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
  70         private static $WriteModules = array (
  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                 'emailuser' => 'ApiEmailUser',
  80         );
  81
  82         /**
  83          * List of available formats: format name => format class
  84          */
  85         private static $Formats = array (
  86                 'json' => 'ApiFormatJson',
  87                 'jsonfm' => 'ApiFormatJson',
  88                 'php' => 'ApiFormatPhp',
  89                 'phpfm' => 'ApiFormatPhp',
  90                 'wddx' => 'ApiFormatWddx',
  91                 'wddxfm' => 'ApiFormatWddx',
  92                 'xml' => 'ApiFormatXml',
  93                 'xmlfm' => 'ApiFormatXml',
  94                 'yaml' => 'ApiFormatYaml',
  95                 'yamlfm' => 'ApiFormatYaml',
  96                 'rawfm' => 'ApiFormatJson',
  97                 'txt' => 'ApiFormatTxt',
  98                 'txtfm' => 'ApiFormatTxt',
  99                 'dbg' => 'ApiFormatDbg',
 100                 'dbgfm' => 'ApiFormatDbg'
 101         );
 102
 103         /**
 104          * List of user roles that are specifically relevant to the API.
 105          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 106          *                           'params' => array ( $someVarToSubst ) ),
 107          *                          );
 108          */
 109         private static $mRights = array( 'writeapi'             => array(       'msg' => 'Use of the write API' ,
 110                                                                                                                                 'params' => array() ),
 111                                                                         'apihighlimits' => array(       'msg' => 'Use higher limits in API queries (Slow queries: $1 results; Fast queries: $2 results)',
 112                                                                                                                                 'params' => array ( ApiMain :: LIMIT_SML2, ApiMain :: LIMIT_BIG2 ) ),
 113                                                                         );
 114
 115
 116         private $mPrinter, $mModules, $mModuleNames, $mFormats, $mFormatNames;
 117         private $mResult, $mAction, $mShowVersions, $mEnableWrite, $mRequest, $mInternalMode, $mSquidMaxage;
 118
 119         /**
 120         * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 121         *
 122         * @param $request object - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 123         * @param $enableWrite bool should be set to true if the api may modify data
 124         */
 125         public function __construct($request, $enableWrite = false) {
 126
 127                 $this->mInternalMode = ($request instanceof FauxRequest);
 128
 129                 // Special handling for the main module: $parent === $this
 130                 parent :: __construct($this, $this->mInternalMode ? 'main_int' : 'main');
 131
 132                 if (!$this->mInternalMode) {
 133
 134                         // Impose module restrictions.
 135                         // If the current user cannot read,
 136                         // Remove all modules other than login
 137                         global $wgUser;
 138
 139                         if( $request->getVal( 'callback' ) !== null ) {
 140                                 // JSON callback allows cross-site reads.
 141                                 // For safety, strip user credentials.
 142                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 143                                 $wgUser = new User();
 144                         }
 145
 146                         if (!$wgUser->isAllowed('read')) {
 147                                 self::$Modules = array(
 148                                         'login'  => self::$Modules['login'],
 149                                         'logout' => self::$Modules['logout'],
 150                                         'help'   => self::$Modules['help'],
 151                                         );
 152                         }
 153                 }
 154
 155                 global $wgAPIModules, $wgEnableWriteAPI; // extension modules
 156                 $this->mModules = $wgAPIModules + self :: $Modules;
 157                 if($wgEnableWriteAPI)
 158                         $this->mModules += self::$WriteModules;
 159
 160                 $this->mModuleNames = array_keys($this->mModules); // todo: optimize
 161                 $this->mFormats = self :: $Formats;
 162                 $this->mFormatNames = array_keys($this->mFormats); // todo: optimize
 163
 164                 $this->mResult = new ApiResult($this);
 165                 $this->mShowVersions = false;
 166                 $this->mEnableWrite = $enableWrite;
 167
 168                 $this->mRequest = & $request;
 169
 170                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 171                 $this->mCommit = false;
 172         }
 173
 174         /**
 175          * Return true if the API was started by other PHP code using FauxRequest
 176          */
 177         public function isInternalMode() {
 178                 return $this->mInternalMode;
 179         }
 180
 181         /**
 182          * Return the request object that contains client's request
 183          */
 184         public function getRequest() {
 185                 return $this->mRequest;
 186         }
 187
 188         /**
 189          * Get the ApiResult object asscosiated with current request
 190          */
 191         public function getResult() {
 192                 return $this->mResult;
 193         }
 194
 195         /**
 196          * This method will simply cause an error if the write mode was disabled
 197          * or if the current user doesn't have the right to use it
 198          */
 199         public function requestWriteMode() {
 200                 global $wgUser;
 201                 if (!$this->mEnableWrite)
 202                         $this->dieUsage('Editing of this wiki through the API' .
