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                 'opensearch' => 'ApiOpenSearch',
  58                 'feedwatchlist' => 'ApiFeedWatchlist',
  59                 'help' => 'ApiHelp',
  60         );
  61
  62         /**
  63          * List of available formats: format name => format class
  64          */
  65         private static $Formats = array (
  66                 'json' => 'ApiFormatJson',
  67                 'jsonfm' => 'ApiFormatJson',
  68                 'php' => 'ApiFormatPhp',
  69                 'phpfm' => 'ApiFormatPhp',
  70                 'wddx' => 'ApiFormatWddx',
  71                 'wddxfm' => 'ApiFormatWddx',
  72                 'xml' => 'ApiFormatXml',
  73                 'xmlfm' => 'ApiFormatXml',
  74                 'yaml' => 'ApiFormatYaml',
  75                 'yamlfm' => 'ApiFormatYaml',
  76                 'rawfm' => 'ApiFormatJson'
  77         );
  78
  79         private $mPrinter, $mModules, $mModuleNames, $mFormats, $mFormatNames;
  80         private $mResult, $mAction, $mShowVersions, $mEnableWrite, $mRequest, $mInternalMode, $mSquidMaxage;
  81
  82         /**
  83         * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
  84         *
  85         * @param $request object - if this is an instance of FauxRequest, errors are thrown and no printing occurs
  86         * @param $enableWrite bool should be set to true if the api may modify data
  87         */
  88         public function __construct($request, $enableWrite = false) {
  89
  90                 $this->mInternalMode = ($request instanceof FauxRequest);
  91
  92                 // Special handling for the main module: $parent === $this
  93                 parent :: __construct($this, $this->mInternalMode ? 'main_int' : 'main');
  94
  95                 if (!$this->mInternalMode) {
  96
  97                         // Impose module restrictions.
  98                         // If the current user cannot read,
  99                         // Remove all modules other than login
 100                         global $wgUser;
 101                         if (!$wgUser->isAllowed('read')) {
 102                                 self::$Modules = array(
 103                                         'login' => self::$Modules['login'],
 104                                         'help' => self::$Modules['help']
 105                                         );
 106                         }
 107                 }
 108
 109                 $this->mModules = self :: $Modules;
 110                 $this->mModuleNames = array_keys($this->mModules); // todo: optimize
 111                 $this->mFormats = self :: $Formats;
 112                 $this->mFormatNames = array_keys($this->mFormats); // todo: optimize
 113
 114                 $this->mResult = new ApiResult($this);
 115                 $this->mShowVersions = false;
 116                 $this->mEnableWrite = $enableWrite;
 117
 118                 $this->mRequest = & $request;
 119
 120                 $this->mSquidMaxage = 0;
 121         }
 122
 123         /**
 124          * Return true if the API was started by other PHP code using FauxRequest
 125          */
 126         public function isInternalMode() {
 127                 return $this->mInternalMode;
 128         }
 129
 130         /**
 131          * Return the request object that contains client's request
 132          */
 133         public function getRequest() {
 134                 return $this->mRequest;
 135         }
 136
 137         /**
 138          * Get the ApiResult object asscosiated with current request
 139          */
 140         public function getResult() {
 141                 return $this->mResult;
 142         }
 143
 144         /**
 145          * This method will simply cause an error if the write mode was disabled for this api.
 146          */
 147         public function requestWriteMode() {
 148                 if (!$this->mEnableWrite)
 149                         $this->dieUsage('Editing of this site is disabled. Make sure the $wgEnableWriteAPI=true; ' .
 150                         'statement is included in the site\'s LocalSettings.php file', 'readonly');
 151         }
 152
 153         /**
 154          * Set how long the response should be cached.
 155          */
 156         public function setCacheMaxAge($maxage) {
 157                 $this->mSquidMaxage = $maxage;
 158         }
 159
 160         /**
 161          * Create an instance of an output formatter by its name
 162          */
 163         public function createPrinterByName($format) {
 164                 return new $this->mFormats[$format] ($this, $format);
 165         }
 166
 167         /**
 168          * Execute api request. Any errors will be handled if the API was called by the remote client.
