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                 'changerights' => 'ApiChangeRights',
  73                 'move' => 'ApiMove'
  74         );
  75
  76         /**
  77          * List of available formats: format name => format class
  78          */
  79         private static $Formats = array (
  80                 'json' => 'ApiFormatJson',
  81                 'jsonfm' => 'ApiFormatJson',
  82                 'php' => 'ApiFormatPhp',
  83                 'phpfm' => 'ApiFormatPhp',
  84                 'wddx' => 'ApiFormatWddx',
  85                 'wddxfm' => 'ApiFormatWddx',
  86                 'xml' => 'ApiFormatXml',
  87                 'xmlfm' => 'ApiFormatXml',
  88                 'yaml' => 'ApiFormatYaml',
  89                 'yamlfm' => 'ApiFormatYaml',
  90                 'rawfm' => 'ApiFormatJson'
  91         );
  92
  93         private $mPrinter, $mModules, $mModuleNames, $mFormats, $mFormatNames;
  94         private $mResult, $mAction, $mShowVersions, $mEnableWrite, $mRequest, $mInternalMode, $mSquidMaxage;
  95
  96         /**
  97         * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
  98         *
  99         * @param $request object - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 100         * @param $enableWrite bool should be set to true if the api may modify data
 101         */
 102         public function __construct($request, $enableWrite = false) {
 103
 104                 $this->mInternalMode = ($request instanceof FauxRequest);
 105
 106                 // Special handling for the main module: $parent === $this
 107                 parent :: __construct($this, $this->mInternalMode ? 'main_int' : 'main');
 108
 109                 if (!$this->mInternalMode) {
 110
 111                         // Impose module restrictions.
 112                         // If the current user cannot read,
 113                         // Remove all modules other than login
 114                         global $wgUser;
 115                         if (!$wgUser->isAllowed('read')) {
 116                                 self::$Modules = array(
 117                                         'login' => self::$Modules['login'],
 118                                         'help' => self::$Modules['help']
 119                                         );
 120                         }
 121                 }
 122
 123                 global $wgAPIModules, $wgEnableWriteAPI; // extension modules
 124                 $this->mModules = $wgAPIModules + self :: $Modules;
 125                 if($wgEnableWriteAPI)
 126                         $this->mModules += self::$WriteModules;
 127
 128                 $this->mModuleNames = array_keys($this->mModules); // todo: optimize
 129                 $this->mFormats = self :: $Formats;
 130                 $this->mFormatNames = array_keys($this->mFormats); // todo: optimize
 131
 132                 $this->mResult = new ApiResult($this);
 133                 $this->mShowVersions = false;
 134                 $this->mEnableWrite = $enableWrite;
 135
 136                 $this->mRequest = & $request;
 137
 138                 $this->mSquidMaxage = 0;
 139         }
 140
 141         /**
 142          * Return true if the API was started by other PHP code using FauxRequest
 143          */
 144         public function isInternalMode() {
 145                 return $this->mInternalMode;
 146         }
 147
 148         /**
 149          * Return the request object that contains client's request
 150          */
 151         public function getRequest() {
 152                 return $this->mRequest;
 153         }
 154
 155         /**
 156          * Get the ApiResult object asscosiated with current request
 157          */
 158         public function getResult() {
 159                 return $this->mResult;
 160         }
 161
 162         /**
 163          * This method will simply cause an error if the write mode was disabled for this api.
 164          */
 165         public function requestWriteMode() {
 166                 if (!$this->mEnableWrite)
 167                         $this->dieUsage('Editing of this site is disabled. Make sure the $wgEnableWriteAPI=true; ' .
 168                         'statement is included in the site\'s LocalSettings.php file', 'noapiwrite');
 169         }
 170
 171         /**
 172          * Set how long the response should be cached.
 173          */
 174         public function setCacheMaxAge($maxage) {
 175                 $this->mSquidMaxage = $maxage;
 176         }
 177
 178         /**
 179          * Create an instance of an output formatter by its name
 180          */
 181         public function createPrinterByName($format) {
 182                 return new $this->mFormats[$format] ($this, $format);
 183         }
 184
 185         /**
 186          * Execute api request. Any errors will be handled if the API was called by the remote client.
 187          */
 188         public function execute() {
 189                 $this->profileIn();
 190                 if ($this->mInternalMode)
 191                         $this->executeAction();
 192                 else
 193                         $this->executeActionWithErrorHandling();
 194                 $this->profileOut();
 195         }
 196
 197         /**
 198          * Execute an action, and in case of an error, erase whatever partial results
 199          * have been accumulated, and replace it with an error message and a help screen.
