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                         $context->setRequest( $request );
 155                 }
 156                 // We set a derivative context so we can change stuff later
 157                 $this->setContext( new DerivativeContext( $context ) );
 158
 159                 $this->mInternalMode = ( $this->getRequest() instanceof FauxRequest );
 160
 161                 // Special handling for the main module: $parent === $this
 162                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 163
 164                 if ( !$this->mInternalMode ) {
 165                         // Impose module restrictions.
 166                         // If the current user cannot read,
 167                         // Remove all modules other than login
 168                         global $wgUser;
 169
 170                         if ( $this->getRequest()->getVal( 'callback' ) !== null ) {
 171                                 // JSON callback allows cross-site reads.
 172                                 // For safety, strip user credentials.
 173                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 174                                 $wgUser = new User();
 175                                 $this->getContext()->setUser( $wgUser );
 176                         }
 177                 }
 178
 179                 global $wgAPIModules; // extension modules
 180                 $this->mModules = $wgAPIModules + self::$Modules;
 181
 182                 $this->mModuleNames = array_keys( $this->mModules );
 183                 $this->mFormats = self::$Formats;
 184                 $this->mFormatNames = array_keys( $this->mFormats );
 185
 186                 $this->mResult = new ApiResult( $this );
 187                 $this->mShowVersions = false;
 188                 $this->mEnableWrite = $enableWrite;
 189
 190                 //$this->mRequest = &$request;
 191
 192                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 193                 $this->mCommit = false;
 194         }
 195
 196         /**
 197          * Return true if the API was started by other PHP code using FauxRequest
 198          * @return bool
 199          */
 200         public function isInternalMode() {
 201                 return $this->mInternalMode;
 202         }
 203
 204         /**
 205          * Return the request object that contains client's request
 206          * @return WebRequest
 207          */
 208         /*public function getRequest() {
 209                 return $this->mRequest;
 210         }*/
 211
 212         /**
 213          * Get the ApiResult object associated with current request
 214          *
 215          * @return ApiResult
 216          */
 217         public function getResult() {
 218                 return $this->mResult;
 219         }
 220
 221         /**
 222          * Get the API module object. Only works after executeAction()
 223          *
 224          * @return ApiBase
 225          */
 226         public function getModule() {
 227                 return $this->mModule;
 228         }
 229
 230         /**
 231          * Get the result formatter object. Only works after setupExecuteAction()
 232          *
 233          * @return ApiFormatBase
 234          */
 235         public function getPrinter() {
 236                 return $this->mPrinter;
 237         }
 238
 239         /**
 240          * Set how long the response should be cached.
 241          *
 242          * @param $maxage
 243          */
 244         public function setCacheMaxAge( $maxage ) {
 245                 $this->setCacheControl( array(
 246                         'max-age' => $maxage,
 247                         's-maxage' => $maxage
 248                 ) );
 249         }
 250
 251         /**
 252          * Set the type of caching headers which will be sent.
 253          *
 254          * @param $mode String One of:
 255          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 256          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 257          *         not provided by any of these means, the object will be private.
 258          *    - 'private':    Cache this object only in private client-side caches.
 259          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 260          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 261          *         set consistently for a given URL, it cannot be set differently depending on
 262          *         things like the contents of the database, or whether the user is logged in.
 263          *
 264          *  If the wiki does not allow anonymous users to read it, the mode set here
 265          *  will be ignored, and private caching headers will always be sent. In other words,
 266          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 267          *  view.
 268          *
 269          *  For user-dependent data, the private mode should generally be used. The
 270          *  anon-public-user-private mode should only be used where there is a particularly
 271          *  good performance reason for caching the anonymous response, but where the
 272          *  response to logged-in users may differ, or may contain private data.
 273          *
 274          *  If this function is never called, then the default will be the private mode.
 275          */
 276         public function setCacheMode( $mode ) {
 277                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 278                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 279                         // Ignore for forwards-compatibility
 280                         return;
 281                 }
 282
 283                 if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 284                         // Private wiki, only private headers
 285                         if ( $mode !== 'private' ) {
 286                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 287                                 return;
 288                         }
 289                 }
 290
 291                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 292                 $this->mCacheMode = $mode;
 293         }
 294
 295         /**
 296          * @deprecated since 1.17 Private caching is now the default, so there is usually no
 297          * need to call this function. If there is a need, you can use
 298          * $this->setCacheMode('private')
 299          */
 300         public function setCachePrivate() {
 301                 $this->setCacheMode( 'private' );
 302         }
 303
 304         /**
 305          * Set directives (key/value pairs) for the Cache-Control header.