 169          */
 170         public function execute() {
 171                 $this->profileIn();
 172                 if ($this->mInternalMode)
 173                         $this->executeAction();
 174                 else
 175                         $this->executeActionWithErrorHandling();
 176                 $this->profileOut();
 177         }
 178
 179         /**
 180          * Execute an action, and in case of an error, erase whatever partial results
 181          * have been accumulated, and replace it with an error message and a help screen.
 182          */
 183         protected function executeActionWithErrorHandling() {
 184
 185                 // In case an error occurs during data output,
 186                 // clear the output buffer and print just the error information
 187                 ob_start();
 188
 189                 try {
 190                         $this->executeAction();
 191                 } catch (Exception $e) {
 192                         //
 193                         // Handle any kind of exception by outputing properly formatted error message.
 194                         // If this fails, an unhandled exception should be thrown so that global error
 195                         // handler will process and log it.
 196                         //
 197
 198                         $errCode = $this->substituteResultWithError($e);
 199
 200                         // Error results should not be cached
 201                         $this->setCacheMaxAge(0);
 202
 203                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 204                         if ($e->getCode() === 0)
 205                                 header($headerStr, true);
 206                         else
 207                                 header($headerStr, true, $e->getCode());
 208
 209                         // Reset and print just the error message
 210                         ob_clean();
 211
 212                         // If the error occured during printing, do a printer->profileOut()
 213                         $this->mPrinter->safeProfileOut();
 214                         $this->printResult(true);
 215                 }
 216
 217                 // Set the cache expiration at the last moment, as any errors may change the expiration.
 218                 // if $this->mSquidMaxage == 0, the expiry time is set to the first second of unix epoch
 219                 $expires = $this->mSquidMaxage == 0 ? 1 : time() + $this->mSquidMaxage;
 220                 header('Expires: ' . wfTimestamp(TS_RFC2822, $expires));
 221                 header('Cache-Control: s-maxage=' . $this->mSquidMaxage . ', must-revalidate, max-age=0');
 222
 223                 if($this->mPrinter->getIsHtml())
 224                         echo wfReportTime();
 225
 226                 ob_end_flush();
 227         }
 228
 229         /**
 230          * Replace the result data with the information about an exception.
 231          * Returns the error code
 232          */
 233         protected function substituteResultWithError($e) {
 234
 235                         // Printer may not be initialized if the extractRequestParams() fails for the main module
 236                         if (!isset ($this->mPrinter)) {
 237                                 // The printer has not been created yet. Try to manually get formatter value.
 238                                 $value = $this->getRequest()->getVal('format', self::API_DEFAULT_FORMAT);
 239                                 if (!in_array($value, $this->mFormatNames))
 240                                         $value = self::API_DEFAULT_FORMAT;
 241
 242                                 $this->mPrinter = $this->createPrinterByName($value);
 243                                 if ($this->mPrinter->getNeedsRawData())
 244                                         $this->getResult()->setRawMode();
 245                         }
 246
 247                         if ($e instanceof UsageException) {
 248                                 //
 249                                 // User entered incorrect parameters - print usage screen
 250                                 //
 251                                 $errMessage = array (
 252                                 'code' => $e->getCodeString(),
 253                                 'info' => $e->getMessage());
 254
 255                                 // Only print the help message when this is for the developer, not runtime
 256                                 if ($this->mPrinter->getIsHtml() || $this->mAction == 'help')
 257                                         ApiResult :: setContent($errMessage, $this->makeHelpMsg());
 258
 259                         } else {
 260                                 //
 261                                 // Something is seriously wrong
 262                                 //
 263                                 $errMessage = array (
 264                                         'code' => 'internal_api_error',
 265                                         'info' => "Exception Caught: {$e->getMessage()}"
 266                                 );
 267                                 ApiResult :: setContent($errMessage, "\n\n{$e->getTraceAsString()}\n\n");
 268                         }
 269
 270                         $this->getResult()->reset();
 271                         $this->getResult()->addValue(null, 'error', $errMessage);
 272
 273                 return $errMessage['code'];
 274         }
 275
 276         /**
 277          * Execute the actual module, without any error handling