 200          */
 201         protected function executeActionWithErrorHandling() {
 202
 203                 // In case an error occurs during data output,
 204                 // clear the output buffer and print just the error information
 205                 ob_start();
 206
 207                 try {
 208                         $this->executeAction();
 209                 } catch (Exception $e) {
 210                         //
 211                         // Handle any kind of exception by outputing properly formatted error message.
 212                         // If this fails, an unhandled exception should be thrown so that global error
 213                         // handler will process and log it.
 214                         //
 215
 216                         $errCode = $this->substituteResultWithError($e);
 217
 218                         // Error results should not be cached
 219                         $this->setCacheMaxAge(0);
 220
 221                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 222                         if ($e->getCode() === 0)
 223                                 header($headerStr, true);
 224                         else
 225                                 header($headerStr, true, $e->getCode());
 226
 227                         // Reset and print just the error message
 228                         ob_clean();
 229
 230                         // If the error occured during printing, do a printer->profileOut()
 231                         $this->mPrinter->safeProfileOut();
 232                         $this->printResult(true);
 233                 }
 234
 235                 // Set the cache expiration at the last moment, as any errors may change the expiration.
 236                 // if $this->mSquidMaxage == 0, the expiry time is set to the first second of unix epoch
 237                 $expires = $this->mSquidMaxage == 0 ? 1 : time() + $this->mSquidMaxage;
 238                 header('Expires: ' . wfTimestamp(TS_RFC2822, $expires));
 239                 header('Cache-Control: s-maxage=' . $this->mSquidMaxage . ', must-revalidate, max-age=0');
 240
 241                 if($this->mPrinter->getIsHtml())
 242                         echo wfReportTime();
 243
 244                 ob_end_flush();
 245         }
 246
 247         /**
 248          * Replace the result data with the information about an exception.
 249          * Returns the error code
 250          */
 251         protected function substituteResultWithError($e) {
 252
 253                         // Printer may not be initialized if the extractRequestParams() fails for the main module
 254                         if (!isset ($this->mPrinter)) {
 255                                 // The printer has not been created yet. Try to manually get formatter value.
 256                                 $value = $this->getRequest()->getVal('format', self::API_DEFAULT_FORMAT);
 257                                 if (!in_array($value, $this->mFormatNames))
 258                                         $value = self::API_DEFAULT_FORMAT;
 259
 260                                 $this->mPrinter = $this->createPrinterByName($value);
 261                                 if ($this->mPrinter->getNeedsRawData())
 262                                         $this->getResult()->setRawMode();
 263                         }
 264
 265                         if ($e instanceof UsageException) {
 266                                 //
 267                                 // User entered incorrect parameters - print usage screen
 268                                 //
 269                                 $errMessage = array (
 270                                 'code' => $e->getCodeString(),
 271                                 'info' => $e->getMessage());
 272
 273                                 // Only print the help message when this is for the developer, not runtime
 274                                 if ($this->mPrinter->getIsHtml() || $this->mAction == 'help')
 275                                         ApiResult :: setContent($errMessage, $this->makeHelpMsg());
 276
 277                         } else {
 278                                 //
 279                                 // Something is seriously wrong
 280                                 //
 281                                 $errMessage = array (
 282                                         'code' => 'internal_api_error_'. get_class($e),
 283                                         'info' => "Exception Caught: {$e->getMessage()}"
 284                                 );
 285                                 ApiResult :: setContent($errMessage, "\n\n{$e->getTraceAsString()}\n\n");
 286                         }
 287
 288                         $this->getResult()->reset();
 289                         $this->getResult()->addValue(null, 'error', $errMessage);
 290
 291                 return $errMessage['code'];
 292         }
 293
 294         /**
 295          * Execute the actual module, without any error handling
 296          */
 297         protected function executeAction() {
 298
 299                 $params = $this->extractRequestParams();
 300
 301                 $this->mShowVersions = $params['version'];
 302                 $this->mAction = $params['action'];
 303
 304                 // Instantiate the module requested by the user
 305                 $module = new $this->mModules[$this->mAction] ($this, $this->mAction);
 306
 307                 if( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 308                         // Check for maxlag
 309                         global $wgLoadBalancer, $wgShowHostnames;
 310                         $maxLag = $params['maxlag'];
 311                         list( $host, $lag ) = $wgLoadBalancer->getMaxLag();
 312                         if ( $lag > $maxLag ) {
 313                                 if( $wgShowHostnames ) {
 314                                         ApiBase :: dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 315                                 } else {
