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 /**
  29  * This is the main API class, used for both external and internal processing.
  30  * When executed, it will create the requested formatter object,
  31  * instantiate and execute an object associated with the needed action,
  32  * and use formatter to print results.
  33  * In case of an exception, an error message will be printed using the same formatter.
  34  *
  35  * To use API from another application, run it using FauxRequest object, in which
  36  * case any internal exceptions will not be handled but passed up to the caller.
  37  * After successful execution, use getResult() for the resulting data.
  38  *
  39  * @ingroup API
  40  */
  41 class ApiMain extends ApiBase {
  42
  43         /**
  44          * When no format parameter is given, this format will be used
  45          */
  46         const API_DEFAULT_FORMAT = 'xmlfm';
  47
  48         /**
  49          * List of available modules: action name => module class
  50          */
  51         private static $Modules = array(
  52                 'login' => 'ApiLogin',
  53                 'logout' => 'ApiLogout',
  54                 'query' => 'ApiQuery',
  55                 'expandtemplates' => 'ApiExpandTemplates',
  56                 'parse' => 'ApiParse',
  57                 'opensearch' => 'ApiOpenSearch',
  58                 'feedcontributions' => 'ApiFeedContributions',
  59                 'feedwatchlist' => 'ApiFeedWatchlist',
  60                 'help' => 'ApiHelp',
  61                 'paraminfo' => 'ApiParamInfo',
  62                 'rsd' => 'ApiRsd',
  63                 'compare' => 'ApiComparePages',
  64                 'tokens' => 'ApiTokens',
  65
  66                 // Write modules
  67                 'purge' => 'ApiPurge',
  68                 'rollback' => 'ApiRollback',
  69                 'delete' => 'ApiDelete',
  70                 'undelete' => 'ApiUndelete',
  71                 'protect' => 'ApiProtect',
  72                 'block' => 'ApiBlock',
  73                 'unblock' => 'ApiUnblock',
  74                 'move' => 'ApiMove',
  75                 'edit' => 'ApiEditPage',
  76                 'upload' => 'ApiUpload',
  77                 'filerevert' => 'ApiFileRevert',
  78                 'emailuser' => 'ApiEmailUser',
  79                 'watch' => 'ApiWatch',
  80                 'patrol' => 'ApiPatrol',
  81                 'import' => 'ApiImport',
  82                 'userrights' => 'ApiUserrights',
  83         );
  84
  85         /**
  86          * List of available formats: format name => format class
  87          */
  88         private static $Formats = array(
  89                 'json' => 'ApiFormatJson',
  90                 'jsonfm' => 'ApiFormatJson',
  91                 'php' => 'ApiFormatPhp',
  92                 'phpfm' => 'ApiFormatPhp',
  93                 'wddx' => 'ApiFormatWddx',
  94                 'wddxfm' => 'ApiFormatWddx',
  95                 'xml' => 'ApiFormatXml',
  96                 'xmlfm' => 'ApiFormatXml',
  97                 'yaml' => 'ApiFormatYaml',
  98                 'yamlfm' => 'ApiFormatYaml',
  99                 'rawfm' => 'ApiFormatJson',
 100                 'txt' => 'ApiFormatTxt',
 101                 'txtfm' => 'ApiFormatTxt',
 102                 'dbg' => 'ApiFormatDbg',
 103                 'dbgfm' => 'ApiFormatDbg',
 104                 'dump' => 'ApiFormatDump',
 105                 'dumpfm' => 'ApiFormatDump',
 106         );
 107
 108         /**
 109          * List of user roles that are specifically relevant to the API.
