includes/api/ApiMain.php

   1 <?php
   2
   3 /*
   4  * Created on Sep 4, 2006
   5  *
   6  * API for MediaWiki 1.8+
   7  *
   8  * Copyright (C) 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, write to the Free Software Foundation, Inc.,
  22  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  * http://www.gnu.org/copyleft/gpl.html
  24  */
  25
  26 if (!defined('MEDIAWIKI')) {
  27         // Eclipse helper - will be ignored in production
  28         require_once ('ApiBase.php');
  29 }
  30
  31 /**
  32  * This is the main API class, used for both external and internal processing.
  33  * When executed, it will create the requested formatter object,
  34  * instantiate and execute an object associated with the needed action,
  35  * and use formatter to print results.
  36  * In case of an exception, an error message will be printed using the same formatter.
  37  *
  38  * To use API from another application, run it using FauxRequest object, in which
  39  * case any internal exceptions will not be handled but passed up to the caller.
  40  * After successful execution, use getResult() for the resulting data.
  41  *
  42  * @addtogroup API
  43  */
  44 class ApiMain extends ApiBase {
  45
  46         /**
  47          * When no format parameter is given, this format will be used
  48          */
  49         const API_DEFAULT_FORMAT = 'xmlfm';
  50
  51         /**
  52          * List of available modules: action name => module class
  53          */
  54         private static $Modules = array (
  55                 'login' => 'ApiLogin',
  56                 'logout' => 'ApiLogout',
  57                 'query' => 'ApiQuery',
  58                 'expandtemplates' => 'ApiExpandTemplates',
  59                 'parse' => 'ApiParse',
  60                 'opensearch' => 'ApiOpenSearch',
  61                 'feedwatchlist' => 'ApiFeedWatchlist',
  62                 'help' => 'ApiHelp',
  63                 'paraminfo' => 'ApiParamInfo',
  64         );
  65
  66         private static $WriteModules = array (
  67                 'rollback' => 'ApiRollback',
  68                 'delete' => 'ApiDelete',
  69                 'undelete' => 'ApiUndelete',
  70                 'protect' => 'ApiProtect',
  71                 'block' => 'ApiBlock',
  72                 'unblock' => 'ApiUnblock',
  73                 'move' => 'ApiMove',
  74                 'edit' => 'ApiEditPage',
  75         );
  76
  77         /**
  78          * List of available formats: format name => format class
  79          */
  80         private static $Formats = array (
  81                 'json' => 'ApiFormatJson',
  82                 'jsonfm' => 'ApiFormatJson',
  83                 'php' => 'ApiFormatPhp',
  84                 'phpfm' => 'ApiFormatPhp',
  85                 'wddx' => 'ApiFormatWddx',
  86                 'wddxfm' => 'ApiFormatWddx',
  87                 'xml' => 'ApiFormatXml',
  88                 'xmlfm' => 'ApiFormatXml',
  89                 'yaml' => 'ApiFormatYaml',
  90                 'yamlfm' => 'ApiFormatYaml',
  91                 'rawfm' => 'ApiFormatJson',
  92                 'txt' => 'ApiFormatTxt',
  93                 'txtfm' => 'ApiFormatTxt',
  94                 'dbg' => 'ApiFormatDbg',
  95                 'dbgfm' => 'ApiFormatDbg'
  96         );
  97
  98         private $mPrinter, $mModules, $mModuleNames, $mFormats, $mFormatNames;
  99         private $mResult, $mAction, $mShowVersions, $mEnableWrite, $mRequest, $mInternalMode, $mSquidMaxage;
 100
 101         /**
 102         * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 103         *
 104         * @param $request object - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 105         * @param $enableWrite bool should be set to true if the api may modify data
 106         */
 107         public function __construct($request, $enableWrite = false) {
 108
 109                 $this->mInternalMode = ($request instanceof FauxRequest);
 110
 111                 // Special handling for the main module: $parent === $this
 112                 parent :: __construct($this, $this->mInternalMode ? 'main_int' : 'main');
 113
 114                 if (!$this->mInternalMode) {
 115
 116                         // Impose module restrictions.
 117                         // If the current user cannot read,
 118                         // Remove all modules other than login
 119                         global $wgUser;
 120
 121                         if( $request->getVal( 'callback' ) !== null ) {
 122                                 // JSON callback allows cross-site reads.
 123                                 // For safety, strip user credentials.
