includes/api/ApiMain.php

   1 <?php
   2
   3 /*
   4  * Created on Sep 4, 2006
   5  *
   6  * API for MediaWiki 1.8+
   7  *
   8  * Copyright (C) 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, write to the Free Software Foundation, Inc.,
  22  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  * http://www.gnu.org/copyleft/gpl.html
  24  */
  25
  26 if ( !defined( 'MEDIAWIKI' ) ) {
  27         // Eclipse helper - will be ignored in production
  28         require_once ( 'ApiBase.php' );
  29 }
  30
  31 /**
  32  * @defgroup API API
  33  */
  34
  35 /**
  36  * This is the main API class, used for both external and internal processing.
  37  * When executed, it will create the requested formatter object,
  38  * instantiate and execute an object associated with the needed action,
  39  * and use formatter to print results.
  40  * In case of an exception, an error message will be printed using the same formatter.
  41  *
  42  * To use API from another application, run it using FauxRequest object, in which
  43  * case any internal exceptions will not be handled but passed up to the caller.
  44  * After successful execution, use getResult() for the resulting data.
  45  *
  46  * @ingroup API
  47  */
  48 class ApiMain extends ApiBase {
  49
  50         /**
  51          * When no format parameter is given, this format will be used
  52          */
  53         const API_DEFAULT_FORMAT = 'xmlfm';
  54
  55         /**
  56          * List of available modules: action name => module class
  57          */
  58         private static $Modules = array (
  59                 'login' => 'ApiLogin',
  60                 'logout' => 'ApiLogout',
  61                 'query' => 'ApiQuery',
  62                 'expandtemplates' => 'ApiExpandTemplates',
  63                 'parse' => 'ApiParse',
  64                 'opensearch' => 'ApiOpenSearch',
  65                 'feedwatchlist' => 'ApiFeedWatchlist',
  66                 'help' => 'ApiHelp',
  67                 'paraminfo' => 'ApiParamInfo',
  68
  69                 // Write modules
  70                 'purge' => 'ApiPurge',
  71                 'rollback' => 'ApiRollback',
  72                 'delete' => 'ApiDelete',
  73                 'undelete' => 'ApiUndelete',
  74                 'protect' => 'ApiProtect',
  75                 'block' => 'ApiBlock',
  76                 'unblock' => 'ApiUnblock',
  77                 'move' => 'ApiMove',
  78                 'edit' => 'ApiEditPage',
  79                 'upload' => 'ApiUpload',
  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         );
 107
 108         /**
 109          * List of user roles that are specifically relevant to the API.
 110          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 111          *                           'params' => array ( $someVarToSubst ) ),
 112          *                          );
 113          */
 114         private static $mRights = array( 'writeapi' => array(
 115                                                 'msg' => 'Use of the write API',
 116                                                 'params' => array()
 117                                         ),
 118                                         'apihighlimits' => array(
 119                                                 '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.',
 120                                                 'params' => array ( ApiMain::LIMIT_SML2, ApiMain::LIMIT_BIG2 )
 121                                         )
 122         );
 123
 124
 125         private $mPrinter, $mModules, $mModuleNames, $mFormats, $mFormatNames;
 126         private $mResult, $mAction, $mShowVersions, $mEnableWrite, $mRequest;
 127         private $mInternalMode, $mSquidMaxage, $mModule;
 128
 129         private $mCacheControl = array( 'must-revalidate' => true );
 130
 131         /**
 132         * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 133         *
 134         * @param $request object - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 135         * @param $enableWrite bool should be set to true if the api may modify data
 136         */
 137         public function __construct( $request, $enableWrite = false ) {
 138
 139                 $this->mInternalMode = ( $request instanceof FauxRequest );
 140
 141                 // Special handling for the main module: $parent === $this
 142                 parent :: __construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 143
 144                 if ( !$this->mInternalMode ) {
 145
 146                         // Impose module restrictions.
 147                         // If the current user cannot read,
 148                         // Remove all modules other than login
 149                         global $wgUser;
 150
 151                         if ( $request->getVal( 'callback' ) !== null ) {
 152                                 // JSON callback allows cross-site reads.
 153                                 // For safety, strip user credentials.
