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                 'options' => 'ApiOptions',
  84         );
  85
  86         /**
  87          * List of available formats: format name => format class
  88          */
  89         private static $Formats = array(
  90                 'json' => 'ApiFormatJson',
  91                 'jsonfm' => 'ApiFormatJson',
  92                 'php' => 'ApiFormatPhp',
  93                 'phpfm' => 'ApiFormatPhp',
  94                 'wddx' => 'ApiFormatWddx',
  95                 'wddxfm' => 'ApiFormatWddx',
  96                 'xml' => 'ApiFormatXml',
  97                 'xmlfm' => 'ApiFormatXml',
  98                 'yaml' => 'ApiFormatYaml',
  99                 'yamlfm' => 'ApiFormatYaml',
 100                 'rawfm' => 'ApiFormatJson',
 101                 'txt' => 'ApiFormatTxt',
 102                 'txtfm' => 'ApiFormatTxt',
 103                 'dbg' => 'ApiFormatDbg',
 104                 'dbgfm' => 'ApiFormatDbg',
 105                 'dump' => 'ApiFormatDump',
 106                 'dumpfm' => 'ApiFormatDump',
 107         );
 108
 109         /**
 110          * List of user roles that are specifically relevant to the API.
 111          * array( 'right' => array ( 'msg'    => 'Some message with a $1',
 112          *                           'params' => array ( $someVarToSubst ) ),
 113          *                          );
 114          */
 115         private static $mRights = array(
 116                 'writeapi' => array(
 117                         'msg' => 'Use of the write API',
 118                         'params' => array()
 119                 ),
 120                 'apihighlimits' => array(
 121                         'msg' => 'Use higher limits in API queries (Slow queries: $1 results; Fast queries: $2 results). The limits for slow queries also apply to multivalue parameters.',
 122                         'params' => array( ApiBase::LIMIT_SML2, ApiBase::LIMIT_BIG2 )
 123                 )
 124         );
 125
 126         /**
 127          * @var ApiFormatBase
 128          */
 129         private $mPrinter;
 130
 131         private $mModules, $mModuleNames, $mFormats, $mFormatNames;
 132         private $mResult, $mAction, $mShowVersions, $mEnableWrite;
 133         private $mInternalMode, $mSquidMaxage, $mModule;
 134
 135         private $mCacheMode = 'private';
 136         private $mCacheControl = array();
 137
 138         /**
 139          * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 140          *
 141          * @param $context IContextSource|WebRequest - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 142          * @param $enableWrite bool should be set to true if the api may modify data
 143          */
 144         public function __construct( $context = null, $enableWrite = false ) {
 145                 if ( $context === null ) {
 146                         $context = RequestContext::getMain();
 147                 } elseif ( $context instanceof WebRequest ) {
 148                         // BC for pre-1.19
 149                         $request = $context;
 150                         $context = RequestContext::getMain();
 151                 }
 152                 // We set a derivative context so we can change stuff later
 153                 $this->setContext( new DerivativeContext( $context ) );
 154
 155                 if ( isset( $request ) ) {
 156                         $this->getContext()->setRequest( $request );
 157                 }
 158
 159                 $this->mInternalMode = ( $this->getRequest() instanceof FauxRequest );
 160
 161                 // Special handling for the main module: $parent === $this
 162                 parent::__construct( $this, $this->mInternalMode ? 'main_int' : 'main' );
 163
 164                 if ( !$this->mInternalMode ) {
 165                         // Impose module restrictions.
 166                         // If the current user cannot read,
 167                         // Remove all modules other than login
 168                         global $wgUser;
 169
 170                         if ( $this->getRequest()->getVal( 'callback' ) !== null ) {
 171                                 // JSON callback allows cross-site reads.
 172                                 // For safety, strip user credentials.
 173                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 174                                 $wgUser = new User();
 175                                 $this->getContext()->setUser( $wgUser );
 176                         }
 177                 }
 178
 179                 global $wgAPIModules; // extension modules
 180                 $this->mModules = $wgAPIModules + self::$Modules;
 181
 182                 $this->mModuleNames = array_keys( $this->mModules );
 183                 $this->mFormats = self::$Formats;
 184                 $this->mFormatNames = array_keys( $this->mFormats );
 185
 186                 $this->mResult = new ApiResult( $this );
 187                 $this->mShowVersions = false;
 188                 $this->mEnableWrite = $enableWrite;
 189
 190                 $this->mSquidMaxage = - 1; // flag for executeActionWithErrorHandling()
 191                 $this->mCommit = false;
 192         }
 193
 194         /**
 195          * Return true if the API was started by other PHP code using FauxRequest
 196          * @return bool
 197          */
 198         public function isInternalMode() {
 199                 return $this->mInternalMode;
 200         }
 201
 202         /**
 203          * Get the ApiResult object associated with current request
 204          *
 205          * @return ApiResult
 206          */
 207         public function getResult() {
 208                 return $this->mResult;
 209         }
 210
 211         /**
 212          * Get the API module object. Only works after executeAction()
 213          *
 214          * @return ApiBase
 215          */
 216         public function getModule() {
 217                 return $this->mModule;
 218         }
 219
 220         /**
 221          * Get the result formatter object. Only works after setupExecuteAction()
 222          *
 223          * @return ApiFormatBase
 224          */
 225         public function getPrinter() {
 226                 return $this->mPrinter;
 227         }
 228
 229         /**
 230          * Set how long the response should be cached.
