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