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  * @defgroup API API
  33  */
  34
  35 /**
  36  * This is the main API class, used for both external and internal processing.
  37  * When executed, it will create the requested formatter object,
  38  * instantiate and execute an object associated with the needed action,
  39  * and use formatter to print results.
  40  * In case of an exception, an error message will be printed using the same formatter.
  41  *
  42  * To use API from another application, run it using FauxRequest object, in which
  43  * case any internal exceptions will not be handled but passed up to the caller.
  44  * After successful execution, use getResult() for the resulting data.
  45  *
  46  * @ingroup API
  47  */
  48 class ApiMain extends ApiBase {
  49
  50         /**
  51          * When no format parameter is given, this format will be used
  52          */
  53         const API_DEFAULT_FORMAT = 'xmlfm';
  54
  55         /**
  56          * List of available modules: action name => module class
  57          */
  58         private static $Modules = array (
  59                 'login' => 'ApiLogin',
  60                 'logout' => 'ApiLogout',
  61                 'query' => 'ApiQuery',
  62                 'expandtemplates' => 'ApiExpandTemplates',
  63                 'parse' => 'ApiParse',
  64                 'opensearch' => 'ApiOpenSearch',
  65                 'feedwatchlist' => 'ApiFeedWatchlist',
  66                 'help' => 'ApiHelp',
  67                 'paraminfo' => 'ApiParamInfo',
  68         );
  69
  70         private static $WriteModules = array (
  71                 'rollback' => 'ApiRollback',
  72                 'delete' => 'ApiDelete',
  73                 'undelete' => 'ApiUndelete',
  74                 'protect' => 'ApiProtect',
  75                 'block' => 'ApiBlock',
  76                 'unblock' => 'ApiUnblock',
  77                 'move' => 'ApiMove',
  78                 'edit' => 'ApiEditPage',
  79         );
  80
  81         /**
  82          * List of available formats: format name => format class
  83          */
  84         private static $Formats = array (
  85                 'json' => 'ApiFormatJson',
  86                 'jsonfm' => 'ApiFormatJson',
  87                 'php' => 'ApiFormatPhp',
  88                 'phpfm' => 'ApiFormatPhp',
  89                 'wddx' => 'ApiFormatWddx',
  90                 'wddxfm' => 'ApiFormatWddx',
  91                 'xml' => 'ApiFormatXml',
  92                 'xmlfm' => 'ApiFormatXml',
  93                 'yaml' => 'ApiFormatYaml',
  94                 'yamlfm' => 'ApiFormatYaml',
  95                 'rawfm' => 'ApiFormatJson',
  96                 'txt' => 'ApiFormatTxt',
  97                 'txtfm' => 'ApiFormatTxt',
  98                 'dbg' => 'ApiFormatDbg',
  99                 'dbgfm' => 'ApiFormatDbg'
 100         );
 101
 102         private $mPrinter, $mModules, $mModuleNames, $mFormats, $mFormatNames;
 103         private $mResult, $mAction, $mShowVersions, $mEnableWrite, $mRequest, $mInternalMode, $mSquidMaxage;
 104
 105         /**
 106         * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 107         *
 108         * @param $request object - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 109         * @param $enableWrite bool should be set to true if the api may modify data
 110         */
 111         public function __construct($request, $enableWrite = false) {
 112
 113                 $this->mInternalMode = ($request instanceof FauxRequest);
 114
 115                 // Special handling for the main module: $parent === $this
 116                 parent :: __construct($this, $this->mInternalMode ? 'main_int' : 'main');
 117
 118                 if (!$this->mInternalMode) {
 119
 120                         // Impose module restrictions.
 121                         // If the current user cannot read,
 122                         // Remove all modules other than login
 123                         global $wgUser;
 124
 125                         if( $request->getVal( 'callback' ) !== null ) {
 126                                 // JSON callback allows cross-site reads.
 127                                 // For safety, strip user credentials.
