includes/api/ApiMain.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Sep 4, 2006
   6  *
   7  * Copyright © 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @file
  25  * @defgroup API API
  26  */
  27
  28 if ( !defined( 'MEDIAWIKI' ) ) {
  29         // Eclipse helper - will be ignored in production
  30         require_once( 'ApiBase.php' );
  31 }
  32
  33 /**
  34  * This is the main API class, used for both external and internal processing.
  35  * When executed, it will create the requested formatter object,
  36  * instantiate and execute an object associated with the needed action,
  37  * and use formatter to print results.
  38  * In case of an exception, an error message will be printed using the same formatter.
  39  *
  40  * To use API from another application, run it using FauxRequest object, in which
  41  * case any internal exceptions will not be handled but passed up to the caller.
  42  * After successful execution, use getResult() for the resulting data.
  43  *
  44  * @ingroup API
  45  */
  46 class ApiMain extends ApiBase {
  47
  48         /**
  49          * When no format parameter is given, this format will be used
  50          */
  51         const API_DEFAULT_FORMAT = 'xmlfm';
  52
  53         /**
  54          * List of available modules: action name => module class
  55          */
  56         private static $Modules = array(
  57                 'login' => 'ApiLogin',
  58                 'logout' => 'ApiLogout',
  59                 'query' => 'ApiQuery',
  60                 'expandtemplates' => 'ApiExpandTemplates',
  61                 'parse' => 'ApiParse',
  62                 'opensearch' => 'ApiOpenSearch',
  63                 'feedcontributions' => 'ApiFeedContributions',
  64                 'feedwatchlist' => 'ApiFeedWatchlist',
  65                 'help' => 'ApiHelp',
  66                 'paraminfo' => 'ApiParamInfo',
  67                 'rsd' => 'ApiRsd',
  68                 'compare' => 'ApiComparePages',
  69
  70                 // Write modules
  71                 'purge' => 'ApiPurge',
  72                 'rollback' => 'ApiRollback',
  73                 'delete' => 'ApiDelete',
  74                 'undelete' => 'ApiUndelete',
  75                 'protect' => 'ApiProtect',
  76                 'block' => 'ApiBlock',
  77                 'unblock' => 'ApiUnblock',
  78                 'move' => 'ApiMove',
  79                 'edit' => 'ApiEditPage',
  80                 'upload' => 'ApiUpload',
  81                 'filerevert' => 'ApiFileRevert',
  82                 'emailuser' => 'ApiEmailUser',
  83                 'watch' => 'ApiWatch',
  84                 'patrol' => 'ApiPatrol',
  85                 'import' => 'ApiImport',
  86                 'userrights' => 'ApiUserrights',
  87         );
  88
  89         /**
  90          * List of available formats: format name => format class
  91          */
  92         private static $Formats = array(
  93                 'json' => 'ApiFormatJson',
  94                 'jsonfm' => 'ApiFormatJson',
  95                 'php' => 'ApiFormatPhp',
  96                 'phpfm' => 'ApiFormatPhp',
  97                 'wddx' => 'ApiFormatWddx',
  98                 'wddxfm' => 'ApiFormatWddx',
  99                 'xml' => 'ApiFormatXml',
 100                 'xmlfm' => 'ApiFormatXml',
 101                 'yaml' => 'ApiFormatYaml',
 102                 'yamlfm' => 'ApiFormatYaml',
 103                 'rawfm' => 'ApiFormatJson',
 104                 'txt' => 'ApiFormatTxt',
 105                 'txtfm' => 'ApiFormatTxt',
 106                 'dbg' => 'ApiFormatDbg',
 107                 'dbgfm' => 'ApiFormatDbg',
 108                 'dump' => 'ApiFormatDump',
 109                 'dumpfm' => 'ApiFormatDump',
 110         );
 111
 112         /**
 113          * List of user roles that are specifically relevant to the API.
