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                 'feedwatchlist' => 'ApiFeedWatchlist',
  64                 'help' => 'ApiHelp',
  65                 'paraminfo' => 'ApiParamInfo',
  66                 'rsd' => 'ApiRsd',
  67
  68                 // Write modules
  69                 'purge' => 'ApiPurge',
  70                 'rollback' => 'ApiRollback',
  71                 'delete' => 'ApiDelete',
  72                 'undelete' => 'ApiUndelete',
  73                 'protect' => 'ApiProtect',
  74                 'block' => 'ApiBlock',
  75                 'unblock' => 'ApiUnblock',
  76                 'move' => 'ApiMove',
  77                 'edit' => 'ApiEditPage',
  78                 'upload' => 'ApiUpload',
  79                 'filerevert' => 'ApiFileRevert',
  80                 'emailuser' => 'ApiEmailUser',
  81                 'watch' => 'ApiWatch',
  82                 'patrol' => 'ApiPatrol',
  83                 'import' => 'ApiImport',
  84                 'userrights' => 'ApiUserrights',
  85         );
  86
  87         /**
  88          * List of available formats: format name => format class
  89          */
  90         private static $Formats = array(
  91                 'json' => 'ApiFormatJson',
  92                 'jsonfm' => 'ApiFormatJson',
  93                 'php' => 'ApiFormatPhp',
  94                 'phpfm' => 'ApiFormatPhp',
  95                 'wddx' => 'ApiFormatWddx',
  96                 'wddxfm' => 'ApiFormatWddx',
  97                 'xml' => 'ApiFormatXml',
  98                 'xmlfm' => 'ApiFormatXml',
  99                 'yaml' => 'ApiFormatYaml',
 100                 'yamlfm' => 'ApiFormatYaml',
 101                 'rawfm' => 'ApiFormatJson',
 102                 'txt' => 'ApiFormatTxt',
 103                 'txtfm' => 'ApiFormatTxt',
 104                 'dbg' => 'ApiFormatDbg',
 105                 'dbgfm' => 'ApiFormatDbg',
 106                 'dump' => 'ApiFormatDump',
 107                 'dumpfm' => 'ApiFormatDump',
 108         );
 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, $mRequest;
 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 $request 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( $request, $enableWrite = false ) {
 146                 $this->mInternalMode = ( $request instanceof FauxRequest );
 147
 148                 // Special handling for the main module: $parent === $this
 149                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 150
 151                 if ( !$this->mInternalMode ) {
 152                         // Impose module restrictions.
 153                         // If the current user cannot read,
 154                         // Remove all modules other than login
 155                         global $wgUser;
 156
 157                         if ( $request->getVal( 'callback' ) !== null ) {
 158                                 // JSON callback allows cross-site reads.
 159                                 // For safety, strip user credentials.
 160                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 161                                 $wgUser = new User();
 162                         }
 163                 }
 164
 165                 global $wgAPIModules; // extension modules
 166                 $this->mModules = $wgAPIModules + self::$Modules;
 167
 168                 $this->mModuleNames = array_keys( $this->mModules );
 169                 $this->mFormats = self::$Formats;
 170                 $this->mFormatNames = array_keys( $this->mFormats );
 171
 172                 $this->mResult = new ApiResult( $this );
 173                 $this->mShowVersions = false;
 174                 $this->mEnableWrite = $enableWrite;
 175
 176                 $this->mRequest = &$request;
 177
 178                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 179                 $this->mCommit = false;
 180         }
 181
 182         /**
 183          * Return true if the API was started by other PHP code using FauxRequest
 184          * @return bool
 185          */
 186         public function isInternalMode() {
 187                 return $this->mInternalMode;
 188         }
 189
 190         /**
 191          * Return the request object that contains client's request
 192          * @return WebRequest
 193          */
 194         public function getRequest() {
 195                 return $this->mRequest;
 196         }
 197
 198         /**
 199          * Get the ApiResult object associated with current request
 200          *
 201          * @return ApiResult
 202          */
 203         public function getResult() {
 204                 return $this->mResult;
 205         }
 206
 207         /**
 208          * Get the API module object. Only works after executeAction()
 209          *
 210          * @return ApiBase
 211          */
 212         public function getModule() {
 213                 return $this->mModule;
 214         }
 215
 216         /**
 217          * Get the result formatter object. Only works after setupExecuteAction()
 218          *
 219          * @return ApiFormatBase
 220          */
 221         public function getPrinter() {
 222                 return $this->mPrinter;
 223         }
 224
 225         /**
 226          * Set how long the response should be cached.
