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