 231          *
 232          * @param $maxage
 233          */
 234         public function setCacheMaxAge( $maxage ) {
 235                 $this->setCacheControl( array(
 236                         'max-age' => $maxage,
 237                         's-maxage' => $maxage
 238                 ) );
 239         }
 240
 241         /**
 242          * Set the type of caching headers which will be sent.
 243          *
 244          * @param $mode String One of:
 245          *    - 'public':     Cache this object in public caches, if the maxage or smaxage
 246          *         parameter is set, or if setCacheMaxAge() was called. If a maximum age is
 247          *         not provided by any of these means, the object will be private.
 248          *    - 'private':    Cache this object only in private client-side caches.
 249          *    - 'anon-public-user-private': Make this object cacheable for logged-out
 250          *         users, but private for logged-in users. IMPORTANT: If this is set, it must be
 251          *         set consistently for a given URL, it cannot be set differently depending on
 252          *         things like the contents of the database, or whether the user is logged in.
 253          *
 254          *  If the wiki does not allow anonymous users to read it, the mode set here
 255          *  will be ignored, and private caching headers will always be sent. In other words,
 256          *  the "public" mode is equivalent to saying that the data sent is as public as a page
 257          *  view.
 258          *
 259          *  For user-dependent data, the private mode should generally be used. The
 260          *  anon-public-user-private mode should only be used where there is a particularly
 261          *  good performance reason for caching the anonymous response, but where the
 262          *  response to logged-in users may differ, or may contain private data.
 263          *
 264          *  If this function is never called, then the default will be the private mode.
 265          */
 266         public function setCacheMode( $mode ) {
 267                 if ( !in_array( $mode, array( 'private', 'public', 'anon-public-user-private' ) ) ) {
 268                         wfDebug( __METHOD__ . ": unrecognised cache mode \"$mode\"\n" );
 269                         // Ignore for forwards-compatibility
 270                         return;
 271                 }
 272
 273                 if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 274                         // Private wiki, only private headers
 275                         if ( $mode !== 'private' ) {
 276                                 wfDebug( __METHOD__ . ": ignoring request for $mode cache mode, private wiki\n" );
 277                                 return;
 278                         }
 279                 }
 280
 281                 wfDebug( __METHOD__ . ": setting cache mode $mode\n" );
 282                 $this->mCacheMode = $mode;
 283         }
 284
 285         /**
 286          * @deprecated since 1.17 Private caching is now the default, so there is usually no
 287          * need to call this function. If there is a need, you can use
 288          * $this->setCacheMode('private')
 289          */
 290         public function setCachePrivate() {
 291                 wfDeprecated( __METHOD__, '1.17' );
 292                 $this->setCacheMode( 'private' );
 293         }
 294
 295         /**
 296          * Set directives (key/value pairs) for the Cache-Control header.
 297          * Boolean values will be formatted as such, by including or omitting
 298          * without an equals sign.
 299          *
 300          * Cache control values set here will only be used if the cache mode is not
 301          * private, see setCacheMode().
 302          *
 303          * @param $directives array
 304          */
 305         public function setCacheControl( $directives ) {
 306                 $this->mCacheControl = $directives + $this->mCacheControl;
 307         }
 308
 309         /**
 310          * Make sure Vary: Cookie and friends are set. Use this when the output of a request
 311          * may be cached for anons but may not be cached for logged-in users.
 312          *
 313          * WARNING: This function must be called CONSISTENTLY for a given URL. This means that a
 314          * given URL must either always or never call this function; if it sometimes does and
 315          * sometimes doesn't, stuff will break.
 316          *
 317          * @deprecated since 1.17 Use setCacheMode( 'anon-public-user-private' )
 318          */
 319         public function setVaryCookie() {
 320                 wfDeprecated( __METHOD__, '1.17' );
 321                 $this->setCacheMode( 'anon-public-user-private' );
 322         }
 323
 324         /**
 325          * Create an instance of an output formatter by its name
 326          *
 327          * @param $format string
 328          *
 329          * @return ApiFormatBase
 330          */
 331         public function createPrinterByName( $format ) {
 332                 if ( !isset( $this->mFormats[$format] ) ) {
 333                         $this->dieUsage( "Unrecognized format: {$format}", 'unknown_format' );
 334                 }
 335                 return new $this->mFormats[$format] ( $this, $format );
 336         }
 337
 338         /**
 339          * Execute api request. Any errors will be handled if the API was called by the remote client.
