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