 114          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 115          *                           'params' => array ( $someVarToSubst ) ),
 116          *                          );
 117          */
 118         private static $mRights = array(
 119                 'writeapi' => array(
 120                         'msg' => 'Use of the write API',
 121                         'params' => array()
 122                 ),
 123                 'apihighlimits' => array(
 124                         'msg' => 'Use higher limits in API queries (Slow queries: $1 results; Fast queries: $2 results). The limits for slow queries also apply to multivalue parameters.',
 125                         'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
 126                 )
 127         );
 128
 129         /**
 130          * @var ApiFormatBase
 131          */
 132         private $mPrinter;
 133
 134         private $mModules, $mModuleNames, $mFormats, $mFormatNames;
 135         private $mResult, $mAction, $mShowVersions, $mEnableWrite, $mRequest;
 136         private $mInternalMode, $mSquidMaxage, $mModule;
 137
 138         private $mCacheMode = 'private';
 139         private $mCacheControl = array();
 140
 141         /**
 142          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 143          *
 144          * @param $request WebRequest - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 145          * @param $enableWrite bool should be set to true if the api may modify data
 146          */
 147         public function __construct( $request, $enableWrite = false ) {
 148                 $this->mInternalMode = ( $request instanceof FauxRequest );
 149
 150                 // Special handling for the main module: $parent === $this
 151                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 152
 153                 if ( !$this->mInternalMode ) {
 154                         // Impose module restrictions.
 155                         // If the current user cannot read,
 156                         // Remove all modules other than login
 157                         global $wgUser;
 158
 159                         if ( $request->getVal( 'callback' ) !== null ) {
 160                                 // JSON callback allows cross-site reads.
 161                                 // For safety, strip user credentials.
 162                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 163                                 $wgUser = new User();
 164                         }
 165                 }
 166
 167                 global $wgAPIModules; // extension modules
 168                 $this->mModules = $wgAPIModules + self::$Modules;
 169
 170                 $this->mModuleNames = array_keys( $this->mModules );
 171                 $this->mFormats = self::$Formats;
 172                 $this->mFormatNames = array_keys( $this->mFormats );
 173
 174                 $this->mResult = new ApiResult( $this );
 175                 $this->mShowVersions = false;
 176                 $this->mEnableWrite = $enableWrite;
 177
 178                 $this->mRequest = &$request;
 179
 180                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 181                 $this->mCommit = false;
 182         }
 183
 184         /**
 185          * Return true if the API was started by other PHP code using FauxRequest
 186          * @return bool
 187          */
 188         public function isInternalMode() {
 189                 return $this->mInternalMode;
 190         }
 191
 192         /**
 193          * Return the request object that contains client's request
 194          * @return WebRequest
 195          */
 196         public function getRequest() {
 197                 return $this->mRequest;
 198         }
 199
 200         /**
 201          * Get the ApiResult object associated with current request
 202          *
 203          * @return ApiResult
 204          */
 205         public function getResult() {
 206                 return $this->mResult;
 207         }
 208
 209         /**
 210          * Get the API module object. Only works after executeAction()
 211          *
 212          * @return ApiBase
 213          */
 214         public function getModule() {
 215                 return $this->mModule;
 216         }
 217
 218         /**
 219          * Get the result formatter object. Only works after setupExecuteAction()
 220          *
 221          * @return ApiFormatBase
 222          */
 223         public function getPrinter() {
 224                 return $this->mPrinter;
 225         }
 226
 227         /**
 228          * Set how long the response should be cached.
 229          *
 230          * @param $maxage
 231          */
 232         public function setCacheMaxAge( $maxage ) {
 233                 $this->setCacheControl( array(
 234                         'max-age' => $maxage,
 235                         's-maxage' => $maxage
 236                 ) );
 237         }
 238
 239         /**
 240          * Set the type of caching headers which will be sent.
 241          *
 242          * @param $mode String One of:
 243          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 244          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 245          *         not provided by any of these means, the object will be private.
 246          *    - 'private':    Cache this object only in private client-side caches.
 247          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 248          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 249          *         set consistently for a given URL, it cannot be set differently depending on
 250          *         things like the contents of the database, or whether the user is logged in.
 251          *
 252          *  If the wiki does not allow anonymous users to read it, the mode set here
 253          *  will be ignored, and private caching headers will always be sent. In other words,
 254          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 255          *  view.