 124                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 125                                 $wgUser = new User();
 126                         }
 127
 128                         if (!$wgUser->isAllowed('read')) {
 129                                 self::$Modules = array(
 130                                         'login'  => self::$Modules['login'],
 131                                         'logout' => self::$Modules['logout'],
 132                                         'help'   => self::$Modules['help'],
 133                                         );
 134                         }
 135                 }
 136
 137                 global $wgAPIModules, $wgEnableWriteAPI; // extension modules
 138                 $this->mModules = $wgAPIModules + self :: $Modules;
 139                 if($wgEnableWriteAPI)
 140                         $this->mModules += self::$WriteModules;
 141
 142                 $this->mModuleNames = array_keys($this->mModules); // todo: optimize
 143                 $this->mFormats = self :: $Formats;
 144                 $this->mFormatNames = array_keys($this->mFormats); // todo: optimize
 145
 146                 $this->mResult = new ApiResult($this);
 147                 $this->mShowVersions = false;
 148                 $this->mEnableWrite = $enableWrite;
 149
 150                 $this->mRequest = & $request;
 151
 152                 $this->mSquidMaxage = 0;
 153         }
 154
 155         /**
 156          * Return true if the API was started by other PHP code using FauxRequest
 157          */
 158         public function isInternalMode() {
 159                 return $this->mInternalMode;
 160         }
 161
 162         /**
 163          * Return the request object that contains client's request
 164          */
 165         public function getRequest() {
 166                 return $this->mRequest;
 167         }
 168
 169         /**
 170          * Get the ApiResult object asscosiated with current request
 171          */
 172         public function getResult() {
 173                 return $this->mResult;
 174         }
 175
 176         /**
 177          * This method will simply cause an error if the write mode was disabled for this api.
 178          */
 179         public function requestWriteMode() {
 180                 if (!$this->mEnableWrite)
 181                         $this->dieUsage('Editing of this site is disabled. Make sure the $wgEnableWriteAPI=true; ' .
 182                         'statement is included in the site\'s LocalSettings.php file', 'noapiwrite');
 183         }
 184
 185         /**
 186          * Set how long the response should be cached.
 187          */
 188         public function setCacheMaxAge($maxage) {
 189                 $this->mSquidMaxage = $maxage;
 190         }
 191
 192         /**
 193          * Create an instance of an output formatter by its name
 194          */
 195         public function createPrinterByName($format) {
 196                 return new $this->mFormats[$format] ($this, $format);
 197         }
 198
 199         /**
 200          * Execute api request. Any errors will be handled if the API was called by the remote client.
 201          */
 202         public function execute() {
 203                 $this->profileIn();
 204                 if ($this->mInternalMode)
 205                         $this->executeAction();
 206                 else
 207                         $this->executeActionWithErrorHandling();
 208                 $this->profileOut();
 209         }
 210
 211         /**
 212          * Execute an action, and in case of an error, erase whatever partial results
 213          * have been accumulated, and replace it with an error message and a help screen.
 214          */
 215         protected function executeActionWithErrorHandling() {
 216
 217                 // In case an error occurs during data output,
 218                 // clear the output buffer and print just the error information
 219                 ob_start();
 220
 221                 try {
 222                         $this->executeAction();
 223                 } catch (Exception $e) {
 224                         //
 225                         // Handle any kind of exception by outputing properly formatted error message.
 226                         // If this fails, an unhandled exception should be thrown so that global error
 227                         // handler will process and log it.
 228                         //
 229
 230                         $errCode = $this->substituteResultWithError($e);
 231
 232                         // Error results should not be cached
 233                         $this->setCacheMaxAge(0);
 234
 235                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 236                         if ($e->getCode() === 0)
 237                                 header($headerStr, true);
 238                         else
 239                                 header($headerStr, true, $e->getCode());
 240
 241                         // Reset and print just the error message
 242                         ob_clean();
 243
 244                         // If the error occured during printing, do a printer->profileOut()
 245                         $this->mPrinter->safeProfileOut();
 246                         $this->printResult(true);
 247                 }
 248
 249                 // Set the cache expiration at the last moment, as any errors may change the expiration.
