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