 203                         ' is disabled. Make sure the $wgEnableWriteAPI=true; ' .
 204                         'statement is included in the wiki\'s ' .
 205                         'LocalSettings.php file', 'noapiwrite');
 206                 if (!$wgUser->isAllowed('writeapi'))
 207                         $this->dieUsage('You\'re not allowed to edit this ' .
 208                         'wiki through the API', 'writeapidenied');
 209         }
 210
 211         /**
 212          * Set how long the response should be cached.
 213          */
 214         public function setCacheMaxAge($maxage) {
 215                 $this->mSquidMaxage = $maxage;
 216         }
 217
 218         /**
 219          * Create an instance of an output formatter by its name
 220          */
 221         public function createPrinterByName($format) {
 222                 return new $this->mFormats[$format] ($this, $format);
 223         }
 224
 225         /**
 226          * Execute api request. Any errors will be handled if the API was called by the remote client.
 227          */
 228         public function execute() {
 229                 $this->profileIn();
 230                 if ($this->mInternalMode)
 231                         $this->executeAction();
 232                 else
 233                         $this->executeActionWithErrorHandling();
 234
 235                 $this->profileOut();
 236         }
 237
 238         /**
 239          * Execute an action, and in case of an error, erase whatever partial results
 240          * have been accumulated, and replace it with an error message and a help screen.
 241          */
 242         protected function executeActionWithErrorHandling() {
 243
 244                 // In case an error occurs during data output,
 245                 // clear the output buffer and print just the error information
 246                 ob_start();
 247
 248                 try {
 249                         $this->executeAction();
 250                 } catch (Exception $e) {
 251                         //
 252                         // Handle any kind of exception by outputing properly formatted error message.
 253                         // If this fails, an unhandled exception should be thrown so that global error
 254                         // handler will process and log it.
 255                         //
 256
 257                         $errCode = $this->substituteResultWithError($e);
 258
 259                         // Error results should not be cached
 260                         $this->setCacheMaxAge(0);
 261
 262                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 263                         if ($e->getCode() === 0)
 264                                 header($headerStr, true);
 265                         else
 266                                 header($headerStr, true, $e->getCode());
 267
 268                         // Reset and print just the error message
 269                         ob_clean();
 270
 271                         // If the error occured during printing, do a printer->profileOut()
 272                         $this->mPrinter->safeProfileOut();
 273                         $this->printResult(true);
 274                 }
 275
 276                 global $wgRequest;
 277                 if($this->mSquidMaxage == -1)
 278                 {
 279                         # Nobody called setCacheMaxAge(), use the (s)maxage parameters
 280                         $smaxage = $wgRequest->getVal('smaxage', 0);
 281                         $maxage = $wgRequest->getVal('maxage', 0);
 282                 }
 283                 else
 284                         $smaxage = $maxage = $this->mSquidMaxage;
 285
 286                 // Set the cache expiration at the last moment, as any errors may change the expiration.
 287                 // if $this->mSquidMaxage == 0, the expiry time is set to the first second of unix epoch
 288                 $exp = min($smaxage, $maxage);
 289                 $expires = ($exp == 0 ? 1 : time() + $exp);
 290                 header('Expires: ' . wfTimestamp(TS_RFC2822, $expires));
 291                 header('Cache-Control: s-maxage=' . $smaxage . ', must-revalidate, max-age=' . $maxage);
 292
 293                 if($this->mPrinter->getIsHtml())
 294                         echo wfReportTime();
 295
 296                 ob_end_flush();
 297         }
 298
 299         /**
 300          * Replace the result data with the information about an exception.
 301          * Returns the error code
 302          */
 303         protected function substituteResultWithError($e) {
 304
 305                         // Printer may not be initialized if the extractRequestParams() fails for the main module
 306                         if (!isset ($this->mPrinter)) {
 307                                 // The printer has not been created yet. Try to manually get formatter value.