 110          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 111          *                           'params' => array ( $someVarToSubst ) ),
 112          *                          );
 113          */
 114         private static $mRights = array(
 115                 'writeapi' => array(
 116                         'msg' => 'Use of the write API',
 117                         'params' => array()
 118                 ),
 119                 'apihighlimits' => array(
 120                         '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.',
 121                         'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
 122                 )
 123         );
 124
 125         /**
 126          * @var ApiFormatBase
 127          */
 128         private $mPrinter;
 129
 130         private $mModules, $mModuleNames, $mFormats, $mFormatNames;
 131         private $mResult, $mAction, $mShowVersions, $mEnableWrite;
 132         private $mInternalMode, $mSquidMaxage, $mModule;
 133
 134         private $mCacheMode = 'private';
 135         private $mCacheControl = array();
 136
 137         /**
 138          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 139          *
 140          * @param $context IContextSource|WebRequest - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 141          * @param $enableWrite bool should be set to true if the api may modify data
 142          */
 143         public function __construct( $context = null, $enableWrite = false ) {
 144                 if ( $context === null ) {
 145                         $context = RequestContext::getMain();
 146                 } elseif ( $context instanceof WebRequest ) {
 147                         // BC for pre-1.19
 148                         $request = $context;
 149                         $context = RequestContext::getMain();
 150                 }
 151                 // We set a derivative context so we can change stuff later
 152                 $this->setContext( new DerivativeContext( $context ) );
 153
 154                 if ( isset( $request ) ) {
 155                         $this->getContext()->setRequest( $request );
 156                 }
 157
 158                 $this->mInternalMode = ( $this->getRequest() instanceof FauxRequest );
 159
 160                 // Special handling for the main module: $parent === $this
 161                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 162
 163                 if ( !$this->mInternalMode ) {
 164                         // Impose module restrictions.
 165                         // If the current user cannot read,
 166                         // Remove all modules other than login
 167                         global $wgUser;
 168
 169                         if ( $this->getRequest()->getVal( 'callback' ) !== null ) {
 170                                 // JSON callback allows cross-site reads.
 171                                 // For safety, strip user credentials.
 172                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 173                                 $wgUser = new User();
 174                                 $this->getContext()->setUser( $wgUser );
 175                         }
 176                 }
 177
 178                 global $wgAPIModules; // extension modules
 179                 $this->mModules = $wgAPIModules + self::$Modules;
 180
 181                 $this->mModuleNames = array_keys( $this->mModules );
 182                 $this->mFormats = self::$Formats;
 183                 $this->mFormatNames = array_keys( $this->mFormats );
 184
 185                 $this->mResult = new ApiResult( $this );
 186                 $this->mShowVersions = false;
 187                 $this->mEnableWrite = $enableWrite;
 188
 189                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 190                 $this->mCommit = false;
 191         }
 192
 193         /**
 194          * Return true if the API was started by other PHP code using FauxRequest
 195          * @return bool
 196          */
 197         public function isInternalMode() {
 198                 return $this->mInternalMode;
 199         }
 200
 201         /**
 202          * Get the ApiResult object associated with current request
 203          *
 204          * @return ApiResult
 205          */
 206         public function getResult() {
 207                 return $this->mResult;
 208         }
 209
 210         /**
 211          * Get the API module object. Only works after executeAction()
 212          *
 213          * @return ApiBase
 214          */
 215         public function getModule() {
 216                 return $this->mModule;
 217         }
 218
 219         /**
 220          * Get the result formatter object. Only works after setupExecuteAction()
 221          *
 222          * @return ApiFormatBase
 223          */
 224         public function getPrinter() {
 225                 return $this->mPrinter;
 226         }
 227
 228         /**
 229          * Set how long the response should be cached.
 230          *
 231          * @param $maxage
 232          */
 233         public function setCacheMaxAge( $maxage ) {
 234                 $this->setCacheControl( array(
 235                         'max-age' => $maxage,
 236                         's-maxage' => $maxage
 237                 ) );
 238         }
 239
 240         /**
 241          * Set the type of caching headers which will be sent.
 242          *
 243          * @param $mode String One of:
 244          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 245          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 246          *         not provided by any of these means, the object will be private.
 247          *    - 'private':    Cache this object only in private client-side caches.
 248          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 249          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 250          *         set consistently for a given URL, it cannot be set differently depending on
 251          *         things like the contents of the database, or whether the user is logged in.
 252          *
 253          *  If the wiki does not allow anonymous users to read it, the mode set here
 254          *  will be ignored, and private caching headers will always be sent. In other words,
 255          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 256          *  view.
 257          *
 258          *  For user-dependent data, the private mode should generally be used. The
 259          *  anon-public-user-private mode should only be used where there is a particularly
 260          *  good performance reason for caching the anonymous response, but where the
 261          *  response to logged-in users may differ, or may contain private data.
 262          *
 263          *  If this function is never called, then the default will be the private mode.