 256          *
 257          *  For user-dependent data, the private mode should generally be used. The
 258          *  anon-public-user-private mode should only be used where there is a particularly
 259          *  good performance reason for caching the anonymous response, but where the
 260          *  response to logged-in users may differ, or may contain private data.
 261          *
 262          *  If this function is never called, then the default will be the private mode.
 263          */
 264         public function setCacheMode( $mode ) {
 265                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 266                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 267                         // Ignore for forwards-compatibility
 268                         return;
 269                 }
 270
 271                 if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 272                         // Private wiki, only private headers
 273                         if ( $mode !== 'private' ) {
 274                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 275                                 return;
 276                         }
 277                 }
 278
 279                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 280                 $this->mCacheMode = $mode;
 281         }
 282
 283         /**
 284          * @deprecated since 1.17 Private caching is now the default, so there is usually no
 285          * need to call this function. If there is a need, you can use
 286          * $this->setCacheMode('private')
 287          */
 288         public function setCachePrivate() {
 289                 $this->setCacheMode( 'private' );
 290         }
 291
 292         /**
 293          * Set directives (key/value pairs) for the Cache-Control header.
 294          * Boolean values will be formatted as such, by including or omitting
 295          * without an equals sign.
 296          *
 297          * Cache control values set here will only be used if the cache mode is not
 298          * private, see setCacheMode().
 299          *
 300          * @param $directives array
 301          */
 302         public function setCacheControl( $directives ) {
 303                 $this->mCacheControl = $directives + $this->mCacheControl;
 304         }
 305
 306         /**
 307          * Make sure Vary: Cookie and friends are set. Use this when the output of a request
 308          * may be cached for anons but may not be cached for logged-in users.
 309          *
 310          * WARNING: This function must be called CONSISTENTLY for a given URL. This means that a
 311          * given URL must either always or never call this function; if it sometimes does and
 312          * sometimes doesn't, stuff will break.
 313          *
 314          * @deprecated since 1.17 Use setCacheMode( 'anon-public-user-private' )
 315          */
 316         public function setVaryCookie() {
 317                 $this->setCacheMode( 'anon-public-user-private' );
 318         }
 319
 320         /**
 321          * Create an instance of an output formatter by its name
 322          *
 323          * @param $format string
 324          *
 325          * @return ApiFormatBase
 326          */
 327         public function createPrinterByName( $format ) {
 328                 if ( !isset( $this->mFormats[$format] ) ) {
 329                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 330                 }
 331                 return new $this->mFormats[$format] ( $this, $format );
 332         }
 333
 334         /**
 335          * Execute api request. Any errors will be handled if the API was called by the remote client.
 336          */
 337         public function execute() {
 338                 $this->profileIn();
 339                 if ( $this->mInternalMode ) {
 340                         $this->executeAction();
 341                 } else {
 342                         $this->executeActionWithErrorHandling();
 343                 }
 344
 345                 $this->profileOut();
 346         }
 347
 348         /**
 349          * Execute an action, and in case of an error, erase whatever partial results
 350          * have been accumulated, and replace it with an error message and a help screen.
 351          */
 352         protected function executeActionWithErrorHandling() {
 353                 // In case an error occurs during data output,
 354                 // clear the output buffer and print just the error information
 355                 ob_start();
 356
 357                 try {
 358                         $this->executeAction();
 359                 } catch ( Exception $e ) {
 360                         // Log it
 361                         if ( $e instanceof MWException ) {
 362                                 wfDebugLog( 'exception', $e->getLogMessage() );
 363                         }
 364
 365                         // Handle any kind of exception by outputing properly formatted error message.
 366                         // If this fails, an unhandled exception should be thrown so that global error
 367                         // handler will process and log it.
 368
 369                         $errCode = $this->substituteResultWithError( $e );
 370
 371                         // Error results should not be cached
 372                         $this->setCacheMode( 'private' );
 373
 374                         $response = $this->getRequest()->response();
 375                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 376                         if ( $e->getCode() === 0 ) {
 377                                 $response->header( $headerStr );
 378                         } else {
 379                                 $response->header( $headerStr, true, $e->getCode() );
 380                         }
 381
 382                         // Reset and print just the error message
 383                         ob_clean();
 384
 385                         // If the error occured during printing, do a printer->profileOut()
 386                         $this->mPrinter->safeProfileOut();
 387                         $this->printResult( true );
 388                 }
 389
 390                 // Send cache headers after any code which might generate an error, to
 391                 // avoid sending public cache headers for errors.