 154                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 155                                 $wgUser = new User();
 156                         }
 157                 }
 158
 159                 global $wgAPIModules; // extension modules
 160                 $this->mModules = $wgAPIModules + self :: $Modules;
 161
 162                 $this->mModuleNames = array_keys( $this->mModules );
 163                 $this->mFormats = self :: $Formats;
 164                 $this->mFormatNames = array_keys( $this->mFormats );
 165
 166                 $this->mResult = new ApiResult( $this );
 167                 $this->mShowVersions = false;
 168                 $this->mEnableWrite = $enableWrite;
 169
 170                 $this->mRequest = & $request;
 171
 172                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 173                 $this->mCommit = false;
 174         }
 175
 176         /**
 177          * Return true if the API was started by other PHP code using FauxRequest
 178          */
 179         public function isInternalMode() {
 180                 return $this->mInternalMode;
 181         }
 182
 183         /**
 184          * Return the request object that contains client's request
 185          */
 186         public function getRequest() {
 187                 return $this->mRequest;
 188         }
 189
 190         /**
 191          * Get the ApiResult object associated with current request
 192          */
 193         public function getResult() {
 194                 return $this->mResult;
 195         }
 196
 197         /**
 198          * Get the API module object. Only works after executeAction()
 199          */
 200         public function getModule() {
 201                 return $this->mModule;
 202         }
 203
 204         /**
 205          * Only kept for backwards compatibility
 206          * @deprecated Use isWriteMode() instead
 207          */
 208         public function requestWriteMode() {
 209                 if ( !$this->mEnableWrite )
 210                         $this->dieUsageMsg( array( 'writedisabled' ) );
 211                 if ( wfReadOnly() )
 212                         $this->dieUsageMsg( array( 'readonlytext' ) );
 213         }
 214
 215         /**
 216          * Set how long the response should be cached.
 217          */
 218         public function setCacheMaxAge( $maxage ) {
 219                 $this->setCacheControl( array(
 220                         'max-age' => $maxage,
 221                         's-maxage' => $maxage
 222                 ) );
 223         }
 224
 225         /**
 226          * Set directives (key/value pairs) for the Cache-Control header.
 227          * Boolean values will be formatted as such, by including or omitting
 228          * without an equals sign.
 229          */
 230         public function setCacheControl( $directives ) {
 231                 $this->mCacheControl = $directives + $this->mCacheControl;
 232         }
 233
 234         /**
 235          * Create an instance of an output formatter by its name
 236          */
 237         public function createPrinterByName( $format ) {
 238                 if ( !isset( $this->mFormats[$format] ) )
 239                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 240                 return new $this->mFormats[$format] ( $this, $format );
 241         }
 242
 243         /**
 244          * Execute api request. Any errors will be handled if the API was called by the remote client.
 245          */
 246         public function execute() {
 247                 $this->profileIn();
 248                 if ( $this->mInternalMode )
 249                         $this->executeAction();
 250                 else
 251                         $this->executeActionWithErrorHandling();
 252
 253                 $this->profileOut();
 254         }
 255
 256         /**
 257          * Execute an action, and in case of an error, erase whatever partial results
 258          * have been accumulated, and replace it with an error message and a help screen.
 259          */
 260         protected function executeActionWithErrorHandling() {
 261
 262                 // In case an error occurs during data output,
 263                 // clear the output buffer and print just the error information
 264                 ob_start();
 265
 266                 try {
 267                         $this->executeAction();
 268                 } catch ( Exception $e ) {
 269                         // Log it
 270                         if ( $e instanceof MWException ) {
 271                                 wfDebugLog( 'exception', $e->getLogMessage() );
 272                         }
 273
 274                         //
 275                         // Handle any kind of exception by outputing properly formatted error message.
 276                         // If this fails, an unhandled exception should be thrown so that global error
 277                         // handler will process and log it.
 278                         //
 279
 280                         $errCode = $this->substituteResultWithError( $e );
 281
 282                         // Error results should not be cached
 283                         $this->setCacheMaxAge( 0 );
 284
 285                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 286                         if ( $e->getCode() === 0 )
 287                                 header( $headerStr );
 288                         else
 289                                 header( $headerStr, true, $e->getCode() );
 290
 291                         // Reset and print just the error message
 292                         ob_clean();
 293
 294                         // If the error occured during printing, do a printer->profileOut()
 295                         $this->mPrinter->safeProfileOut();
 296                         $this->printResult( true );
 297                 }
 298
 299                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 300                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 301                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 302                 }
 303                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 304                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 305                 }
 306
 307                 // Set the cache expiration at the last moment, as any errors may change the expiration.
