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                 'query' => 'ApiQuery',
  57                 'expandtemplates' => 'ApiExpandTemplates',
  58                 'render' => 'ApiRender',
  59                 'parse' => 'ApiParse',
  60                 'opensearch' => 'ApiOpenSearch',
  61                 'feedwatchlist' => 'ApiFeedWatchlist',
  62                 'help' => 'ApiHelp',
  63         );
  64
  65         private static $WriteModules = array (
  66                 'rollback' => 'ApiRollback',
  67                 'delete' => 'ApiDelete',
  68                 'undelete' => 'ApiUndelete',
  69                 'protect' => 'ApiProtect',
  70                 'block' => 'ApiBlock',
  71                 'unblock' => 'ApiUnblock',
  72                 'move' => 'ApiMove',
  73                 #'changerights' => 'ApiChangeRights'
  74                 # Disabled for now
  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         );
  93
  94         private $mPrinter, $mModules, $mModuleNames, $mFormats, $mFormatNames;
  95         private $mResult, $mAction, $mShowVersions, $mEnableWrite, $mRequest, $mInternalMode, $mSquidMaxage;
  96
  97         /**
  98         * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
  99         *
 100         * @param $request object - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 101         * @param $enableWrite bool should be set to true if the api may modify data
 102         */
 103         public function __construct($request, $enableWrite = false) {
 104
 105                 $this->mInternalMode = ($request instanceof FauxRequest);
 106
 107                 // Special handling for the main module: $parent === $this
 108                 parent :: __construct($this, $this->mInternalMode ? 'main_int' : 'main');
 109
 110                 if (!$this->mInternalMode) {
 111
 112                         // Impose module restrictions.
 113                         // If the current user cannot read,
 114                         // Remove all modules other than login
 115                         global $wgUser;
 116                         if (!$wgUser->isAllowed('read')) {
 117                                 self::$Modules = array(
 118                                         'login' => self::$Modules['login'],
 119                                         'help' => self::$Modules['help']
 120                                         );
 121                         }
 122                 }
 123
 124                 global $wgAPIModules, $wgEnableWriteAPI; // extension modules
 125                 $this->mModules = $wgAPIModules + self :: $Modules;
 126                 if($wgEnableWriteAPI)
 127                         $this->mModules += self::$WriteModules;
 128
 129                 $this->mModuleNames = array_keys($this->mModules); // todo: optimize
 130                 $this->mFormats = self :: $Formats;
 131                 $this->mFormatNames = array_keys($this->mFormats); // todo: optimize
 132
 133                 $this->mResult = new ApiResult($this);
 134                 $this->mShowVersions = false;
 135                 $this->mEnableWrite = $enableWrite;
 136
 137                 $this->mRequest = & $request;
 138
 139                 $this->mSquidMaxage = 0;
 140         }
 141
 142         /**
 143          * Return true if the API was started by other PHP code using FauxRequest
 144          */
 145         public function isInternalMode() {
 146                 return $this->mInternalMode;
 147         }
 148
 149         /**
 150          * Return the request object that contains client's request
 151          */
 152         public function getRequest() {
 153                 return $this->mRequest;
 154         }
 155
 156         /**
 157          * Get the ApiResult object asscosiated with current request
 158          */
 159         public function getResult() {
 160                 return $this->mResult;
 161         }
 162
 163         /**
 164          * This method will simply cause an error if the write mode was disabled for this api.
 165          */
 166         public function requestWriteMode() {
 167                 if (!$this->mEnableWrite)
 168                         $this->dieUsage('Editing of this site is disabled. Make sure the $wgEnableWriteAPI=true; ' .
 169                         'statement is included in the site\'s LocalSettings.php file', 'noapiwrite');
 170         }
 171
 172         /**
 173          * Set how long the response should be cached.
 174          */
 175         public function setCacheMaxAge($maxage) {
 176                 $this->mSquidMaxage = $maxage;
 177         }
 178
 179         /**
 180          * Create an instance of an output formatter by its name
 181          */
 182         public function createPrinterByName($format) {
 183                 return new $this->mFormats[$format] ($this, $format);
 184         }
 185
 186         /**
 187          * Execute api request. Any errors will be handled if the API was called by the remote client.
 188          */
 189         public function execute() {
 190                 $this->profileIn();
 191                 if ($this->mInternalMode)
 192                         $this->executeAction();
 193                 else
 194                         $this->executeActionWithErrorHandling();
 195                 $this->profileOut();
 196         }
 197
 198         /**
 199          * Execute an action, and in case of an error, erase whatever partial results
 200          * have been accumulated, and replace it with an error message and a help screen.
