includes/api/ApiMain.php

   1 <?php
   2
   3 /*
   4  * Created on Sep 4, 2006
   5  *
   6  * API for MediaWiki 1.8+
   7  *
   8  * Copyright (C) 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, write to the Free Software Foundation, Inc.,
  22  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  * http://www.gnu.org/copyleft/gpl.html
  24  */
  25
  26 if (!defined('MEDIAWIKI')) {
  27         // Eclipse helper - will be ignored in production
  28         require_once ('ApiBase.php');
  29 }
  30
  31 /**
  32  * @defgroup API API
  33  */
  34
  35 /**
  36  * This is the main API class, used for both external and internal processing.
  37  * When executed, it will create the requested formatter object,
  38  * instantiate and execute an object associated with the needed action,
  39  * and use formatter to print results.
  40  * In case of an exception, an error message will be printed using the same formatter.
  41  *
  42  * To use API from another application, run it using FauxRequest object, in which
  43  * case any internal exceptions will not be handled but passed up to the caller.
  44  * After successful execution, use getResult() for the resulting data.
  45  *
  46  * @ingroup API
  47  */
  48 class ApiMain extends ApiBase {
  49
  50         /**
  51          * When no format parameter is given, this format will be used
  52          */
  53         const API_DEFAULT_FORMAT = 'xmlfm';
  54
  55         /**
  56          * List of available modules: action name => module class
  57          */
  58         private static $Modules = array (
  59                 'login' => 'ApiLogin',
  60                 'logout' => 'ApiLogout',
  61                 'query' => 'ApiQuery',
  62                 'expandtemplates' => 'ApiExpandTemplates',
  63                 'parse' => 'ApiParse',
  64                 'opensearch' => 'ApiOpenSearch',
  65                 'feedwatchlist' => 'ApiFeedWatchlist',
  66                 'help' => 'ApiHelp',
  67                 'paraminfo' => 'ApiParamInfo',
  68         );
  69
  70         private static $WriteModules = array (
  71                 'rollback' => 'ApiRollback',
  72                 'delete' => 'ApiDelete',
  73                 'undelete' => 'ApiUndelete',
  74                 'protect' => 'ApiProtect',
  75                 'block' => 'ApiBlock',
  76                 'unblock' => 'ApiUnblock',
  77                 'move' => 'ApiMove',
  78                 'edit' => 'ApiEditPage',
  79                 'emailuser' => 'ApiEmailUser',
  80         );
  81
  82         /**
  83          * List of available formats: format name => format class
  84          */
  85         private static $Formats = array (
  86                 'json' => 'ApiFormatJson',
  87                 'jsonfm' => 'ApiFormatJson',
  88                 'php' => 'ApiFormatPhp',
  89                 'phpfm' => 'ApiFormatPhp',
  90                 'wddx' => 'ApiFormatWddx',
  91                 'wddxfm' => 'ApiFormatWddx',
  92                 'xml' => 'ApiFormatXml',
  93                 'xmlfm' => 'ApiFormatXml',
  94                 'yaml' => 'ApiFormatYaml',
  95                 'yamlfm' => 'ApiFormatYaml',
  96                 'rawfm' => 'ApiFormatJson',
  97                 'txt' => 'ApiFormatTxt',
  98                 'txtfm' => 'ApiFormatTxt',
  99                 'dbg' => 'ApiFormatDbg',
 100                 'dbgfm' => 'ApiFormatDbg'
 101         );
 102
 103         private $mPrinter, $mModules, $mModuleNames, $mFormats, $mFormatNames;
 104         private $mResult, $mAction, $mShowVersions, $mEnableWrite, $mRequest, $mInternalMode, $mSquidMaxage;
 105
 106         /**
 107         * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 108         *
 109         * @param $request object - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 110         * @param $enableWrite bool should be set to true if the api may modify data
 111         */
 112         public function __construct($request, $enableWrite = false) {
 113
 114                 $this->mInternalMode = ($request instanceof FauxRequest);
 115
 116                 // Special handling for the main module: $parent === $this
 117                 parent :: __construct($this, $this->mInternalMode ? 'main_int' : 'main');
 118
 119                 if (!$this->mInternalMode) {
 120
 121                         // Impose module restrictions.
 122                         // If the current user cannot read,
 123                         // Remove all modules other than login
 124                         global $wgUser;
 125
 126                         if( $request->getVal( 'callback' ) !== null ) {
 127                                 // JSON callback allows cross-site reads.
 128                                 // For safety, strip user credentials.