 264          */
 265         public function setCacheMode( $mode ) {
 266                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 267                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 268                         // Ignore for forwards-compatibility
 269                         return;
 270                 }
 271
 272                 if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 273                         // Private wiki, only private headers
 274                         if ( $mode !== 'private' ) {
 275                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 276                                 return;
 277                         }
 278                 }
 279
 280                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 281                 $this->mCacheMode = $mode;
 282         }
 283
 284         /**
 285          * @deprecated since 1.17 Private caching is now the default, so there is usually no
 286          * need to call this function. If there is a need, you can use
 287          * $this->setCacheMode('private')
 288          */
 289         public function setCachePrivate() {
 290                 wfDeprecated( __METHOD__, '1.17' );
 291                 $this->setCacheMode( 'private' );
 292         }
 293
 294         /**
 295          * Set directives (key/value pairs) for the Cache-Control header.
 296          * Boolean values will be formatted as such, by including or omitting
 297          * without an equals sign.
 298          *
 299          * Cache control values set here will only be used if the cache mode is not
 300          * private, see setCacheMode().
 301          *
 302          * @param $directives array
 303          */
 304         public function setCacheControl( $directives ) {
 305                 $this->mCacheControl = $directives + $this->mCacheControl;
 306         }
 307
 308         /**
 309          * Make sure Vary: Cookie and friends are set. Use this when the output of a request
 310          * may be cached for anons but may not be cached for logged-in users.
 311          *
 312          * WARNING: This function must be called CONSISTENTLY for a given URL. This means that a
 313          * given URL must either always or never call this function; if it sometimes does and
 314          * sometimes doesn't, stuff will break.
 315          *
 316          * @deprecated since 1.17 Use setCacheMode( 'anon-public-user-private' )
 317          */
 318         public function setVaryCookie() {
 319                 wfDeprecated( __METHOD__, '1.17' );
 320                 $this->setCacheMode( 'anon-public-user-private' );
 321         }
 322
 323         /**
 324          * Create an instance of an output formatter by its name
 325          *
 326          * @param $format string
 327          *
 328          * @return ApiFormatBase
 329          */
 330         public function createPrinterByName( $format ) {
 331                 if ( !isset( $this->mFormats[$format] ) ) {
 332                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 333                 }
 334                 return new $this->mFormats[$format] ( $this, $format );
 335         }
 336
 337         /**
 338          * Execute api request. Any errors will be handled if the API was called by the remote client.
 339          */
 340         public function execute() {
 341                 $this->profileIn();
 342                 if ( $this->mInternalMode ) {
 343                         $this->executeAction();
 344                 } else {
 345                         $this->executeActionWithErrorHandling();
 346                 }
 347
 348                 $this->profileOut();
 349         }
 350
 351         /**
 352          * Execute an action, and in case of an error, erase whatever partial results
 353          * have been accumulated, and replace it with an error message and a help screen.
 354          */
 355         protected function executeActionWithErrorHandling() {
 356                 // In case an error occurs during data output,
 357                 // clear the output buffer and print just the error information
 358                 ob_start();
 359
 360                 try {
 361                         $this->executeAction();
 362                 } catch ( Exception $e ) {
 363                         // Log it
 364                         if ( $e instanceof MWException ) {
 365                                 wfDebugLog( 'exception', $e->getLogMessage() );
 366                         }
 367
 368                         // Handle any kind of exception by outputing properly formatted error message.
 369                         // If this fails, an unhandled exception should be thrown so that global error
 370                         // handler will process and log it.
 371
 372                         $errCode = $this->substituteResultWithError( $e );
 373
 374                         // Error results should not be cached
 375                         $this->setCacheMode( 'private' );
 376
 377                         $response = $this->getRequest()->response();
 378                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 379                         if ( $e->getCode() === 0 ) {
 380                                 $response->header( $headerStr );
 381                         } else {
 382                                 $response->header( $headerStr, true, $e->getCode() );
 383                         }
 384
 385                         // Reset and print just the error message
 386                         ob_clean();
 387
 388                         // If the error occured during printing, do a printer->profileOut()
 389                         $this->mPrinter->safeProfileOut();
 390                         $this->printResult( true );
 391                 }
 392
 393                 // Send cache headers after any code which might generate an error, to
 394                 // avoid sending public cache headers for errors.