 201          */
 202         protected function executeActionWithErrorHandling() {
 203
 204                 // In case an error occurs during data output,
 205                 // clear the output buffer and print just the error information
 206                 ob_start();
 207
 208                 try {
 209                         $this->executeAction();
 210                 } catch (Exception $e) {
 211                         //
 212                         // Handle any kind of exception by outputing properly formatted error message.
 213                         // If this fails, an unhandled exception should be thrown so that global error
 214                         // handler will process and log it.
 215                         //
 216
 217                         $errCode = $this->substituteResultWithError($e);
 218
 219                         // Error results should not be cached
 220                         $this->setCacheMaxAge(0);
 221
 222                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 223                         if ($e->getCode() === 0)
 224                                 header($headerStr, true);
 225                         else
 226                                 header($headerStr, true, $e->getCode());
 227
 228                         // Reset and print just the error message
 229                         ob_clean();
 230
 231                         // If the error occured during printing, do a printer->profileOut()
 232                         $this->mPrinter->safeProfileOut();
 233                         $this->printResult(true);
 234                 }
 235
 236                 // Set the cache expiration at the last moment, as any errors may change the expiration.
 237                 // if $this->mSquidMaxage == 0, the expiry time is set to the first second of unix epoch
 238                 $expires = $this->mSquidMaxage == 0 ? 1 : time() + $this->mSquidMaxage;
 239                 header('Expires: ' . wfTimestamp(TS_RFC2822, $expires));
 240                 header('Cache-Control: s-maxage=' . $this->mSquidMaxage . ', must-revalidate, max-age=0');
 241
 242                 if($this->mPrinter->getIsHtml())
 243                         echo wfReportTime();
 244
 245                 ob_end_flush();
 246         }
 247
 248         /**
 249          * Replace the result data with the information about an exception.
 250          * Returns the error code
 251          */
 252         protected function substituteResultWithError($e) {
 253
 254                         // Printer may not be initialized if the extractRequestParams() fails for the main module
 255                         if (!isset ($this->mPrinter)) {
 256                                 // The printer has not been created yet. Try to manually get formatter value.
 257                                 $value = $this->getRequest()->getVal('format', self::API_DEFAULT_FORMAT);
 258                                 if (!in_array($value, $this->mFormatNames))
 259                                         $value = self::API_DEFAULT_FORMAT;
 260
 261                                 $this->mPrinter = $this->createPrinterByName($value);
 262                                 if ($this->mPrinter->getNeedsRawData())
 263                                         $this->getResult()->setRawMode();
 264                         }
 265
 266                         if ($e instanceof UsageException) {
 267                                 //
 268                                 // User entered incorrect parameters - print usage screen
 269                                 //
 270                                 $errMessage = array (
 271                                 'code' => $e->getCodeString(),
 272                                 'info' => $e->getMessage());
 273
 274                                 // Only print the help message when this is for the developer, not runtime
 275                                 if ($this->mPrinter->getIsHtml() || $this->mAction == 'help')
 276                                         ApiResult :: setContent($errMessage, $this->makeHelpMsg());
 277
 278                         } else {
 279                                 //
 280                                 // Something is seriously wrong
 281                                 //
 282                                 $errMessage = array (
 283                                         'code' => 'internal_api_error_'. get_class($e),
 284                                         'info' => "Exception Caught: {$e->getMessage()}"
 285                                 );
 286                                 ApiResult :: setContent($errMessage, "\n\n{$e->getTraceAsString()}\n\n");
 287                         }
 288
 289                         $this->getResult()->reset();
 290                         $this->getResult()->addValue(null, 'error', $errMessage);
 291
 292                 return $errMessage['code'];
 293         }
 294
 295         /**
 296          * Execute the actual module, without any error handling
 297          */
 298         protected function executeAction() {
 299
 300                 $params = $this->extractRequestParams();
 301
 302                 $this->mShowVersions = $params['version'];
 303                 $this->mAction = $params['action'];
 304
 305                 // Instantiate the module requested by the user
 306                 $module = new $this->mModules[$this->mAction] ($this, $this->mAction);
 307
 308                 if( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 309                         // Check for maxlag
 310                         global $wgLoadBalancer, $wgShowHostnames;
 311                         $maxLag = $params['maxlag'];
 312                         list( $host, $lag ) = $wgLoadBalancer->getMaxLag();
 313                         if ( $lag > $maxLag ) {
 314                                 if( $wgShowHostnames ) {
 315                                         ApiBase :: dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 316                                 } else {