 392                 $this->sendCacheHeaders();
 393
 394                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 395                         echo wfReportTime();
 396                 }
 397
 398                 ob_end_flush();
 399         }
 400
 401         protected function sendCacheHeaders() {
 402                 $response = $this->getRequest()->response();
 403
 404                 if ( $this->mCacheMode == 'private' ) {
 405                         $response->header( 'Cache-Control: private' );
 406                         return;
 407                 }
 408
 409                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 410                         global $wgUseXVO, $wgOut;
 411                         $response->header( 'Vary: Accept-Encoding, Cookie' );
 412                         if ( $wgUseXVO ) {
 413                                 $response->header( $wgOut->getXVO() );
 414                                 if ( $wgOut->haveCacheVaryCookies() ) {
 415                                         // Logged in, mark this request private
 416                                         $response->header( 'Cache-Control: private' );
 417                                         return;
 418                                 }
 419                                 // Logged out, send normal public headers below
 420                         } elseif ( session_id() != '' ) {
 421                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 422                                 // Mark request private
 423                                 $response->header( 'Cache-Control: private' );
 424                                 return;
 425                         } // else no XVO and anonymous, send public headers below
 426                 }
 427
 428                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 429                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 430                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 431                 }
 432                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 433                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 434                 }
 435
 436                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 437                         // Public cache not requested
 438                         // Sending a Vary header in this case is harmless, and protects us
 439                         // against conditional calls of setCacheMaxAge().
 440                         $response->header( 'Cache-Control: private' );
 441                         return;
 442                 }
 443
 444                 $this->mCacheControl['public'] = true;
 445
 446                 // Send an Expires header
 447                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 448                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 449                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 450
 451                 // Construct the Cache-Control header
 452                 $ccHeader = '';
 453                 $separator = '';
 454                 foreach ( $this->mCacheControl as $name => $value ) {
 455                         if ( is_bool( $value ) ) {
 456                                 if ( $value ) {
 457                                         $ccHeader .= $separator . $name;
 458                                         $separator = ', ';
 459                                 }
 460                         } else {
 461                                 $ccHeader .= $separator . "$name=$value";
 462                                 $separator = ', ';
 463                         }
 464                 }
 465
 466                 $response->header( "Cache-Control: $ccHeader" );
 467         }
 468
 469         /**
 470          * Replace the result data with the information about an exception.
 471          * Returns the error code
 472          * @param $e Exception
 473          * @return string
 474          */
 475         protected function substituteResultWithError( $e ) {
 476                 $result = $this->getResult();
 477                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 478                 if ( !isset ( $this->mPrinter ) ) {
 479                         // The printer has not been created yet. Try to manually get formatter value.
 480                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 481                         if ( !in_array( $value, $this->mFormatNames ) ) {
 482                                 $value = self::API_DEFAULT_FORMAT;
 483                         }
 484
 485                         $this->mPrinter = $this->createPrinterByName( $value );
 486                         if ( $this->mPrinter->getNeedsRawData() ) {
 487                                 $result->setRawMode();
 488                         }
 489                 }
 490
 491                 if ( $e instanceof UsageException ) {
 492                         // User entered incorrect parameters - print usage screen
 493                         $errMessage = $e->getMessageArray();
 494
 495                         // Only print the help message when this is for the developer, not runtime
 496                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 497                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 498                         }
 499
 500                 } else {
 501                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 502                         // Something is seriously wrong
 503                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 504                                 $info = 'Database query error';
 505                         } else {
 506                                 $info = "Exception Caught: {$e->getMessage()}";
 507                         }
 508
 509                         $errMessage = array(
 510                                 'code' => 'internal_api_error_' . get_class( $e ),
 511                                 'info' => $info,
 512                         );
 513                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 514                 }
 515
 516                 $result->reset();
 517                 $result->disableSizeCheck();
 518                 // Re-add the id
 519                 $requestid = $this->getParameter( 'requestid' );
 520                 if ( !is_null( $requestid ) ) {
 521                         $result->addValue( null, 'requestid', $requestid );
 522                 }
 523                 // servedby is especially useful when debugging errors
 524                 $result->addValue( null, 'servedby', wfHostName() );
 525                 $result->addValue( null, 'error', $errMessage );
 526
 527                 return $errMessage['code'];
 528         }
 529
 530         /**
 531          * Set up for the execution.
