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