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',          // LOGIN is temporarily disabled until it becomes more secure
  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, $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                 $this->mModules = self :: $Modules;
  96                 $this->mModuleNames = array_keys($this->mModules); // todo: optimize
  97                 $this->mFormats = self :: $Formats;
  98                 $this->mFormatNames = array_keys($this->mFormats); // todo: optimize
  99
 100                 $this->mResult = new ApiResult($this);
 101                 $this->mShowVersions = false;
 102                 $this->mEnableWrite = $enableWrite;
 103
 104                 $this->mRequest = & $request;
 105
 106                 $this->mSquidMaxage = 0;
 107         }
 108
 109         /**
 110          * Return the request object that contains client's request
 111          */
 112         public function getRequest() {
 113                 return $this->mRequest;
 114         }
 115
 116         /**
 117          * Get the ApiResult object asscosiated with current request
 118          */
 119         public function getResult() {
 120                 return $this->mResult;
 121         }
 122
 123         /**
 124          * This method will simply cause an error if the write mode was disabled for this api.
 125          */
 126         public function requestWriteMode() {
 127                 if (!$this->mEnableWrite)
 128                         $this->dieUsage('Editing of this site is disabled. Make sure the $wgEnableWriteAPI=true; ' .
 129                         'statement is included in the site\'s LocalSettings.php file', 'readonly');
 130         }
 131
 132         /**
 133          * Set how long the response should be cached.
 134          */
 135         public function setCacheMaxAge($maxage) {
 136                 $this->mSquidMaxage = $maxage;
 137         }
 138
 139         /**
 140          * Create an instance of an output formatter by its name
 141          */
 142         public function createPrinterByName($format) {
 143                 return new $this->mFormats[$format] ($this, $format);
 144         }
 145
 146         /**
 147          * Execute api request. Any errors will be handled if the API was called by the remote client.
 148          */
 149         public function execute() {
 150                 $this->profileIn();
 151                 if ($this->mInternalMode)
 152                         $this->executeAction();
 153                 else
 154                         $this->executeActionWithErrorHandling();
 155                 $this->profileOut();
 156         }
 157
 158         /**
 159          * Execute an action, and in case of an error, erase whatever partial results
 160          * have been accumulated, and replace it with an error message and a help screen.
 161          */
 162         protected function executeActionWithErrorHandling() {
 163
 164                 // In case an error occurs during data output,
 165                 // clear the output buffer and print just the error information
 166                 ob_start();
 167
 168                 try {
 169                         $this->executeAction();
 170                 } catch (Exception $e) {
 171                         //
 172                         // Handle any kind of exception by outputing properly formatted error message.
 173                         // If this fails, an unhandled exception should be thrown so that global error
 174                         // handler will process and log it.
 175                         //
 176
 177                         // Error results should not be cached
 178                         $this->setCacheMaxAge(0);
 179
 180                         // Printer may not be initialized if the extractRequestParams() fails for the main module
 181                         if (!isset ($this->mPrinter)) {
 182                                 $this->mPrinter = $this->createPrinterByName(self :: API_DEFAULT_FORMAT);
 183                                 if ($this->mPrinter->getNeedsRawData())
 184                                         $this->getResult()->setRawMode();
 185                         }
 186
 187                         if ($e instanceof UsageException) {
 188                                 //
 189                                 // User entered incorrect parameters - print usage screen
 190                                 //
 191                                 $errMessage = array (
 192                                 'code' => $e->getCodeString(), 'info' => $e->getMessage());
 193                                 ApiResult :: setContent($errMessage, $this->makeHelpMsg());
 194
 195                         } else {
 196                                 //
 197                                 // Something is seriously wrong
 198                                 //
 199                                 $errMessage = array (
 200                                         'code' => 'internal_api_error',
 201                                         'info' => "Exception Caught: {$e->getMessage()}"
 202                                 );
 203                                 ApiResult :: setContent($errMessage, "\n\n{$e->getTraceAsString()}\n\n");
 204                         }
 205
 206                         $headerStr = 'MediaWiki-API-Error: ' . $errMessage['code'];
 207                         if ($e->getCode() === 0)
 208                                 header($headerStr, true);
 209                         else
 210                                 header($headerStr, true, $e->getCode());
 211
 212                         // Reset and print just the error message
 213                         ob_clean();
 214                         $this->getResult()->reset();
 215                         $this->getResult()->addValue(null, 'error', $errMessage);
 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          * Execute the actual module, without any error handling
 236          */
 237         protected function executeAction() {
 238                 $action = $format = $version = null;
 239                 extract($this->extractRequestParams());
 240                 $this->mShowVersions = $version;
 241
 242                 // Instantiate the module requested by the user
 243                 $module = new $this->mModules[$action] ($this, $action);
 244
 245                 if (!$this->mInternalMode) {
 246
 247                         // See if custom printer is used
 248                         $this->mPrinter = $module->getCustomPrinter();
 249                         if (is_null($this->mPrinter)) {
 250                                 // Create an appropriate printer
 251                                 $this->mPrinter = $this->createPrinterByName($format);
 252                         }
 253
 254                         if ($this->mPrinter->getNeedsRawData())
 255                                 $this->getResult()->setRawMode();
 256                 }
 257
 258                 // Execute
 259                 $module->profileIn();
 260                 $module->execute();
 261                 $module->profileOut();
 262
 263                 if (!$this->mInternalMode) {
 264                         // Print result data
 265                         $this->printResult(false);
 266                 }
 267         }
 268
 269         /**
 270          * Print results using the current printer
 271          */
 272         protected function printResult($isError) {
 273                 $printer = $this->mPrinter;
 274                 $printer->profileIn();
 275                 $printer->initPrinter($isError);
 276                 $printer->execute();
 277                 $printer->closePrinter();
 278                 $printer->profileOut();
 279         }
 280
 281         /**
 282          * See ApiBase for description.