 250                 // if $this->mSquidMaxage == 0, the expiry time is set to the first second of unix epoch
 251                 $expires = $this->mSquidMaxage == 0 ? 1 : time() + $this->mSquidMaxage;
 252                 header('Expires: ' . wfTimestamp(TS_RFC2822, $expires));
 253                 header('Cache-Control: s-maxage=' . $this->mSquidMaxage . ', must-revalidate, max-age=0');
 254
 255                 if($this->mPrinter->getIsHtml())
 256                         echo wfReportTime();
 257
 258                 ob_end_flush();
 259         }
 260
 261         /**
 262          * Replace the result data with the information about an exception.
 263          * Returns the error code
 264          */
 265         protected function substituteResultWithError($e) {
 266
 267                         // Printer may not be initialized if the extractRequestParams() fails for the main module
 268                         if (!isset ($this->mPrinter)) {
 269                                 // The printer has not been created yet. Try to manually get formatter value.
 270                                 $value = $this->getRequest()->getVal('format', self::API_DEFAULT_FORMAT);
 271                                 if (!in_array($value, $this->mFormatNames))
 272                                         $value = self::API_DEFAULT_FORMAT;
 273
 274                                 $this->mPrinter = $this->createPrinterByName($value);
 275                                 if ($this->mPrinter->getNeedsRawData())
 276                                         $this->getResult()->setRawMode();
 277                         }
 278
 279                         if ($e instanceof UsageException) {
 280                                 //
 281                                 // User entered incorrect parameters - print usage screen
 282                                 //
 283                                 $errMessage = array (
 284                                 'code' => $e->getCodeString(),
 285                                 'info' => $e->getMessage());
 286
 287                                 // Only print the help message when this is for the developer, not runtime
 288                                 if ($this->mPrinter->getIsHtml() || $this->mAction == 'help')
 289                                         ApiResult :: setContent($errMessage, $this->makeHelpMsg());
 290
 291                         } else {
 292                                 //
 293                                 // Something is seriously wrong
 294                                 //
 295                                 $errMessage = array (
 296                                         'code' => 'internal_api_error_'. get_class($e),
 297                                         'info' => "Exception Caught: {$e->getMessage()}"
 298                                 );
 299                                 ApiResult :: setContent($errMessage, "\n\n{$e->getTraceAsString()}\n\n");
 300                         }
 301
 302                         $this->getResult()->reset();
 303                         $this->getResult()->addValue(null, 'error', $errMessage);
 304
 305                 return $errMessage['code'];
 306         }
 307
 308         /**
 309          * Execute the actual module, without any error handling
 310          */
 311         protected function executeAction() {
 312
 313                 $params = $this->extractRequestParams();
 314
 315                 $this->mShowVersions = $params['version'];
 316                 $this->mAction = $params['action'];
 317
 318                 // Instantiate the module requested by the user
 319                 $module = new $this->mModules[$this->mAction] ($this, $this->mAction);
 320
 321                 if( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 322                         // Check for maxlag
 323                         global $wgLoadBalancer, $wgShowHostnames;
 324                         $maxLag = $params['maxlag'];
 325                         list( $host, $lag ) = $wgLoadBalancer->getMaxLag();
 326                         if ( $lag > $maxLag ) {
 327                                 if( $wgShowHostnames ) {
 328                                         ApiBase :: dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 329                                 } else {
 330                                         ApiBase :: dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 331                                 }
 332                                 return;
 333                         }
 334                 }
 335
 336                 if (!$this->mInternalMode) {
 337                         // Ignore mustBePosted() for internal calls
 338                         if($module->mustBePosted() && !$this->mRequest->wasPosted())
 339                                 $this->dieUsage("The {$this->mAction} module requires a POST request", 'mustbeposted');
 340
 341                         // See if custom printer is used
 342                         $this->mPrinter = $module->getCustomPrinter();
 343                         if (is_null($this->mPrinter)) {
 344                                 // Create an appropriate printer
 345                                 $this->mPrinter = $this->createPrinterByName($params['format']);
 346                         }
 347
 348                         if ($this->mPrinter->getNeedsRawData())
 349                                 $this->getResult()->setRawMode();
 350                 }
 351
 352                 // Execute
 353                 $module->profileIn();
 354                 $module->execute();
 355                 $module->profileOut();
 356
 357                 if (!$this->mInternalMode) {
 358                         // Print result data
 359                         $this->printResult(false);
 360                 }
 361         }
 362
 363         /**
 364          * Print results using the current printer
 365          */
 366         protected function printResult($isError) {
 367                 $printer = $this->mPrinter;
 368                 $printer->profileIn();
 369
 370                 /* If the help message is requested in the default (xmlfm) format,
 371                  * tell the printer not to escape ampersands so that our links do
 372                  * not break. */
 373                 $params = $this->extractRequestParams();
 374                 $printer->setUnescapeAmps ( ( $this->mAction == 'help' || $isError )
 375                                 && $params['format'] == ApiMain::API_DEFAULT_FORMAT );
 376
 377                 $printer->initPrinter($isError);
 378
 379                 $printer->execute();
 380                 $printer->closePrinter();
 381                 $printer->profileOut();
 382         }
 383
 384         /**
 385          * See ApiBase for description.