 317                                         ApiBase :: dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 318                                 }
 319                                 return;
 320                         }
 321                 }
 322
 323                 if (!$this->mInternalMode) {
 324
 325                         // See if custom printer is used
 326                         $this->mPrinter = $module->getCustomPrinter();
 327                         if (is_null($this->mPrinter)) {
 328                                 // Create an appropriate printer
 329                                 $this->mPrinter = $this->createPrinterByName($params['format']);
 330                         }
 331
 332                         if ($this->mPrinter->getNeedsRawData())
 333                                 $this->getResult()->setRawMode();
 334                 }
 335
 336                 // Execute
 337                 $module->profileIn();
 338                 $module->execute();
 339                 $module->profileOut();
 340
 341                 if (!$this->mInternalMode) {
 342                         // Print result data
 343                         $this->printResult(false);
 344                 }
 345         }
 346
 347         /**
 348          * Print results using the current printer
 349          */
 350         protected function printResult($isError) {
 351                 $printer = $this->mPrinter;
 352                 $printer->profileIn();
 353
 354                 /* If the help message is requested in the default (xmlfm) format,
 355                  * tell the printer not to escape ampersands so that our links do
 356                  * not break. */
 357                 $params = $this->extractRequestParams();
 358                 $printer->setUnescapeAmps ( ( $this->mAction == 'help' || $isError )
 359                                 && $params['format'] == ApiMain::API_DEFAULT_FORMAT );
 360
 361                 $printer->initPrinter($isError);
 362
 363                 $printer->execute();
 364                 $printer->closePrinter();
 365                 $printer->profileOut();
 366         }
 367
 368         /**
 369          * See ApiBase for description.
 370          */
 371         protected function getAllowedParams() {
 372                 return array (
 373                         'format' => array (
 374                                 ApiBase :: PARAM_DFLT => ApiMain :: API_DEFAULT_FORMAT,
 375                                 ApiBase :: PARAM_TYPE => $this->mFormatNames
 376                         ),
 377                         'action' => array (
 378                                 ApiBase :: PARAM_DFLT => 'help',
 379                                 ApiBase :: PARAM_TYPE => $this->mModuleNames
 380                         ),
 381                         'version' => false,
 382                         'maxlag'  => array (
 383                                 ApiBase :: PARAM_TYPE => 'integer'
 384                         ),
 385                 );
 386         }
 387
 388         /**
 389          * See ApiBase for description.
 390          */
 391         protected function getParamDescription() {
 392                 return array (
 393                         'format' => 'The format of the output',
 394                         'action' => 'What action you would like to perform',
 395                         'version' => 'When showing help, include version for each module',
 396                         'maxlag' => 'Maximum lag'
 397                 );
 398         }
 399
 400         /**
 401          * See ApiBase for description.
 402          */
 403         protected function getDescription() {
 404                 return array (
 405                         '',
 406                         '',
 407                         '******************************************************************',
 408                         '**                                                              **',
 409                         '**  This is an auto-generated MediaWiki API documentation page  **',
 410                         '**                                                              **',
 411                         '**                  Documentation and Examples:                 **',
 412                         '**               http://www.mediawiki.org/wiki/API              **',
 413                         '**                                                              **',
 414                         '******************************************************************',
 415                         '',
 416                         'Status:          All features shown on this page should be working, but the API',
 417                         '                 is still in active development, and  may change at any time.',
 418                         '                 Make sure to monitor our mailing list for any updates.',
 419                         '',
 420                         'Documentation:   http://www.mediawiki.org/wiki/API',
 421                         'Mailing list:    http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 422                         'Bugs & Requests: http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 423                         '',
 424                         '',
 425                         '',
 426                         '',
 427                         '',
 428                 );
 429         }
 430
 431         /**
 432          * Returns an array of strings with credits for the API
 433          */
 434         protected function getCredits() {
 435                 return array(
 436                         'This API is being implemented by Yuri Astrakhan [[User:Yurik]] / <Firstname><Lastname>@gmail.com',
 437                         'Please leave your comments and suggestions at http://www.mediawiki.org/wiki/API'
 438                 );
 439         }
 440
 441         /**
 442          * Override the parent to generate help messages for all available modules.
