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                 'emailuser' => 'ApiEmailUser',
  80                 'watch' => 'ApiWatch',
  81                 'patrol' => 'ApiPatrol',
  82                 'import' => 'ApiImport',
  83                 'userrights' => 'ApiUserrights',
  84         );
  85
  86         /**
  87          * List of available formats: format name => format class
  88          */
  89         private static $Formats = array(
  90                 'json' => 'ApiFormatJson',
  91                 'jsonfm' => 'ApiFormatJson',
  92                 'php' => 'ApiFormatPhp',
  93                 'phpfm' => 'ApiFormatPhp',
  94                 'wddx' => 'ApiFormatWddx',
  95                 'wddxfm' => 'ApiFormatWddx',
  96                 'xml' => 'ApiFormatXml',
  97                 'xmlfm' => 'ApiFormatXml',
  98                 'yaml' => 'ApiFormatYaml',
  99                 'yamlfm' => 'ApiFormatYaml',
 100                 'rawfm' => 'ApiFormatJson',
 101                 'txt' => 'ApiFormatTxt',
 102                 'txtfm' => 'ApiFormatTxt',
 103                 'dbg' => 'ApiFormatDbg',
 104                 'dbgfm' => 'ApiFormatDbg',
 105                 'dump' => 'ApiFormatDump',
 106                 'dumpfm' => 'ApiFormatDump',
 107         );
 108
 109         /**
 110          * List of user roles that are specifically relevant to the API.
 111          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 112          *                           'params' => array ( $someVarToSubst ) ),
 113          *                          );
 114          */
 115         private static $mRights = array(
 116                 'writeapi' => array(
 117                         'msg' => 'Use of the write API',
 118                         'params' => array()
 119                 ),
 120                 'apihighlimits' => array(
 121                         '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.',
 122                         'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
 123                 )
 124         );
 125
 126         /**
 127          * @var ApiFormatBase
 128          */
 129         private $mPrinter;
 130
 131         private $mModules, $mModuleNames, $mFormats, $mFormatNames;
 132         private $mResult, $mAction, $mShowVersions, $mEnableWrite, $mRequest;
 133         private $mInternalMode, $mSquidMaxage, $mModule;
 134
 135         private $mCacheMode = 'private';
 136         private $mCacheControl = array();
 137
 138         /**
 139          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 140          *
 141          * @param $request WebRequest - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 142          * @param $enableWrite bool should be set to true if the api may modify data
 143          */
 144         public function __construct( $request, $enableWrite = false ) {
 145                 $this->mInternalMode = ( $request instanceof FauxRequest );
 146
 147                 // Special handling for the main module: $parent === $this
 148                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 149
 150                 if ( !$this->mInternalMode ) {
 151                         // Impose module restrictions.
 152                         // If the current user cannot read,
 153                         // Remove all modules other than login
 154                         global $wgUser;
 155
 156                         if ( $request->getVal( 'callback' ) !== null ) {
 157                                 // JSON callback allows cross-site reads.
 158                                 // For safety, strip user credentials.
 159                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 160                                 $wgUser = new User();
 161                         }
 162                 }
 163
 164                 global $wgAPIModules; // extension modules
 165                 $this->mModules = $wgAPIModules + self::$Modules;
 166
 167                 $this->mModuleNames = array_keys( $this->mModules );
 168                 $this->mFormats = self::$Formats;
 169                 $this->mFormatNames = array_keys( $this->mFormats );
 170
 171                 $this->mResult = new ApiResult( $this );
 172                 $this->mShowVersions = false;
 173                 $this->mEnableWrite = $enableWrite;
 174
 175                 $this->mRequest = &$request;
 176
 177                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 178                 $this->mCommit = false;
 179         }
 180
 181         /**
 182          * Return true if the API was started by other PHP code using FauxRequest
 183          * @return bool
 184          */
 185         public function isInternalMode() {
 186                 return $this->mInternalMode;
 187         }
 188
 189         /**
 190          * Return the request object that contains client's request
 191          * @return WebRequest
 192          */
 193         public function getRequest() {
 194                 return $this->mRequest;
 195         }
 196
 197         /**
 198          * Get the ApiResult object associated with current request
 199          *
 200          * @return ApiResult
 201          */
 202         public function getResult() {
 203                 return $this->mResult;
 204         }
 205
 206         /**
 207          * Get the API module object. Only works after executeAction()
 208          *
 209          * @return ApiBase
 210          */
 211         public function getModule() {
 212                 return $this->mModule;
 213         }
 214
 215         /**
 216          * Get the result formatter object. Only works after setupExecuteAction()
 217          *
 218          * @return ApiFormatBase
 219          */
 220         public function getPrinter() {
 221                 return $this->mPrinter;
 222         }
 223
 224         /**
 225          * Set how long the response should be cached.