 278          */
 279         protected function executeAction() {
 280
 281                 $params = $this->extractRequestParams();
 282
 283                 $this->mShowVersions = $params['version'];
 284                 $this->mAction = $params['action'];
 285
 286                 // Instantiate the module requested by the user
 287                 $module = new $this->mModules[$this->mAction] ($this, $this->mAction);
 288
 289                 if (!$this->mInternalMode) {
 290
 291                         // See if custom printer is used
 292                         $this->mPrinter = $module->getCustomPrinter();
 293                         if (is_null($this->mPrinter)) {
 294                                 // Create an appropriate printer
 295                                 $this->mPrinter = $this->createPrinterByName($params['format']);
 296                         }
 297
 298                         if ($this->mPrinter->getNeedsRawData())
 299                                 $this->getResult()->setRawMode();
 300                 }
 301
 302                 // Execute
 303                 $module->profileIn();
 304                 $module->execute();
 305                 $module->profileOut();
 306
 307                 if (!$this->mInternalMode) {
 308                         // Print result data
 309                         $this->printResult(false);
 310                 }
 311         }
 312
 313         /**
 314          * Print results using the current printer
 315          */
 316         protected function printResult($isError) {
 317                 $printer = $this->mPrinter;
 318                 $printer->profileIn();
 319                 $printer->initPrinter($isError);
 320                 $printer->execute();
 321                 $printer->closePrinter();
 322                 $printer->profileOut();
 323         }
 324
 325         /**
 326          * See ApiBase for description.
 327          */
 328         protected function getAllowedParams() {
 329                 return array (
 330                         'format' => array (
 331                                 ApiBase :: PARAM_DFLT => ApiMain :: API_DEFAULT_FORMAT,
 332                                 ApiBase :: PARAM_TYPE => $this->mFormatNames
 333                         ),
 334                         'action' => array (
 335                                 ApiBase :: PARAM_DFLT => 'help',
 336                                 ApiBase :: PARAM_TYPE => $this->mModuleNames
 337                         ),
 338                         'version' => false
 339                 );
 340         }
 341
 342         /**
 343          * See ApiBase for description.
 344          */
 345         protected function getParamDescription() {
 346                 return array (
 347                         'format' => 'The format of the output',
 348                         'action' => 'What action you would like to perform',
 349                         'version' => 'When showing help, include version for each module'
 350                 );
 351         }
 352
 353         /**
 354          * See ApiBase for description.
 355          */
 356         protected function getDescription() {
 357                 return array (
 358                         '',
 359                         '',
 360                         '******************************************************************',
 361                         '**                                                              **',
 362                         '**  This is an auto-generated MediaWiki API documentation page  **',
 363                         '**                                                              **',
 364                         '**                  Documentation and Examples:                 **',
 365                         '**               http://www.mediawiki.org/wiki/API              **',
 366                         '**                                                              **',
 367                         '******************************************************************',
 368                         '',
 369                         'Status:          All features shown on this page should be working, but the API',
 370                         '                 is still in active development, and  may change at any time.',
 371                         '                 Make sure to monitor our mailing list for any updates.',
 372                         '',
 373                         'Documentation:   http://www.mediawiki.org/wiki/API',
 374                         'Mailing list:    http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 375                         'Bugs & Requests: http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 376                         '',
 377                         '',
 378                         '',
 379                         '',
 380                         '',
 381                 );
 382         }
 383
 384         /**
 385          * Returns an array of strings with credits for the API
 386          */
 387         protected function getCredits() {
 388                 return array(
 389                         'This API is being implemented by Yuri Astrakhan [[User:Yurik]] / <Firstname><Lastname>@gmail.com',
 390                         'Please leave your comments and suggestions at http://www.mediawiki.org/wiki/API'
 391                 );
 392         }
 393
 394         /**
 395          * Override the parent to generate help messages for all available modules.