 128                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 129                                 $wgUser = new User();
 130                         }
 131
 132                         if (!$wgUser->isAllowed('read')) {
 133                                 self::$Modules = array(
 134                                         'login'  => self::$Modules['login'],
 135                                         'logout' => self::$Modules['logout'],
 136                                         'help'   => self::$Modules['help'],
 137                                         );
 138                         }
 139                 }
 140
 141                 global $wgAPIModules, $wgEnableWriteAPI; // extension modules
 142                 $this->mModules = $wgAPIModules + self :: $Modules;
 143                 if($wgEnableWriteAPI)
 144                         $this->mModules += self::$WriteModules;
 145
 146                 $this->mModuleNames = array_keys($this->mModules); // todo: optimize
 147                 $this->mFormats = self :: $Formats;
 148                 $this->mFormatNames = array_keys($this->mFormats); // todo: optimize
 149
 150                 $this->mResult = new ApiResult($this);
 151                 $this->mShowVersions = false;
 152                 $this->mEnableWrite = $enableWrite;
 153
 154                 $this->mRequest = & $request;
 155
 156                 $this->mSquidMaxage = 0;
 157                 $this->mCommit = false;
 158         }
 159
 160         /**
 161          * Return true if the API was started by other PHP code using FauxRequest
 162          */
 163         public function isInternalMode() {
 164                 return $this->mInternalMode;
 165         }
 166
 167         /**
 168          * Return the request object that contains client's request
 169          */
 170         public function getRequest() {
 171                 return $this->mRequest;
 172         }
 173
 174         /**
 175          * Get the ApiResult object asscosiated with current request
 176          */
 177         public function getResult() {
 178                 return $this->mResult;
 179         }
 180
 181         /**
 182          * This method will simply cause an error if the write mode was disabled for this api.
 183          */
 184         public function requestWriteMode() {
 185                 if (!$this->mEnableWrite)
 186                         $this->dieUsage('Editing of this site is disabled. Make sure the $wgEnableWriteAPI=true; ' .
 187                         'statement is included in the site\'s LocalSettings.php file', 'noapiwrite');
 188         }
 189
 190         /**
 191          * Set how long the response should be cached.
 192          */
 193         public function setCacheMaxAge($maxage) {
 194                 $this->mSquidMaxage = $maxage;
 195         }
 196
 197         /**
 198          * Create an instance of an output formatter by its name
 199          */
 200         public function createPrinterByName($format) {
 201                 return new $this->mFormats[$format] ($this, $format);
 202         }
 203
 204         /**
 205          * Execute api request. Any errors will be handled if the API was called by the remote client.
 206          */
 207         public function execute() {
 208                 $this->profileIn();
 209                 if ($this->mInternalMode)
 210                         $this->executeAction();
 211                 else
 212                         $this->executeActionWithErrorHandling();
 213
 214                 $this->profileOut();
 215         }
 216
 217         /**
 218          * Execute an action, and in case of an error, erase whatever partial results
 219          * have been accumulated, and replace it with an error message and a help screen.
 220          */
 221         protected function executeActionWithErrorHandling() {
 222
 223                 // In case an error occurs during data output,
 224                 // clear the output buffer and print just the error information
 225                 ob_start();
 226
 227                 try {
 228                         $this->executeAction();
 229                 } catch (Exception $e) {
 230                         //
 231                         // Handle any kind of exception by outputing properly formatted error message.
 232                         // If this fails, an unhandled exception should be thrown so that global error
 233                         // handler will process and log it.
 234                         //
 235
 236                         $errCode = $this->substituteResultWithError($e);
 237
 238                         // Error results should not be cached
 239                         $this->setCacheMaxAge(0);
 240
 241                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 242                         if ($e->getCode() === 0)
 243                                 header($headerStr, true);
 244                         else
 245                                 header($headerStr, true, $e->getCode());
 246
 247                         // Reset and print just the error message
 248                         ob_clean();
 249
 250                         // If the error occured during printing, do a printer->profileOut()
 251                         $this->mPrinter->safeProfileOut();
 252                         $this->printResult(true);
 253                 }
 254
 255                 // Set the cache expiration at the last moment, as any errors may change the expiration.
 256                 // if $this->mSquidMaxage == 0, the expiry time is set to the first second of unix epoch
 257                 $expires = $this->mSquidMaxage == 0 ? 1 : time() + $this->mSquidMaxage;
 258                 header('Expires: ' . wfTimestamp(TS_RFC2822, $expires));
 259                 header('Cache-Control: s-maxage=' . $this->mSquidMaxage . ', must-revalidate, max-age=0');
 260
 261                 if($this->mPrinter->getIsHtml())
 262                         echo wfReportTime();
 263
 264                 ob_end_flush();
 265         }
 266
 267         /**
 268          * Replace the result data with the information about an exception.