 226          */
 227         public function setCacheMaxAge( $maxage ) {
 228                 $this->setCacheControl( array(
 229                         'max-age' => $maxage,
 230                         's-maxage' => $maxage
 231                 ) );
 232         }
 233
 234         /**
 235          * Set the type of caching headers which will be sent.
 236          *
 237          * @param $mode String One of:
 238          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 239          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 240          *         not provided by any of these means, the object will be private.
 241          *    - 'private':    Cache this object only in private client-side caches.
 242          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 243          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 244          *         set consistently for a given URL, it cannot be set differently depending on
 245          *         things like the contents of the database, or whether the user is logged in.
 246          *
 247          *  If the wiki does not allow anonymous users to read it, the mode set here
 248          *  will be ignored, and private caching headers will always be sent. In other words,
 249          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 250          *  view.
 251          *
 252          *  For user-dependent data, the private mode should generally be used. The
 253          *  anon-public-user-private mode should only be used where there is a particularly
 254          *  good performance reason for caching the anonymous response, but where the
 255          *  response to logged-in users may differ, or may contain private data.
 256          *
 257          *  If this function is never called, then the default will be the private mode.
 258          */
 259         public function setCacheMode( $mode ) {
 260                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 261                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 262                         // Ignore for forwards-compatibility
 263                         return;
 264                 }
 265
 266                 if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 267                         // Private wiki, only private headers
 268                         if ( $mode !== 'private' ) {
 269                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 270                                 return;
 271                         }
 272                 }
 273
 274                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 275                 $this->mCacheMode = $mode;
 276         }
 277
 278         /**
 279          * @deprecated Private caching is now the default, so there is usually no
 280          * need to call this function. If there is a need, you can use
 281          * $this->setCacheMode('private')
 282          */
 283         public function setCachePrivate() {
 284                 $this->setCacheMode( 'private' );
 285         }
 286
 287         /**
 288          * Set directives (key/value pairs) for the Cache-Control header.
 289          * Boolean values will be formatted as such, by including or omitting
 290          * without an equals sign.
 291          *
 292          * Cache control values set here will only be used if the cache mode is not
 293          * private, see setCacheMode().
 294          */
 295         public function setCacheControl( $directives ) {
 296                 $this->mCacheControl = $directives + $this->mCacheControl;
 297         }
 298
 299         /**
 300          * Make sure Vary: Cookie and friends are set. Use this when the output of a request
 301          * may be cached for anons but may not be cached for logged-in users.
 302          *
 303          * WARNING: This function must be called CONSISTENTLY for a given URL. This means that a
 304          * given URL must either always or never call this function; if it sometimes does and
 305          * sometimes doesn't, stuff will break.
 306          *
 307          * @deprecated Use setCacheMode( 'anon-public-user-private' )
 308          */
 309         public function setVaryCookie() {
 310                 $this->setCacheMode( 'anon-public-user-private' );
 311         }
 312
 313         /**
 314          * Create an instance of an output formatter by its name
 315          *
 316          * @return ApiFormatBase
 317          */
 318         public function createPrinterByName( $format ) {
 319                 if ( !isset( $this->mFormats[$format] ) ) {
 320                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 321                 }
 322                 return new $this->mFormats[$format] ( $this, $format );
 323         }
 324
 325         /**
 326          * Execute api request. Any errors will be handled if the API was called by the remote client.
 327          */
 328         public function execute() {
 329                 $this->profileIn();
 330                 if ( $this->mInternalMode ) {
 331                         $this->executeAction();
 332                 } else {
 333                         $this->executeActionWithErrorHandling();
 334                 }
 335
 336                 $this->profileOut();
 337         }
 338
 339         /**
 340          * Execute an action, and in case of an error, erase whatever partial results
 341          * have been accumulated, and replace it with an error message and a help screen.