 308                 // if $this->mSquidMaxage == 0, the expiry time is set to the first second of unix epoch
 309                 $exp = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 310                 $expires = ( $exp == 0 ? 1 : time() + $exp );
 311                 header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expires ) );
 312
 313                 // Construct the Cache-Control header
 314                 $ccHeader = '';
 315                 $separator = '';
 316                 foreach ( $this->mCacheControl as $name => $value ) {
 317                         if ( is_bool( $value ) ) {
 318                                 if ( $value ) {
 319                                         $ccHeader .= $separator . $name;
 320                                         $separator = ', ';
 321                                 }
 322                         } else {
 323                                 $ccHeader .= $separator . "$name=$value";
 324                                 $separator = ', ';
 325                         }
 326                 }
 327
 328                 header( "Cache-Control: $ccHeader" );
 329
 330                 if ( $this->mPrinter->getIsHtml() )
 331                         echo wfReportTime();
 332
 333                 ob_end_flush();
 334         }
 335
 336         /**
 337          * Replace the result data with the information about an exception.
 338          * Returns the error code
 339          */
 340         protected function substituteResultWithError( $e ) {
 341
 342                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 343                 if ( !isset ( $this->mPrinter ) ) {
 344                         // The printer has not been created yet. Try to manually get formatter value.
 345                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 346                         if ( !in_array( $value, $this->mFormatNames ) )
 347                                 $value = self::API_DEFAULT_FORMAT;
 348
 349                         $this->mPrinter = $this->createPrinterByName( $value );
 350                         if ( $this->mPrinter->getNeedsRawData() )
 351                                 $this->getResult()->setRawMode();
 352                 }
 353
 354                 if ( $e instanceof UsageException ) {
 355                         //
 356                         // User entered incorrect parameters - print usage screen
 357                         //
 358                         $errMessage = $e->getMessageArray();
 359
 360                         // Only print the help message when this is for the developer, not runtime
 361                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' )
 362                                 ApiResult :: setContent( $errMessage, $this->makeHelpMsg() );
 363
 364                 } else {
 365                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 366                         //
 367                         // Something is seriously wrong
 368                         //
 369                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 370                                 $info = "Database query error";
 371                         } else {
 372                                 $info = "Exception Caught: {$e->getMessage()}";
 373                         }
 374
 375                         $errMessage = array (
 376                                 'code' => 'internal_api_error_' . get_class( $e ),
 377                                 'info' => $info,
 378                         );
 379                         ApiResult :: setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : "" );
 380                 }
 381
 382                 $this->getResult()->reset();
 383                 $this->getResult()->disableSizeCheck();
 384                 // Re-add the id
 385                 $requestid = $this->getParameter( 'requestid' );
 386                 if ( !is_null( $requestid ) )
 387                         $this->getResult()->addValue( null, 'requestid', $requestid );
 388                 $this->getResult()->addValue( null, 'error', $errMessage );
 389
 390                 return $errMessage['code'];
 391         }
 392
 393         /**
 394          * Execute the actual module, without any error handling
 395          */
 396         protected function executeAction() {
 397                 // First add the id to the top element
 398                 $requestid = $this->getParameter( 'requestid' );
 399                 if ( !is_null( $requestid ) )
 400                         $this->getResult()->addValue( null, 'requestid', $requestid );
 401
 402                 $params = $this->extractRequestParams();
 403
 404                 $this->mShowVersions = $params['version'];
 405                 $this->mAction = $params['action'];
 406
 407                 if ( !is_string( $this->mAction ) ) {
 408                         $this->dieUsage( "The API requires a valid action parameter", 'unknown_action' );
 409                 }
 410
 411                 // Instantiate the module requested by the user
 412                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 413                 $this->mModule = $module;
 414
 415                 $moduleParams = $module->extractRequestParams();
 416
 417                 // Die if token required, but not provided (unless there is a gettoken parameter)
 418                 $salt = $module->getTokenSalt();
 419                 if ( $salt !== false && !isset( $moduleParams['gettoken'] ) )
 420                 {
 421                         if ( !isset( $moduleParams['token'] ) ) {
 422                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 423                         } else {
