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