 227          */
 228         public function setCacheMaxAge( $maxage ) {
 229                 $this->setCacheControl( array(
 230                         'max-age' => $maxage,
 231                         's-maxage' => $maxage
 232                 ) );
 233         }
 234
 235         /**
 236          * Set the type of caching headers which will be sent.
 237          *
 238          * @param $mode String One of:
 239          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 240          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 241          *         not provided by any of these means, the object will be private.
 242          *    - 'private':    Cache this object only in private client-side caches.
 243          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 244          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 245          *         set consistently for a given URL, it cannot be set differently depending on
 246          *         things like the contents of the database, or whether the user is logged in.
 247          *
 248          *  If the wiki does not allow anonymous users to read it, the mode set here
 249          *  will be ignored, and private caching headers will always be sent. In other words,
 250          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 251          *  view.
 252          *
 253          *  For user-dependent data, the private mode should generally be used. The
 254          *  anon-public-user-private mode should only be used where there is a particularly
 255          *  good performance reason for caching the anonymous response, but where the
 256          *  response to logged-in users may differ, or may contain private data.
 257          *
 258          *  If this function is never called, then the default will be the private mode.
 259          */
 260         public function setCacheMode( $mode ) {
 261                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 262                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 263                         // Ignore for forwards-compatibility
 264                         return;
 265                 }
 266
 267                 if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 268                         // Private wiki, only private headers
 269                         if ( $mode !== 'private' ) {
 270                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 271                                 return;
 272                         }
 273                 }
 274
 275                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 276                 $this->mCacheMode = $mode;
 277         }
 278
 279         /**
 280          * @deprecated Private caching is now the default, so there is usually no
 281          * need to call this function. If there is a need, you can use
 282          * $this->setCacheMode('private')
 283          */
 284         public function setCachePrivate() {
 285                 $this->setCacheMode( 'private' );
 286         }
 287
 288         /**
 289          * Set directives (key/value pairs) for the Cache-Control header.
 290          * Boolean values will be formatted as such, by including or omitting
 291          * without an equals sign.
 292          *
 293          * Cache control values set here will only be used if the cache mode is not
 294          * private, see setCacheMode().
 295          */
 296         public function setCacheControl( $directives ) {
 297                 $this->mCacheControl = $directives + $this->mCacheControl;
 298         }
 299
 300         /**
 301          * Make sure Vary: Cookie and friends are set. Use this when the output of a request
 302          * may be cached for anons but may not be cached for logged-in users.
 303          *
 304          * WARNING: This function must be called CONSISTENTLY for a given URL. This means that a
 305          * given URL must either always or never call this function; if it sometimes does and
 306          * sometimes doesn't, stuff will break.
 307          *
 308          * @deprecated Use setCacheMode( 'anon-public-user-private' )
 309          */
 310         public function setVaryCookie() {
 311                 $this->setCacheMode( 'anon-public-user-private' );
 312         }
 313
 314         /**
 315          * Create an instance of an output formatter by its name
 316          *
 317          * @return ApiFormatBase
 318          */
 319         public function createPrinterByName( $format ) {
 320                 if ( !isset( $this->mFormats[$format] ) ) {
 321                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 322                 }
 323                 return new $this->mFormats[$format] ( $this, $format );
 324         }
 325
 326         /**
 327          * Execute api request. Any errors will be handled if the API was called by the remote client.
 328          */
 329         public function execute() {
 330                 $this->profileIn();
 331                 if ( $this->mInternalMode ) {
 332                         $this->executeAction();
 333                 } else {
 334                         $this->executeActionWithErrorHandling();
 335                 }
 336
 337                 $this->profileOut();
 338         }
 339
 340         /**
 341          * Execute an action, and in case of an error, erase whatever partial results
 342          * have been accumulated, and replace it with an error message and a help screen.