 306          * Boolean values will be formatted as such, by including or omitting
 307          * without an equals sign.
 308          *
 309          * Cache control values set here will only be used if the cache mode is not
 310          * private, see setCacheMode().
 311          *
 312          * @param $directives array
 313          */
 314         public function setCacheControl( $directives ) {
 315                 $this->mCacheControl = $directives + $this->mCacheControl;
 316         }
 317
 318         /**
 319          * Make sure Vary: Cookie and friends are set. Use this when the output of a request
 320          * may be cached for anons but may not be cached for logged-in users.
 321          *
 322          * WARNING: This function must be called CONSISTENTLY for a given URL. This means that a
 323          * given URL must either always or never call this function; if it sometimes does and
 324          * sometimes doesn't, stuff will break.
 325          *
 326          * @deprecated since 1.17 Use setCacheMode( 'anon-public-user-private' )
 327          */
 328         public function setVaryCookie() {
 329                 $this->setCacheMode( 'anon-public-user-private' );
 330         }
 331
 332         /**
 333          * Create an instance of an output formatter by its name
 334          *
 335          * @param $format string
 336          *
 337          * @return ApiFormatBase
 338          */
 339         public function createPrinterByName( $format ) {
 340                 if ( !isset( $this->mFormats[$format] ) ) {
 341                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 342                 }
 343                 return new $this->mFormats[$format] ( $this, $format );
 344         }
 345
 346         /**
 347          * Execute api request. Any errors will be handled if the API was called by the remote client.
 348          */
 349         public function execute() {
 350                 $this->profileIn();
 351                 if ( $this->mInternalMode ) {
 352                         $this->executeAction();
 353                 } else {
 354                         $this->executeActionWithErrorHandling();
 355                 }
 356
 357                 $this->profileOut();
 358         }
 359
 360         /**
 361          * Execute an action, and in case of an error, erase whatever partial results
 362          * have been accumulated, and replace it with an error message and a help screen.
 363          */
 364         protected function executeActionWithErrorHandling() {
 365                 // In case an error occurs during data output,
 366                 // clear the output buffer and print just the error information
 367                 ob_start();
 368
 369                 try {
 370                         $this->executeAction();
 371                 } catch ( Exception $e ) {
 372                         // Log it
 373                         if ( $e instanceof MWException ) {
 374                                 wfDebugLog( 'exception', $e->getLogMessage() );
 375                         }
 376
 377                         // Handle any kind of exception by outputing properly formatted error message.
 378                         // If this fails, an unhandled exception should be thrown so that global error
 379                         // handler will process and log it.
 380
 381                         $errCode = $this->substituteResultWithError( $e );
 382
 383                         // Error results should not be cached
 384                         $this->setCacheMode( 'private' );
 385
 386                         $response = $this->getRequest()->response();
 387                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 388                         if ( $e->getCode() === 0 ) {
 389                                 $response->header( $headerStr );
 390                         } else {
 391                                 $response->header( $headerStr, true, $e->getCode() );
 392                         }
 393
 394                         // Reset and print just the error message
 395                         ob_clean();
 396
 397                         // If the error occured during printing, do a printer->profileOut()
 398                         $this->mPrinter->safeProfileOut();
 399                         $this->printResult( true );
 400                 }
 401
 402                 // Send cache headers after any code which might generate an error, to
 403                 // avoid sending public cache headers for errors.