 129                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 130                                 $wgUser = new User();
 131                         }
 132
 133                         if (!$wgUser->isAllowed('read')) {
 134                                 self::$Modules = array(
 135                                         'login'  => self::$Modules['login'],
 136                                         'logout' => self::$Modules['logout'],
 137                                         'help'   => self::$Modules['help'],
 138                                         );
 139                         }
 140                 }
 141
 142                 global $wgAPIModules, $wgEnableWriteAPI; // extension modules
 143                 $this->mModules = $wgAPIModules + self :: $Modules;
 144                 if($wgEnableWriteAPI)
 145                         $this->mModules += self::$WriteModules;
 146
 147                 $this->mModuleNames = array_keys($this->mModules); // todo: optimize
 148                 $this->mFormats = self :: $Formats;
 149                 $this->mFormatNames = array_keys($this->mFormats); // todo: optimize
 150
 151                 $this->mResult = new ApiResult($this);
 152                 $this->mShowVersions = false;
 153                 $this->mEnableWrite = $enableWrite;
 154
 155                 $this->mRequest = & $request;
 156
 157                 $this->mSquidMaxage = -1; // flag for executeActionWithErrorHandling()
 158                 $this->mCommit = false;
 159         }
 160
 161         /**
 162          * Return true if the API was started by other PHP code using FauxRequest
 163          */
 164         public function isInternalMode() {
 165                 return $this->mInternalMode;
 166         }
 167
 168         /**
 169          * Return the request object that contains client's request
 170          */
 171         public function getRequest() {
 172                 return $this->mRequest;
 173         }
 174
 175         /**
 176          * Get the ApiResult object asscosiated with current request
 177          */
 178         public function getResult() {
 179                 return $this->mResult;
 180         }
 181
 182         /**
 183          * This method will simply cause an error if the write mode was disabled
 184          * or if the current user doesn't have the right to use it
 185          */
 186         public function requestWriteMode() {
 187                 global $wgUser;
 188                 if (!$this->mEnableWrite)
 189                         $this->dieUsage('Editing of this wiki through the API' .
 190                         ' is disabled. Make sure the $wgEnableWriteAPI=true; ' .
 191                         'statement is included in the wiki\'s ' .
 192                         'LocalSettings.php file', 'noapiwrite');
 193                 if (!$wgUser->isAllowed('writeapi'))
 194                         $this->dieUsage('You\'re not allowed to edit this ' .
 195                         'wiki through the API', 'writeapidenied');
 196         }
 197
 198         /**
 199          * Set how long the response should be cached.
 200          */
 201         public function setCacheMaxAge($maxage) {
 202                 $this->mSquidMaxage = $maxage;
 203         }
 204
 205         /**
 206          * Create an instance of an output formatter by its name
 207          */
 208         public function createPrinterByName($format) {
 209                 return new $this->mFormats[$format] ($this, $format);
 210         }
 211
 212         /**
 213          * Execute api request. Any errors will be handled if the API was called by the remote client.
 214          */
 215         public function execute() {
 216                 $this->profileIn();
 217                 if ($this->mInternalMode)
 218                         $this->executeAction();
 219                 else
 220                         $this->executeActionWithErrorHandling();
 221
 222                 $this->profileOut();
 223         }
 224
 225         /**
 226          * Execute an action, and in case of an error, erase whatever partial results
 227          * have been accumulated, and replace it with an error message and a help screen.
 228          */
 229         protected function executeActionWithErrorHandling() {
 230
 231                 // In case an error occurs during data output,
 232                 // clear the output buffer and print just the error information
 233                 ob_start();
 234
 235                 try {
 236                         $this->executeAction();
 237                 } catch (Exception $e) {
 238                         //
 239                         // Handle any kind of exception by outputing properly formatted error message.
 240                         // If this fails, an unhandled exception should be thrown so that global error
 241                         // handler will process and log it.
 242                         //
 243
 244                         $errCode = $this->substituteResultWithError($e);
 245
 246                         // Error results should not be cached
 247                         $this->setCacheMaxAge(0);
 248
 249                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 250                         if ($e->getCode() === 0)
 251                                 header($headerStr, true);
 252                         else
 253                                 header($headerStr, true, $e->getCode());
 254
 255                         // Reset and print just the error message
 256                         ob_clean();
 257
 258                         // If the error occured during printing, do a printer->profileOut()
 259                         $this->mPrinter->safeProfileOut();
 260                         $this->printResult(true);
 261                 }
 262
 263                 $params = $this->extractRequestParams();
 264                 if($this->mSquidMaxage == -1)
 265                         # Nobody called setCacheMaxAge(), use the smaxage parameter
 266                         $this->mSquidMaxage = $params['smaxage'];
 267
 268                 // Set the cache expiration at the last moment, as any errors may change the expiration.