 342          */
 343         protected function executeActionWithErrorHandling() {
 344                 // In case an error occurs during data output,
 345                 // clear the output buffer and print just the error information
 346                 ob_start();
 347
 348                 try {
 349                         $this->executeAction();
 350                 } catch ( Exception $e ) {
 351                         // Log it
 352                         if ( $e instanceof MWException ) {
 353                                 wfDebugLog( 'exception', $e->getLogMessage() );
 354                         }
 355
 356                         //
 357                         // Handle any kind of exception by outputing properly formatted error message.
 358                         // If this fails, an unhandled exception should be thrown so that global error
 359                         // handler will process and log it.
 360                         //
 361
 362                         $errCode = $this->substituteResultWithError( $e );
 363
 364                         // Error results should not be cached
 365                         $this->setCacheMode( 'private' );
 366
 367                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 368                         if ( $e->getCode() === 0 ) {
 369                                 header( $headerStr );
 370                         } else {
 371                                 header( $headerStr, true, $e->getCode() );
 372                         }
 373
 374                         // Reset and print just the error message
 375                         ob_clean();
 376
 377                         // If the error occured during printing, do a printer->profileOut()
 378                         $this->mPrinter->safeProfileOut();
 379                         $this->printResult( true );
 380                 }
 381
 382                 // Send cache headers after any code which might generate an error, to
 383                 // avoid sending public cache headers for errors.
 384                 $this->sendCacheHeaders();
 385
 386                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 387                         echo wfReportTime();
 388                 }
 389
 390                 ob_end_flush();
 391         }
 392
 393         protected function sendCacheHeaders() {
 394                 if ( $this->mCacheMode == 'private' ) {
 395                         header( 'Cache-Control: private' );
 396                         return;
 397                 }
 398
 399                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 400                         global $wgUseXVO, $wgOut;
 401                         header( 'Vary: Accept-Encoding, Cookie' );
 402                         if ( $wgUseXVO ) {
 403                                 header( $wgOut->getXVO() );
 404                                 if ( $wgOut->haveCacheVaryCookies() ) {
 405                                         // Logged in, mark this request private
 406                                         header( 'Cache-Control: private' );
 407                                         return;
 408                                 }
 409                                 // Logged out, send normal public headers below
 410                         } elseif ( session_id() != '' ) {
 411                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 412                                 // Mark request private
 413                                 header( 'Cache-Control: private' );
 414                                 return;
 415                         } // else no XVO and anonymous, send public headers below
 416                 }
 417
 418                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 419                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 420                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 421                 }
 422                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 423                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 424                 }
 425
 426                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 427                         // Public cache not requested
 428                         // Sending a Vary header in this case is harmless, and protects us
 429                         // against conditional calls of setCacheMaxAge().
 430                         header( 'Cache-Control: private' );
 431                         return;
 432                 }
 433
 434                 $this->mCacheControl['public'] = true;
 435
 436                 // Send an Expires header
 437                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 438                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 439                 header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 440
 441                 // Construct the Cache-Control header
 442                 $ccHeader = '';
 443                 $separator = '';
 444                 foreach ( $this->mCacheControl as $name => $value ) {
 445                         if ( is_bool( $value ) ) {
 446                                 if ( $value ) {
 447                                         $ccHeader .= $separator . $name;
 448                                         $separator = ', ';
 449                                 }
 450                         } else {
 451                                 $ccHeader .= $separator . "$name=$value";
 452                                 $separator = ', ';
 453                         }
 454                 }
 455
 456                 header( "Cache-Control: $ccHeader" );
 457         }
 458
 459         /**
 460          * Replace the result data with the information about an exception.
 461          * Returns the error code
 462          * @param $e Exception
 463          * @return string
 464          */
 465         protected function substituteResultWithError( $e ) {
 466                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 467                 if ( !isset ( $this->mPrinter ) ) {
 468                         // The printer has not been created yet. Try to manually get formatter value.