 316                                         ApiBase :: dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 317                                 }
 318                                 return;
 319                         }
 320                 }
 321
 322                 if (!$this->mInternalMode) {
 323
 324                         // See if custom printer is used
 325                         $this->mPrinter = $module->getCustomPrinter();
 326                         if (is_null($this->mPrinter)) {
 327                                 // Create an appropriate printer
 328                                 $this->mPrinter = $this->createPrinterByName($params['format']);
 329                         }
 330
 331                         if ($this->mPrinter->getNeedsRawData())
 332                                 $this->getResult()->setRawMode();
 333                 }
 334
 335                 // Execute
 336                 $module->profileIn();
 337                 $module->execute();
 338                 $module->profileOut();
 339
 340                 if (!$this->mInternalMode) {
 341                         // Print result data
 342                         $this->printResult(false);
 343                 }
 344         }
 345
 346         /**
 347          * Print results using the current printer
 348          */
 349         protected function printResult($isError) {
 350                 $printer = $this->mPrinter;
 351                 $printer->profileIn();
 352
 353                 /* If the help message is requested in the default (xmlfm) format,
 354                  * tell the printer not to escape ampersands so that our links do
 355                  * not break. */
 356                 $params = $this->extractRequestParams();
 357                 $printer->setUnescapeAmps ( ( $this->mAction == 'help' || $isError )
 358                                 && $params['format'] == ApiMain::API_DEFAULT_FORMAT );
 359
 360                 $printer->initPrinter($isError);
 361
 362                 $printer->execute();
 363                 $printer->closePrinter();
 364                 $printer->profileOut();
 365         }
 366
 367         /**
 368          * See ApiBase for description.
 369          */
 370         protected function getAllowedParams() {
 371                 return array (
 372                         'format' => array (
 373                                 ApiBase :: PARAM_DFLT => ApiMain :: API_DEFAULT_FORMAT,
 374                                 ApiBase :: PARAM_TYPE => $this->mFormatNames
 375                         ),
 376                         'action' => array (
 377                                 ApiBase :: PARAM_DFLT => 'help',
 378                                 ApiBase :: PARAM_TYPE => $this->mModuleNames
 379                         ),
 380                         'version' => false,
 381                         'maxlag'  => array (
 382                                 ApiBase :: PARAM_TYPE => 'integer'
 383                         ),
 384                 );
 385         }
 386
 387         /**
 388          * See ApiBase for description.
 389          */
 390         protected function getParamDescription() {
 391                 return array (
 392                         'format' => 'The format of the output',
 393                         'action' => 'What action you would like to perform',
 394                         'version' => 'When showing help, include version for each module',
 395                         'maxlag' => 'Maximum lag'
 396                 );
 397         }
 398
 399         /**
 400          * See ApiBase for description.
 401          */
 402         protected function getDescription() {
 403                 return array (
 404                         '',
 405                         '',
 406                         '******************************************************************',
 407                         '**                                                              **',
 408                         '**  This is an auto-generated MediaWiki API documentation page  **',
 409                         '**                                                              **',
 410                         '**                  Documentation and Examples:                 **',
 411                         '**               http://www.mediawiki.org/wiki/API              **',
 412                         '**                                                              **',
 413                         '******************************************************************',
 414                         '',
 415                         'Status:          All features shown on this page should be working, but the API',
 416                         '                 is still in active development, and  may change at any time.',
 417                         '                 Make sure to monitor our mailing list for any updates.',
 418                         '',
 419                         'Documentation:   http://www.mediawiki.org/wiki/API',
 420                         'Mailing list:    http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 421                         'Bugs & Requests: http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 422                         '',
 423                         '',
 424                         '',
 425                         '',
 426                         '',
 427                 );
 428         }
 429
 430         /**
 431          * Returns an array of strings with credits for the API
 432          */
 433         protected function getCredits() {
 434                 return array(
 435                         'This API is being implemented by Yuri Astrakhan [[User:Yurik]] / <Firstname><Lastname>@gmail.com',
 436                         'Please leave your comments and suggestions at http://www.mediawiki.org/wiki/API'
 437                 );
 438         }
 439
 440         /**
 441          * Override the parent to generate help messages for all available modules.