 269                 // if $this->mSquidMaxage == 0, the expiry time is set to the first second of unix epoch
 270                 $expires = $this->mSquidMaxage == 0 ? 1 : time() + $this->mSquidMaxage;
 271                 header('Expires: ' . wfTimestamp(TS_RFC2822, $expires));
 272                 header('Cache-Control: s-maxage=' . $this->mSquidMaxage . ', must-revalidate, max-age=0');
 273
 274                 if($this->mPrinter->getIsHtml())
 275                         echo wfReportTime();
 276
 277                 ob_end_flush();
 278         }
 279
 280         /**
 281          * Replace the result data with the information about an exception.
 282          * Returns the error code
 283          */
 284         protected function substituteResultWithError($e) {
 285
 286                         // Printer may not be initialized if the extractRequestParams() fails for the main module
 287                         if (!isset ($this->mPrinter)) {
 288                                 // The printer has not been created yet. Try to manually get formatter value.
 289                                 $value = $this->getRequest()->getVal('format', self::API_DEFAULT_FORMAT);
 290                                 if (!in_array($value, $this->mFormatNames))
 291                                         $value = self::API_DEFAULT_FORMAT;
 292
 293                                 $this->mPrinter = $this->createPrinterByName($value);
 294                                 if ($this->mPrinter->getNeedsRawData())
 295                                         $this->getResult()->setRawMode();
 296                         }
 297
 298                         if ($e instanceof UsageException) {
 299                                 //
 300                                 // User entered incorrect parameters - print usage screen
 301                                 //
 302                                 $errMessage = array (
 303                                 'code' => $e->getCodeString(),
 304                                 'info' => $e->getMessage());
 305
 306                                 // Only print the help message when this is for the developer, not runtime
 307                                 if ($this->mPrinter->getIsHtml() || $this->mAction == 'help')
 308                                         ApiResult :: setContent($errMessage, $this->makeHelpMsg());
 309
 310                         } else {
 311                                 //
 312                                 // Something is seriously wrong
 313                                 //
 314                                 $errMessage = array (
 315                                         'code' => 'internal_api_error_'. get_class($e),
 316                                         'info' => "Exception Caught: {$e->getMessage()}"
 317                                 );
 318                                 ApiResult :: setContent($errMessage, "\n\n{$e->getTraceAsString()}\n\n");
 319                         }
 320
 321                         $this->getResult()->reset();
 322                         $this->getResult()->addValue(null, 'error', $errMessage);
 323
 324                 return $errMessage['code'];
 325         }
 326
 327         /**
 328          * Execute the actual module, without any error handling
 329          */
 330         protected function executeAction() {
 331
 332                 $params = $this->extractRequestParams();
 333
 334                 $this->mShowVersions = $params['version'];
 335                 $this->mAction = $params['action'];
 336
 337                 // Instantiate the module requested by the user
 338                 $module = new $this->mModules[$this->mAction] ($this, $this->mAction);
 339
 340                 if( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 341                         // Check for maxlag
 342                         global $wgShowHostnames;
 343                         $maxLag = $params['maxlag'];
 344                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 345                         if ( $lag > $maxLag ) {
 346                                 if( $wgShowHostnames ) {
 347                                         ApiBase :: dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 348                                 } else {
 349                                         ApiBase :: dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 350                                 }
 351                                 return;
 352                         }
 353                 }
 354
 355                 if (!$this->mInternalMode) {
 356                         // Ignore mustBePosted() for internal calls
 357                         if($module->mustBePosted() && !$this->mRequest->wasPosted())
 358                                 $this->dieUsage("The {$this->mAction} module requires a POST request", 'mustbeposted');
 359
 360                         // See if custom printer is used
 361                         $this->mPrinter = $module->getCustomPrinter();
 362                         if (is_null($this->mPrinter)) {
 363                                 // Create an appropriate printer
 364                                 $this->mPrinter = $this->createPrinterByName($params['format']);
 365                         }
 366
 367                         if ($this->mPrinter->getNeedsRawData())
 368                                 $this->getResult()->setRawMode();
 369                 }
 370
 371                 // Execute
 372                 $module->profileIn();
 373                 $module->execute();
 374                 $module->profileOut();
 375
 376                 if (!$this->mInternalMode) {
 377                         // Print result data
 378                         $this->printResult(false);
 379                 }
 380         }
 381
 382         /**
 383          * Print results using the current printer
 384          */
 385         protected function printResult($isError) {
 386                 $printer = $this->mPrinter;
 387                 $printer->profileIn();
 388
 389                 /* If the help message is requested in the default (xmlfm) format,
 390                  * tell the printer not to escape ampersands so that our links do
 391                  * not break. */
 392                 $printer->setUnescapeAmps ( ( $this->mAction == 'help' || $isError )
 393                                 && $this->getParameter('format') == ApiMain::API_DEFAULT_FORMAT );
 394
 395                 $printer->initPrinter($isError);
 396
 397                 $printer->execute();
 398                 $printer->closePrinter();
 399                 $printer->profileOut();
 400         }
 401
 402         /**
 403          * See ApiBase for description.