 469                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 470                         if ( !in_array( $value, $this->mFormatNames ) ) {
 471                                 $value = self::API_DEFAULT_FORMAT;
 472                         }
 473
 474                         $this->mPrinter = $this->createPrinterByName( $value );
 475                         if ( $this->mPrinter->getNeedsRawData() ) {
 476                                 $this->getResult()->setRawMode();
 477                         }
 478                 }
 479
 480                 if ( $e instanceof UsageException ) {
 481                         //
 482                         // User entered incorrect parameters - print usage screen
 483                         //
 484                         $errMessage = $e->getMessageArray();
 485
 486                         // Only print the help message when this is for the developer, not runtime
 487                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 488                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 489                         }
 490
 491                 } else {
 492                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 493                         //
 494                         // Something is seriously wrong
 495                         //
 496                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 497                                 $info = 'Database query error';
 498                         } else {
 499                                 $info = "Exception Caught: {$e->getMessage()}";
 500                         }
 501
 502                         $errMessage = array(
 503                                 'code' => 'internal_api_error_' . get_class( $e ),
 504                                 'info' => $info,
 505                         );
 506                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 507                 }
 508
 509                 $this->getResult()->reset();
 510                 $this->getResult()->disableSizeCheck();
 511                 // Re-add the id
 512                 $requestid = $this->getParameter( 'requestid' );
 513                 if ( !is_null( $requestid ) ) {
 514                         $this->getResult()->addValue( null, 'requestid', $requestid );
 515                 }
 516                 // servedby is especially useful when debugging errors
 517                 $this->getResult()->addValue( null, 'servedby', wfHostName() );
 518                 $this->getResult()->addValue( null, 'error', $errMessage );
 519
 520                 return $errMessage['code'];
 521         }
 522
 523         /**
 524          * Set up for the execution.
 525          * @return array
 526          */
 527         protected function setupExecuteAction() {
 528                 // First add the id to the top element
 529                 $requestid = $this->getParameter( 'requestid' );
 530                 if ( !is_null( $requestid ) ) {
 531                         $this->getResult()->addValue( null, 'requestid', $requestid );
 532                 }
 533                 $servedby = $this->getParameter( 'servedby' );
 534                 if ( $servedby ) {
 535                         $this->getResult()->addValue( null, 'servedby', wfHostName() );
 536                 }
 537
 538                 $params = $this->extractRequestParams();
 539
 540                 $this->mShowVersions = $params['version'];
 541                 $this->mAction = $params['action'];
 542
 543                 if ( !is_string( $this->mAction ) ) {
 544                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 545                 }
 546
 547                 return $params;
 548         }
 549
 550         /**
 551          * Set up the module for response
 552          * @return ApiBase The module that will handle this action
 553          */
 554         protected function setupModule() {
 555                 // Instantiate the module requested by the user
 556                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 557                 $this->mModule = $module;
 558
 559                 $moduleParams = $module->extractRequestParams();
 560
 561                 // Die if token required, but not provided (unless there is a gettoken parameter)
 562                 $salt = $module->getTokenSalt();
 563                 if ( $salt !== false && !isset( $moduleParams['gettoken'] ) ) {
 564                         if ( !isset( $moduleParams['token'] ) ) {
 565                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 566                         } else {
 567                                 global $wgUser;
 568                                 if ( !$wgUser->matchEditToken( $moduleParams['token'], $salt ) ) {
 569                                         $this->dieUsageMsg( array( 'sessionfailure' ) );
 570                                 }
 571                         }
 572                 }
 573                 return $module;
 574         }
 575
 576         /**
 577          * Check the max lag if necessary
 578          * @param $module ApiBase object: Api module being used
 579          * @param $params Array an array containing the request parameters.
