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