 404                 $this->sendCacheHeaders();
 405
 406                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 407                         echo wfReportTime();
 408                 }
 409
 410                 ob_end_flush();
 411         }
 412
 413         protected function sendCacheHeaders() {
 414                 global $wgUseXVO, $wgOut, $wgVaryOnXFP;
 415                 $response = $this->getRequest()->response();
 416
 417                 if ( $this->mCacheMode == 'private' ) {
 418                         $response->header( 'Cache-Control: private' );
 419                         return;
 420                 }
 421
 422                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 423                         $xfp = $wgVaryOnXFP ? ', X-Forwarded-Proto' : '';
 424                         $response->header( 'Vary: Accept-Encoding, Cookie' . $xfp );
 425                         if ( $wgUseXVO ) {
 426                                 if ( $wgVaryOnXFP ) {
 427                                         $wgOut->addVaryHeader( 'X-Forwarded-Proto' );
 428                                 }
 429                                 $response->header( $wgOut->getXVO() );
 430                                 if ( $wgOut->haveCacheVaryCookies() ) {
 431                                         // Logged in, mark this request private
 432                                         $response->header( 'Cache-Control: private' );
 433                                         return;
 434                                 }
 435                                 // Logged out, send normal public headers below
 436                         } elseif ( session_id() != '' ) {
 437                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 438                                 // Mark request private
 439                                 $response->header( 'Cache-Control: private' );
 440                                 return;
 441                         } // else no XVO and anonymous, send public headers below
 442                 }
 443
 444                 // Send public headers
 445                 if ( $wgVaryOnXFP ) {
 446                         $response->header( 'Vary: Accept-Encoding, X-Forwarded-Proto' );
 447                         if ( $wgUseXVO ) {
 448                                 // Bleeeeegh. Our header setting system sucks
 449                                 $response->header( 'X-Vary-Options: Accept-Encoding;list-contains=gzip, X-Forwarded-Proto' );
 450                         }
 451                 }
 452
 453                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 454                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 455                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 456                 }
 457                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 458                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 459                 }
 460
 461                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 462                         // Public cache not requested
 463                         // Sending a Vary header in this case is harmless, and protects us
 464                         // against conditional calls of setCacheMaxAge().
 465                         $response->header( 'Cache-Control: private' );
 466                         return;
 467                 }
 468
 469                 $this->mCacheControl['public'] = true;
 470
 471                 // Send an Expires header
 472                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 473                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 474                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 475
 476                 // Construct the Cache-Control header
 477                 $ccHeader = '';
 478                 $separator = '';
 479                 foreach ( $this->mCacheControl as $name => $value ) {
 480                         if ( is_bool( $value ) ) {
 481                                 if ( $value ) {
 482                                         $ccHeader .= $separator . $name;
 483                                         $separator = ', ';
 484                                 }
 485                         } else {
 486                                 $ccHeader .= $separator . "$name=$value";
 487                                 $separator = ', ';
 488                         }
 489                 }
 490
 491                 $response->header( "Cache-Control: $ccHeader" );
 492         }
 493
 494         /**
 495          * Replace the result data with the information about an exception.
 496          * Returns the error code
 497          * @param $e Exception
 498          * @return string
 499          */
 500         protected function substituteResultWithError( $e ) {
 501                 global $wgShowHostnames;
 502
 503                 $result = $this->getResult();
 504                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 505                 if ( !isset ( $this->mPrinter ) ) {
 506                         // The printer has not been created yet. Try to manually get formatter value.
 507                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 508                         if ( !in_array( $value, $this->mFormatNames ) ) {
 509                                 $value = self::API_DEFAULT_FORMAT;
 510                         }
 511
 512                         $this->mPrinter = $this->createPrinterByName( $value );
 513                         if ( $this->mPrinter->getNeedsRawData() ) {
 514                                 $result->setRawMode();
 515                         }
 516                 }
 517
 518                 if ( $e instanceof UsageException ) {
 519                         // User entered incorrect parameters - print usage screen
 520                         $errMessage = $e->getMessageArray();
 521
 522                         // Only print the help message when this is for the developer, not runtime
 523                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 524                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 525                         }
 526
 527                 } else {
 528                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 529                         // Something is seriously wrong
 530                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 531                                 $info = 'Database query error';
 532                         } else {
 533                                 $info = "Exception Caught: {$e->getMessage()}";
 534                         }
 535
 536                         $errMessage = array(
 537                                 'code' => 'internal_api_error_' . get_class( $e ),
 538                                 'info' => $info,
 539                         );
 540                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 541                 }
 542
 543                 $result->reset();
 544                 $result->disableSizeCheck();
 545                 // Re-add the id
 546                 $requestid = $this->getParameter( 'requestid' );
 547                 if ( !is_null( $requestid ) ) {
 548                         $result->addValue( null, 'requestid', $requestid );
 549                 }
 550
 551                 if ( $wgShowHostnames ) {
 552                         // servedby is especially useful when debugging errors
 553                         $result->addValue( null, 'servedby', wfHostName() );
 554                 }
 555
 556                 $result->addValue( null, 'error', $errMessage );
 557
 558                 return $errMessage['code'];
 559         }
 560
 561         /**
 562          * Set up for the execution.