 532          * @return array
 533          */
 534         protected function setupExecuteAction() {
 535                 // First add the id to the top element
 536                 $result = $this->getResult();
 537                 $requestid = $this->getParameter( 'requestid' );
 538                 if ( !is_null( $requestid ) ) {
 539                         $result->addValue( null, 'requestid', $requestid );
 540                 }
 541                 $servedby = $this->getParameter( 'servedby' );
 542                 if ( $servedby ) {
 543                         $result->addValue( null, 'servedby', wfHostName() );
 544                 }
 545
 546                 $params = $this->extractRequestParams();
 547
 548                 $this->mShowVersions = $params['version'];
 549                 $this->mAction = $params['action'];
 550
 551                 if ( !is_string( $this->mAction ) ) {
 552                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 553                 }
 554
 555                 return $params;
 556         }
 557
 558         /**
 559          * Set up the module for response
 560          * @return ApiBase The module that will handle this action
 561          */
 562         protected function setupModule() {
 563                 // Instantiate the module requested by the user
 564                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 565                 $this->mModule = $module;
 566
 567                 $moduleParams = $module->extractRequestParams();
 568
 569                 // Die if token required, but not provided (unless there is a gettoken parameter)
 570                 $salt = $module->getTokenSalt();
 571                 if ( $salt !== false && !isset( $moduleParams['gettoken'] ) ) {
 572                         if ( !isset( $moduleParams['token'] ) ) {
 573                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 574                         } else {
 575                                 global $wgUser;
 576                                 if ( !$wgUser->matchEditToken( $moduleParams['token'], $salt, $this->getRequest() ) ) {
 577                                         $this->dieUsageMsg( 'sessionfailure' );
 578                                 }
 579                         }
 580                 }
 581                 return $module;
 582         }
 583
 584         /**
 585          * Check the max lag if necessary
 586          * @param $module ApiBase object: Api module being used
 587          * @param $params Array an array containing the request parameters.
 588          * @return boolean True on success, false should exit immediately
 589          */
 590         protected function checkMaxLag( $module, $params ) {
 591                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 592                         // Check for maxlag
 593                         global $wgShowHostnames;
 594                         $maxLag = $params['maxlag'];
 595                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 596                         if ( $lag > $maxLag ) {
 597                                 $response = $this->getRequest()->response();
 598
 599                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 600                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 601
 602                                 if ( $wgShowHostnames ) {
 603                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 604                                 } else {
 605                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 606                                 }
 607                                 return false;
 608                         }
 609                 }
 610                 return true;
 611         }
 612
 613         /**
 614          * Check for sufficient permissions to execute
 615          * @param $module ApiBase An Api module
 616          */
 617         protected function checkExecutePermissions( $module ) {
 618                 global $wgUser;
 619                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 620                         !$wgUser->isAllowed( 'read' ) )
 621                 {
 622                         $this->dieUsageMsg( 'readrequired' );
 623                 }
 624                 if ( $module->isWriteMode() ) {
 625                         if ( !$this->mEnableWrite ) {
 626                                 $this->dieUsageMsg( 'writedisabled' );
 627                         }
 628                         if ( !$wgUser->isAllowed( 'writeapi' ) ) {
 629                                 $this->dieUsageMsg( 'writerequired' );
 630                         }
 631                         if ( wfReadOnly() ) {
 632                                 $this->dieReadOnly();
 633                         }
 634                 }
 635         }
 636
 637         /**
 638          * Check POST for external response and setup result printer
 639          * @param $module ApiBase An Api module
 640          * @param $params Array an array with the request parameters
 641          */
 642         protected function setupExternalResponse( $module, $params ) {
 643                 // Ignore mustBePosted() for internal calls
 644                 if ( $module->mustBePosted() && !$this->mRequest->wasPosted() ) {
 645                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 646                 }
 647
 648                 // See if custom printer is used
 649                 $this->mPrinter = $module->getCustomPrinter();