 343          */
 344         protected function executeActionWithErrorHandling() {
 345                 // In case an error occurs during data output,
 346                 // clear the output buffer and print just the error information
 347                 ob_start();
 348
 349                 try {
 350                         $this->executeAction();
 351                 } catch ( Exception $e ) {
 352                         // Log it
 353                         if ( $e instanceof MWException ) {
 354                                 wfDebugLog( 'exception', $e->getLogMessage() );
 355                         }
 356
 357                         //
 358                         // Handle any kind of exception by outputing properly formatted error message.
 359                         // If this fails, an unhandled exception should be thrown so that global error
 360                         // handler will process and log it.
 361                         //
 362
 363                         $errCode = $this->substituteResultWithError( $e );
 364
 365                         // Error results should not be cached
 366                         $this->setCacheMode( 'private' );
 367
 368                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 369                         if ( $e->getCode() === 0 ) {
 370                                 header( $headerStr );
 371                         } else {
 372                                 header( $headerStr, true, $e->getCode() );
 373                         }
 374
 375                         // Reset and print just the error message
 376                         ob_clean();
 377
 378                         // If the error occured during printing, do a printer->profileOut()
 379                         $this->mPrinter->safeProfileOut();
 380                         $this->printResult( true );
 381                 }
 382
 383                 // Send cache headers after any code which might generate an error, to
 384                 // avoid sending public cache headers for errors.
 385                 $this->sendCacheHeaders();
 386
 387                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 388                         echo wfReportTime();
 389                 }
 390
 391                 ob_end_flush();
 392         }
 393
 394         protected function sendCacheHeaders() {
 395                 if ( $this->mCacheMode == 'private' ) {
 396                         header( 'Cache-Control: private' );
 397                         return;
 398                 }
 399
 400                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 401                         global $wgUseXVO, $wgOut;
 402                         header( 'Vary: Accept-Encoding, Cookie' );
 403                         if ( $wgUseXVO ) {
 404                                 header( $wgOut->getXVO() );
 405                                 if ( $wgOut->haveCacheVaryCookies() ) {
 406                                         // Logged in, mark this request private
 407                                         header( 'Cache-Control: private' );
 408                                         return;
 409                                 }
 410                                 // Logged out, send normal public headers below
 411                         } elseif ( session_id() != '' ) {
 412                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 413                                 // Mark request private
 414                                 header( 'Cache-Control: private' );
 415                                 return;
 416                         } // else no XVO and anonymous, send public headers below
 417                 }
 418
 419                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 420                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 421                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 422                 }
 423                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 424                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 425                 }
 426
 427                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 428                         // Public cache not requested
 429                         // Sending a Vary header in this case is harmless, and protects us
 430                         // against conditional calls of setCacheMaxAge().
 431                         header( 'Cache-Control: private' );
 432                         return;
 433                 }
 434
 435                 $this->mCacheControl['public'] = true;
 436
 437                 // Send an Expires header
 438                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 439                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 440                 header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 441
 442                 // Construct the Cache-Control header
 443                 $ccHeader = '';
 444                 $separator = '';
 445                 foreach ( $this->mCacheControl as $name => $value ) {
 446                         if ( is_bool( $value ) ) {
 447                                 if ( $value ) {
 448                                         $ccHeader .= $separator . $name;
 449                                         $separator = ', ';
 450                                 }
 451                         } else {
 452                                 $ccHeader .= $separator . "$name=$value";
 453                                 $separator = ', ';
 454                         }
 455                 }
 456
 457                 header( "Cache-Control: $ccHeader" );
 458         }
 459
 460         /**
 461          * Replace the result data with the information about an exception.
 462          * Returns the error code
 463          * @param $e Exception
 464          * @return string
 465          */
 466         protected function substituteResultWithError( $e ) {
 467                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 468                 if ( !isset ( $this->mPrinter ) ) {
 469                         // The printer has not been created yet. Try to manually get formatter value.