 563          * @return array
 564          */
 565         protected function setupExecuteAction() {
 566                 global $wgShowHostnames;
 567
 568                 // First add the id to the top element
 569                 $result = $this->getResult();
 570                 $requestid = $this->getParameter( 'requestid' );
 571                 if ( !is_null( $requestid ) ) {
 572                         $result->addValue( null, 'requestid', $requestid );
 573                 }
 574
 575                 if ( $wgShowHostnames ) {
 576                         $servedby = $this->getParameter( 'servedby' );
 577                         if ( $servedby ) {
 578                                 $result->addValue( null, 'servedby', wfHostName() );
 579                         }
 580                 }
 581
 582                 $params = $this->extractRequestParams();
 583
 584                 $this->mShowVersions = $params['version'];
 585                 $this->mAction = $params['action'];
 586
 587                 if ( !is_string( $this->mAction ) ) {
 588                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 589                 }
 590
 591                 return $params;
 592         }
 593
 594         /**
 595          * Set up the module for response
 596          * @return ApiBase The module that will handle this action
 597          */
 598         protected function setupModule() {
 599                 // Instantiate the module requested by the user
 600                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 601                 $this->mModule = $module;
 602
 603                 $moduleParams = $module->extractRequestParams();
 604
 605                 // Die if token required, but not provided (unless there is a gettoken parameter)
 606                 $salt = $module->getTokenSalt();
 607                 if ( $salt !== false && !isset( $moduleParams['gettoken'] ) ) {
 608                         if ( !isset( $moduleParams['token'] ) ) {
 609                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 610                         } else {
 611                                 if ( !$this->getUser()->matchEditToken( $moduleParams['token'], $salt, $this->getRequest() ) ) {
 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                         // Print result data
 720                         $this->printResult( false );
 721                 }
 722         }
 723
 724         /**
 725          * Print results using the current printer
 726          *
 727          * @param $isError bool
 728          */
 729         protected function printResult( $isError ) {
 730                 $this->getResult()->cleanUpUTF8();
 731                 $printer = $this->mPrinter;
 732                 $printer->profileIn();
 733
 734                 /**
 735                  * If the help message is requested in the default (xmlfm) format,
 736                  * tell the printer not to escape ampersands so that our links do
 737                  * not break.
 738                  */
 739                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 740                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 741
 742                 $printer->initPrinter( $isError );
 743
 744                 $printer->execute();
 745                 $printer->closePrinter();
 746                 $printer->profileOut();
 747         }
 748
 749         /**
 750          * @return bool
 751          */
 752         public function isReadMode() {
 753                 return false;
 754         }
 755
 756         /**
 757          * See ApiBase for description.
 758          *
 759          * @return array
 760          */
 761         public function getAllowedParams() {
 762                 return array(
 763                         'format' => array(
 764                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 765                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 766                         ),
 767                         'action' => array(
 768                                 ApiBase::PARAM_DFLT => 'help',
 769                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 770                         ),
 771                         'version' => false,
 772                         'maxlag'  => array(
 773                                 ApiBase::PARAM_TYPE => 'integer'
 774                         ),
 775                         'smaxage' => array(
 776                                 ApiBase::PARAM_TYPE => 'integer',
 777                                 ApiBase::PARAM_DFLT => 0
 778                         ),
 779                         'maxage' => array(
 780                                 ApiBase::PARAM_TYPE => 'integer',
 781                                 ApiBase::PARAM_DFLT => 0
 782                         ),
 783                         'requestid' => null,
 784                         'servedby'  => false,
 785                 );
 786         }
 787
 788         /**
 789          * See ApiBase for description.
 790          *
 791          * @return array
 792          */
 793         public function getParamDescription() {
 794                 return array(
 795                         'format' => 'The format of the output',
 796                         'action' => 'What action you would like to perform. See below for module help',
 797                         'version' => 'When showing help, include version for each module',
 798                         'maxlag' => array(
 799                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
 800                                 'To save actions causing any more site replication lag, this parameter can make the client',
 801                                 'wait until the replication lag is less than the specified value.',
 802                                 'In case of a replag error, a HTTP 503 error is returned, with the message like',
 803                                 '"Waiting for $host: $lag seconds lagged\n".',
 804                                 'See http://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
 805                         ),
 806                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 807                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 808                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 809                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 810                 );
 811         }
 812
 813         /**
 814          * See ApiBase for description.