 340          */
 341         public function execute() {
 342                 $this->profileIn();
 343                 if ( $this->mInternalMode ) {
 344                         $this->executeAction();
 345                 } else {
 346                         $this->executeActionWithErrorHandling();
 347                 }
 348
 349                 $this->profileOut();
 350         }
 351
 352         /**
 353          * Execute an action, and in case of an error, erase whatever partial results
 354          * have been accumulated, and replace it with an error message and a help screen.
 355          */
 356         protected function executeActionWithErrorHandling() {
 357                 // In case an error occurs during data output,
 358                 // clear the output buffer and print just the error information
 359                 ob_start();
 360
 361                 try {
 362                         $this->executeAction();
 363                 } catch ( Exception $e ) {
 364                         // Log it
 365                         if ( !( $e instanceof UsageException ) ) {
 366                                 wfDebugLog( 'exception', $e->getLogMessage() );
 367                         }
 368
 369                         // Handle any kind of exception by outputing properly formatted error message.
 370                         // If this fails, an unhandled exception should be thrown so that global error
 371                         // handler will process and log it.
 372
 373                         $errCode = $this->substituteResultWithError( $e );
 374
 375                         // Error results should not be cached
 376                         $this->setCacheMode( 'private' );
 377
 378                         $response = $this->getRequest()->response();
 379                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 380                         if ( $e->getCode() === 0 ) {
 381                                 $response->header( $headerStr );
 382                         } else {
 383                                 $response->header( $headerStr, true, $e->getCode() );
 384                         }
 385
 386                         // Reset and print just the error message
 387                         ob_clean();
 388
 389                         // If the error occured during printing, do a printer->profileOut()
 390                         $this->mPrinter->safeProfileOut();
 391                         $this->printResult( true );
 392                 }
 393
 394                 // Send cache headers after any code which might generate an error, to
 395                 // avoid sending public cache headers for errors.
 396                 $this->sendCacheHeaders();
 397
 398                 if ( $this->mPrinter->getIsHtml() && !$this->mPrinter->isDisabled() ) {
 399                         echo wfReportTime();
 400                 }
 401
 402                 ob_end_flush();
 403         }
 404
 405         protected function sendCacheHeaders() {
 406                 global $wgUseXVO, $wgVaryOnXFP;
 407                 $response = $this->getRequest()->response();
 408                 $out = $this->getOutput();
 409
 410                 if ( $wgVaryOnXFP ) {
 411                         $out->addVaryHeader( 'X-Forwarded-Proto' );
 412                 }
 413
 414                 if ( $this->mCacheMode == 'private' ) {
 415                         $response->header( 'Cache-Control: private' );
 416                         return;
 417                 }
 418
 419                 if ( $this->mCacheMode == 'anon-public-user-private' ) {
 420                         $out->addVaryHeader( 'Cookie' );
 421                         $response->header( $out->getVaryHeader() );
 422                         if ( $wgUseXVO ) {
 423                                 $response->header( $out->getXVO() );
 424                                 if ( $out->haveCacheVaryCookies() ) {
 425                                         // Logged in, mark this request private
 426                                         $response->header( 'Cache-Control: private' );
 427                                         return;
 428                                 }
 429                                 // Logged out, send normal public headers below
 430                         } elseif ( session_id() != '' ) {
 431                                 // Logged in or otherwise has session (e.g. anonymous users who have edited)
 432                                 // Mark request private
 433                                 $response->header( 'Cache-Control: private' );
 434                                 return;
 435                         } // else no XVO and anonymous, send public headers below
 436                 }
 437
 438                 // Send public headers
 439                 $response->header( $out->getVaryHeader() );
 440                 if ( $wgUseXVO ) {
 441                         $response->header( $out->getXVO() );
 442                 }
 443
 444                 // If nobody called setCacheMaxAge(), use the (s)maxage parameters
 445                 if ( !isset( $this->mCacheControl['s-maxage'] ) ) {
 446                         $this->mCacheControl['s-maxage'] = $this->getParameter( 'smaxage' );
 447                 }
 448                 if ( !isset( $this->mCacheControl['max-age'] ) ) {
 449                         $this->mCacheControl['max-age'] = $this->getParameter( 'maxage' );
 450                 }
 451
 452                 if ( !$this->mCacheControl['s-maxage'] && !$this->mCacheControl['max-age'] ) {
 453                         // Public cache not requested
 454                         // Sending a Vary header in this case is harmless, and protects us
 455                         // against conditional calls of setCacheMaxAge().