 650                 if ( is_null( $this->mPrinter ) ) {
 651                         // Create an appropriate printer
 652                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 653                 }
 654
 655                 if ( $this->mPrinter->getNeedsRawData() ) {
 656                         $this->getResult()->setRawMode();
 657                 }
 658         }
 659
 660         /**
 661          * Execute the actual module, without any error handling
 662          */
 663         protected function executeAction() {
 664                 $params = $this->setupExecuteAction();
 665                 $module = $this->setupModule();
 666
 667                 $this->checkExecutePermissions( $module );
 668
 669                 if ( !$this->checkMaxLag( $module, $params ) ) {
 670                         return;
 671                 }
 672
 673                 if ( !$this->mInternalMode ) {
 674                         $this->setupExternalResponse( $module, $params );
 675                 }
 676
 677                 // Execute
 678                 $module->profileIn();
 679                 $module->execute();
 680                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 681                 $module->profileOut();
 682
 683                 if ( !$this->mInternalMode ) {
 684                         // Print result data
 685                         $this->printResult( false );
 686                 }
 687         }
 688
 689         /**
 690          * Print results using the current printer
 691          *
 692          * @param $isError bool
 693          */
 694         protected function printResult( $isError ) {
 695                 $this->getResult()->cleanUpUTF8();
 696                 $printer = $this->mPrinter;
 697                 $printer->profileIn();
 698
 699                 /**
 700                  * If the help message is requested in the default (xmlfm) format,
 701                  * tell the printer not to escape ampersands so that our links do
 702                  * not break.
 703                  */
 704                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 705                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 706
 707                 $printer->initPrinter( $isError );
 708
 709                 $printer->execute();
 710                 $printer->closePrinter();
 711                 $printer->profileOut();
 712         }
 713
 714         /**
 715          * @return bool
 716          */
 717         public function isReadMode() {
 718                 return false;
 719         }
 720
 721         /**
 722          * See ApiBase for description.
 723          *
 724          * @return array
 725          */
 726         public function getAllowedParams() {
 727                 return array(
 728                         'format' => array(
 729                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 730                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 731                         ),
 732                         'action' => array(
 733                                 ApiBase::PARAM_DFLT => 'help',
 734                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 735                         ),
 736                         'version' => false,
 737                         'maxlag'  => array(
 738                                 ApiBase::PARAM_TYPE => 'integer'
 739                         ),
 740                         'smaxage' => array(
 741                                 ApiBase::PARAM_TYPE => 'integer',
 742                                 ApiBase::PARAM_DFLT => 0
 743                         ),
 744                         'maxage' => array(
 745                                 ApiBase::PARAM_TYPE => 'integer',
 746                                 ApiBase::PARAM_DFLT => 0
 747                         ),
 748                         'requestid' => null,
 749                         'servedby'  => false,
 750                 );
 751         }
 752
 753         /**
 754          * See ApiBase for description.
 755          *
 756          * @return array
 757          */
 758         public function getParamDescription() {
 759                 return array(
 760                         'format' => 'The format of the output',
 761                         'action' => 'What action you would like to perform. See below for module help',
 762                         'version' => 'When showing help, include version for each module',
 763                         'maxlag' => array(
 764                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
 765                                 'To save actions causing any more site replication lag, this parameter can make the client',
 766                                 'wait until the replication lag is less than the specified value.',
 767                                 'In case of a replag error, a HTTP 503 error is returned, with the message like',
 768                                 '"Waiting for $host: $lag seconds lagged\n".',
 769                                 'See http://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
 770                         ),
 771                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 772                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 773                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 774                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 775                 );
 776         }
 777
 778         /**
 779          * See ApiBase for description.