 580          * @return boolean True on success, false should exit immediately
 581          */
 582         protected function checkMaxLag( $module, $params ) {
 583                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 584                         // Check for maxlag
 585                         global $wgShowHostnames;
 586                         $maxLag = $params['maxlag'];
 587                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 588                         if ( $lag > $maxLag ) {
 589                                 header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 590                                 header( 'X-Database-Lag: ' . intval( $lag ) );
 591                                 if ( $wgShowHostnames ) {
 592                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 593                                 } else {
 594                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 595                                 }
 596                                 return false;
 597                         }
 598                 }
 599                 return true;
 600         }
 601
 602
 603         /**
 604          * Check for sufficient permissions to execute
 605          * @param $module ApiBase An Api module
 606          */
 607         protected function checkExecutePermissions( $module ) {
 608                 global $wgUser;
 609                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 610                         !$wgUser->isAllowed( 'read' ) )
 611                 {
 612                         $this->dieUsageMsg( array( 'readrequired' ) );
 613                 }
 614                 if ( $module->isWriteMode() ) {
 615                         if ( !$this->mEnableWrite ) {
 616                                 $this->dieUsageMsg( array( 'writedisabled' ) );
 617                         }
 618                         if ( !$wgUser->isAllowed( 'writeapi' ) ) {
 619                                 $this->dieUsageMsg( array( 'writerequired' ) );
 620                         }
 621                         if ( wfReadOnly() ) {
 622                                 $this->dieReadOnly();
 623                         }
 624                 }
 625         }
 626
 627         /**
 628          * Check POST for external response and setup result printer
 629          * @param $module ApiBase An Api module
 630          * @param $params Array an array with the request parameters
 631          */
 632         protected function setupExternalResponse( $module, $params ) {
 633                 // Ignore mustBePosted() for internal calls
 634                 if ( $module->mustBePosted() && !$this->mRequest->wasPosted() ) {
 635                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 636                 }
 637
 638                 // See if custom printer is used
 639                 $this->mPrinter = $module->getCustomPrinter();
 640                 if ( is_null( $this->mPrinter ) ) {
 641                         // Create an appropriate printer
 642                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 643                 }
 644
 645                 if ( $this->mPrinter->getNeedsRawData() ) {
 646                         $this->getResult()->setRawMode();
 647                 }
 648         }
 649
 650         /**
 651          * Execute the actual module, without any error handling
 652          */
 653         protected function executeAction() {
 654                 $params = $this->setupExecuteAction();
 655                 $module = $this->setupModule();
 656
 657                 $this->checkExecutePermissions( $module );
 658
 659                 if ( !$this->checkMaxLag( $module, $params ) ) {
 660                         return;
 661                 }
 662
 663                 if ( !$this->mInternalMode ) {
 664                         $this->setupExternalResponse( $module, $params );
 665                 }
 666
 667                 // Execute
 668                 $module->profileIn();
 669                 $module->execute();
 670                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 671                 $module->profileOut();
 672
 673                 if ( !$this->mInternalMode ) {
 674                         // Print result data
 675                         $this->printResult( false );
 676                 }
 677         }
 678
 679         /**
 680          * Print results using the current printer
 681          */
 682         protected function printResult( $isError ) {
 683                 $this->getResult()->cleanUpUTF8();
 684                 $printer = $this->mPrinter;
 685                 $printer->profileIn();
 686
 687                 /**
 688                  * If the help message is requested in the default (xmlfm) format,
 689                  * tell the printer not to escape ampersands so that our links do
 690                  * not break.
 691                  */
 692                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 693                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 694
 695                 $printer->initPrinter( $isError );
 696
 697                 $printer->execute();
 698                 $printer->closePrinter();
 699                 $printer->profileOut();
 700         }
 701
 702         /**
 703          * @return bool
 704          */
 705         public function isReadMode() {
 706                 return false;
 707         }
 708
 709         /**
 710          * See ApiBase for description.
 711          */
 712         public function getAllowedParams() {
 713                 return array(
 714                         'format' => array(
 715                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 716                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 717                         ),
 718                         'action' => array(
 719                                 ApiBase::PARAM_DFLT => 'help',
 720                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 721                         ),
 722                         'version' => false,
 723                         'maxlag'  => array(
 724                                 ApiBase::PARAM_TYPE => 'integer'
 725                         ),
 726                         'smaxage' => array(
 727                                 ApiBase::PARAM_TYPE => 'integer',
 728                                 ApiBase::PARAM_DFLT => 0
 729                         ),
 730                         'maxage' => array(
 731                                 ApiBase::PARAM_TYPE => 'integer',
 732                                 ApiBase::PARAM_DFLT => 0
 733                         ),
 734                         'requestid' => null,
 735                         'servedby'  => false,
 736                 );
 737         }
 738
 739         /**
 740          * See ApiBase for description.
 741          */
 742         public function getParamDescription() {
 743                 return array(
 744                         'format' => 'The format of the output',
 745                         'action' => 'What action you would like to perform. See below for module help',
 746                         'version' => 'When showing help, include version for each module',
 747                         'maxlag' => 'Maximum lag',
 748                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 749                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 750                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 751                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 752                 );
 753         }
 754
 755         /**
 756          * See ApiBase for description.