 456                         $response->header( 'Cache-Control: private' );
 457                         return;
 458                 }
 459
 460                 $this->mCacheControl['public'] = true;
 461
 462                 // Send an Expires header
 463                 $maxAge = min( $this->mCacheControl['s-maxage'], $this->mCacheControl['max-age'] );
 464                 $expiryUnixTime = ( $maxAge == 0 ? 1 : time() + $maxAge );
 465                 $response->header( 'Expires: ' . wfTimestamp( TS_RFC2822, $expiryUnixTime ) );
 466
 467                 // Construct the Cache-Control header
 468                 $ccHeader = '';
 469                 $separator = '';
 470                 foreach ( $this->mCacheControl as $name => $value ) {
 471                         if ( is_bool( $value ) ) {
 472                                 if ( $value ) {
 473                                         $ccHeader .= $separator . $name;
 474                                         $separator = ', ';
 475                                 }
 476                         } else {
 477                                 $ccHeader .= $separator . "$name=$value";
 478                                 $separator = ', ';
 479                         }
 480                 }
 481
 482                 $response->header( "Cache-Control: $ccHeader" );
 483         }
 484
 485         /**
 486          * Replace the result data with the information about an exception.
 487          * Returns the error code
 488          * @param $e Exception
 489          * @return string
 490          */
 491         protected function substituteResultWithError( $e ) {
 492                 global $wgShowHostnames;
 493
 494                 $result = $this->getResult();
 495                 // Printer may not be initialized if the extractRequestParams() fails for the main module
 496                 if ( !isset ( $this->mPrinter ) ) {
 497                         // The printer has not been created yet. Try to manually get formatter value.
 498                         $value = $this->getRequest()->getVal( 'format', self::API_DEFAULT_FORMAT );
 499                         if ( !in_array( $value, $this->mFormatNames ) ) {
 500                                 $value = self::API_DEFAULT_FORMAT;
 501                         }
 502
 503                         $this->mPrinter = $this->createPrinterByName( $value );
 504                         if ( $this->mPrinter->getNeedsRawData() ) {
 505                                 $result->setRawMode();
 506                         }
 507                 }
 508
 509                 if ( $e instanceof UsageException ) {
 510                         // User entered incorrect parameters - print usage screen
 511                         $errMessage = $e->getMessageArray();
 512
 513                         // Only print the help message when this is for the developer, not runtime
 514                         if ( $this->mPrinter->getWantsHelp() || $this->mAction == 'help' ) {
 515                                 ApiResult::setContent( $errMessage, $this->makeHelpMsg() );
 516                         }
 517
 518                 } else {
 519                         global $wgShowSQLErrors, $wgShowExceptionDetails;
 520                         // Something is seriously wrong
 521                         if ( ( $e instanceof DBQueryError ) && !$wgShowSQLErrors ) {
 522                                 $info = 'Database query error';
 523                         } else {
 524                                 $info = "Exception Caught: {$e->getMessage()}";
 525                         }
 526
 527                         $errMessage = array(
 528                                 'code' => 'internal_api_error_' . get_class( $e ),
 529                                 'info' => $info,
 530                         );
 531                         ApiResult::setContent( $errMessage, $wgShowExceptionDetails ? "\n\n{$e->getTraceAsString()}\n\n" : '' );
 532                 }
 533
 534                 $result->reset();
 535                 $result->disableSizeCheck();
 536                 // Re-add the id
 537                 $requestid = $this->getParameter( 'requestid' );
 538                 if ( !is_null( $requestid ) ) {
 539                         $result->addValue( null, 'requestid', $requestid );
 540                 }
 541
 542                 if ( $wgShowHostnames ) {
 543                         // servedby is especially useful when debugging errors
 544                         $result->addValue( null, 'servedby', wfHostName() );
 545                 }
 546
 547                 $result->addValue( null, 'error', $errMessage );
 548
 549                 return $errMessage['code'];
 550         }
 551
 552         /**
 553          * Set up for the execution.