 443          */
 444         public function makeHelpMsg() {
 445
 446                 $this->mPrinter->setHelp();
 447
 448                 // Use parent to make default message for the main module
 449                 $msg = parent :: makeHelpMsg();
 450
 451                 $astriks = str_repeat('*** ', 10);
 452                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 453                 foreach( $this->mModules as $moduleName => $unused ) {
 454                         $module = new $this->mModules[$moduleName] ($this, $moduleName);
 455                         $msg .= self::makeHelpMsgHeader($module, 'action');
 456                         $msg2 = $module->makeHelpMsg();
 457                         if ($msg2 !== false)
 458                                 $msg .= $msg2;
 459                         $msg .= "\n";
 460                 }
 461
 462                 $msg .= "\n$astriks Formats  $astriks\n\n";
 463                 foreach( $this->mFormats as $formatName => $unused ) {
 464                         $module = $this->createPrinterByName($formatName);
 465                         $msg .= self::makeHelpMsgHeader($module, 'format');
 466                         $msg2 = $module->makeHelpMsg();
 467                         if ($msg2 !== false)
 468                                 $msg .= $msg2;
 469                         $msg .= "\n";
 470                 }
 471
 472                 $msg .= "\n*** Credits: ***\n   " . implode("\n   ", $this->getCredits()) . "\n";
 473
 474
 475                 return $msg;
 476         }
 477
 478         public static function makeHelpMsgHeader($module, $paramName) {
 479                 $modulePrefix = $module->getModulePrefix();
 480                 if (!empty($modulePrefix))
 481                         $modulePrefix = "($modulePrefix) ";
 482
 483                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 484         }
 485
 486         private $mIsBot = null;
 487         private $mIsSysop = null;
 488         private $mCanApiHighLimits = null;
 489
 490         /**
 491          * Returns true if the currently logged in user is a bot, false otherwise
 492          * OBSOLETE, use canApiHighLimits() instead
 493          */
 494         public function isBot() {
 495                 if (!isset ($this->mIsBot)) {
 496                         global $wgUser;
 497                         $this->mIsBot = $wgUser->isAllowed('bot');
 498                 }
 499                 return $this->mIsBot;
 500         }
 501
 502         /**
 503          * Similar to isBot(), this method returns true if the logged in user is
 504          * a sysop, and false if not.
 505          * OBSOLETE, use canApiHighLimits() instead
 506          */
 507         public function isSysop() {
 508                 if (!isset ($this->mIsSysop)) {
 509                         global $wgUser;
 510                         $this->mIsSysop = in_array( 'sysop', $wgUser->getGroups());
 511                 }
 512
 513                 return $this->mIsSysop;
 514         }
 515
 516         public function canApiHighLimits() {
 517                 if (!isset($this->mCanApiHighLimits)) {
 518                         global $wgUser;
 519                         $this->mCanApiHighLimits = $wgUser->isAllowed('apihighlimits');
 520                 }
 521
 522                 return $this->mCanApiHighLimits;
 523         }
 524
 525         public function getShowVersions() {
 526                 return $this->mShowVersions;
 527         }
 528
 529         /**
 530          * Returns the version information of this file, plus it includes
 531          * the versions for all files that are not callable proper API modules
 532          */
 533         public function getVersion() {
 534                 $vers = array ();
 535                 $vers[] = 'MediaWiki ' . SpecialVersion::getVersion();
 536                 $vers[] = __CLASS__ . ': $Id$';
 537                 $vers[] = ApiBase :: getBaseVersion();
 538                 $vers[] = ApiFormatBase :: getBaseVersion();
 539                 $vers[] = ApiQueryBase :: getBaseVersion();
 540                 $vers[] = ApiFormatFeedWrapper :: getVersion(); // not accessible with format=xxx
 541                 return $vers;
 542         }
 543
 544         /**
 545          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
 546          * classes who wish to add their own modules to their lexicon or override the
 547          * behavior of inherent ones.
 548          *
 549          * @access protected
 550          * @param $mdlName String The identifier for this module.
 551          * @param $mdlClass String The class where this module is implemented.
 552          */
 553         protected function addModule( $mdlName, $mdlClass ) {
 554                 $this->mModules[$mdlName] = $mdlClass;
 555         }
 556
 557         /**
 558          * Add or overwrite an output format for this ApiMain. Intended for use by extending
 559          * classes who wish to add to or modify current formatters.
 560          *
 561          * @access protected
 562          * @param $fmtName The identifier for this format.
 563          * @param $fmtClass The class implementing this format.
 564          */
 565         protected function addFormat( $fmtName, $fmtClass ) {
 566                 $this->mFormats[$fmtName] = $fmtClass;
 567         }
 568 }
 569
 570 /**
 571  * This exception will be thrown when dieUsage is called to stop module execution.
 572  * The exception handling code will print a help screen explaining how this API may be used.
 573  *
 574  * @addtogroup API
 575  */
 576 class UsageException extends Exception {
 577
 578         private $mCodestr;
 579
 580         public function __construct($message, $codestr, $code = 0) {
 581                 parent :: __construct($message, $code);
 582                 $this->mCodestr = $codestr;
 583         }
 584         public function getCodeString() {
 585                 return $this->mCodestr;
 586         }
 587         public function __toString() {
 588                 return "{$this->getCodeString()}: {$this->getMessage()}";
 589         }
 590 }
 591
 592