 395                 $this->sendCacheHeaders();
 396
 397                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 398                         echo wfReportTime();
 399                 }
 400
 401                 ob_end_flush();
 402         }
 403
 404         protected function sendCacheHeaders() {
 405                 global $wgUseXVO, $wgVaryOnXFP;
 406                 $response = $this->getRequest()->response();
 407
 408                 if ( $this->mCacheMode == 'private' ) {
 409                         $response->header( 'Cache-Control: private' );
 410                         return;
 411                 }
 412
 413                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 414                         $xfp = $wgVaryOnXFP ? ', X-Forwarded-Proto' : '';
 415                         $response->header( 'Vary: Accept-Encoding, Cookie' . $xfp );
 416                         if ( $wgUseXVO ) {
 417                                 $out = $this->getOutput();
 418                                 if ( $wgVaryOnXFP ) {
 419                                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 420                                 }
 421                                 $response->header( $out->getXVO() );
 422                                 if ( $out->haveCacheVaryCookies() ) {
 423                                         // Logged in, mark this request private
 424                                         $response->header( 'Cache-Control: private' );
 425                                         return;
 426                                 }
 427                                 // Logged out, send normal public headers below
 428                         } elseif ( session_id() != '' ) {
 429                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 430                                 // Mark request private
 431                                 $response->header( 'Cache-Control: private' );
 432                                 return;
 433                         } // else no XVO and anonymous, send public headers below
 434                 }
 435
 436                 // Send public headers
 437                 if ( $wgVaryOnXFP ) {
 438                         $response->header( 'Vary: Accept-Encoding, X-Forwarded-Proto' );
 439                         if ( $wgUseXVO ) {
 440                                 // Bleeeeegh. Our header setting system sucks
 441                                 $response->header( 'X-Vary-Options: Accept-Encoding;list-contains=gzip, X-Forwarded-Proto' );
 442                         }
 443                 }
 444
 445                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 446                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 447                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 448                 }
 449                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 450                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 451                 }
 452
 453                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 454                         // Public cache not requested
 455                         // Sending a Vary header in this case is harmless, and protects us
 456                         // against conditional calls of setCacheMaxAge().
 457                         $response->header( 'Cache-Control: private' );
 458                         return;
 459                 }
 460
 461                 $this->mCacheControl['public'] = true;
 462
 463                 // Send an Expires header
 464                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 465                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 466                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 467
 468                 // Construct the Cache-Control header
 469                 $ccHeader = '';
 470                 $separator = '';
 471                 foreach ( $this->mCacheControl as $name => $value ) {
 472                         if ( is_bool( $value ) ) {
 473                                 if ( $value ) {
 474                                         $ccHeader .= $separator . $name;
 475                                         $separator = ', ';
 476                                 }
 477                         } else {
 478                                 $ccHeader .= $separator . "$name=$value";
 479                                 $separator = ', ';
 480                         }
 481                 }
 482
 483                 $response->header( "Cache-Control: $ccHeader" );
 484         }
 485
 486         /**
 487          * Replace the result data with the information about an exception.
 488          * Returns the error code
 489          * @param $e Exception
 490          * @return string
 491          */
 492         protected function substituteResultWithError( $e ) {
 493                 global $wgShowHostnames;
 494
 495                 $result = $this->getResult();
 496                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 497                 if ( !isset ( $this->mPrinter ) ) {
 498                         // The printer has not been created yet. Try to manually get formatter value.