 554          * @return array
 555          */
 556         protected function setupExecuteAction() {
 557                 global $wgShowHostnames;
 558
 559                 // First add the id to the top element
 560                 $result = $this->getResult();
 561                 $requestid = $this->getParameter( 'requestid' );
 562                 if ( !is_null( $requestid ) ) {
 563                         $result->addValue( null, 'requestid', $requestid );
 564                 }
 565
 566                 if ( $wgShowHostnames ) {
 567                         $servedby = $this->getParameter( 'servedby' );
 568                         if ( $servedby ) {
 569                                 $result->addValue( null, 'servedby', wfHostName() );
 570                         }
 571                 }
 572
 573                 $params = $this->extractRequestParams();
 574
 575                 $this->mShowVersions = $params['version'];
 576                 $this->mAction = $params['action'];
 577
 578                 if ( !is_string( $this->mAction ) ) {
 579                         $this->dieUsage( 'The API requires a valid action parameter', 'unknown_action' );
 580                 }
 581
 582                 return $params;
 583         }
 584
 585         /**
 586          * Set up the module for response
 587          * @return ApiBase The module that will handle this action
 588          */
 589         protected function setupModule() {
 590                 // Instantiate the module requested by the user
 591                 $module = new $this->mModules[$this->mAction] ( $this, $this->mAction );
 592                 $this->mModule = $module;
 593
 594                 $moduleParams = $module->extractRequestParams();
 595
 596                 // Die if token required, but not provided (unless there is a gettoken parameter)
 597                 if ( isset( $moduleParams['gettoken'] ) ) {
 598                         $gettoken = $moduleParams['gettoken'];
 599                 } else {
 600                         $gettoken = false;
 601                 }
 602
 603                 $salt = $module->getTokenSalt();
 604                 if ( $salt !== false && !$gettoken ) {
 605                         if ( !isset( $moduleParams['token'] ) ) {
 606                                 $this->dieUsageMsg( array( 'missingparam', 'token' ) );
 607                         } else {
 608                                 if ( !$this->getUser()->matchEditToken( $moduleParams['token'], $salt, $this->getContext()->getRequest() ) ) {
 609                                         $this->dieUsageMsg( 'sessionfailure' );
 610                                 }
 611                         }
 612                 }
 613                 return $module;
 614         }
 615
 616         /**
 617          * Check the max lag if necessary
 618          * @param $module ApiBase object: Api module being used
 619          * @param $params Array an array containing the request parameters.
 620          * @return boolean True on success, false should exit immediately
 621          */
 622         protected function checkMaxLag( $module, $params ) {
 623                 if ( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 624                         // Check for maxlag
 625                         global $wgShowHostnames;
 626                         $maxLag = $params['maxlag'];
 627                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 628                         if ( $lag > $maxLag ) {
 629                                 $response = $this->getRequest()->response();
 630
 631                                 $response->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
 632                                 $response->header( 'X-Database-Lag: ' . intval( $lag ) );
 633
 634                                 if ( $wgShowHostnames ) {
 635                                         $this->dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 636                                 } else {
 637                                         $this->dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 638                                 }
 639                                 return false;
 640                         }
 641                 }
 642                 return true;
 643         }
 644
 645         /**
 646          * Check for sufficient permissions to execute
 647          * @param $module ApiBase An Api module
 648          */
 649         protected function checkExecutePermissions( $module ) {
 650                 $user = $this->getUser();
 651                 if ( $module->isReadMode() && !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) &&
 652                         !$user->isAllowed( 'read' ) )
 653                 {
 654                         $this->dieUsageMsg( 'readrequired' );
 655                 }
 656                 if ( $module->isWriteMode() ) {
 657                         if ( !$this->mEnableWrite ) {
 658                                 $this->dieUsageMsg( 'writedisabled' );
 659                         }
 660                         if ( !$user->isAllowed( 'writeapi' ) ) {
 661                                 $this->dieUsageMsg( 'writerequired' );
 662                         }
 663                         if ( wfReadOnly() ) {
 664                                 $this->dieReadOnly();
 665                         }
 666                 }
 667         }
 668
 669         /**
 670          * Check POST for external response and setup result printer
 671          * @param $module ApiBase An Api module
 672          * @param $params Array an array with the request parameters
 673          */
 674         protected function setupExternalResponse( $module, $params ) {
 675                 // Ignore mustBePosted() for internal calls
 676                 if ( $module->mustBePosted() && !$this->getRequest()->wasPosted() ) {
 677                         $this->dieUsageMsg( array( 'mustbeposted', $this->mAction ) );
 678                 }
 679
 680                 // See if custom printer is used
 681                 $this->mPrinter = $module->getCustomPrinter();
 682                 if ( is_null( $this->mPrinter ) ) {
 683                         // Create an appropriate printer
 684                         $this->mPrinter = $this->createPrinterByName( $params['format'] );
 685                 }
 686
 687                 if ( $this->mPrinter->getNeedsRawData() ) {
 688                         $this->getResult()->setRawMode();
 689                 }
 690         }
 691
 692         /**
 693          * Execute the actual module, without any error handling
 694          */
 695         protected function executeAction() {
 696                 $params = $this->setupExecuteAction();
 697                 $module = $this->setupModule();
 698
 699                 $this->checkExecutePermissions( $module );
 700
 701                 if ( !$this->checkMaxLag( $module, $params ) ) {
 702                         return;
 703                 }
 704
 705                 if ( !$this->mInternalMode ) {
 706                         $this->setupExternalResponse( $module, $params );
 707                 }
 708
 709                 // Execute
 710                 $module->profileIn();
 711                 $module->execute();
 712                 wfRunHooks( 'APIAfterExecute', array( &$module ) );
 713                 $module->profileOut();
 714
 715                 if ( !$this->mInternalMode ) {
 716                         //append Debug information
 717                         MWDebug::appendDebugInfoToApiResult( $this->getContext(), $this->getResult() );
 718
 719                         // Print result data
 720                         $this->printResult( false );
 721                 }
 722         }
 723
 724         /**
 725          * Print results using the current printer
 726          *
 727          * @param $isError bool
 728          */
 729         protected function printResult( $isError ) {
 730                 $this->getResult()->cleanUpUTF8();
 731                 $printer = $this->mPrinter;
 732                 $printer->profileIn();
 733
 734                 /**
 735                  * If the help message is requested in the default (xmlfm) format,
 736                  * tell the printer not to escape ampersands so that our links do
 737                  * not break.