 269          * Returns the error code
 270          */
 271         protected function substituteResultWithError($e) {
 272
 273                         // Printer may not be initialized if the extractRequestParams() fails for the main module
 274                         if (!isset ($this->mPrinter)) {
 275                                 // The printer has not been created yet. Try to manually get formatter value.
 276                                 $value = $this->getRequest()->getVal('format', self::API_DEFAULT_FORMAT);
 277                                 if (!in_array($value, $this->mFormatNames))
 278                                         $value = self::API_DEFAULT_FORMAT;
 279
 280                                 $this->mPrinter = $this->createPrinterByName($value);
 281                                 if ($this->mPrinter->getNeedsRawData())
 282                                         $this->getResult()->setRawMode();
 283                         }
 284
 285                         if ($e instanceof UsageException) {
 286                                 //
 287                                 // User entered incorrect parameters - print usage screen
 288                                 //
 289                                 $errMessage = array (
 290                                 'code' => $e->getCodeString(),
 291                                 'info' => $e->getMessage());
 292
 293                                 // Only print the help message when this is for the developer, not runtime
 294                                 if ($this->mPrinter->getIsHtml() || $this->mAction == 'help')
 295                                         ApiResult :: setContent($errMessage, $this->makeHelpMsg());
 296
 297                         } else {
 298                                 //
 299                                 // Something is seriously wrong
 300                                 //
 301                                 $errMessage = array (
 302                                         'code' => 'internal_api_error_'. get_class($e),
 303                                         'info' => "Exception Caught: {$e->getMessage()}"
 304                                 );
 305                                 ApiResult :: setContent($errMessage, "\n\n{$e->getTraceAsString()}\n\n");
 306                         }
 307
 308                         $this->getResult()->reset();
 309                         $this->getResult()->addValue(null, 'error', $errMessage);
 310
 311                 return $errMessage['code'];
 312         }
 313
 314         /**
 315          * Execute the actual module, without any error handling
 316          */
 317         protected function executeAction() {
 318
 319                 $params = $this->extractRequestParams();
 320
 321                 $this->mShowVersions = $params['version'];
 322                 $this->mAction = $params['action'];
 323
 324                 // Instantiate the module requested by the user
 325                 $module = new $this->mModules[$this->mAction] ($this, $this->mAction);
 326
 327                 if( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 328                         // Check for maxlag
 329                         global $wgShowHostnames;
 330                         $maxLag = $params['maxlag'];
 331                         list( $host, $lag ) = wfGetLB()->getMaxLag();
 332                         if ( $lag > $maxLag ) {
 333                                 if( $wgShowHostnames ) {
 334                                         ApiBase :: dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 335                                 } else {
 336                                         ApiBase :: dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 337                                 }
 338                                 return;
 339                         }
 340                 }
 341
 342                 if (!$this->mInternalMode) {
 343                         // Ignore mustBePosted() for internal calls
 344                         if($module->mustBePosted() && !$this->mRequest->wasPosted())
 345                                 $this->dieUsage("The {$this->mAction} module requires a POST request", 'mustbeposted');
 346
 347                         // See if custom printer is used
 348                         $this->mPrinter = $module->getCustomPrinter();
 349                         if (is_null($this->mPrinter)) {
 350                                 // Create an appropriate printer
 351                                 $this->mPrinter = $this->createPrinterByName($params['format']);
 352                         }
 353
 354                         if ($this->mPrinter->getNeedsRawData())
 355                                 $this->getResult()->setRawMode();
 356                 }
 357
 358                 // Execute
 359                 $module->profileIn();
 360                 $module->execute();
 361                 $module->profileOut();
 362
 363                 if (!$this->mInternalMode) {
 364                         // Print result data
 365                         $this->printResult(false);
 366                 }
 367         }
 368
 369         /**
 370          * Print results using the current printer
 371          */
 372         protected function printResult($isError) {
 373                 $printer = $this->mPrinter;
 374                 $printer->profileIn();
 375
 376                 /* If the help message is requested in the default (xmlfm) format,
 377                  * tell the printer not to escape ampersands so that our links do
 378                  * not break. */
 379                 $printer->setUnescapeAmps ( ( $this->mAction == 'help' || $isError )
 380                                 && $this->getParameter('format') == ApiMain::API_DEFAULT_FORMAT );
 381
 382                 $printer->initPrinter($isError);
 383
 384                 $printer->execute();
 385                 $printer->closePrinter();
 386                 $printer->profileOut();
 387         }
 388
 389         /**
 390          * See ApiBase for description.
