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