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                 'render' => 'ApiRender',
  60                 'parse' => 'ApiParse',
  61                 'opensearch' => 'ApiOpenSearch',
  62                 'feedwatchlist' => 'ApiFeedWatchlist',
  63                 'help' => 'ApiHelp',
  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
 327                         // See if custom printer is used
 328                         $this->mPrinter = $module->getCustomPrinter();
 329                         if (is_null($this->mPrinter)) {
 330                                 // Create an appropriate printer
 331                                 $this->mPrinter = $this->createPrinterByName($params['format']);
 332                         }
 333
 334                         if ($this->mPrinter->getNeedsRawData())
 335                                 $this->getResult()->setRawMode();
 336                 }
 337
 338                 // Execute
 339                 $module->profileIn();
 340                 $module->execute();
 341                 $module->profileOut();
 342
 343                 if (!$this->mInternalMode) {
 344                         // Print result data
 345                         $this->printResult(false);
 346                 }
 347         }
 348
 349         /**
 350          * Print results using the current printer
 351          */
 352         protected function printResult($isError) {
 353                 $printer = $this->mPrinter;
 354                 $printer->profileIn();
 355
 356                 /* If the help message is requested in the default (xmlfm) format,
 357                  * tell the printer not to escape ampersands so that our links do
 358                  * not break. */
 359                 $params = $this->extractRequestParams();
 360                 $printer->setUnescapeAmps ( ( $this->mAction == 'help' || $isError )
 361                                 && $params['format'] == ApiMain::API_DEFAULT_FORMAT );
 362
 363                 $printer->initPrinter($isError);
 364
 365                 $printer->execute();
 366                 $printer->closePrinter();
 367                 $printer->profileOut();
 368         }
 369
 370         /**
 371          * See ApiBase for description.
 372          */
 373         protected function getAllowedParams() {
 374                 return array (
 375                         'format' => array (
 376                                 ApiBase :: PARAM_DFLT => ApiMain :: API_DEFAULT_FORMAT,
 377                                 ApiBase :: PARAM_TYPE => $this->mFormatNames
 378                         ),
 379                         'action' => array (
 380                                 ApiBase :: PARAM_DFLT => 'help',
 381                                 ApiBase :: PARAM_TYPE => $this->mModuleNames
 382                         ),
 383                         'version' => false,
 384                         'maxlag'  => array (
 385                                 ApiBase :: PARAM_TYPE => 'integer'
 386                         ),
 387                 );
 388         }
 389
 390         /**
 391          * See ApiBase for description.
 392          */
 393         protected function getParamDescription() {
 394                 return array (
 395                         'format' => 'The format of the output',
 396                         'action' => 'What action you would like to perform',
 397                         'version' => 'When showing help, include version for each module',
 398                         'maxlag' => 'Maximum lag'
 399                 );
 400         }
 401
 402         /**
 403          * See ApiBase for description.
 404          */
 405         protected function getDescription() {
 406                 return array (
 407                         '',
 408                         '',
 409                         '******************************************************************',
 410                         '**                                                              **',
 411                         '**  This is an auto-generated MediaWiki API documentation page  **',
 412                         '**                                                              **',
 413                         '**                  Documentation and Examples:                 **',
 414                         '**               http://www.mediawiki.org/wiki/API              **',
 415                         '**                                                              **',
 416                         '******************************************************************',
 417                         '',
 418                         'Status:          All features shown on this page should be working, but the API',
 419                         '                 is still in active development, and  may change at any time.',
 420                         '                 Make sure to monitor our mailing list for any updates.',
 421                         '',
 422                         'Documentation:   http://www.mediawiki.org/wiki/API',
 423                         'Mailing list:    http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 424                         'Bugs & Requests: http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 425                         '',
 426                         '',
 427                         '',
 428                         '',
 429                         '',
 430                 );
 431         }
 432
 433         /**
 434          * Returns an array of strings with credits for the API
 435          */
 436         protected function getCredits() {
 437                 return array(
 438                         'This API is being implemented by Yuri Astrakhan [[User:Yurik]] / <Firstname><Lastname>@gmail.com',
 439                         'Please leave your comments and suggestions at http://www.mediawiki.org/wiki/API'
 440                 );
 441         }
 442
 443         /**
 444          * Override the parent to generate help messages for all available modules.