 499                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 500                         if ( !in_array( $value, $this->mFormatNames ) ) {
 501                                 $value = self::API_DEFAULT_FORMAT;
 502                         }
 503
 504                         $this->mPrinter = $this->createPrinterByName( $value );
 505                         if ( $this->mPrinter->getNeedsRawData() ) {
 506                                 $result->setRawMode();
 507                         }
 508                 }
 509
 510                 if ( $e instanceof UsageException ) {
 511                         // User entered incorrect parameters - print usage screen
 512                         $errMessage = $e->getMessageArray();
 513
 514                         // Only print the help message when this is for the developer, not runtime
 515                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 516                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 517                         }
 518
 519                 } else {
 520                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 521                         // Something is seriously wrong
 522                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 523                                 $info = 'Database query error';
 524                         } else {
 525                                 $info = "Exception Caught: {$e->getMessage()}";
 526                         }
 527
 528                         $errMessage = array(
 529                                 'code' => 'internal_api_error_' . get_class( $e ),
 530                                 'info' => $info,
 531                         );
 532                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 533                 }
 534
 535                 $result->reset();
 536                 $result->disableSizeCheck();
 537                 // Re-add the id
 538                 $requestid = $this->getParameter( 'requestid' );
 539                 if ( !is_null( $requestid ) ) {
 540                         $result->addValue( null, 'requestid', $requestid );
 541                 }
 542
 543                 if ( $wgShowHostnames ) {
 544                         // servedby is especially useful when debugging errors
 545                         $result->addValue( null, 'servedby', wfHostName() );
 546                 }
 547
 548                 $result->addValue( null, 'error', $errMessage );
 549
 550                 return $errMessage['code'];
 551         }
 552
 553         /**
 554          * Set up for the execution.
 555          * @return array
 556          */
 557         protected function setupExecuteAction() {
 558                 global $wgShowHostnames;
 559
 560                 // First add the id to the top element
 561                 $result = $this->getResult();
 562                 $requestid = $this->getParameter( 'requestid' );
 563                 if ( !is_null( $requestid ) ) {
 564                         $result->addValue( null, 'requestid', $requestid );
 565                 }
 566
 567                 if ( $wgShowHostnames ) {
 568                         $servedby = $this->getParameter( 'servedby' );
 569                         if ( $servedby ) {
 570                                 $result->addValue( null, 'servedby', wfHostName() );
 571                         }
 572                 }
 573
 574                 $params = $this->extractRequestParams();
 575
 576                 $this->mShowVersions = $params['version'];
 577                 $this->mAction = $params['action'];
 578
 579                 if ( !is_string( $this->mAction ) ) {
 580                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 581                 }
 582
 583                 return $params;
 584         }
 585
 586         /**
 587          * Set up the module for response
 588          * @return ApiBase The module that will handle this action
 589          */
 590         protected function setupModule() {
 591                 // Instantiate the module requested by the user
 592                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 593                 $this->mModule = $module;
 594
 595                 $moduleParams = $module->extractRequestParams();
 596
 597                 // Die if token required, but not provided (unless there is a gettoken parameter)
 598                 $salt = $module->getTokenSalt();
 599                 if ( $salt !== false && isset( $moduleParams['gettoken'] ) && !$moduleParams['gettoken'] ) {
 600                         if ( !isset( $moduleParams['token'] ) ) {
 601                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 602                         } else {
 603                                 if ( !$this->getUser()->matchEditToken( $moduleParams['token'], $salt ) ) {
 604                                         $this->dieUsageMsg( 'sessionfailure' );
 605                                 }
 606                         }
 607                 }
 608                 return $module;
 609         }
 610
 611         /**
 612          * Check the max lag if necessary
 613          * @param $module ApiBase object: Api module being used
 614          * @param $params Array an array containing the request parameters.