 386          */
 387         public function getAllowedParams() {
 388                 return array (
 389                         'format' => array (
 390                                 ApiBase :: PARAM_DFLT => ApiMain :: API_DEFAULT_FORMAT,
 391                                 ApiBase :: PARAM_TYPE => $this->mFormatNames
 392                         ),
 393                         'action' => array (
 394                                 ApiBase :: PARAM_DFLT => 'help',
 395                                 ApiBase :: PARAM_TYPE => $this->mModuleNames
 396                         ),
 397                         'version' => false,
 398                         'maxlag'  => array (
 399                                 ApiBase :: PARAM_TYPE => 'integer'
 400                         ),
 401                 );
 402         }
 403
 404         /**
 405          * See ApiBase for description.
 406          */
 407         public function getParamDescription() {
 408                 return array (
 409                         'format' => 'The format of the output',
 410                         'action' => 'What action you would like to perform',
 411                         'version' => 'When showing help, include version for each module',
 412                         'maxlag' => 'Maximum lag'
 413                 );
 414         }
 415
 416         /**
 417          * See ApiBase for description.
 418          */
 419         public function getDescription() {
 420                 return array (
 421                         '',
 422                         '',
 423                         '******************************************************************',
 424                         '**                                                              **',
 425                         '**  This is an auto-generated MediaWiki API documentation page  **',
 426                         '**                                                              **',
 427                         '**                  Documentation and Examples:                 **',
 428                         '**               http://www.mediawiki.org/wiki/API              **',
 429                         '**                                                              **',
 430                         '******************************************************************',
 431                         '',
 432                         'Status:          All features shown on this page should be working, but the API',
 433                         '                 is still in active development, and  may change at any time.',
 434                         '                 Make sure to monitor our mailing list for any updates.',
 435                         '',
 436                         'Documentation:   http://www.mediawiki.org/wiki/API',
 437                         'Mailing list:    http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 438                         'Bugs & Requests: http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 439                         '',
 440                         '',
 441                         '',
 442                         '',
 443                         '',
 444                 );
 445         }
 446
 447         /**
 448          * Returns an array of strings with credits for the API
 449          */
 450         protected function getCredits() {
 451                 return array(
 452                         'API developers:',
 453                         '    Roan Kattouw <Firstname>.<Lastname>@home.nl (lead developer Sep 2007-present)',
 454                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 455                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 456                         '',
 457                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 458                         'or file a bug report at http://bugzilla.wikimedia.org/'
 459                 );
 460         }
 461
 462         /**
 463          * Override the parent to generate help messages for all available modules.
 464          */
 465         public function makeHelpMsg() {
 466
 467                 $this->mPrinter->setHelp();
 468
 469                 // Use parent to make default message for the main module
 470                 $msg = parent :: makeHelpMsg();
 471
 472                 $astriks = str_repeat('*** ', 10);
 473                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 474                 foreach( $this->mModules as $moduleName => $unused ) {
 475                         $module = new $this->mModules[$moduleName] ($this, $moduleName);
 476                         $msg .= self::makeHelpMsgHeader($module, 'action');
 477                         $msg2 = $module->makeHelpMsg();
 478                         if ($msg2 !== false)
 479                                 $msg .= $msg2;
 480                         $msg .= "\n";
 481                 }
 482
 483                 $msg .= "\n$astriks Formats  $astriks\n\n";
 484                 foreach( $this->mFormats as $formatName => $unused ) {
 485                         $module = $this->createPrinterByName($formatName);
 486                         $msg .= self::makeHelpMsgHeader($module, 'format');
 487                         $msg2 = $module->makeHelpMsg();
 488                         if ($msg2 !== false)
 489                                 $msg .= $msg2;
 490                         $msg .= "\n";
 491                 }
 492
 493                 $msg .= "\n*** Credits: ***\n   " . implode("\n   ", $this->getCredits()) . "\n";
 494
 495
 496                 return $msg;
 497         }
 498
 499         public static function makeHelpMsgHeader($module, $paramName) {
 500                 $modulePrefix = $module->getModulePrefix();
 501                 if (!empty($modulePrefix))
 502                         $modulePrefix = "($modulePrefix) ";
 503
 504                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 505         }
 506
 507         private $mIsBot = null;
 508         private $mIsSysop = null;
 509         private $mCanApiHighLimits = null;
 510
 511         /**
 512          * Returns true if the currently logged in user is a bot, false otherwise
 513          * OBSOLETE, use canApiHighLimits() instead
 514          */
 515         public function isBot() {
 516                 if (!isset ($this->mIsBot)) {
 517                         global $wgUser;
 518                         $this->mIsBot = $wgUser->isAllowed('bot');
 519                 }
 520                 return $this->mIsBot;
 521         }
 522
 523         /**
 524          * Similar to isBot(), this method returns true if the logged in user is
 525          * a sysop, and false if not.
