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