 404          */
 405         public function getAllowedParams() {
 406                 return array (
 407                         'format' => array (
 408                                 ApiBase :: PARAM_DFLT => ApiMain :: API_DEFAULT_FORMAT,
 409                                 ApiBase :: PARAM_TYPE => $this->mFormatNames
 410                         ),
 411                         'action' => array (
 412                                 ApiBase :: PARAM_DFLT => 'help',
 413                                 ApiBase :: PARAM_TYPE => $this->mModuleNames
 414                         ),
 415                         'version' => false,
 416                         'maxlag'  => array (
 417                                 ApiBase :: PARAM_TYPE => 'integer'
 418                         ),
 419                         'smaxage' => array (
 420                                 ApiBase :: PARAM_TYPE => 'integer',
 421                                 ApiBase :: PARAM_DFLT => 0
 422                         ),
 423                 );
 424         }
 425
 426         /**
 427          * See ApiBase for description.
 428          */
 429         public function getParamDescription() {
 430                 return array (
 431                         'format' => 'The format of the output',
 432                         'action' => 'What action you would like to perform',
 433                         'version' => 'When showing help, include version for each module',
 434                         'maxlag' => 'Maximum lag',
 435                         'smaxage' => 'Cache the result for this many seconds. Errors are never cached',
 436                 );
 437         }
 438
 439         /**
 440          * See ApiBase for description.
 441          */
 442         public function getDescription() {
 443                 return array (
 444                         '',
 445                         '',
 446                         '******************************************************************',
 447                         '**                                                              **',
 448                         '**  This is an auto-generated MediaWiki API documentation page  **',
 449                         '**                                                              **',
 450                         '**                  Documentation and Examples:                 **',
 451                         '**               http://www.mediawiki.org/wiki/API              **',
 452                         '**                                                              **',
 453                         '******************************************************************',
 454                         '',
 455                         'Status:          All features shown on this page should be working, but the API',
 456                         '                 is still in active development, and  may change at any time.',
 457                         '                 Make sure to monitor our mailing list for any updates.',
 458                         '',
 459                         'Documentation:   http://www.mediawiki.org/wiki/API',
 460                         'Mailing list:    http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 461                         'Bugs & Requests: http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 462                         '',
 463                         '',
 464                         '',
 465                         '',
 466                         '',
 467                 );
 468         }
 469
 470         /**
 471          * Returns an array of strings with credits for the API
 472          */
 473         protected function getCredits() {
 474                 return array(
 475                         'API developers:',
 476                         '    Roan Kattouw <Firstname>.<Lastname>@home.nl (lead developer Sep 2007-present)',
 477                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 478                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 479                         '',
 480                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 481                         'or file a bug report at http://bugzilla.wikimedia.org/'
 482                 );
 483         }
 484
 485         /**
 486          * Override the parent to generate help messages for all available modules.