 526          * OBSOLETE, use canApiHighLimits() instead
 527          */
 528         public function isSysop() {
 529                 if (!isset ($this->mIsSysop)) {
 530                         global $wgUser;
 531                         $this->mIsSysop = in_array( 'sysop', $wgUser->getGroups());
 532                 }
 533
 534                 return $this->mIsSysop;
 535         }
 536
 537         public function canApiHighLimits() {
 538                 if (!isset($this->mCanApiHighLimits)) {
 539                         global $wgUser;
 540                         $this->mCanApiHighLimits = $wgUser->isAllowed('apihighlimits');
 541                 }
 542
 543                 return $this->mCanApiHighLimits;
 544         }
 545
 546         public function getShowVersions() {
 547                 return $this->mShowVersions;
 548         }
 549
 550         /**
 551          * Returns the version information of this file, plus it includes
 552          * the versions for all files that are not callable proper API modules
 553          */
 554         public function getVersion() {
 555                 $vers = array ();
 556                 $vers[] = 'MediaWiki ' . SpecialVersion::getVersion();
 557                 $vers[] = __CLASS__ . ': $Id$';
 558                 $vers[] = ApiBase :: getBaseVersion();
 559                 $vers[] = ApiFormatBase :: getBaseVersion();
 560                 $vers[] = ApiQueryBase :: getBaseVersion();
 561                 $vers[] = ApiFormatFeedWrapper :: getVersion(); // not accessible with format=xxx
 562                 return $vers;
 563         }
 564
 565         /**
 566          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
 567          * classes who wish to add their own modules to their lexicon or override the
 568          * behavior of inherent ones.
 569          *
 570          * @access protected
 571          * @param $mdlName String The identifier for this module.
 572          * @param $mdlClass String The class where this module is implemented.
 573          */
 574         protected function addModule( $mdlName, $mdlClass ) {
 575                 $this->mModules[$mdlName] = $mdlClass;
 576         }
 577
 578         /**
 579          * Add or overwrite an output format for this ApiMain. Intended for use by extending
 580          * classes who wish to add to or modify current formatters.
 581          *
 582          * @access protected
 583          * @param $fmtName The identifier for this format.
 584          * @param $fmtClass The class implementing this format.
 585          */
 586         protected function addFormat( $fmtName, $fmtClass ) {
 587                 $this->mFormats[$fmtName] = $fmtClass;
 588         }
 589
 590         /**
 591          * Get the array mapping module names to class names
 592          */
 593         function getModules() {
 594                 return $this->mModules;
 595         }
 596 }
 597
 598 /**
 599  * This exception will be thrown when dieUsage is called to stop module execution.
 600  * The exception handling code will print a help screen explaining how this API may be used.
 601  *
 602  * @addtogroup API
 603  */
 604 class UsageException extends Exception {
 605
 606         private $mCodestr;
 607
 608         public function __construct($message, $codestr, $code = 0) {
 609                 parent :: __construct($message, $code);
 610                 $this->mCodestr = $codestr;
 611         }
 612         public function getCodeString() {
 613                 return $this->mCodestr;
 614         }
 615         public function __toString() {
 616                 return "{$this->getCodeString()}: {$this->getMessage()}";
 617         }
 618 }
 619
 620