 615          * @return boolean True on success, false should exit immediately
 616          */
 617         protected function checkMaxLag( $module, $params ) {
 618                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 619                         // Check for maxlag
 620                         global $wgShowHostnames;
 621                         $maxLag = $params['maxlag'];
 622                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 623                         if ( $lag > $maxLag ) {
 624                                 $response = $this->getRequest()->response();
 625
 626                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 627                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 628
 629                                 if ( $wgShowHostnames ) {
 630                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 631                                 } else {
 632                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 633                                 }
 634                                 return false;
 635                         }
 636                 }
 637                 return true;
 638         }
 639
 640         /**
 641          * Check for sufficient permissions to execute
 642          * @param $module ApiBase An Api module
 643          */
 644         protected function checkExecutePermissions( $module ) {
 645                 $user = $this->getUser();
 646                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 647                         !$user->isAllowed( 'read' ) )
 648                 {
 649                         $this->dieUsageMsg( 'readrequired' );
 650                 }
 651                 if ( $module->isWriteMode() ) {
 652                         if ( !$this->mEnableWrite ) {
 653                                 $this->dieUsageMsg( 'writedisabled' );
 654                         }
 655                         if ( !$user->isAllowed( 'writeapi' ) ) {
 656                                 $this->dieUsageMsg( 'writerequired' );
 657                         }
 658                         if ( wfReadOnly() ) {
 659                                 $this->dieReadOnly();
 660                         }
 661                 }
 662         }
 663
 664         /**
 665          * Check POST for external response and setup result printer
 666          * @param $module ApiBase An Api module
 667          * @param $params Array an array with the request parameters
 668          */
 669         protected function setupExternalResponse( $module, $params ) {
 670                 // Ignore mustBePosted() for internal calls
 671                 if ( $module->mustBePosted() && !$this->getRequest()->wasPosted() ) {
 672                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 673                 }
 674
 675                 // See if custom printer is used
 676                 $this->mPrinter = $module->getCustomPrinter();
 677                 if ( is_null( $this->mPrinter ) ) {
 678                         // Create an appropriate printer
 679                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 680                 }
 681
 682                 if ( $this->mPrinter->getNeedsRawData() ) {
 683                         $this->getResult()->setRawMode();
 684                 }
 685         }
 686
 687         /**
 688          * Execute the actual module, without any error handling
 689          */
 690         protected function executeAction() {
 691                 $params = $this->setupExecuteAction();
 692                 $module = $this->setupModule();
 693
 694                 $this->checkExecutePermissions( $module );
 695
 696                 if ( !$this->checkMaxLag( $module, $params ) ) {
 697                         return;
 698                 }
 699
 700                 if ( !$this->mInternalMode ) {
 701                         $this->setupExternalResponse( $module, $params );
 702                 }
 703
 704                 // Execute
 705                 $module->profileIn();
 706                 $module->execute();
 707                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 708                 $module->profileOut();
 709
 710                 if ( !$this->mInternalMode ) {
 711                         // Print result data
 712                         $this->printResult( false );
 713                 }
 714         }
 715
 716         /**
 717          * Print results using the current printer
 718          *
 719          * @param $isError bool
 720          */
 721         protected function printResult( $isError ) {
 722                 $this->getResult()->cleanUpUTF8();
 723                 $printer = $this->mPrinter;
 724                 $printer->profileIn();
 725
 726                 /**
 727                  * If the help message is requested in the default (xmlfm) format,
 728                  * tell the printer not to escape ampersands so that our links do
 729                  * not break.
 730                  */
 731                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 732                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 733
 734                 $printer->initPrinter( $isError );
 735
 736                 $printer->execute();
 737                 $printer->closePrinter();
 738                 $printer->profileOut();
 739         }
 740
 741         /**
 742          * @return bool
 743          */
 744         public function isReadMode() {
 745                 return false;
 746         }
 747
 748         /**
 749          * See ApiBase for description.
 750          *
 751          * @return array
 752          */
 753         public function getAllowedParams() {
 754                 return array(
 755                         'format' => array(
 756                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 757                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 758                         ),
 759                         'action' => array(
 760                                 ApiBase::PARAM_DFLT => 'help',
 761                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 762                         ),
 763                         'version' => false,
 764                         'maxlag'  => array(
 765                                 ApiBase::PARAM_TYPE => 'integer'
 766                         ),
 767                         'smaxage' => array(
 768                                 ApiBase::PARAM_TYPE => 'integer',
 769                                 ApiBase::PARAM_DFLT => 0
 770                         ),
 771                         'maxage' => array(
 772                                 ApiBase::PARAM_TYPE => 'integer',
 773                                 ApiBase::PARAM_DFLT => 0
 774                         ),
 775                         'requestid' => null,
 776                         'servedby'  => false,
 777                 );
 778         }
 779
 780         /**
 781          * See ApiBase for description.
 782          *
 783          * @return array
 784          */
 785         public function getParamDescription() {
 786                 return array(
 787                         'format' => 'The format of the output',
 788                         'action' => 'What action you would like to perform. See below for module help',
 789                         'version' => 'When showing help, include version for each module',
 790                         'maxlag' => array(
 791                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
 792                                 'To save actions causing any more site replication lag, this parameter can make the client',
 793                                 'wait until the replication lag is less than the specified value.',
 794                                 'In case of a replag error, a HTTP 503 error is returned, with the message like',
 795                                 '"Waiting for $host: $lag seconds lagged\n".',
 796                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
 797                         ),
 798                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 799                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 800                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 801                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 802                 );
 803         }
 804
 805         /**
 806          * See ApiBase for description.