 308                                 $value = $this->getRequest()->getVal('format', self::API_DEFAULT_FORMAT);
 309                                 if (!in_array($value, $this->mFormatNames))
 310                                         $value = self::API_DEFAULT_FORMAT;
 311
 312                                 $this->mPrinter = $this->createPrinterByName($value);
 313                                 if ($this->mPrinter->getNeedsRawData())
 314                                         $this->getResult()->setRawMode();
 315                         }
 316
 317                         if ($e instanceof UsageException) {
 318                                 //
 319                                 // User entered incorrect parameters - print usage screen
 320                                 //
 321                                 $errMessage = array (
 322                                 'code' => $e->getCodeString(),
 323                                 'info' => $e->getMessage());
 324
 325                                 // Only print the help message when this is for the developer, not runtime
 326                                 if ($this->mPrinter->getIsHtml() || $this->mAction == 'help')
 327                                         ApiResult :: setContent($errMessage, $this->makeHelpMsg());
 328
 329                         } else {
 330                                 global $wgShowSQLErrors, $wgShowExceptionDetails;
 331                                 //
 332                                 // Something is seriously wrong
 333                                 //
 334                                 if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 335                                         $info = "Database query error";
 336                                 } else {
 337                                         $info = "Exception Caught: {$e->getMessage()}";
 338                                 }
 339
 340                                 $errMessage = array (
 341                                         'code' => 'internal_api_error_'. get_class($e),
 342                                         'info' => $info,
 343                                 );
 344                                 ApiResult :: setContent($errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : "" );
 345                         }
 346
 347                         $this->getResult()->reset();
 348                         $this->getResult()->addValue(null, 'error', $errMessage);
 349
 350                 return $errMessage['code'];
 351         }
 352
 353         /**
 354          * Execute the actual module, without any error handling
 355          */
 356         protected function executeAction() {
 357
 358                 $params = $this->extractRequestParams();
 359
 360                 $this->mShowVersions = $params['version'];
 361                 $this->mAction = $params['action'];
 362
 363                 if( !is_string( $this->mAction ) ) {
 364                         $this->dieUsage( "The API requires a valid action parameter", 'unknown_action' );
 365                 }
 366
 367                 // Instantiate the module requested by the user
 368                 $module = new $this->mModules[$this->mAction] ($this, $this->mAction);
 369
 370                 if( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 371                         // Check for maxlag
 372                         global $wgShowHostnames;
 373                         $maxLag = $params['maxlag'];
 374                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 375                         if ( $lag > $maxLag ) {
 376                                 if( $wgShowHostnames ) {
 377                                         ApiBase :: dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 378                                 } else {
 379                                         ApiBase :: dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 380                                 }
 381                                 return;
 382                         }
 383                 }
 384
 385                 if (!$this->mInternalMode) {
 386                         // Ignore mustBePosted() for internal calls
 387                         if($module->mustBePosted() && !$this->mRequest->wasPosted())
 388                                 $this->dieUsage("The {$this->mAction} module requires a POST request", 'mustbeposted');
 389
 390                         // See if custom printer is used
 391                         $this->mPrinter = $module->getCustomPrinter();
 392                         if (is_null($this->mPrinter)) {
 393                                 // Create an appropriate printer
 394                                 $this->mPrinter = $this->createPrinterByName($params['format']);
 395                         }
 396
 397                         if ($this->mPrinter->getNeedsRawData())
 398                                 $this->getResult()->setRawMode();
 399                 }
 400
 401                 // Execute
 402                 $module->profileIn();
 403                 $module->execute();
 404                 $module->profileOut();
 405
 406                 if (!$this->mInternalMode) {
 407                         // Print result data
 408                         $this->printResult(false);
 409                 }
 410         }
 411
 412         /**
 413          * Print results using the current printer
 414          */
 415         protected function printResult($isError) {
 416                 $printer = $this->mPrinter;
 417                 $printer->profileIn();
 418
 419                 /* If the help message is requested in the default (xmlfm) format,
 420                  * tell the printer not to escape ampersands so that our links do
 421                  * not break. */
 422                 $printer->setUnescapeAmps ( ( $this->mAction == 'help' || $isError )
 423                                 && $this->getParameter('format') == ApiMain::API_DEFAULT_FORMAT );
 424
 425                 $printer->initPrinter($isError);
 426
 427                 $printer->execute();
 428                 $printer->closePrinter();
 429                 $printer->profileOut();
 430         }
 431
 432         /**
 433          * See ApiBase for description.