 757          */
 758         public function getDescription() {
 759                 return array(
 760                         '',
 761                         '',
 762                         '**********************************************************************************************************',
 763                         '**                                                                                                      **',
 764                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 765                         '**                                                                                                      **',
 766                         '**                                    Documentation and Examples:                                       **',
 767                         '**                                 http://www.mediawiki.org/wiki/API                                    **',
 768                         '**                                                                                                      **',
 769                         '**********************************************************************************************************',
 770                         '',
 771                         'Status:                All features shown on this page should be working, but the API',
 772                         '                       is still in active development, and  may change at any time.',
 773                         '                       Make sure to monitor our mailing list for any updates',
 774                         '',
 775                         'Documentation:         http://www.mediawiki.org/wiki/API',
 776                         'Mailing list:          http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 777                         'Api Announcements:     http://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 778                         'Bugs & Requests:       http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 779                         '',
 780                         '',
 781                         '',
 782                         '',
 783                         '',
 784                 );
 785         }
 786
 787         public function getPossibleErrors() {
 788                 return array_merge( parent::getPossibleErrors(), array(
 789                         array( 'readonlytext' ),
 790                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 791                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 792                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 793                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 794                 ) );
 795         }
 796
 797         /**
 798          * Returns an array of strings with credits for the API
 799          */
 800         protected function getCredits() {
 801                 return array(
 802                         'API developers:',
 803                         '    Roan Kattouw <Firstname>.<Lastname>@gmail.com (lead developer Sep 2007-present)',
 804                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 805                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 806                         '    Sam Reed - sam @ reedyboy . net',
 807                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 808                         '',
 809                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 810                         'or file a bug report at http://bugzilla.wikimedia.org/'
 811                 );
 812         }
 813         /**
 814          * Sets whether the pretty-printer should format *bold* and $italics$
 815          */
 816         public function setHelp( $help = true ) {
 817                 $this->mPrinter->setHelp( $help );
 818         }
 819
 820         /**
 821          * Override the parent to generate help messages for all available modules.
 822          */
 823         public function makeHelpMsg() {
 824                 global $wgMemc, $wgAPICacheHelpTimeout;
 825                 $this->setHelp();
 826                 // Get help text from cache if present
 827                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
 828                         SpecialVersion::getVersion( 'nodb' ) .
 829                         $this->getMain()->getShowVersions() );
 830                 if ( $wgAPICacheHelpTimeout > 0 ) {
 831                         $cached = $wgMemc->get( $key );
 832                         if ( $cached ) {
 833                                 return $cached;
 834                         }
 835                 }
 836                 $retval = $this->reallyMakeHelpMsg();
 837                 if ( $wgAPICacheHelpTimeout > 0 ) {
 838                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
 839                 }
 840                 return $retval;
 841         }
 842
 843         public function reallyMakeHelpMsg() {
 844                 $this->setHelp();
 845
 846                 // Use parent to make default message for the main module
 847                 $msg = parent::makeHelpMsg();
 848
 849                 $astriks = str_repeat( '*** ', 14 );
 850                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 851                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
 852                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
 853                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
 854                         $msg2 = $module->makeHelpMsg();
 855                         if ( $msg2 !== false ) {
 856                                 $msg .= $msg2;
 857                         }
 858                         $msg .= "\n";
 859                 }
 860
 861                 $msg .= "\n$astriks Permissions $astriks\n\n";
 862                 foreach ( self::$mRights as $right => $rightMsg ) {
 863                         $groups = User::getGroupsWithPermission( $right );
 864                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
 865                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
 866
 867                 }
 868
 869                 $msg .= "\n$astriks Formats  $astriks\n\n";
 870                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
 871                         $module = $this->createPrinterByName( $formatName );
 872                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
 873                         $msg2 = $module->makeHelpMsg();
 874                         if ( $msg2 !== false ) {
 875                                 $msg .= $msg2;
 876                         }
 877                         $msg .= "\n";
 878                 }
 879
 880                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
 881
 882                 return $msg;
 883         }
 884
 885         /**
 886          * @static
 887          * @param  $module ApiBase
 888          * @param  $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
 889          * @return string
 890          */
 891         public static function makeHelpMsgHeader( $module, $paramName ) {
 892                 $modulePrefix = $module->getModulePrefix();
 893                 if ( strval( $modulePrefix ) !== '' ) {
 894                         $modulePrefix = "($modulePrefix) ";
 895                 }
 896
 897                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 898         }
 899
 900         private $mIsBot = null;
 901         private $mIsSysop = null;
 902         private $mCanApiHighLimits = null;
 903
 904         /**
 905          * Returns true if the currently logged in user is a bot, false otherwise
 906          * OBSOLETE, use canApiHighLimits() instead
 907          */
 908         public function isBot() {
 909                 if ( !isset( $this->mIsBot ) ) {
 910                         global $wgUser;
 911                         $this->mIsBot = $wgUser->isAllowed( 'bot' );
 912                 }
 913                 return $this->mIsBot;
 914         }
 915
 916         /**
 917          * Similar to isBot(), this method returns true if the logged in user is
 918          * a sysop, and false if not.