 807          *
 808          * @return array
 809          */
 810         public function getDescription() {
 811                 return array(
 812                         '',
 813                         '',
 814                         '**********************************************************************************************************',
 815                         '**                                                                                                      **',
 816                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 817                         '**                                                                                                      **',
 818                         '**                                     Documentation and Examples:                                      **',
 819                         '**                                  https://www.mediawiki.org/wiki/API                                  **',
 820                         '**                                                                                                      **',
 821                         '**********************************************************************************************************',
 822                         '',
 823                         'Status:                All features shown on this page should be working, but the API',
 824                         '                       is still in active development, and may change at any time.',
 825                         '                       Make sure to monitor our mailing list for any updates',
 826                         '',
 827                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
 828                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
 829                         '                       header and the error code sent back will be set to the same value',
 830                         '',
 831                         '                       In the case of an invalid action being passed, these will have a value',
 832                         '                       of "unknown_action"',
 833                         '',
 834                         '                       For more information see https://www.mediawiki.org/wiki/API:Errors_and_warnings',
 835                         '',
 836                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
 837                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
 838                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 839                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 840                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 841                         '',
 842                         '',
 843                         '',
 844                         '',
 845                         '',
 846                 );
 847         }
 848
 849         /**
 850          * @return array
 851          */
 852         public function getPossibleErrors() {
 853                 return array_merge( parent::getPossibleErrors(), array(
 854                         array( 'readonlytext' ),
 855                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 856                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 857                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 858                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 859                 ) );
 860         }
 861
 862         /**
 863          * Returns an array of strings with credits for the API
 864          * @return array
 865          */
 866         protected function getCredits() {
 867                 return array(
 868                         'API developers:',
 869                         '    Roan Kattouw <Firstname>.<Lastname>@gmail.com (lead developer Sep 2007-present)',
 870                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 871                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 872                         '    Sam Reed - sam @ reedyboy . net',
 873                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 874                         '',
 875                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 876                         'or file a bug report at https://bugzilla.wikimedia.org/'
 877                 );
 878         }
 879
 880         /**
 881          * Sets whether the pretty-printer should format *bold* and $italics$
 882          *
 883          * @param $help bool
 884          */
 885         public function setHelp( $help = true ) {
 886                 $this->mPrinter->setHelp( $help );
 887         }
 888
 889         /**
 890          * Override the parent to generate help messages for all available modules.
 891          *
 892          * @return string
 893          */
 894         public function makeHelpMsg() {
 895                 global $wgMemc, $wgAPICacheHelpTimeout;
 896                 $this->setHelp();
 897                 // Get help text from cache if present
 898                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
 899                         SpecialVersion::getVersion( 'nodb' ) .
 900                         $this->getShowVersions() );
 901                 if ( $wgAPICacheHelpTimeout > 0 ) {
 902                         $cached = $wgMemc->get( $key );
 903                         if ( $cached ) {
 904                                 return $cached;
 905                         }
 906                 }
 907                 $retval = $this->reallyMakeHelpMsg();
 908                 if ( $wgAPICacheHelpTimeout > 0 ) {
 909                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
 910                 }
 911                 return $retval;
 912         }
 913
 914         /**
 915          * @return mixed|string
 916          */
 917         public function reallyMakeHelpMsg() {
 918                 $this->setHelp();
 919
 920                 // Use parent to make default message for the main module
 921                 $msg = parent::makeHelpMsg();
 922
 923                 $astriks = str_repeat( '*** ', 14 );
 924                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 925                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
 926                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
 927                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