 470                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 471                         if ( !in_array( $value, $this->mFormatNames ) ) {
 472                                 $value = self::API_DEFAULT_FORMAT;
 473                         }
 474
 475                         $this->mPrinter = $this->createPrinterByName( $value );
 476                         if ( $this->mPrinter->getNeedsRawData() ) {
 477                                 $this->getResult()->setRawMode();
 478                         }
 479                 }
 480
 481                 if ( $e instanceof UsageException ) {
 482                         // User entered incorrect parameters - print usage screen
 483                         $errMessage = $e->getMessageArray();
 484
 485                         // Only print the help message when this is for the developer, not runtime
 486                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 487                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 488                         }
 489
 490                 } else {
 491                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 492                         // Something is seriously wrong
 493                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 494                                 $info = 'Database query error';
 495                         } else {
 496                                 $info = "Exception Caught: {$e->getMessage()}";
 497                         }
 498
 499                         $errMessage = array(
 500                                 'code' => 'internal_api_error_' . get_class( $e ),
 501                                 'info' => $info,
 502                         );
 503                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 504                 }
 505
 506                 $this->getResult()->reset();
 507                 $this->getResult()->disableSizeCheck();
 508                 // Re-add the id
 509                 $requestid = $this->getParameter( 'requestid' );
 510                 if ( !is_null( $requestid ) ) {
 511                         $this->getResult()->addValue( null, 'requestid', $requestid );
 512                 }
 513                 // servedby is especially useful when debugging errors
 514                 $this->getResult()->addValue( null, 'servedby', wfHostName() );
 515                 $this->getResult()->addValue( null, 'error', $errMessage );
 516
 517                 return $errMessage['code'];
 518         }
 519
 520         /**
 521          * Set up for the execution.
 522          * @return array
 523          */
 524         protected function setupExecuteAction() {
 525                 // First add the id to the top element
 526                 $requestid = $this->getParameter( 'requestid' );
 527                 if ( !is_null( $requestid ) ) {
 528                         $this->getResult()->addValue( null, 'requestid', $requestid );
 529                 }
 530                 $servedby = $this->getParameter( 'servedby' );
 531                 if ( $servedby ) {
 532                         $this->getResult()->addValue( null, 'servedby', wfHostName() );
 533                 }
 534
 535                 $params = $this->extractRequestParams();
 536
 537                 $this->mShowVersions = $params['version'];
 538                 $this->mAction = $params['action'];
 539
 540                 if ( !is_string( $this->mAction ) ) {
 541                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 542                 }
 543
 544                 return $params;
 545         }
 546
 547         /**
 548          * Set up the module for response
 549          * @return ApiBase The module that will handle this action
 550          */
 551         protected function setupModule() {
 552                 // Instantiate the module requested by the user
 553                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 554                 $this->mModule = $module;
 555
 556                 $moduleParams = $module->extractRequestParams();
 557
 558                 // Die if token required, but not provided (unless there is a gettoken parameter)
 559                 $salt = $module->getTokenSalt();
 560                 if ( $salt !== false && !isset( $moduleParams['gettoken'] ) ) {
 561                         if ( !isset( $moduleParams['token'] ) ) {
 562                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 563                         } else {
 564                                 global $wgUser;
 565                                 if ( !$wgUser->matchEditToken( $moduleParams['token'], $salt, $this->getMain()->getRequest() ) ) {
 566                                         $this->dieUsageMsg( array( 'sessionfailure' ) );
 567                                 }
 568                         }
 569                 }
 570                 return $module;
 571         }
 572
 573         /**
 574          * Check the max lag if necessary
 575          * @param $module ApiBase object: Api module being used
 576          * @param $params Array an array containing the request parameters.