 445          */
 446         public function makeHelpMsg() {
 447
 448                 $this->mPrinter->setHelp();
 449
 450                 // Use parent to make default message for the main module
 451                 $msg = parent :: makeHelpMsg();
 452
 453                 $astriks = str_repeat('*** ', 10);
 454                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 455                 foreach( $this->mModules as $moduleName => $unused ) {
 456                         $module = new $this->mModules[$moduleName] ($this, $moduleName);
 457                         $msg .= self::makeHelpMsgHeader($module, 'action');
 458                         $msg2 = $module->makeHelpMsg();
 459                         if ($msg2 !== false)
 460                                 $msg .= $msg2;
 461                         $msg .= "\n";
 462                 }
 463
 464                 $msg .= "\n$astriks Formats  $astriks\n\n";
 465                 foreach( $this->mFormats as $formatName => $unused ) {
 466                         $module = $this->createPrinterByName($formatName);
 467                         $msg .= self::makeHelpMsgHeader($module, 'format');
 468                         $msg2 = $module->makeHelpMsg();
 469                         if ($msg2 !== false)
 470                                 $msg .= $msg2;
 471                         $msg .= "\n";
 472                 }
 473
 474                 $msg .= "\n*** Credits: ***\n   " . implode("\n   ", $this->getCredits()) . "\n";
 475
 476
 477                 return $msg;
 478         }
 479
 480         public static function makeHelpMsgHeader($module, $paramName) {
 481                 $modulePrefix = $module->getModulePrefix();
 482                 if (!empty($modulePrefix))
 483                         $modulePrefix = "($modulePrefix) ";
 484
 485                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 486         }
 487
 488         private $mIsBot = null;
 489         private $mIsSysop = null;
 490         private $mCanApiHighLimits = null;
 491
 492         /**
 493          * Returns true if the currently logged in user is a bot, false otherwise
 494          * OBSOLETE, use canApiHighLimits() instead
 495          */
 496         public function isBot() {
 497                 if (!isset ($this->mIsBot)) {
 498                         global $wgUser;
 499                         $this->mIsBot = $wgUser->isAllowed('bot');
 500                 }
 501                 return $this->mIsBot;
 502         }
 503
 504         /**
 505          * Similar to isBot(), this method returns true if the logged in user is
 506          * a sysop, and false if not.
 507          * OBSOLETE, use canApiHighLimits() instead
 508          */
 509         public function isSysop() {
 510                 if (!isset ($this->mIsSysop)) {
 511                         global $wgUser;
 512                         $this->mIsSysop = in_array( 'sysop', $wgUser->getGroups());
 513                 }
 514
 515                 return $this->mIsSysop;
 516         }
 517
 518         public function canApiHighLimits() {
 519                 if (!isset($this->mCanApiHighLimits)) {
 520                         global $wgUser;
 521                         $this->mCanApiHighLimits = $wgUser->isAllowed('apihighlimits');
 522                 }
 523
 524                 return $this->mCanApiHighLimits;
 525         }
 526
 527         public function getShowVersions() {
 528                 return $this->mShowVersions;
 529         }
 530
 531         /**
 532          * Returns the version information of this file, plus it includes
 533          * the versions for all files that are not callable proper API modules
 534          */
 535         public function getVersion() {
 536                 $vers = array ();
 537                 $vers[] = 'MediaWiki ' . SpecialVersion::getVersion();
 538                 $vers[] = __CLASS__ . ': $Id$';
 539                 $vers[] = ApiBase :: getBaseVersion();
 540                 $vers[] = ApiFormatBase :: getBaseVersion();
 541                 $vers[] = ApiQueryBase :: getBaseVersion();
 542                 $vers[] = ApiFormatFeedWrapper :: getVersion(); // not accessible with format=xxx
 543                 return $vers;
 544         }
 545
 546         /**
 547          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
 548          * classes who wish to add their own modules to their lexicon or override the
 549          * behavior of inherent ones.
 550          *
 551          * @access protected
 552          * @param $mdlName String The identifier for this module.
 553          * @param $mdlClass String The class where this module is implemented.
 554          */
 555         protected function addModule( $mdlName, $mdlClass ) {
 556                 $this->mModules[$mdlName] = $mdlClass;
 557         }
 558
 559         /**
 560          * Add or overwrite an output format for this ApiMain. Intended for use by extending
 561          * classes who wish to add to or modify current formatters.
 562          *
 563          * @access protected
 564          * @param $fmtName The identifier for this format.
 565          * @param $fmtClass The class implementing this format.
 566          */
 567         protected function addFormat( $fmtName, $fmtClass ) {
 568                 $this->mFormats[$fmtName] = $fmtClass;
 569         }
 570 }
 571
 572 /**
 573  * This exception will be thrown when dieUsage is called to stop module execution.
 574  * The exception handling code will print a help screen explaining how this API may be used.
 575  *
 576  * @addtogroup API
 577  */
 578 class UsageException extends Exception {
 579
 580         private $mCodestr;
 581
 582         public function __construct($message, $codestr, $code = 0) {
 583                 parent :: __construct($message, $code);
 584                 $this->mCodestr = $codestr;
 585         }
 586         public function getCodeString() {
 587                 return $this->mCodestr;
 588         }
 589         public function __toString() {
 590                 return "{$this->getCodeString()}: {$this->getMessage()}";
 591         }
 592 }
 593
 594