 780          *
 781          * @return array
 782          */
 783         public function getDescription() {
 784                 return array(
 785                         '',
 786                         '',
 787                         '**********************************************************************************************************',
 788                         '**                                                                                                      **',
 789                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 790                         '**                                                                                                      **',
 791                         '**                                    Documentation and Examples:                                       **',
 792                         '**                                 http://www.mediawiki.org/wiki/API                                    **',
 793                         '**                                                                                                      **',
 794                         '**********************************************************************************************************',
 795                         '',
 796                         'Status:                All features shown on this page should be working, but the API',
 797                         '                       is still in active development, and may change at any time.',
 798                         '                       Make sure to monitor our mailing list for any updates',
 799                         '',
 800                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
 801                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
 802                         '                       header and the error code sent back will be set to the same value',
 803                         '',
 804                         '                       In the case of an invalid action being passed, these will have a value',
 805                         '                       of "unknown_action"',
 806                         '',
 807                         'Documentation:         http://www.mediawiki.org/wiki/API',
 808                         'Mailing list:          http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 809                         'Api Announcements:     http://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 810                         'Bugs & Requests:       http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 811                         '',
 812                         '',
 813                         '',
 814                         '',
 815                         '',
 816                 );
 817         }
 818
 819         /**
 820          * @return array
 821          */
 822         public function getPossibleErrors() {
 823                 return array_merge( parent::getPossibleErrors(), array(
 824                         array( 'readonlytext' ),
 825                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 826                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 827                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 828                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 829                 ) );
 830         }
 831
 832         /**
 833          * Returns an array of strings with credits for the API
 834          * @return array
 835          */
 836         protected function getCredits() {
 837                 return array(
 838                         'API developers:',
 839                         '    Roan Kattouw <Firstname>.<Lastname>@gmail.com (lead developer Sep 2007-present)',
 840                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 841                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 842                         '    Sam Reed - sam @ reedyboy . net',
 843                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 844                         '',
 845                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 846                         'or file a bug report at http://bugzilla.wikimedia.org/'
 847                 );
 848         }
 849
 850         /**
 851          * Sets whether the pretty-printer should format *bold* and $italics$
 852          *
 853          * @param $help bool
 854          */
 855         public function setHelp( $help = true ) {
 856                 $this->mPrinter->setHelp( $help );
 857         }
 858
 859         /**
 860          * Override the parent to generate help messages for all available modules.
 861          *
 862          * @return string
 863          */
 864         public function makeHelpMsg() {
 865                 global $wgMemc, $wgAPICacheHelpTimeout;
 866                 $this->setHelp();
 867                 // Get help text from cache if present
 868                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
 869                         SpecialVersion::getVersion( 'nodb' ) .
 870                         $this->getShowVersions() );
 871                 if ( $wgAPICacheHelpTimeout > 0 ) {
 872                         $cached = $wgMemc->get( $key );
 873                         if ( $cached ) {
 874                                 return $cached;
 875                         }
 876                 }
 877                 $retval = $this->reallyMakeHelpMsg();
 878                 if ( $wgAPICacheHelpTimeout > 0 ) {
 879                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
 880                 }
 881                 return $retval;
 882         }
 883
 884         /**
 885          * @return mixed|string
 886          */
 887         public function reallyMakeHelpMsg() {
 888                 $this->setHelp();
 889
 890                 // Use parent to make default message for the main module
 891                 $msg = parent::makeHelpMsg();
 892
 893                 $astriks = str_repeat( '*** ', 14 );
 894                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 895                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
 896                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
 897                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
 898                         $msg2 = $module->makeHelpMsg();
 899                         if ( $msg2 !== false ) {