 577          * @return boolean True on success, false should exit immediately
 578          */
 579         protected function checkMaxLag( $module, $params ) {
 580                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 581                         // Check for maxlag
 582                         global $wgShowHostnames;
 583                         $maxLag = $params['maxlag'];
 584                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 585                         if ( $lag > $maxLag ) {
 586                                 header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 587                                 header( 'X-Database-Lag: ' . intval( $lag ) );
 588                                 if ( $wgShowHostnames ) {
 589                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 590                                 } else {
 591                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 592                                 }
 593                                 return false;
 594                         }
 595                 }
 596                 return true;
 597         }
 598
 599
 600         /**
 601          * Check for sufficient permissions to execute
 602          * @param $module ApiBase An Api module
 603          */
 604         protected function checkExecutePermissions( $module ) {
 605                 global $wgUser;
 606                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 607                         !$wgUser->isAllowed( 'read' ) )
 608                 {
 609                         $this->dieUsageMsg( array( 'readrequired' ) );
 610                 }
 611                 if ( $module->isWriteMode() ) {
 612                         if ( !$this->mEnableWrite ) {
 613                                 $this->dieUsageMsg( array( 'writedisabled' ) );
 614                         }
 615                         if ( !$wgUser->isAllowed( 'writeapi' ) ) {
 616                                 $this->dieUsageMsg( array( 'writerequired' ) );
 617                         }
 618                         if ( wfReadOnly() ) {
 619                                 $this->dieReadOnly();
 620                         }
 621                 }
 622         }
 623
 624         /**
 625          * Check POST for external response and setup result printer
 626          * @param $module ApiBase An Api module
 627          * @param $params Array an array with the request parameters
 628          */
 629         protected function setupExternalResponse( $module, $params ) {
 630                 // Ignore mustBePosted() for internal calls
 631                 if ( $module->mustBePosted() && !$this->mRequest->wasPosted() ) {
 632                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 633                 }
 634
 635                 // See if custom printer is used
 636                 $this->mPrinter = $module->getCustomPrinter();
 637                 if ( is_null( $this->mPrinter ) ) {
 638                         // Create an appropriate printer
 639                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 640                 }
 641
 642                 if ( $this->mPrinter->getNeedsRawData() ) {
 643                         $this->getResult()->setRawMode();
 644                 }
 645         }
 646
 647         /**
 648          * Execute the actual module, without any error handling
 649          */
 650         protected function executeAction() {
 651                 $params = $this->setupExecuteAction();
 652                 $module = $this->setupModule();
 653
 654                 $this->checkExecutePermissions( $module );
 655
 656                 if ( !$this->checkMaxLag( $module, $params ) ) {
 657                         return;
 658                 }
 659
 660                 if ( !$this->mInternalMode ) {
 661                         $this->setupExternalResponse( $module, $params );
 662                 }
 663
 664                 // Execute
 665                 $module->profileIn();
 666                 $module->execute();
 667                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 668                 $module->profileOut();
 669
 670                 if ( !$this->mInternalMode ) {
 671                         // Print result data
 672                         $this->printResult( false );
 673                 }
 674         }
 675
 676         /**
 677          * Print results using the current printer
 678          */
 679         protected function printResult( $isError ) {
 680                 $this->getResult()->cleanUpUTF8();
 681                 $printer = $this->mPrinter;
 682                 $printer->profileIn();
 683
 684                 /**
 685                  * If the help message is requested in the default (xmlfm) format,
 686                  * tell the printer not to escape ampersands so that our links do
 687                  * not break.
 688                  */
 689                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 690                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 691
 692                 $printer->initPrinter( $isError );
 693
 694                 $printer->execute();
 695                 $printer->closePrinter();
 696                 $printer->profileOut();
 697         }
 698
 699         /**
 700          * @return bool
 701          */
 702         public function isReadMode() {
 703                 return false;
 704         }
 705
 706         /**
 707          * See ApiBase for description.
 708          */
 709         public function getAllowedParams() {
 710                 return array(
 711                         'format' => array(
 712                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 713                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 714                         ),
 715                         'action' => array(
 716                                 ApiBase::PARAM_DFLT => 'help',
 717                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 718                         ),
 719                         'version' => false,
 720                         'maxlag'  => array(
 721                                 ApiBase::PARAM_TYPE => 'integer'
 722                         ),
 723                         'smaxage' => array(
 724                                 ApiBase::PARAM_TYPE => 'integer',
 725                                 ApiBase::PARAM_DFLT => 0
 726                         ),
 727                         'maxage' => array(
 728                                 ApiBase::PARAM_TYPE => 'integer',
 729                                 ApiBase::PARAM_DFLT => 0
 730                         ),
 731                         'requestid' => null,
 732                         'servedby'  => false,
 733                 );
 734         }
 735
 736         /**
 737          * See ApiBase for description.
 738          */
 739         public function getParamDescription() {
 740                 return array(
 741                         'format' => 'The format of the output',
 742                         'action' => 'What action you would like to perform. See below for module help',
 743                         'version' => 'When showing help, include version for each module',
 744                         'maxlag' => 'Maximum lag',
 745                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 746                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 747                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 748                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 749                 );
 750         }
 751
 752         /**
 753          * See ApiBase for description.