 928                         $msg2 = $module->makeHelpMsg();
 929                         if ( $msg2 !== false ) {
 930                                 $msg .= $msg2;
 931                         }
 932                         $msg .= "\n";
 933                 }
 934
 935                 $msg .= "\n$astriks Permissions $astriks\n\n";
 936                 foreach ( self::$mRights as $right => $rightMsg ) {
 937                         $groups = User::getGroupsWithPermission( $right );
 938                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
 939                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
 940
 941                 }
 942
 943                 $msg .= "\n$astriks Formats  $astriks\n\n";
 944                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
 945                         $module = $this->createPrinterByName( $formatName );
 946                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
 947                         $msg2 = $module->makeHelpMsg();
 948                         if ( $msg2 !== false ) {
 949                                 $msg .= $msg2;
 950                         }
 951                         $msg .= "\n";
 952                 }
 953
 954                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
 955
 956                 return $msg;
 957         }
 958
 959         /**
 960          * @param $module ApiBase
 961          * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
 962          * @return string
 963          */
 964         public static function makeHelpMsgHeader( $module, $paramName ) {
 965                 $modulePrefix = $module->getModulePrefix();
 966                 if ( strval( $modulePrefix ) !== '' ) {
 967                         $modulePrefix = "($modulePrefix) ";
 968                 }
 969
 970                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 971         }
 972
 973         private $mCanApiHighLimits = null;
 974
 975         /**
 976          * Check whether the current user is allowed to use high limits
 977          * @return bool
 978          */
 979         public function canApiHighLimits() {
 980                 if ( !isset( $this->mCanApiHighLimits ) ) {
 981                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
 982                 }
 983
 984                 return $this->mCanApiHighLimits;
 985         }
 986
 987         /**
 988          * Check whether the user wants us to show version information in the API help
 989          * @return bool
 990          */
 991         public function getShowVersions() {
 992                 return $this->mShowVersions;
 993         }
 994
 995         /**
 996          * Returns the version information of this file, plus it includes
 997          * the versions for all files that are not callable proper API modules
 998          *
 999          * @return array
1000          */
1001         public function getVersion() {
1002                 $vers = array();
1003                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    https://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
1004                 $vers[] = __CLASS__ . ': $Id$';
1005                 $vers[] = ApiBase::getBaseVersion();
1006                 $vers[] = ApiFormatBase::getBaseVersion();
1007                 $vers[] = ApiQueryBase::getBaseVersion();
1008                 return $vers;
1009         }
1010
1011         /**
1012          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1013          * classes who wish to add their own modules to their lexicon or override the
1014          * behavior of inherent ones.
1015          *
1016          * @param $mdlName String The identifier for this module.
1017          * @param $mdlClass String The class where this module is implemented.
1018          */
1019         protected function addModule( $mdlName, $mdlClass ) {
1020                 $this->mModules[$mdlName] = $mdlClass;
1021         }
1022
1023         /**
1024          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1025          * classes who wish to add to or modify current formatters.
1026          *
1027          * @param $fmtName string The identifier for this format.
1028          * @param $fmtClass ApiFormatBase The class implementing this format.
1029          */
1030         protected function addFormat( $fmtName, $fmtClass ) {
1031                 $this->mFormats[$fmtName] = $fmtClass;
1032         }
1033
1034         /**
1035          * Get the array mapping module names to class names
1036          * @return array
1037          */
1038         function getModules() {
1039                 return $this->mModules;
1040         }
1041
1042         /**
1043          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1044          *
1045          * @since 1.18
1046          * @return array
1047          */
1048         public function getFormats() {
1049                 return $this->mFormats;
1050         }
1051 }
1052
1053 /**
1054  * This exception will be thrown when dieUsage is called to stop module execution.
1055  * The exception handling code will print a help screen explaining how this API may be used.
1056  *
1057  * @ingroup API
1058  */
1059 class UsageException extends MWException {
1060
1061         private $mCodestr;
1062         private $mExtraData;
1063
1064         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1065                 parent::__construct( $message, $code );
1066                 $this->mCodestr = $codestr;
1067                 $this->mExtraData = $extradata;
1068         }
1069
1070         /**
1071          * @return string
1072          */
1073         public function getCodeString() {
1074                 return $this->mCodestr;
1075         }
1076
1077         /**
1078          * @return array
1079          */
1080         public function getMessageArray() {
1081                 $result = array(
1082                         'code' => $this->mCodestr,
1083                         'info' => $this->getMessage()
1084                 );
1085                 if ( is_array( $this->mExtraData ) ) {
1086                         $result = array_merge( $result, $this->mExtraData );
1087                 }
1088                 return $result;
1089         }
1090
1091         /**
1092          * @return string
1093          */
1094         public function __toString() {
1095                 return "{$this->getCodeString()}: {$this->getMessage()}";
1096         }
1097 }