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