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