) {
 915                                 return $cached;
 916                         }
 917                 }
 918                 $retval = $this->reallyMakeHelpMsg();
 919                 if ( $wgAPICacheHelpTimeout > 0 ) {
 920                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
 921                 }
 922                 return $retval;
 923         }
 924
 925         /**
 926          * @return mixed|string
 927          */
 928         public function reallyMakeHelpMsg() {
 929                 $this->setHelp();
 930
 931                 // Use parent to make default message for the main module
 932                 $msg = parent::makeHelpMsg();
 933
 934                 $astriks = str_repeat( '*** ', 14 );
 935                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 936                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
 937                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
 938                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
 939                         $msg2 = $module->makeHelpMsg();
 940                         if ( $msg2 !== false ) {
 941                                 $msg .= $msg2;
 942                         }
 943                         $msg .= "\n";
 944                 }
 945
 946                 $msg .= "\n$astriks Permissions $astriks\n\n";
 947                 foreach ( self::$mRights as $right => $rightMsg ) {
 948                         $groups = User::getGroupsWithPermission( $right );
 949                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
 950                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
 951
 952                 }
 953
 954                 $msg .= "\n$astriks Formats  $astriks\n\n";
 955                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
 956                         $module = $this->createPrinterByName( $formatName );
 957                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
 958                         $msg2 = $module->makeHelpMsg();
 959                         if ( $msg2 !== false ) {
 960                                 $msg .= $msg2;
 961                         }
 962                         $msg .= "\n";
 963                 }
 964
 965                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
 966
 967                 return $msg;
 968         }
 969
 970         /**
 971          * @param $module ApiBase
 972          * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
 973          * @return string
 974          */
 975         public static function makeHelpMsgHeader( $module, $paramName ) {
 976                 $modulePrefix = $module->getModulePrefix();
 977                 if ( strval( $modulePrefix ) !== '' ) {
 978                         $modulePrefix = "($modulePrefix) ";
 979                 }
 980
 981                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 982         }
 983
 984         private $mCanApiHighLimits = null;
 985
 986         /**
 987          * Check whether the current user is allowed to use high limits
 988          * @return bool
 989          */
 990         public function canApiHighLimits() {
 991                 if ( !isset( $this->mCanApiHighLimits ) ) {
 992                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
 993                 }
 994
 995                 return $this->mCanApiHighLimits;
 996         }
 997
 998         /**
 999          * Check whether the user wants us to show version information in the API help
1000          * @return bool
1001          */
1002         public function getShowVersions() {
1003                 return $this->mShowVersions;
1004         }
1005
1006         /**
1007          * Returns the version information of this file, plus it includes
1008          * the versions for all files that are not callable proper API modules
1009          *
1010          * @return array
1011          */
1012         public function getVersion() {
1013                 $vers = array();
1014                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    https://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
1015                 $vers[] = __CLASS__ . ': $Id$';
1016                 $vers[] = ApiBase::getBaseVersion();
1017                 $vers[] = ApiFormatBase::getBaseVersion();
1018                 $vers[] = ApiQueryBase::getBaseVersion();
1019                 return $vers;
1020         }
1021
1022         /**
1023          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1024          * classes who wish to add their own modules to their lexicon or override the
1025          * behavior of inherent ones.
1026          *
1027          * @param $mdlName String The identifier for this module.
1028          * @param $mdlClass String The class where this module is implemented.
1029          */
1030         protected function addModule( $mdlName, $mdlClass ) {
1031                 $this->mModules[$mdlName] = $mdlClass;
1032         }
1033
1034         /**
1035          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1036          * classes who wish to add to or modify current formatters.
1037          *
1038          * @param $fmtName string The identifier for this format.
1039          * @param $fmtClass ApiFormatBase The class implementing this format.
1040          */
1041         protected function addFormat( $fmtName, $fmtClass ) {
1042                 $this->mFormats[$fmtName] = $fmtClass;
1043         }
1044
1045         /**
1046          * Get the array mapping module names to class names
1047          * @return array
1048          */
1049         function getModules() {
1050                 return $this->mModules;
1051         }
1052
1053         /**
1054          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1055          *
1056          * @since 1.18
1057          * @return array
1058          */
1059         public function getFormats() {
1060                 return $this->mFormats;
1061         }
1062 }
1063
1064 /**
1065  * This exception will be thrown when dieUsage is called to stop module execution.
1066  * The exception handling code will print a help screen explaining how this API may be used.
1067  *
1068  * @ingroup API
1069  */
1070 class UsageException extends MWException {
1071
1072         private $mCodestr;
1073         private $mExtraData;
1074
1075         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1076                 parent::__construct( $message, $code );
1077                 $this->mCodestr = $codestr;
1078                 $this->mExtraData = $extradata;
1079         }
1080
1081         /**
1082          * @return string
1083          */
1084         public function getCodeString() {
1085                 return $this->mCodestr;
1086         }
1087
1088         /**
1089          * @return array
1090          */
1091         public function getMessageArray() {
1092                 $result = array(
1093                         'code' => $this->mCodestr,
1094                         'info' => $this->getMessage()
1095                 );
1096                 if ( is_array( $this->mExtraData ) ) {
1097                         $result = array_merge( $result, $this->mExtraData );
1098                 }
1099                 return $result;
1100         }
1101
1102         /**
1103          * @return string
1104          */
1105         public function __toString() {
1106                 return "{$this->getCodeString()}: {$this->getMessage()}";
1107         }
1108 }