 815          *
 816          * @return array
 817          */
 818         public function getDescription() {
 819                 return array(
 820                         '',
 821                         '',
 822                         '**********************************************************************************************************',
 823                         '**                                                                                                      **',
 824                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 825                         '**                                                                                                      **',
 826                         '**                                    Documentation and Examples:                                       **',
 827                         '**                                 http://www.mediawiki.org/wiki/API                                    **',
 828                         '**                                                                                                      **',
 829                         '**********************************************************************************************************',
 830                         '',
 831                         'Status:                All features shown on this page should be working, but the API',
 832                         '                       is still in active development, and may change at any time.',
 833                         '                       Make sure to monitor our mailing list for any updates',
 834                         '',
 835                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
 836                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
 837                         '                       header and the error code sent back will be set to the same value',
 838                         '',
 839                         '                       In the case of an invalid action being passed, these will have a value',
 840                         '                       of "unknown_action"',
 841                         '',
 842                         '                       For more information see http://www.mediawiki.org/wiki/API:Errors_and_warnings',
 843                         '',
 844                         'Documentation:         http://www.mediawiki.org/wiki/API:Main_page',
 845                         'FAQ                    http://www.mediawiki.org/wiki/API:FAQ',
 846                         'Mailing list:          http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 847                         'Api Announcements:     http://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 848                         'Bugs & Requests:       http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 849                         '',
 850                         '',
 851                         '',
 852                         '',
 853                         '',
 854                 );
 855         }
 856
 857         /**
 858          * @return array
 859          */
 860         public function getPossibleErrors() {
 861                 return array_merge( parent::getPossibleErrors(), array(
 862                         array( 'readonlytext' ),
 863                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 864                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 865                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 866                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 867                 ) );
 868         }
 869
 870         /**
 871          * Returns an array of strings with credits for the API
 872          * @return array
 873          */
 874         protected function getCredits() {
 875                 return array(
 876                         'API developers:',
 877                         '    Roan Kattouw <Firstname>.<Lastname>@gmail.com (lead developer Sep 2007-present)',
 878                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 879                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 880                         '    Sam Reed - sam @ reedyboy . net',
 881                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 882                         '',
 883                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 884                         'or file a bug report at http://bugzilla.wikimedia.org/'
 885                 );
 886         }
 887
 888         /**
 889          * Sets whether the pretty-printer should format *bold* and $italics$
 890          *
 891          * @param $help bool
 892          */
 893         public function setHelp( $help = true ) {
 894                 $this->mPrinter->setHelp( $help );
 895         }
 896
 897         /**
 898          * Override the parent to generate help messages for all available modules.
 899          *
 900          * @return string
 901          */
 902         public function makeHelpMsg() {
 903                 global $wgMemc, $wgAPICacheHelpTimeout;
 904                 $this->setHelp();
 905                 // Get help text from cache if present
 906                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
 907                         SpecialVersion::getVersion( 'nodb' ) .
 908                         $this->getShowVersions() );
 909                 if ( $wgAPICacheHelpTimeout > 0 ) {
 910                         $cached = $wgMemc->get( $key );
 911                         if ( $cached ) {
 912                                 return $cached;
 913                         }
 914                 }
 915                 $retval = $this->reallyMakeHelpMsg();
 916                 if ( $wgAPICacheHelpTimeout > 0 ) {
 917                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
 918                 }
 919                 return $retval;
 920         }
 921
 922         /**
 923          * @return mixed|string
 924          */
 925         public function reallyMakeHelpMsg() {
 926                 $this->setHelp();
 927
 928                 // Use parent to make default message for the main module
 929                 $msg = parent::makeHelpMsg();
 930
 931                 $astriks = str_repeat( '*** ', 14 );
 932                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 933                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
 934                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