 391          */
 392         public function getAllowedParams() {
 393                 return array (
 394                         'format' => array (
 395                                 ApiBase :: PARAM_DFLT => ApiMain :: API_DEFAULT_FORMAT,
 396                                 ApiBase :: PARAM_TYPE => $this->mFormatNames
 397                         ),
 398                         'action' => array (
 399                                 ApiBase :: PARAM_DFLT => 'help',
 400                                 ApiBase :: PARAM_TYPE => $this->mModuleNames
 401                         ),
 402                         'version' => false,
 403                         'maxlag'  => array (
 404                                 ApiBase :: PARAM_TYPE => 'integer'
 405                         ),
 406                 );
 407         }
 408
 409         /**
 410          * See ApiBase for description.
 411          */
 412         public function getParamDescription() {
 413                 return array (
 414                         'format' => 'The format of the output',
 415                         'action' => 'What action you would like to perform',
 416                         'version' => 'When showing help, include version for each module',
 417                         'maxlag' => 'Maximum lag'
 418                 );
 419         }
 420
 421         /**
 422          * See ApiBase for description.
 423          */
 424         public function getDescription() {
 425                 return array (
 426                         '',
 427                         '',
 428                         '******************************************************************',
 429                         '**                                                              **',
 430                         '**  This is an auto-generated MediaWiki API documentation page  **',
 431                         '**                                                              **',
 432                         '**                  Documentation and Examples:                 **',
 433                         '**               http://www.mediawiki.org/wiki/API              **',
 434                         '**                                                              **',
 435                         '******************************************************************',
 436                         '',
 437                         'Status:          All features shown on this page should be working, but the API',
 438                         '                 is still in active development, and  may change at any time.',
 439                         '                 Make sure to monitor our mailing list for any updates.',
 440                         '',
 441                         'Documentation:   http://www.mediawiki.org/wiki/API',
 442                         'Mailing list:    http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 443                         'Bugs & Requests: http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 444                         '',
 445                         '',
 446                         '',
 447                         '',
 448                         '',
 449                 );
 450         }
 451
 452         /**
 453          * Returns an array of strings with credits for the API
 454          */
 455         protected function getCredits() {
 456                 return array(
 457                         'API developers:',
 458                         '    Roan Kattouw <Firstname>.<Lastname>@home.nl (lead developer Sep 2007-present)',
 459                         '    Victor Vasiliev - vasilvv at gee mail dot com',
 460                         '    Yuri Astrakhan <Firstname><Lastname>@gmail.com (creator, lead developer Sep 2006-Sep 2007)',
 461                         '',
 462                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 463                         'or file a bug report at http://bugzilla.wikimedia.org/'
 464                 );
 465         }
 466
 467         /**
 468          * Override the parent to generate help messages for all available modules.
 469          */
 470         public function makeHelpMsg() {
 471
 472                 $this->mPrinter->setHelp();
 473
 474                 // Use parent to make default message for the main module
 475                 $msg = parent :: makeHelpMsg();
 476
 477                 $astriks = str_repeat('*** ', 10);
 478                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 479                 foreach( $this->mModules as $moduleName => $unused ) {
 480                         $module = new $this->mModules[$moduleName] ($this, $moduleName);
 481                         $msg .= self::makeHelpMsgHeader($module, 'action');
 482                         $msg2 = $module->makeHelpMsg();
 483                         if ($msg2 !== false)
 484                                 $msg .= $msg2;
 485                         $msg .= "\n";
 486                 }
 487
 488                 $msg .= "\n$astriks Formats  $astriks\n\n";
 489                 foreach( $this->mFormats as $formatName => $unused ) {
 490                         $module = $this->createPrinterByName($formatName);
 491                         $msg .= self::makeHelpMsgHeader($module, 'format');
 492                         $msg2 = $module->makeHelpMsg();
 493                         if ($msg2 !== false)
 494                                 $msg .= $msg2;
 495                         $msg .= "\n";
 496                 }
 497
 498                 $msg .= "\n*** Credits: ***\n   " . implode("\n   ", $this->getCredits()) . "\n";
 499
 500
 501                 return $msg;
 502         }
 503
 504         public static function makeHelpMsgHeader($module, $paramName) {
 505                 $modulePrefix = $module->getModulePrefix();
 506                 if (!empty($modulePrefix))
 507                         $modulePrefix = "($modulePrefix) ";
 508
 509                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 510         }
 511
 512         private $mIsBot = null;
 513         private $mIsSysop = null;
 514         private $mCanApiHighLimits = null;
 515
 516         /**
 517          * Returns true if the currently logged in user is a bot, false otherwise
 518          * OBSOLETE, use canApiHighLimits() instead
 519          */
 520         public function isBot() {
 521                 if (!isset ($this->mIsBot)) {
 522                         global $wgUser;
 523                         $this->mIsBot = $wgUser->isAllowed('bot');
 524                 }
 525                 return $this->mIsBot;
 526         }
 527
 528         /**
 529          * Similar to isBot(), this method returns true if the logged in user is
 530          * a sysop, and false if not.