 738                  */
 739                 $printer->setUnescapeAmps( ( $this->mAction == 'help' || $isError )
 740                                 && $printer->getFormat() == 'XML' && $printer->getIsHtml() );
 741
 742                 $printer->initPrinter( $isError );
 743
 744                 $printer->execute();
 745                 $printer->closePrinter();
 746                 $printer->profileOut();
 747         }
 748
 749         /**
 750          * @return bool
 751          */
 752         public function isReadMode() {
 753                 return false;
 754         }
 755
 756         /**
 757          * See ApiBase for description.
 758          *
 759          * @return array
 760          */
 761         public function getAllowedParams() {
 762                 return array(
 763                         'format' => array(
 764                                 ApiBase::PARAM_DFLT => ApiMain::API_DEFAULT_FORMAT,
 765                                 ApiBase::PARAM_TYPE => $this->mFormatNames
 766                         ),
 767                         'action' => array(
 768                                 ApiBase::PARAM_DFLT => 'help',
 769                                 ApiBase::PARAM_TYPE => $this->mModuleNames
 770                         ),
 771                         'version' => false,
 772                         'maxlag'  => array(
 773                                 ApiBase::PARAM_TYPE => 'integer'
 774                         ),
 775                         'smaxage' => array(
 776                                 ApiBase::PARAM_TYPE => 'integer',
 777                                 ApiBase::PARAM_DFLT => 0
 778                         ),
 779                         'maxage' => array(
 780                                 ApiBase::PARAM_TYPE => 'integer',
 781                                 ApiBase::PARAM_DFLT => 0
 782                         ),
 783                         'requestid' => null,
 784                         'servedby'  => false,
 785                 );
 786         }
 787
 788         /**
 789          * See ApiBase for description.
 790          *
 791          * @return array
 792          */
 793         public function getParamDescription() {
 794                 return array(
 795                         'format' => 'The format of the output',
 796                         'action' => 'What action you would like to perform. See below for module help',
 797                         'version' => 'When showing help, include version for each module',
 798                         'maxlag' => array(
 799                                 'Maximum lag can be used when MediaWiki is installed on a database replicated cluster.',
 800                                 'To save actions causing any more site replication lag, this parameter can make the client',
 801                                 'wait until the replication lag is less than the specified value.',
 802                                 'In case of a replag error, a HTTP 503 error is returned, with the message like',
 803                                 '"Waiting for $host: $lag seconds lagged\n".',
 804                                 'See https://www.mediawiki.org/wiki/Manual:Maxlag_parameter for more information',
 805                         ),
 806                         'smaxage' => 'Set the s-maxage header to this many seconds. Errors are never cached',
 807                         'maxage' => 'Set the max-age header to this many seconds. Errors are never cached',
 808                         'requestid' => 'Request ID to distinguish requests. This will just be output back to you',
 809                         'servedby' => 'Include the hostname that served the request in the results. Unconditionally shown on error',
 810                 );
 811         }
 812
 813         /**
 814          * See ApiBase for description.