 935                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
 936                         $msg2 = $module->makeHelpMsg();
 937                         if ( $msg2 !== false ) {
 938                                 $msg .= $msg2;
 939                         }
 940                         $msg .= "\n";
 941                 }
 942
 943                 $msg .= "\n$astriks Permissions $astriks\n\n";
 944                 foreach ( self::$mRights as $right => $rightMsg ) {
 945                         $groups = User::getGroupsWithPermission( $right );
 946                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
 947                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
 948
 949                 }
 950
 951                 $msg .= "\n$astriks Formats  $astriks\n\n";
 952                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
 953                         $module = $this->createPrinterByName( $formatName );
 954                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
 955                         $msg2 = $module->makeHelpMsg();
 956                         if ( $msg2 !== false ) {
 957                                 $msg .= $msg2;
 958                         }
 959                         $msg .= "\n";
 960                 }
 961
 962                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
 963
 964                 return $msg;
 965         }
 966
 967         /**
 968          * @param $module ApiBase
 969          * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
 970          * @return string
 971          */
 972         public static function makeHelpMsgHeader( $module, $paramName ) {
 973                 $modulePrefix = $module->getModulePrefix();
 974                 if ( strval( $modulePrefix ) !== '' ) {
 975                         $modulePrefix = "($modulePrefix) ";
 976                 }
 977
 978                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 979         }
 980
 981         private $mCanApiHighLimits = null;
 982
 983         /**
 984          * Check whether the current user is allowed to use high limits
 985          * @return bool
 986          */
 987         public function canApiHighLimits() {
 988                 if ( !isset( $this->mCanApiHighLimits ) ) {
 989                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
 990                 }
 991
 992                 return $this->mCanApiHighLimits;
 993         }
 994
 995         /**
 996          * Check whether the user wants us to show version information in the API help
 997          * @return bool
 998          */
 999         public function getShowVersions() {
1000                 return $this->mShowVersions;
1001         }
1002
1003         /**
1004          * Returns the version information of this file, plus it includes
1005          * the versions for all files that are not callable proper API modules
1006          *
1007          * @return array
1008          */
1009         public function getVersion() {
1010                 $vers = array();
1011                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    http://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
1012                 $vers[] = __CLASS__ . ': $Id$';
1013                 $vers[] = ApiBase::getBaseVersion();
1014                 $vers[] = ApiFormatBase::getBaseVersion();
1015                 $vers[] = ApiQueryBase::getBaseVersion();
1016                 return $vers;
1017         }
1018
1019         /**
1020          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1021          * classes who wish to add their own modules to their lexicon or override the
1022          * behavior of inherent ones.
1023          *
1024          * @param $mdlName String The identifier for this module.
1025          * @param $mdlClass String The class where this module is implemented.
1026          */
1027         protected function addModule( $mdlName, $mdlClass ) {
1028                 $this->mModules[$mdlName] = $mdlClass;
1029         }
1030
1031         /**
1032          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1033          * classes who wish to add to or modify current formatters.
1034          *
1035          * @param $fmtName string The identifier for this format.
1036          * @param $fmtClass ApiFormatBase The class implementing this format.
1037          */
1038         protected function addFormat( $fmtName, $fmtClass ) {
1039                 $this->mFormats[$fmtName] = $fmtClass;
1040         }
1041
1042         /**
1043          * Get the array mapping module names to class names
1044          * @return array
1045          */
1046         function getModules() {
1047                 return $this->mModules;
1048         }
1049
1050         /**
1051          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1052          *
1053          * @since 1.18
1054          * @return array
1055          */
1056         public function getFormats() {
1057                 return $this->mFormats;
1058         }
1059 }
1060
1061 /**
1062  * This exception will be thrown when dieUsage is called to stop module execution.
1063  * The exception handling code will print a help screen explaining how this API may be used.
1064  *
1065  * @ingroup API
1066  */
1067 class UsageException extends Exception {
1068
1069         private $mCodestr;
1070         private $mExtraData;
1071
1072         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1073                 parent::__construct( $message, $code );
1074                 $this->mCodestr = $codestr;
1075                 $this->mExtraData = $extradata;
1076         }
1077
1078         /**
1079          * @return string
1080          */
1081         public function getCodeString() {
1082                 return $this->mCodestr;
1083         }
1084
1085         /**
1086          * @return array
1087          */
1088         public function getMessageArray() {
1089                 $result = array(
1090                         'code' => $this->mCodestr,
1091                         'info' => $this->getMessage()
1092                 );
1093                 if ( is_array( $this->mExtraData ) ) {
1094                         $result = array_merge( $result, $this->mExtraData );
1095                 }
1096                 return $result;
1097         }
1098
1099         /**
1100          * @return string
1101          */
1102         public function __toString() {
1103                 return "{$this->getCodeString()}: {$this->getMessage()}";
1104         }
1105 }