 424                                 global $wgUser;
 425                                 if ( !$wgUser->matchEditToken( $moduleParams['token'], $salt ) ) {
 426                                         $this->dieUsageMsg( array( 'sessionfailure' ) );
 427                                 }
 428                         }
 429                 }
 430
 431                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 432                         // Check for maxlag
 433                         global $wgShowHostnames;
 434                         $maxLag = $params['maxlag'];
 435                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 436                         if ( $lag > $maxLag ) {
 437                                 header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 438                                 header( 'X-Database-Lag: ' . intval( $lag ) );
 439                                 if ( $wgShowHostnames ) {
 440                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 441                                 } else {
 442                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 443                                 }
 444                                 return;
 445                         }
 446                 }
 447
 448                 global $wgUser, $wgGroupPermissions;
 449                 if ( $module->isReadMode() && !$wgGroupPermissions['*']['read'] && !$wgUser->isAllowed( 'read' ) )
 450                         $this->dieUsageMsg( array( 'readrequired' ) );
 451                 if ( $module->isWriteMode() ) {
 452                         if ( !$this->mEnableWrite )
 453                                 $this->dieUsageMsg( array( 'writedisabled' ) );
 454                         if ( !$wgUser->isAllowed( 'writeapi' ) )
 455                                 $this->dieUsageMsg( array( 'writerequired' ) );
 456                         if ( wfReadOnly() )
 457                                 $this->dieReadOnly();
 458                 }
 459
 460                 if ( !$this->mInternalMode ) {
 461                         // Ignore mustBePosted() for internal calls
 462                         if ( $module->mustBePosted() && !$this->mRequest->wasPosted() )
 463                                 $this->dieUsageMsg( array ( 'mustbeposted', $this->mAction ) );
 464
 465                         // See if custom printer is used
 466                         $this->mPrinter = $module->getCustomPrinter();
 467                         if ( is_null( $this->mPrinter ) ) {
 468                                 // Create an appropriate printer
 469                                 $this->mPrinter = $this->createPrinterByName( $params['format'] );
 470                         }
 471
 472                         if ( $this->mPrinter->getNeedsRawData() )
 473                                 $this->getResult()->setRawMode();
 474                 }
 475
 476                 // Execute
 477                 $module->profileIn();
 478                 $module->execute();
 479                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 480                 $module->profileOut();
 481
 482                 if ( !$this->mInternalMode ) {
 483                         // Print result data
 484                         $this->printResult( false );
 485                 }
 486         }
 487
 488         /**
 489          * Print results using the current printer
 490          */
 491         protected function printResult( $isError ) {
 492                 $this->getResult()->cleanUpUTF8();
 493                 $printer = $this->mPrinter;
 494                 $printer->profileIn();
 495
 496                 /* If the help message is requested in the default (xmlfm) format,
 497                  * tell the printer not to escape ampersands so that our links do
 498                  * not break. */
 499                 $printer->setUnescapeAmps ( ( $this->mAction == 'help' || $isError )
 500                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 501
 502                 $printer->initPrinter( $isError );
 503
 504                 $printer->execute();
 505                 $printer->closePrinter();
 506                 $printer->profileOut();
 507         }
 508
 509         public function isReadMode() {
 510                 return false;
 511         }
 512
 513         /**
 514          * See ApiBase for description.
 515          */
 516         public function getAllowedParams() {
 517                 return array (
 518                         'format' => array (
 519                                 ApiBase :: PARAM_DFLT => ApiMain :: API_DEFAULT_FORMAT,
 520                                 ApiBase :: PARAM_TYPE => $this->mFormatNames
 521                         ),
 522                         'action' => array (
 523                                 ApiBase :: PARAM_DFLT => 'help',
 524                                 ApiBase :: PARAM_TYPE => $this->mModuleNames
 525                         ),
 526                         'version' => false,
 527                         'maxlag'  => array (
 528                                 ApiBase :: PARAM_TYPE => 'integer'
 529                         ),
 530                         'smaxage' => array (
 531                                 ApiBase :: PARAM_TYPE => 'integer',
 532                                 ApiBase :: PARAM_DFLT => 0
 533                         ),
 534                         'maxage' => array (
 535                                 ApiBase :: PARAM_TYPE => 'integer',
 536                                 ApiBase :: PARAM_DFLT => 0
 537                         ),
 538                         'requestid' => null,
 539                 );
 540         }
 541
 542         /**
 543          * See ApiBase for description.