 754          */
 755         public function getDescription() {
 756                 return array(
 757                         '',
 758                         '',
 759                         '**********************************************************************************************************',
 760                         '**                                                                                                      **',
 761                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 762                         '**                                                                                                      **',
 763                         '**                                    Documentation and Examples:                                       **',
 764                         '**                                 http://www.mediawiki.org/wiki/API                                    **',
 765                         '**                                                                                                      **',
 766                         '**********************************************************************************************************',
 767                         '',
 768                         'Status:                All features shown on this page should be working, but the API',
 769                         '                       is still in active development, and  may change at any time.',
 770                         '                       Make sure to monitor our mailing list for any updates',
 771                         '',
 772                         'Documentation:         http://www.mediawiki.org/wiki/API',
 773                         'Mailing list:          http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 774                         'Api Announcements:     http://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 775                         'Bugs & Requests:       http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 776                         '',
 777                         '',
 778                         '',
 779                         '',
 780                         '',
 781                 );
 782         }
 783
 784         public function getPossibleErrors() {
 785                 return array_merge( parent::getPossibleErrors(), array(
 786                         array( 'readonlytext' ),
 787                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 788                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 789                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 790                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 791                 ) );
 792         }
 793
 794         /**
 795          * Returns an array of strings with credits for the API
 796          */
 797         protected function getCredits() {
 798                 return array(
 799                         'API developers:',
 800                         '    Roan Kattouw <Firstname>.<Lastname>@gmail.com (lead developer Sep 2007-present)',
 801                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 802                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 803                         '    Sam Reed - sam @ reedyboy . net',
 804                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 805                         '',
 806                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 807                         'or file a bug report at http://bugzilla.wikimedia.org/'
 808                 );
 809         }
 810         /**
 811          * Sets whether the pretty-printer should format *bold* and $italics$
 812          */
 813         public function setHelp( $help = true ) {
 814                 $this->mPrinter->setHelp( $help );
 815         }
 816
 817         /**
 818          * Override the parent to generate help messages for all available modules.
 819          */
 820         public function makeHelpMsg() {
 821                 global $wgMemc, $wgAPICacheHelpTimeout;
 822                 $this->setHelp();
 823                 // Get help text from cache if present
 824                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
 825                         SpecialVersion::getVersion( 'nodb' ) .
 826                         $this->getMain()->getShowVersions() );
 827                 if ( $wgAPICacheHelpTimeout > 0 ) {
 828                         $cached = $wgMemc->get( $key );
 829                         if ( $cached ) {
 830                                 return $cached;
 831                         }
 832                 }
 833                 $retval = $this->reallyMakeHelpMsg();
 834                 if ( $wgAPICacheHelpTimeout > 0 ) {
 835                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
 836                 }
 837                 return $retval;
 838         }
 839
 840         public function reallyMakeHelpMsg() {
 841                 $this->setHelp();
 842
 843                 // Use parent to make default message for the main module
 844                 $msg = parent::makeHelpMsg();
 845
 846                 $astriks = str_repeat( '*** ', 14 );
 847                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 848                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
 849                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
 850                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
 851                         $msg2 = $module->makeHelpMsg();
 852                         if ( $msg2 !== false ) {
 853                                 $msg .= $msg2;
 854                         }
 855                         $msg .= "\n";
 856                 }
 857
 858                 $msg .= "\n$astriks Permissions $astriks\n\n";
 859                 foreach ( self::$mRights as $right => $rightMsg ) {
 860                         $groups = User::getGroupsWithPermission( $right );
 861                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
 862                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
 863
 864                 }
 865
 866                 $msg .= "\n$astriks Formats  $astriks\n\n";
 867                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
 868                         $module = $this->createPrinterByName( $formatName );
 869                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
 870                         $msg2 = $module->makeHelpMsg();
 871                         if ( $msg2 !== false ) {
 872                                 $msg .= $msg2;
 873                         }
 874                         $msg .= "\n";
 875                 }
 876
 877                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
 878
 879                 return $msg;
 880         }
 881
 882         /**
 883          * @static
 884          * @param  $module ApiBase
 885          * @param  $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
 886          * @return string
 887          */
 888         public static function makeHelpMsgHeader( $module, $paramName ) {
 889                 $modulePrefix = $module->getModulePrefix();
 890                 if ( strval( $modulePrefix ) !== '' ) {
 891                         $modulePrefix = "($modulePrefix) ";
 892                 }
 893
 894                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 895         }
 896
 897         private $mIsBot = null;
 898         private $mIsSysop = null;
 899         private $mCanApiHighLimits = null;
 900
 901         /**
 902          * Returns true if the currently logged in user is a bot, false otherwise
 903          * OBSOLETE, use canApiHighLimits() instead
 904          */
 905         public function isBot() {
 906                 if ( !isset( $this->mIsBot ) ) {
 907                         global $wgUser;
 908                         $this->mIsBot = $wgUser->isAllowed( 'bot' );
 909                 }
 910                 return $this->mIsBot;
 911         }
 912
 913         /**
 914          * Similar to isBot(), this method returns true if the logged in user is
 915          * a sysop, and false if not.