 442          */
 443         public function makeHelpMsg() {
 444
 445                 $this->mPrinter->setHelp();
 446
 447                 // Use parent to make default message for the main module
 448                 $msg = parent :: makeHelpMsg();
 449
 450                 $astriks = str_repeat('*** ', 10);
 451                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 452                 foreach( $this->mModules as $moduleName => $unused ) {
 453                         $module = new $this->mModules[$moduleName] ($this, $moduleName);
 454                         $msg .= self::makeHelpMsgHeader($module, 'action');
 455                         $msg2 = $module->makeHelpMsg();
 456                         if ($msg2 !== false)
 457                                 $msg .= $msg2;
 458                         $msg .= "\n";
 459                 }
 460
 461                 $msg .= "\n$astriks Formats  $astriks\n\n";
 462                 foreach( $this->mFormats as $formatName => $unused ) {
 463                         $module = $this->createPrinterByName($formatName);
 464                         $msg .= self::makeHelpMsgHeader($module, 'format');
 465                         $msg2 = $module->makeHelpMsg();
 466                         if ($msg2 !== false)
 467                                 $msg .= $msg2;
 468                         $msg .= "\n";
 469                 }
 470
 471                 $msg .= "\n*** Credits: ***\n   " . implode("\n   ", $this->getCredits()) . "\n";
 472
 473
 474                 return $msg;
 475         }
 476
 477         public static function makeHelpMsgHeader($module, $paramName) {
 478                 $modulePrefix = $module->getModulePrefix();
 479                 if (!empty($modulePrefix))
 480                         $modulePrefix = "($modulePrefix) ";
 481
 482                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 483         }
 484
 485         private $mIsBot = null;
 486         private $mIsSysop = null;
 487         private $mCanApiHighLimits = null;
 488
 489         /**
 490          * Returns true if the currently logged in user is a bot, false otherwise
 491          * OBSOLETE, use canApiHighLimits() instead
 492          */
 493         public function isBot() {
 494                 if (!isset ($this->mIsBot)) {
 495                         global $wgUser;
 496                         $this->mIsBot = $wgUser->isAllowed('bot');
 497                 }
 498                 return $this->mIsBot;
 499         }
 500
 501         /**
 502          * Similar to isBot(), this method returns true if the logged in user is
 503          * a sysop, and false if not.
 504          * OBSOLETE, use canApiHighLimits() instead
 505          */
 506         public function isSysop() {
 507                 if (!isset ($this->mIsSysop)) {
 508                         global $wgUser;
 509                         $this->mIsSysop = in_array( 'sysop', $wgUser->getGroups());
 510                 }
 511
 512                 return $this->mIsSysop;
 513         }
 514
 515         public function canApiHighLimits() {
 516                 if (!isset($this->mCanApiHighLimits)) {
 517                         global $wgUser;
 518                         $this->mCanApiHighLimits = $wgUser->isAllowed('apihighlimits');
 519                 }
 520
 521                 return $this->mCanApiHighLimits;
 522         }
 523
 524         public function getShowVersions() {
 525                 return $this->mShowVersions;
 526         }
 527
 528         /**
 529          * Returns the version information of this file, plus it includes
 530          * the versions for all files that are not callable proper API modules
 531          */
 532         public function getVersion() {
 533                 $vers = array ();
 534                 $vers[] = 'MediaWiki ' . SpecialVersion::getVersion();
 535                 $vers[] = __CLASS__ . ': $Id$';
 536                 $vers[] = ApiBase :: getBaseVersion();
 537                 $vers[] = ApiFormatBase :: getBaseVersion();
 538                 $vers[] = ApiQueryBase :: getBaseVersion();
 539                 $vers[] = ApiFormatFeedWrapper :: getVersion(); // not accessible with format=xxx
 540                 return $vers;
 541         }
 542
 543         /**
 544          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
 545          * classes who wish to add their own modules to their lexicon or override the
 546          * behavior of inherent ones.
 547          *
 548          * @access protected
 549          * @param $mdlName String The identifier for this module.
 550          * @param $mdlClass String The class where this module is implemented.
 551          */
 552         protected function addModule( $mdlName, $mdlClass ) {
 553                 $this->mModules[$mdlName] = $mdlClass;
 554         }
 555
 556         /**
 557          * Add or overwrite an output format for this ApiMain. Intended for use by extending
 558          * classes who wish to add to or modify current formatters.
 559          *
 560          * @access protected
 561          * @param $fmtName The identifier for this format.
 562          * @param $fmtClass The class implementing this format.
 563          */
 564         protected function addFormat( $fmtName, $fmtClass ) {
 565                 $this->mFormats[$fmtName] = $fmtClass;
 566         }
 567 }
 568
 569 /**
 570  * This exception will be thrown when dieUsage is called to stop module execution.
 571  * The exception handling code will print a help screen explaining how this API may be used.
 572  *
 573  * @addtogroup API
 574  */
 575 class UsageException extends Exception {
 576
 577         private $mCodestr;
 578
 579         public function __construct($message, $codestr, $code = 0) {
 580                 parent :: __construct($message, $code);
 581                 $this->mCodestr = $codestr;
 582         }
 583         public function getCodeString() {
 584                 return $this->mCodestr;
 585         }
 586         public function __toString() {
 587                 return "{$this->getCodeString()}: {$this->getMessage()}";
 588         }
 589 }
 590
 591