 900                                 $msg .= $msg2;
 901                         }
 902                         $msg .= "\n";
 903                 }
 904
 905                 $msg .= "\n$astriks Permissions $astriks\n\n";
 906                 foreach ( self::$mRights as $right => $rightMsg ) {
 907                         $groups = User::getGroupsWithPermission( $right );
 908                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
 909                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
 910
 911                 }
 912
 913                 $msg .= "\n$astriks Formats  $astriks\n\n";
 914                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
 915                         $module = $this->createPrinterByName( $formatName );
 916                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
 917                         $msg2 = $module->makeHelpMsg();
 918                         if ( $msg2 !== false ) {
 919                                 $msg .= $msg2;
 920                         }
 921                         $msg .= "\n";
 922                 }
 923
 924                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
 925
 926                 return $msg;
 927         }
 928
 929         /**
 930          * @param $module ApiBase
 931          * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
 932          * @return string
 933          */
 934         public static function makeHelpMsgHeader( $module, $paramName ) {
 935                 $modulePrefix = $module->getModulePrefix();
 936                 if ( strval( $modulePrefix ) !== '' ) {
 937                         $modulePrefix = "($modulePrefix) ";
 938                 }
 939
 940                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 941         }
 942
 943         private $mCanApiHighLimits = null;
 944
 945         /**
 946          * Check whether the current user is allowed to use high limits
 947          * @return bool
 948          */
 949         public function canApiHighLimits() {
 950                 if ( !isset( $this->mCanApiHighLimits ) ) {
 951                         global $wgUser;
 952                         $this->mCanApiHighLimits = $wgUser->isAllowed( 'apihighlimits' );
 953                 }
 954
 955                 return $this->mCanApiHighLimits;
 956         }
 957
 958         /**
 959          * Check whether the user wants us to show version information in the API help
 960          * @return bool
 961          */
 962         public function getShowVersions() {
 963                 return $this->mShowVersions;
 964         }
 965
 966         /**
 967          * Returns the version information of this file, plus it includes
 968          * the versions for all files that are not callable proper API modules
 969          *
 970          * @return array
 971          */
 972         public function getVersion() {
 973                 $vers = array();
 974                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    http://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
 975                 $vers[] = __CLASS__ . ': $Id$';
 976                 $vers[] = ApiBase::getBaseVersion();
 977                 $vers[] = ApiFormatBase::getBaseVersion();
 978                 $vers[] = ApiQueryBase::getBaseVersion();
 979                 return $vers;
 980         }
 981
 982         /**
 983          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
 984          * classes who wish to add their own modules to their lexicon or override the
 985          * behavior of inherent ones.
 986          *
 987          * @param $mdlName String The identifier for this module.
 988          * @param $mdlClass String The class where this module is implemented.
 989          */
 990         protected function addModule( $mdlName, $mdlClass ) {
 991                 $this->mModules[$mdlName] = $mdlClass;
 992         }
 993
 994         /**
 995          * Add or overwrite an output format for this ApiMain. Intended for use by extending
 996          * classes who wish to add to or modify current formatters.
 997          *
 998          * @param $fmtName string The identifier for this format.
 999          * @param $fmtClass ApiFormatBase The class implementing this format.
1000          */
1001         protected function addFormat( $fmtName, $fmtClass ) {
1002                 $this->mFormats[$fmtName] = $fmtClass;
1003         }
1004
1005         /**
1006          * Get the array mapping module names to class names
1007          * @return array
1008          */
1009         function getModules() {
1010                 return $this->mModules;
1011         }
1012
1013         /**
1014          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1015          *
1016          * @since 1.18
1017          * @return array
1018          */
1019         public function getFormats() {
1020                 return $this->mFormats;
1021         }
1022 }
1023
1024 /**
1025  * This exception will be thrown when dieUsage is called to stop module execution.
1026  * The exception handling code will print a help screen explaining how this API may be used.
1027  *
1028  * @ingroup API
1029  */
1030 class UsageException extends Exception {
1031
1032         private $mCodestr;
1033         private $mExtraData;
1034
1035         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1036                 parent::__construct( $message, $code );
1037                 $this->mCodestr = $codestr;
1038                 $this->mExtraData = $extradata;
1039         }
1040
1041         /**
1042          * @return string
1043          */
1044         public function getCodeString() {
1045                 return $this->mCodestr;
1046         }
1047
1048         /**
1049          * @return array
1050          */
1051         public function getMessageArray() {
1052                 $result = array(
1053                         'code' => $this->mCodestr,
1054                         'info' => $this->getMessage()
1055                 );
1056                 if ( is_array( $this->mExtraData ) ) {
1057                         $result = array_merge( $result, $this->mExtraData );
1058                 }
1059                 return $result;
1060         }
1061
1062         /**
1063          * @return string
1064          */
1065         public function __toString() {
1066                 return "{$this->getCodeString()}: {$this->getMessage()}";
1067         }
1068 }