 916          * OBSOLETE, use canApiHighLimits() instead
 917          */
 918         public function isSysop() {
 919                 if ( !isset( $this->mIsSysop ) ) {
 920                         global $wgUser;
 921                         $this->mIsSysop = in_array( 'sysop', $wgUser->getGroups() );
 922                 }
 923
 924                 return $this->mIsSysop;
 925         }
 926
 927         /**
 928          * Check whether the current user is allowed to use high limits
 929          * @return bool
 930          */
 931         public function canApiHighLimits() {
 932                 if ( !isset( $this->mCanApiHighLimits ) ) {
 933                         global $wgUser;
 934                         $this->mCanApiHighLimits = $wgUser->isAllowed( 'apihighlimits' );
 935                 }
 936
 937                 return $this->mCanApiHighLimits;
 938         }
 939
 940         /**
 941          * Check whether the user wants us to show version information in the API help
 942          * @return bool
 943          */
 944         public function getShowVersions() {
 945                 return $this->mShowVersions;
 946         }
 947
 948         /**
 949          * Returns the version information of this file, plus it includes
 950          * the versions for all files that are not callable proper API modules
 951          */
 952         public function getVersion() {
 953                 $vers = array ();
 954                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    http://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
 955                 $vers[] = __CLASS__ . ': $Id$';
 956                 $vers[] = ApiBase::getBaseVersion();
 957                 $vers[] = ApiFormatBase::getBaseVersion();
 958                 $vers[] = ApiQueryBase::getBaseVersion();
 959                 return $vers;
 960         }
 961
 962         /**
 963          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
 964          * classes who wish to add their own modules to their lexicon or override the
 965          * behavior of inherent ones.
 966          *
 967          * @param $mdlName String The identifier for this module.
 968          * @param $mdlClass String The class where this module is implemented.
 969          */
 970         protected function addModule( $mdlName, $mdlClass ) {
 971                 $this->mModules[$mdlName] = $mdlClass;
 972         }
 973
 974         /**
 975          * Add or overwrite an output format for this ApiMain. Intended for use by extending
 976          * classes who wish to add to or modify current formatters.
 977          *
 978          * @param $fmtName The identifier for this format.
 979          * @param $fmtClass The class implementing this format.
 980          */
 981         protected function addFormat( $fmtName, $fmtClass ) {
 982                 $this->mFormats[$fmtName] = $fmtClass;
 983         }
 984
 985         /**
 986          * Get the array mapping module names to class names
 987          * @return array
 988          */
 989         function getModules() {
 990                 return $this->mModules;
 991         }
 992 }
 993
 994 /**
 995  * This exception will be thrown when dieUsage is called to stop module execution.
 996  * The exception handling code will print a help screen explaining how this API may be used.
 997  *
 998  * @ingroup API
 999  */
1000 class UsageException extends Exception {
1001
1002         private $mCodestr;
1003         private $mExtraData;
1004
1005         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1006                 parent::__construct( $message, $code );
1007                 $this->mCodestr = $codestr;
1008                 $this->mExtraData = $extradata;
1009         }
1010
1011         public function getCodeString() {
1012                 return $this->mCodestr;
1013         }
1014
1015         public function getMessageArray() {
1016                 $result = array(
1017                         'code' => $this->mCodestr,
1018                         'info' => $this->getMessage()
1019                 );
1020                 if ( is_array( $this->mExtraData ) ) {
1021                         $result = array_merge( $result, $this->mExtraData );
1022                 }
1023                 return $result;
1024         }
1025
1026         public function __toString() {
1027                 return "{$this->getCodeString()}: {$this->getMessage()}";
1028         }
1029 }