 544          */
 545         public function getParamDescription() {
 546                 return array (
 547                         'format' => 'The format of the output',
 548                         'action' => 'What action you would like to perform',
 549                         'version' => 'When showing help, include version for each module',
 550                         'maxlag' => 'Maximum lag',
 551                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 552                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 553                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 554                 );
 555         }
 556
 557         /**
 558          * See ApiBase for description.
 559          */
 560         public function getDescription() {
 561                 return array (
 562                         '',
 563                         '',
 564                         '******************************************************************',
 565                         '**                                                              **',
 566                         '**  This is an auto-generated MediaWiki API documentation page  **',
 567                         '**                                                              **',
 568                         '**                  Documentation and Examples:                 **',
 569                         '**               http://www.mediawiki.org/wiki/API              **',
 570                         '**                                                              **',
 571                         '******************************************************************',
 572                         '',
 573                         'Status:          All features shown on this page should be working, but the API',
 574                         '                 is still in active development, and  may change at any time.',
 575                         '                 Make sure to monitor our mailing list for any updates.',
 576                         '',
 577                         'Documentation:   http://www.mediawiki.org/wiki/API',
 578                         'Mailing list:    http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 579                         'Bugs & Requests: http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 580                         '',
 581                         '',
 582                         '',
 583                         '',
 584                         '',
 585                 );
 586         }
 587
 588     public function getPossibleErrors() {
 589                 return array_merge( parent::getPossibleErrors(), array(
 590                         array( 'readonlytext' ),
 591                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 592                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 593                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 594                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 595         ) );
 596         }
 597
 598         /**
 599          * Returns an array of strings with credits for the API
 600          */
 601         protected function getCredits() {
 602                 return array(
 603                         'API developers:',
 604                         '    Roan Kattouw <Firstname>.<Lastname>@home.nl (lead developer Sep 2007-present)',
 605                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 606                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 607                         '    Sam Reed - sam @ reedyboy . net',
 608                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 609                         '',
 610                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 611                         'or file a bug report at http://bugzilla.wikimedia.org/'
 612                 );
 613         }
 614
 615         /**
 616          * Override the parent to generate help messages for all available modules.
 617          */
 618         public function makeHelpMsg() {
 619                 global $wgMemc, $wgAPICacheHelp, $wgAPICacheHelpTimeout;
 620                 $this->mPrinter->setHelp();
 621                 // Get help text from cache if present
 622                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
 623                         SpecialVersion::getVersion( 'nodb' ) .
 624                         $this->getMain()->getShowVersions() );
 625                 if ( $wgAPICacheHelp ) {
 626                         $cached = $wgMemc->get( $key );
 627                         if ( $cached )
 628                                 return $cached;
 629                 }
 630                 $retval = $this->reallyMakeHelpMsg();
 631                 if ( $wgAPICacheHelp )
 632                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
 633                 return $retval;
 634         }
 635
 636         public function reallyMakeHelpMsg() {
 637
 638                 $this->mPrinter->setHelp();
 639
 640                 // Use parent to make default message for the main module
 641                 $msg = parent :: makeHelpMsg();
 642
 643                 $astriks = str_repeat( '*** ', 10 );
 644                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 645                 foreach ( $this->mModules as $moduleName => $unused ) {
 646                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
 647                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
 648                         $msg2 = $module->makeHelpMsg();
 649                         if ( $msg2 !== false )
 650                                 $msg .= $msg2;
 651                         $msg .= "\n";
 652                 }
 653
 654                 $msg .= "\n$astriks Permissions $astriks\n\n";
 655                 foreach ( self :: $mRights as $right => $rightMsg ) {
 656                         $groups = User::getGroupsWithPermission( $right );
 657                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
 658                                                 "\nGranted to:\n  " . str_replace( "*", "all", implode( ", ", $groups ) ) . "\n";
 659
 660                 }
 661
 662                 $msg .= "\n$astriks Formats  $astriks\n\n";
 663                 foreach ( $this->mFormats as $formatName => $unused ) {
 664                         $module = $this->createPrinterByName( $formatName );
 665                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
 666                         $msg2 = $module->makeHelpMsg();
 667                         if ( $msg2 !== false )
 668                                 $msg .= $msg2;
 669                         $msg .= "\n";
 670                 }
 671
 672                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
 673
 674
 675                 return $msg;
 676         }
 677
 678         public static function makeHelpMsgHeader( $module, $paramName ) {
 679                 $modulePrefix = $module->getModulePrefix();
 680                 if ( strval( $modulePrefix ) !== '' )
 681                         $modulePrefix = "($modulePrefix) ";
 682
 683                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 684         }
 685
 686         private $mIsBot = null;
 687         private $mIsSysop = null;
 688         private $mCanApiHighLimits = null;
 689
 690         /**
 691          * Returns true if the currently logged in user is a bot, false otherwise
 692          * OBSOLETE, use canApiHighLimits() instead
 693          */
 694         public function isBot() {
 695                 if ( !isset ( $this->mIsBot ) ) {
 696                         global $wgUser;
 697                         $this->mIsBot = $wgUser->isAllowed( 'bot' );
 698                 }
 699                 return $this->mIsBot;
 700         }
 701
 702         /**
 703          * Similar to isBot(), this method returns true if the logged in user is
 704          * a sysop, and false if not.