 815          *
 816          * @return array
 817          */
 818         public function getDescription() {
 819                 return array(
 820                         '',
 821                         '',
 822                         '**********************************************************************************************************',
 823                         '**                                                                                                      **',
 824                         '**                      This is an auto-generated MediaWiki API documentation page                      **',
 825                         '**                                                                                                      **',
 826                         '**                                     Documentation and Examples:                                      **',
 827                         '**                                  https://www.mediawiki.org/wiki/API                                  **',
 828                         '**                                                                                                      **',
 829                         '**********************************************************************************************************',
 830                         '',
 831                         'Status:                All features shown on this page should be working, but the API',
 832                         '                       is still in active development, and may change at any time.',
 833                         '                       Make sure to monitor our mailing list for any updates',
 834                         '',
 835                         'Erroneous requests:    When erroneous requests are sent to the API, a HTTP header will be sent',
 836                         '                       with the key "MediaWiki-API-Error" and then both the value of the',
 837                         '                       header and the error code sent back will be set to the same value',
 838                         '',
 839                         '                       In the case of an invalid action being passed, these will have a value',
 840                         '                       of "unknown_action"',
 841                         '',
 842                         '                       For more information see https://www.mediawiki.org/wiki/API:Errors_and_warnings',
 843                         '',
 844                         'Documentation:         https://www.mediawiki.org/wiki/API:Main_page',
 845                         'FAQ                    https://www.mediawiki.org/wiki/API:FAQ',
 846                         'Mailing list:          https://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 847                         'Api Announcements:     https://lists.wikimedia.org/mailman/listinfo/mediawiki-api-announce',
 848                         'Bugs & Requests:       https://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 849                         '',
 850                         '',
 851                         '',
 852                         '',
 853                         '',
 854                 );
 855         }
 856
 857         /**
 858          * @return array
 859          */
 860         public function getPossibleErrors() {
 861                 return array_merge( parent::getPossibleErrors(), array(
 862                         array( 'readonlytext' ),
 863                         array( 'code' => 'unknown_format', 'info' => 'Unrecognized format: format' ),
 864                         array( 'code' => 'unknown_action', 'info' => 'The API requires a valid action parameter' ),
 865                         array( 'code' => 'maxlag', 'info' => 'Waiting for host: x seconds lagged' ),
 866                         array( 'code' => 'maxlag', 'info' => 'Waiting for a database server: x seconds lagged' ),
 867                 ) );
 868         }
 869
 870         /**
 871          * Returns an array of strings with credits for the API
 872          * @return array
 873          */
 874         protected function getCredits() {
 875                 return array(
 876                         'API developers:',
 877                         '    Roan Kattouw <Firstname>.<Lastname>@gmail.com (lead developer Sep 2007-present)',
 878                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 879                         '    Bryan Tong Minh - bryan . tongminh @ gmail . com',
 880                         '    Sam Reed - sam @ reedyboy . net',
 881                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 882                         '',
 883                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 884                         'or file a bug report at https://bugzilla.wikimedia.org/'
 885                 );
 886         }
 887
 888         /**
 889          * Sets whether the pretty-printer should format *bold* and $italics$
 890          *
 891          * @param $help bool
 892          */
 893         public function setHelp( $help = true ) {
 894                 $this->mPrinter->setHelp( $help );
 895         }
 896
 897         /**
 898          * Override the parent to generate help messages for all available modules.
 899          *
 900          * @return string
 901          */
 902         public function makeHelpMsg() {
 903                 global $wgMemc, $wgAPICacheHelpTimeout;
 904                 $this->setHelp();
 905                 // Get help text from cache if present
 906                 $key = wfMemcKey( 'apihelp', $this->getModuleName(),
 907                         SpecialVersion::getVersion( 'nodb' ) .
 908                         $this->getShowVersions() );
 909                 if ( $wgAPICacheHelpTimeout > 0 ) {
 910                         $cached = $wgMemc->get( $key );
 911                         if ( $cached ) {
 912                                 return $cached;
 913                         }
 914                 }
 915                 $retval = $this->reallyMakeHelpMsg();
 916                 if ( $wgAPICacheHelpTimeout > 0 ) {
 917                         $wgMemc->set( $key, $retval, $wgAPICacheHelpTimeout );
 918                 }
 919                 return $retval;
 920         }
 921
 922         /**
 923          * @return mixed|string
 924          */
 925         public function reallyMakeHelpMsg() {
 926                 $this->setHelp();
 927
 928                 // Use parent to make default message for the main module
 929                 $msg = parent::makeHelpMsg();
 930
 931                 $astriks = str_repeat( '*** ', 14 );
 932                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 933                 foreach ( array_keys( $this->mModules ) as $moduleName ) {
 934                         $module = new $this->mModules[$moduleName] ( $this, $moduleName );
 935                         $msg .= self::makeHelpMsgHeader( $module, 'action' );
 936                         $msg2 = $module->makeHelpMsg();
 937                         if ( $msg2 !== false ) {
 938                                 $msg .= $msg2;
 939                         }
 940                         $msg .= "\n";
 941                 }
 942
 943                 $msg .= "\n$astriks Permissions $astriks\n\n";
 944                 foreach ( self::$mRights as $right => $rightMsg ) {
 945                         $groups = User::getGroupsWithPermission( $right );
 946                         $msg .= "* " . $right . " *\n  " . wfMsgReplaceArgs( $rightMsg[ 'msg' ], $rightMsg[ 'params' ] ) .