 487          */
 488         public function makeHelpMsg() {
 489
 490                 $this->mPrinter->setHelp();
 491
 492                 // Use parent to make default message for the main module
 493                 $msg = parent :: makeHelpMsg();
 494
 495                 $astriks = str_repeat('*** ', 10);
 496                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 497                 foreach( $this->mModules as $moduleName => $unused ) {
 498                         $module = new $this->mModules[$moduleName] ($this, $moduleName);
 499                         $msg .= self::makeHelpMsgHeader($module, 'action');
 500                         $msg2 = $module->makeHelpMsg();
 501                         if ($msg2 !== false)
 502                                 $msg .= $msg2;
 503                         $msg .= "\n";
 504                 }
 505
 506                 $msg .= "\n$astriks Formats  $astriks\n\n";
 507                 foreach( $this->mFormats as $formatName => $unused ) {
 508                         $module = $this->createPrinterByName($formatName);
 509                         $msg .= self::makeHelpMsgHeader($module, 'format');
 510                         $msg2 = $module->makeHelpMsg();
 511                         if ($msg2 !== false)
 512                                 $msg .= $msg2;
 513                         $msg .= "\n";
 514                 }
 515
 516                 $msg .= "\n*** Credits: ***\n   " . implode("\n   ", $this->getCredits()) . "\n";
 517
 518
 519                 return $msg;
 520         }
 521
 522         public static function makeHelpMsgHeader($module, $paramName) {
 523                 $modulePrefix = $module->getModulePrefix();
 524                 if (!empty($modulePrefix))
 525                         $modulePrefix = "($modulePrefix) ";
 526
 527                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 528         }
 529
 530         private $mIsBot = null;
 531         private $mIsSysop = null;
 532         private $mCanApiHighLimits = null;
 533
 534         /**
 535          * Returns true if the currently logged in user is a bot, false otherwise
 536          * OBSOLETE, use canApiHighLimits() instead
 537          */
 538         public function isBot() {
 539                 if (!isset ($this->mIsBot)) {
 540                         global $wgUser;
 541                         $this->mIsBot = $wgUser->isAllowed('bot');
 542                 }
 543                 return $this->mIsBot;
 544         }
 545
 546         /**
 547          * Similar to isBot(), this method returns true if the logged in user is
 548          * a sysop, and false if not.
 549          * OBSOLETE, use canApiHighLimits() instead
 550          */
 551         public function isSysop() {
 552                 if (!isset ($this->mIsSysop)) {
 553                         global $wgUser;
 554                         $this->mIsSysop = in_array( 'sysop', $wgUser->getGroups());
 555                 }
 556
 557                 return $this->mIsSysop;
 558         }
 559
 560         /**
 561          * Check whether the current user is allowed to use high limits
 562          * @return bool
 563          */
 564         public function canApiHighLimits() {
 565                 if (!isset($this->mCanApiHighLimits)) {
 566                         global $wgUser;
 567                         $this->mCanApiHighLimits = $wgUser->isAllowed('apihighlimits');
 568                 }
 569
 570                 return $this->mCanApiHighLimits;
 571         }
 572
 573         /**
 574          * Check whether the user wants us to show version information in the API help
 575          * @return bool
 576          */
 577         public function getShowVersions() {
 578                 return $this->mShowVersions;
 579         }
 580
 581         /**
 582          * Returns the version information of this file, plus it includes
 583          * the versions for all files that are not callable proper API modules
 584          */
 585         public function getVersion() {
 586                 $vers = array ();
 587                 $vers[] = 'MediaWiki ' . SpecialVersion::getVersion();
 588                 $vers[] = __CLASS__ . ': $Id$';
 589                 $vers[] = ApiBase :: getBaseVersion();
 590                 $vers[] = ApiFormatBase :: getBaseVersion();
 591                 $vers[] = ApiQueryBase :: getBaseVersion();
 592                 $vers[] = ApiFormatFeedWrapper :: getVersion(); // not accessible with format=xxx
 593                 return $vers;
 594         }
 595
 596         /**
 597          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
 598          * classes who wish to add their own modules to their lexicon or override the
 599          * behavior of inherent ones.
 600          *
 601          * @access protected
 602          * @param $mdlName String The identifier for this module.
 603          * @param $mdlClass String The class where this module is implemented.
 604          */
 605         protected function addModule( $mdlName, $mdlClass ) {
 606                 $this->mModules[$mdlName] = $mdlClass;
 607         }
 608
 609         /**
 610          * Add or overwrite an output format for this ApiMain. Intended for use by extending
 611          * classes who wish to add to or modify current formatters.
 612          *
 613          * @access protected
 614          * @param $fmtName The identifier for this format.
 615          * @param $fmtClass The class implementing this format.
 616          */
 617         protected function addFormat( $fmtName, $fmtClass ) {
 618                 $this->mFormats[$fmtName] = $fmtClass;
 619         }
 620
 621         /**
 622          * Get the array mapping module names to class names
 623          */
 624         function getModules() {
 625                 return $this->mModules;
 626         }
 627 }
 628
 629 /**
 630  * This exception will be thrown when dieUsage is called to stop module execution.
 631  * The exception handling code will print a help screen explaining how this API may be used.
 632  *
 633  * @ingroup API
 634  */
 635 class UsageException extends Exception {
 636
 637         private $mCodestr;
 638
 639         public function __construct($message, $codestr, $code = 0) {
 640                 parent :: __construct($message, $code);
 641                 $this->mCodestr = $codestr;
 642         }
 643         public function getCodeString() {
 644                 return $this->mCodestr;
 645         }
 646         public function __toString() {
 647                 return "{$this->getCodeString()}: {$this->getMessage()}";
 648         }
 649 }