 705          * OBSOLETE, use canApiHighLimits() instead
 706          */
 707         public function isSysop() {
 708                 if ( !isset ( $this->mIsSysop ) ) {
 709                         global $wgUser;
 710                         $this->mIsSysop = in_array( 'sysop', $wgUser->getGroups() );
 711                 }
 712
 713                 return $this->mIsSysop;
 714         }
 715
 716         /**
 717          * Check whether the current user is allowed to use high limits
 718          * @return bool
 719          */
 720         public function canApiHighLimits() {
 721                 if ( !isset( $this->mCanApiHighLimits ) ) {
 722                         global $wgUser;
 723                         $this->mCanApiHighLimits = $wgUser->isAllowed( 'apihighlimits' );
 724                 }
 725
 726                 return $this->mCanApiHighLimits;
 727         }
 728
 729         /**
 730          * Check whether the user wants us to show version information in the API help
 731          * @return bool
 732          */
 733         public function getShowVersions() {
 734                 return $this->mShowVersions;
 735         }
 736
 737         /**
 738          * Returns the version information of this file, plus it includes
 739          * the versions for all files that are not callable proper API modules
 740          */
 741         public function getVersion() {
 742                 $vers = array ();
 743                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    http://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
 744                 $vers[] = __CLASS__ . ': $Id$';
 745                 $vers[] = ApiBase :: getBaseVersion();
 746                 $vers[] = ApiFormatBase :: getBaseVersion();
 747                 $vers[] = ApiQueryBase :: getBaseVersion();
 748                 return $vers;
 749         }
 750
 751         /**
 752          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
 753          * classes who wish to add their own modules to their lexicon or override the
 754          * behavior of inherent ones.
 755          *
 756          * @access protected
 757          * @param $mdlName String The identifier for this module.
 758          * @param $mdlClass String The class where this module is implemented.
 759          */
 760         protected function addModule( $mdlName, $mdlClass ) {
 761                 $this->mModules[$mdlName] = $mdlClass;
 762         }
 763
 764         /**
 765          * Add or overwrite an output format for this ApiMain. Intended for use by extending
 766          * classes who wish to add to or modify current formatters.
 767          *
 768          * @access protected
 769          * @param $fmtName The identifier for this format.
 770          * @param $fmtClass The class implementing this format.
 771          */
 772         protected function addFormat( $fmtName, $fmtClass ) {
 773                 $this->mFormats[$fmtName] = $fmtClass;
 774         }
 775
 776         /**
 777          * Get the array mapping module names to class names
 778          */
 779         function getModules() {
 780                 return $this->mModules;
 781         }
 782 }
 783
 784 /**
 785  * This exception will be thrown when dieUsage is called to stop module execution.
 786  * The exception handling code will print a help screen explaining how this API may be used.
 787  *
 788  * @ingroup API
 789  */
 790 class UsageException extends Exception {
 791
 792         private $mCodestr;
 793         private $mExtraData;
 794
 795         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
 796                 parent :: __construct( $message, $code );
 797                 $this->mCodestr = $codestr;
 798                 $this->mExtraData = $extradata;
 799         }
 800         public function getCodeString() {
 801                 return $this->mCodestr;
 802         }
 803         public function getMessageArray() {
 804                 $result = array (
 805                                 'code' => $this->mCodestr,
 806                                 'info' => $this->getMessage()
 807                 );
 808                 if ( is_array( $this->mExtraData ) )
 809                         $result = array_merge( $result, $this->mExtraData );
 810                 return $result;
 811         }
 812         public function __toString() {
 813                 return "{$this->getCodeString()}: {$this->getMessage()}";
 814         }
 815 }