 947                                                 "\nGranted to:\n  " . str_replace( '*', 'all', implode( ', ', $groups ) ) . "\n\n";
 948
 949                 }
 950
 951                 $msg .= "\n$astriks Formats  $astriks\n\n";
 952                 foreach ( array_keys( $this->mFormats ) as $formatName ) {
 953                         $module = $this->createPrinterByName( $formatName );
 954                         $msg .= self::makeHelpMsgHeader( $module, 'format' );
 955                         $msg2 = $module->makeHelpMsg();
 956                         if ( $msg2 !== false ) {
 957                                 $msg .= $msg2;
 958                         }
 959                         $msg .= "\n";
 960                 }
 961
 962                 $msg .= "\n*** Credits: ***\n   " . implode( "\n   ", $this->getCredits() ) . "\n";
 963
 964                 return $msg;
 965         }
 966
 967         /**
 968          * @param $module ApiBase
 969          * @param $paramName String What type of request is this? e.g. action, query, list, prop, meta, format
 970          * @return string
 971          */
 972         public static function makeHelpMsgHeader( $module, $paramName ) {
 973                 $modulePrefix = $module->getModulePrefix();
 974                 if ( strval( $modulePrefix ) !== '' ) {
 975                         $modulePrefix = "($modulePrefix) ";
 976                 }
 977
 978                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 979         }
 980
 981         private $mCanApiHighLimits = null;
 982
 983         /**
 984          * Check whether the current user is allowed to use high limits
 985          * @return bool
 986          */
 987         public function canApiHighLimits() {
 988                 if ( !isset( $this->mCanApiHighLimits ) ) {
 989                         $this->mCanApiHighLimits = $this->getUser()->isAllowed( 'apihighlimits' );
 990                 }
 991
 992                 return $this->mCanApiHighLimits;
 993         }
 994
 995         /**
 996          * Check whether the user wants us to show version information in the API help
 997          * @return bool
 998          */
 999         public function getShowVersions() {
1000                 return $this->mShowVersions;
1001         }
1002
1003         /**
1004          * Returns the version information of this file, plus it includes
1005          * the versions for all files that are not callable proper API modules
1006          *
1007          * @return array
1008          */
1009         public function getVersion() {
1010                 $vers = array();
1011                 $vers[] = 'MediaWiki: ' . SpecialVersion::getVersion() . "\n    https://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/";
1012                 $vers[] = __CLASS__ . ': $Id$';
1013                 $vers[] = ApiBase::getBaseVersion();
1014                 $vers[] = ApiFormatBase::getBaseVersion();
1015                 $vers[] = ApiQueryBase::getBaseVersion();
1016                 return $vers;
1017         }
1018
1019         /**
1020          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
1021          * classes who wish to add their own modules to their lexicon or override the
1022          * behavior of inherent ones.
1023          *
1024          * @param $mdlName String The identifier for this module.
1025          * @param $mdlClass String The class where this module is implemented.
1026          */
1027         protected function addModule( $mdlName, $mdlClass ) {
1028                 $this->mModules[$mdlName] = $mdlClass;
1029         }
1030
1031         /**
1032          * Add or overwrite an output format for this ApiMain. Intended for use by extending
1033          * classes who wish to add to or modify current formatters.
1034          *
1035          * @param $fmtName string The identifier for this format.
1036          * @param $fmtClass ApiFormatBase The class implementing this format.
1037          */
1038         protected function addFormat( $fmtName, $fmtClass ) {
1039                 $this->mFormats[$fmtName] = $fmtClass;
1040         }
1041
1042         /**
1043          * Get the array mapping module names to class names
1044          * @return array
1045          */
1046         function getModules() {
1047                 return $this->mModules;
1048         }
1049
1050         /**
1051          * Returns the list of supported formats in form ( 'format' => 'ClassName' )
1052          *
1053          * @since 1.18
1054          * @return array
1055          */
1056         public function getFormats() {
1057                 return $this->mFormats;
1058         }
1059 }
1060
1061 /**
1062  * This exception will be thrown when dieUsage is called to stop module execution.
1063  * The exception handling code will print a help screen explaining how this API may be used.
1064  *
1065  * @ingroup API
1066  */
1067 class UsageException extends MWException {
1068
1069         private $mCodestr;
1070         private $mExtraData;
1071
1072         public function __construct( $message, $codestr, $code = 0, $extradata = null ) {
1073                 parent::__construct( $message, $code );
1074                 $this->mCodestr = $codestr;
1075                 $this->mExtraData = $extradata;
1076         }
1077
1078         /**
1079          * @return string
1080          */
1081         public function getCodeString() {
1082                 return $this->mCodestr;
1083         }
1084
1085         /**
1086          * @return array
1087          */
1088         public function getMessageArray() {
1089                 $result = array(
1090                         'code' => $this->mCodestr,
1091                         'info' => $this->getMessage()
1092                 );
1093                 if ( is_array( $this->mExtraData ) ) {
1094                         $result = array_merge( $result, $this->mExtraData );
1095                 }
1096                 return $result;
1097         }
1098
1099         /**
1100          * @return string
1101          */
1102         public function __toString() {
1103                 return "{$this->getCodeString()}: {$this->getMessage()}";
1104         }
1105 }