 434          */
 435         public function getAllowedParams() {
 436                 return array (
 437                         'format' => array (
 438                                 ApiBase :: PARAM_DFLT => ApiMain :: API_DEFAULT_FORMAT,
 439                                 ApiBase :: PARAM_TYPE => $this->mFormatNames
 440                         ),
 441                         'action' => array (
 442                                 ApiBase :: PARAM_DFLT => 'help',
 443                                 ApiBase :: PARAM_TYPE => $this->mModuleNames
 444                         ),
 445                         'version' => false,
 446                         'maxlag'  => array (
 447                                 ApiBase :: PARAM_TYPE => 'integer'
 448                         ),
 449                         'smaxage' => array (
 450                                 ApiBase :: PARAM_TYPE => 'integer',
 451                                 ApiBase :: PARAM_DFLT => 0
 452                         ),
 453                         'maxage' => array (
 454                                 ApiBase :: PARAM_TYPE => 'integer',
 455                                 ApiBase :: PARAM_DFLT => 0
 456                         ),
 457                 );
 458         }
 459
 460         /**
 461          * See ApiBase for description.
 462          */
 463         public function getParamDescription() {
 464                 return array (
 465                         'format' => 'The format of the output',
 466                         'action' => 'What action you would like to perform',
 467                         'version' => 'When showing help, include version for each module',
 468                         'maxlag' => 'Maximum lag',
 469                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 470                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 471                 );
 472         }
 473
 474         /**
 475          * See ApiBase for description.
 476          */
 477         public function getDescription() {
 478                 return array (
 479                         '',
 480                         '',
 481                         '******************************************************************',
 482                         '**                                                              **',
 483                         '**  This is an auto-generated MediaWiki API documentation page  **',
 484                         '**                                                              **',
 485                         '**                  Documentation and Examples:                 **',
 486                         '**               http://www.mediawiki.org/wiki/API              **',
 487                         '**                                                              **',
 488                         '******************************************************************',
 489                         '',
 490                         'Status:          All features shown on this page should be working, but the API',
 491                         '                 is still in active development, and  may change at any time.',
 492                         '                 Make sure to monitor our mailing list for any updates.',
 493                         '',
 494                         'Documentation:   http://www.mediawiki.org/wiki/API',
 495                         'Mailing list:    http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 496                         'Bugs & Requests: http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 497                         '',
 498                         '',
 499                         '',
 500                         '',
 501                         '',
 502                 );
 503         }
 504
 505         /**
 506          * Returns an array of strings with credits for the API
 507          */
 508         protected function getCredits() {
 509                 return array(
 510                         'API developers:',
 511                         '    Roan Kattouw <Firstname>.<Lastname>@home.nl (lead developer Sep 2007-present)',
 512                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 513                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 514                         '',
 515                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 516                         'or file a bug report at http://bugzilla.wikimedia.org/'
 517                 );
 518         }
 519
 520         /**
 521          * Override the parent to generate help messages for all available modules.
 522          */
 523         public function makeHelpMsg() {
 524
 525                 $this->mPrinter->setHelp();
 526
 527                 // Use parent to make default message for the main module
 528                 $msg = parent :: makeHelpMsg();
 529
 530                 $astriks = str_repeat('*** ', 10);
 531                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 532                 foreach( $this->mModules as $moduleName => $unused ) {
 533                         $module = new $this->mModules[$moduleName] ($this, $moduleName);
 534                         $msg .= self::makeHelpMsgHeader($module, 'action');
 535                         $msg2 = $module->makeHelpMsg();
 536                         if ($msg2 !== false)
 537                                 $msg .= $msg2;
 538                         $msg .= "\n";
 539                 }
 540
 541                 $msg .= "\n$astriks Permissions $astriks\n\n";
 542                 foreach ( self :: $mRights as $right => $rightMsg ) {
 543                         $groups = User::getGroupsWithPermission( $right );
 544                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
 545                                                 "\nGranted to:\n  " . str_replace( "*", "all", implode( ", ", $groups ) ) . "\n";
 546
 547                 }
 548
 549                 $msg .= "\n$astriks Formats  $astriks\n\n";
 550                 foreach( $this->mFormats as $formatName => $unused ) {
 551                         $module = $this->createPrinterByName($formatName);
 552                         $msg .= self::makeHelpMsgHeader($module, 'format');
 553                         $msg2 = $module->makeHelpMsg();
 554                         if ($msg2 !== false)
 555                                 $msg .= $msg2;
 556                         $msg .= "\n";
 557                 }
 558
 559                 $msg .= "\n*** Credits: ***\n   " . implode("\n   ", $this->getCredits()) . "\n";
 560
 561
 562                 return $msg;
 563         }
 564
 565         public static function makeHelpMsgHeader($module, $paramName) {
 566                 $modulePrefix = $module->getModulePrefix();
 567                 if (!empty($modulePrefix))
 568                         $modulePrefix = "($modulePrefix) ";
 569
 570                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 571         }
 572
 573         private $mIsBot = null;
 574         private $mIsSysop = null;
 575         private $mCanApiHighLimits = null;
 576
 577         /**
 578          * Returns true if the currently logged in user is a bot, false otherwise
 579          * OBSOLETE, use canApiHighLimits() instead
 580          */
 581         public function isBot() {
 582                 if (!isset ($this->mIsBot)) {
 583                         global $wgUser;
 584                         $this->mIsBot = $wgUser->isAllowed('bot');
 585                 }
 586                 return $this->mIsBot;
 587         }
 588
 589         /**
 590          * Similar to isBot(), this method returns true if the logged in user is
 591          * a sysop, and false if not.