 531          * OBSOLETE, use canApiHighLimits() instead
 532          */
 533         public function isSysop() {
 534                 if (!isset ($this->mIsSysop)) {
 535                         global $wgUser;
 536                         $this->mIsSysop = in_array( 'sysop', $wgUser->getGroups());
 537                 }
 538
 539                 return $this->mIsSysop;
 540         }
 541
 542         /**
 543          * Check whether the current user is allowed to use high limits
 544          * @return bool
 545          */
 546         public function canApiHighLimits() {
 547                 if (!isset($this->mCanApiHighLimits)) {
 548                         global $wgUser;
 549                         $this->mCanApiHighLimits = $wgUser->isAllowed('apihighlimits');
 550                 }
 551
 552                 return $this->mCanApiHighLimits;
 553         }
 554
 555         /**
 556          * Check whether the user wants us to show version information in the API help
 557          * @return bool
 558          */
 559         public function getShowVersions() {
 560                 return $this->mShowVersions;
 561         }
 562
 563         /**
 564          * Returns the version information of this file, plus it includes
 565          * the versions for all files that are not callable proper API modules
 566          */
 567         public function getVersion() {
 568                 $vers = array ();
 569                 $vers[] = 'MediaWiki ' . SpecialVersion::getVersion();
 570                 $vers[] = __CLASS__ . ': $Id$';
 571                 $vers[] = ApiBase :: getBaseVersion();
 572                 $vers[] = ApiFormatBase :: getBaseVersion();
 573                 $vers[] = ApiQueryBase :: getBaseVersion();
 574                 $vers[] = ApiFormatFeedWrapper :: getVersion(); // not accessible with format=xxx
 575                 return $vers;
 576         }
 577
 578         /**
 579          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
 580          * classes who wish to add their own modules to their lexicon or override the
 581          * behavior of inherent ones.
 582          *
 583          * @access protected
 584          * @param $mdlName String The identifier for this module.
 585          * @param $mdlClass String The class where this module is implemented.
 586          */
 587         protected function addModule( $mdlName, $mdlClass ) {
 588                 $this->mModules[$mdlName] = $mdlClass;
 589         }
 590
 591         /**
 592          * Add or overwrite an output format for this ApiMain. Intended for use by extending
 593          * classes who wish to add to or modify current formatters.
 594          *
 595          * @access protected
 596          * @param $fmtName The identifier for this format.
 597          * @param $fmtClass The class implementing this format.
 598          */
 599         protected function addFormat( $fmtName, $fmtClass ) {
 600                 $this->mFormats[$fmtName] = $fmtClass;
 601         }
 602
 603         /**
 604          * Get the array mapping module names to class names
 605          */
 606         function getModules() {
 607                 return $this->mModules;
 608         }
 609 }
 610
 611 /**
 612  * This exception will be thrown when dieUsage is called to stop module execution.
 613  * The exception handling code will print a help screen explaining how this API may be used.
 614  *
 615  * @ingroup API
 616  */
 617 class UsageException extends Exception {
 618
 619         private $mCodestr;
 620
 621         public function __construct($message, $codestr, $code = 0) {
 622                 parent :: __construct($message, $code);
 623                 $this->mCodestr = $codestr;
 624         }
 625         public function getCodeString() {
 626                 return $this->mCodestr;
 627         }
 628         public function __toString() {
 629                 return "{$this->getCodeString()}: {$this->getMessage()}";
 630         }
 631 }