 919          * OBSOLETE, use canApiHighLimits() instead
 920          */
 921         public function isSysop() {
 922                 if ( !isset( $this->mIsSysop ) ) {
 923                         global $wgUser;
 924                         $this->mIsSysop = in_array( 'sysop', $wgUser->getGroups() );
 925                 }
 926
 927                 return $this->mIsSysop;
 928         }
 929
 930         /**
 931          * Check whether the current user is allowed to use high limits
 932          * @return bool
 933          */
 934         public function canApiHighLimits() {
 935                 if ( !isset( $this->mCanApiHighLimits ) ) {
 936                         global $wgUser;
 937                         $this->mCanApiHighLimits = $wgUser->isAllowed( 'apihighlimits' );
 938                 }
 939
 940                 return $this->mCanApiHighLimits;
 941         }
 942
 943         /**
 944          * Check whether the user wants us to show version information in the API help
 945          * @return bool
 946          */
 947         public function getShowVersions() {
 948                 return $this->mShowVersions;
 949         }
 950
 951         /**
 952          * Returns the version information of this file, plus it includes
 953          * the versions for all files that are not callable proper API modules
 954          */
 955         public function getVersion() {
 956                 $vers = array ();
 957                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    http://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
 958                 $vers[] = __CLASS__ . ': $Id$';
 959                 $vers[] = ApiBase::getBaseVersion();
 960                 $vers[] = ApiFormatBase::getBaseVersion();
 961                 $vers[] = ApiQueryBase::getBaseVersion();
 962                 return $vers;
 963         }
 964
 965         /**
 966          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
 967          * classes who wish to add their own modules to their lexicon or override the
 968          * behavior of inherent ones.
 969          *
 970          * @param $mdlName String The identifier for this module.
 971          * @param $mdlClass String The class where this module is implemented.
 972          */
 973         protected function addModule( $mdlName, $mdlClass ) {
 974                 $this->mModules[$mdlName] = $mdlClass;
 975         }
 976
 977         /**
 978          * Add or overwrite an output format for this ApiMain. Intended for use by extending
 979          * classes who wish to add to or modify current formatters.
 980          *
 981          * @param $fmtName The identifier for this format.
 982          * @param $fmtClass The class implementing this format.
 983          */
 984         protected function addFormat( $fmtName, $fmtClass ) {
 985                 $this->mFormats[$fmtName] = $fmtClass;
 986         }
 987
 988         /**
 989          * Get the array mapping module names to class names
 990          * @return array
 991          */
 992         function getModules() {
 993                 return $this->mModules;
 994         }
 995 }
 996
 997 /**
 998  * This exception will be thrown when dieUsage is called to stop module execution.
 999  * The exception handling code will print a help screen explaining how this API may be used.
1000  *
1001  * @ingroup API
1002  */
1003 class UsageException extends Exception {
1004
1005         private $mCodestr;
1006         private $mExtraData;
1007
1008         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1009                 parent::__construct( $message, $code );
1010                 $this->mCodestr = $codestr;
1011                 $this->mExtraData = $extradata;
1012         }
1013
1014         public function getCodeString() {
1015                 return $this->mCodestr;
1016         }
1017
1018         public function getMessageArray() {
1019                 $result = array(
1020                         'code' => $this->mCodestr,
1021                         'info' => $this->getMessage()
1022                 );
1023                 if ( is_array( $this->mExtraData ) ) {
1024                         $result = array_merge( $result, $this->mExtraData );
1025                 }
1026                 return $result;
1027         }
1028
1029         public function __toString() {
1030                 return "{$this->getCodeString()}: {$this->getMessage()}";
1031         }
1032 }