 592          * OBSOLETE, use canApiHighLimits() instead
 593          */
 594         public function isSysop() {
 595                 if (!isset ($this->mIsSysop)) {
 596                         global $wgUser;
 597                         $this->mIsSysop = in_array( 'sysop', $wgUser->getGroups());
 598                 }
 599
 600                 return $this->mIsSysop;
 601         }
 602
 603         /**
 604          * Check whether the current user is allowed to use high limits
 605          * @return bool
 606          */
 607         public function canApiHighLimits() {
 608                 if (!isset($this->mCanApiHighLimits)) {
 609                         global $wgUser;
 610                         $this->mCanApiHighLimits = $wgUser->isAllowed('apihighlimits');
 611                 }
 612
 613                 return $this->mCanApiHighLimits;
 614         }
 615
 616         /**
 617          * Check whether the user wants us to show version information in the API help
 618          * @return bool
 619          */
 620         public function getShowVersions() {
 621                 return $this->mShowVersions;
 622         }
 623
 624         /**
 625          * Returns the version information of this file, plus it includes
 626          * the versions for all files that are not callable proper API modules
 627          */
 628         public function getVersion() {
 629                 $vers = array ();
 630                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    http://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
 631                 $vers[] = __CLASS__ . ': $Id$';
 632                 $vers[] = ApiBase :: getBaseVersion();
 633                 $vers[] = ApiFormatBase :: getBaseVersion();
 634                 $vers[] = ApiQueryBase :: getBaseVersion();
 635                 $vers[] = ApiFormatFeedWrapper :: getVersion(); // not accessible with format=xxx
 636                 return $vers;
 637         }
 638
 639         /**
 640          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
 641          * classes who wish to add their own modules to their lexicon or override the
 642          * behavior of inherent ones.
 643          *
 644          * @access protected
 645          * @param $mdlName String The identifier for this module.
 646          * @param $mdlClass String The class where this module is implemented.
 647          */
 648         protected function addModule( $mdlName, $mdlClass ) {
 649                 $this->mModules[$mdlName] = $mdlClass;
 650         }
 651
 652         /**
 653          * Add or overwrite an output format for this ApiMain. Intended for use by extending
 654          * classes who wish to add to or modify current formatters.
 655          *
 656          * @access protected
 657          * @param $fmtName The identifier for this format.
 658          * @param $fmtClass The class implementing this format.
 659          */
 660         protected function addFormat( $fmtName, $fmtClass ) {
 661                 $this->mFormats[$fmtName] = $fmtClass;
 662         }
 663
 664         /**
 665          * Get the array mapping module names to class names
 666          */
 667         function getModules() {
 668                 return $this->mModules;
 669         }
 670 }
 671
 672 /**
 673  * This exception will be thrown when dieUsage is called to stop module execution.
 674  * The exception handling code will print a help screen explaining how this API may be used.
 675  *
 676  * @ingroup API
 677  */
 678 class UsageException extends Exception {
 679
 680         private $mCodestr;
 681
 682         public function __construct($message, $codestr, $code = 0) {
 683                 parent :: __construct($message, $code);
 684                 $this->mCodestr = $codestr;
 685         }
 686         public function getCodeString() {
 687                 return $this->mCodestr;
 688         }
 689         public function __toString() {
 690                 return "{$this->getCodeString()}: {$this->getMessage()}";
 691         }
 692 }