 396          */
 397         public function makeHelpMsg() {
 398
 399                 // Use parent to make default message for the main module
 400                 $msg = parent :: makeHelpMsg();
 401
 402                 $astriks = str_repeat('*** ', 10);
 403                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 404                 foreach( $this->mModules as $moduleName => $unused ) {
 405                         $module = new $this->mModules[$moduleName] ($this, $moduleName);
 406                         $msg .= self::makeHelpMsgHeader($module, 'action');
 407                         $msg2 = $module->makeHelpMsg();
 408                         if ($msg2 !== false)
 409                                 $msg .= $msg2;
 410                         $msg .= "\n";
 411                 }
 412
 413                 $msg .= "\n$astriks Formats  $astriks\n\n";
 414                 foreach( $this->mFormats as $formatName => $unused ) {
 415                         $module = $this->createPrinterByName($formatName);
 416                         $msg .= self::makeHelpMsgHeader($module, 'format');
 417                         $msg2 = $module->makeHelpMsg();
 418                         if ($msg2 !== false)
 419                                 $msg .= $msg2;
 420                         $msg .= "\n";
 421                 }
 422
 423                 $msg .= "\n*** Credits: ***\n   " . implode("\n   ", $this->getCredits()) . "\n";
 424
 425
 426                 return $msg;
 427         }
 428
 429         public static function makeHelpMsgHeader($module, $paramName) {
 430                 $modulePrefix = $module->getModulePrefix();
 431                 if (!empty($modulePrefix))
 432                         $modulePrefix = "($modulePrefix) ";
 433
 434                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 435         }
 436
 437         private $mIsBot = null;
 438
 439         private $mIsSysop = null;
 440
 441         /**
 442          * Returns true if the currently logged in user is a bot, false otherwise
 443          */
 444         public function isBot() {
 445                 if (!isset ($this->mIsBot)) {
 446                         global $wgUser;
 447                         $this->mIsBot = $wgUser->isAllowed('bot');
 448                 }
 449                 return $this->mIsBot;
 450         }
 451
 452         /**
 453          * Similar to isBot(), this method returns true if the logged in user is
 454          * a sysop, and false if not.
 455          */
 456         public function isSysop() {
 457                 if (!isset ($this->mIsSysop)) {
 458                         global $wgUser;
 459                         $this->mIsSysop = in_array( 'sysop', $wgUser->getGroups());
 460                 }
 461
 462                 return $this->mIsSysop;
 463         }
 464
 465         public function getShowVersions() {
 466                 return $this->mShowVersions;
 467         }
 468
 469         /**
 470          * Returns the version information of this file, plus it includes
 471          * the versions for all files that are not callable proper API modules
 472          */
 473         public function getVersion() {
 474                 $vers = array ();
 475                 $vers[] = 'MediaWiki ' . SpecialVersion::getVersion();
 476                 $vers[] = __CLASS__ . ': $Id$';
 477                 $vers[] = ApiBase :: getBaseVersion();
 478                 $vers[] = ApiFormatBase :: getBaseVersion();
 479                 $vers[] = ApiQueryBase :: getBaseVersion();
 480                 $vers[] = ApiFormatFeedWrapper :: getVersion(); // not accessible with format=xxx
 481                 return $vers;
 482         }
 483
 484         /**
 485          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
 486          * classes who wish to add their own modules to their lexicon or override the
 487          * behavior of inherent ones.
 488          *
 489          * @access protected
 490          * @param $mdlName String The identifier for this module.
 491          * @param $mdlClass String The class where this module is implemented.
 492          */
 493         protected function addModule( $mdlName, $mdlClass ) {
 494                 $this->mModules[$mdlName] = $mdlClass;
 495         }
 496
 497         /**
 498          * Add or overwrite an output format for this ApiMain. Intended for use by extending
 499          * classes who wish to add to or modify current formatters.
 500          *
 501          * @access protected
 502          * @param $fmtName The identifier for this format.
 503          * @param $fmtClass The class implementing this format.
 504          */
 505         protected function addFormat( $fmtName, $fmtClass ) {
 506                 $this->mFormats[$fmtName] = $fmtClass;
 507         }
 508 }
 509
 510 /**
 511  * This exception will be thrown when dieUsage is called to stop module execution.
 512  * The exception handling code will print a help screen explaining how this API may be used.
 513  *
 514  * @addtogroup API
 515  */
 516 class UsageException extends Exception {
 517
 518         private $mCodestr;
 519
 520         public function __construct($message, $codestr, $code = 0) {
 521                 parent :: __construct($message, $code);
 522                 $this->mCodestr = $codestr;
 523         }
 524         public function getCodeString() {
 525                 return $this->mCodestr;
 526         }
 527         public function __toString() {
 528                 return "{$this->getCodeString()}: {$this->getMessage()}";
 529         }
 530 }
 531