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