 283          */
 284         protected function getAllowedParams() {
 285                 return array (
 286                         'format' => array (
 287                                 ApiBase :: PARAM_DFLT => ApiMain :: API_DEFAULT_FORMAT,
 288                                 ApiBase :: PARAM_TYPE => $this->mFormatNames
 289                         ),
 290                         'action' => array (
 291                                 ApiBase :: PARAM_DFLT => 'help',
 292                                 ApiBase :: PARAM_TYPE => $this->mModuleNames
 293                         ),
 294                         'version' => false
 295                 );
 296         }
 297
 298         /**
 299          * See ApiBase for description.
 300          */
 301         protected function getParamDescription() {
 302                 return array (
 303                         'format' => 'The format of the output',
 304                         'action' => 'What action you would like to perform',
 305                         'version' => 'When showing help, include version for each module'
 306                 );
 307         }
 308
 309         /**
 310          * See ApiBase for description.
 311          */
 312         protected function getDescription() {
 313                 return array (
 314                         '',
 315                         'This API allows programs to access various functions of MediaWiki software.',
 316                         'For more details see API Home Page @ http://www.mediawiki.org/wiki/API',
 317                         '',
 318                         'Status: ALPHA -- all features shown on this page should be working,',
 319                         '                 but the API is still in active development, and  may change at any time.',
 320                         '                 Make sure you monitor changes to this page, wikitech-l mailing list,',
 321                         '                 or the source code in the includes/api directory for any changes.',
 322                         ''
 323                 );
 324         }
 325
 326         /**
 327          * Returns an array of strings with credits for the API
 328          */
 329         protected function getCredits() {
 330                 return array(
 331                         'This API is being implemented by Yuri Astrakhan [[User:Yurik]] / <Firstname><Lastname>@gmail.com',
 332                         'Please leave your comments and suggestions at http://www.mediawiki.org/wiki/API'
 333                 );
 334         }
 335
 336         /**
 337          * Override the parent to generate help messages for all available modules.
 338          */
 339         public function makeHelpMsg() {
 340
 341                 // Use parent to make default message for the main module
 342                 $msg = parent :: makeHelpMsg();
 343
 344                 $astriks = str_repeat('*** ', 10);
 345                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 346                 foreach( $this->mModules as $moduleName => $unused ) {
 347                         $module = new $this->mModules[$moduleName] ($this, $moduleName);
 348                         $msg .= self::makeHelpMsgHeader($module, 'action');
 349                         $msg2 = $module->makeHelpMsg();
 350                         if ($msg2 !== false)
 351                                 $msg .= $msg2;
 352                         $msg .= "\n";
 353                 }
 354
 355                 $msg .= "\n$astriks Formats  $astriks\n\n";
 356                 foreach( $this->mFormats as $formatName => $unused ) {
 357                         $module = $this->createPrinterByName($formatName);
 358                         $msg .= self::makeHelpMsgHeader($module, 'format');
 359                         $msg2 = $module->makeHelpMsg();
 360                         if ($msg2 !== false)
 361                                 $msg .= $msg2;
 362                         $msg .= "\n";
 363                 }
 364
 365                 $msg .= "\n*** Credits: ***\n   " . implode("\n   ", $this->getCredits()) . "\n";
 366
 367
 368                 return $msg;
 369         }
 370
 371         public static function makeHelpMsgHeader($module, $paramName) {
 372                 $paramPrefix = $module->getParamPrefix();
 373                 if (!empty($paramPrefix))
 374                         $paramPrefix = "($paramPrefix) ";
 375
 376                 return "* $paramName={$module->getModuleName()} $paramPrefix*";
 377         }
 378
 379         private $mIsBot = null;
 380
 381         private $mIsSysop = null;
 382
 383         /**
 384          * Returns true if the currently logged in user is a bot, false otherwise
 385          */
 386         public function isBot() {
 387                 if (!isset ($this->mIsBot)) {
 388                         global $wgUser;
 389                         $this->mIsBot = $wgUser->isAllowed('bot');
 390                 }
 391                 return $this->mIsBot;
 392         }
 393
 394         /**
 395          * Similar to isBot(), this method returns true if the logged in user is
 396          * a sysop, and false if not.
 397          */
 398         public function isSysop() {
 399                 if (!isset ($this->mIsSysop)) {
 400                         global $wgUser;
 401                         $this->mIsSysop = in_array( 'sysop',
 402                                 $wgUser->getGroups());
 403                 }
 404
 405                 return $this->mIsSysop;
 406         }
 407
 408         public function getShowVersions() {
 409                 return $this->mShowVersions;
 410         }
 411
 412         /**
 413          * Returns the version information of this file, plus it includes
 414          * the versions for all files that are not callable proper API modules
 415          */
 416         public function getVersion() {
 417                 $vers = array ();
 418                 $vers[] = __CLASS__ . ': $Id$';
 419                 $vers[] = ApiBase :: getBaseVersion();
 420                 $vers[] = ApiFormatBase :: getBaseVersion();
 421                 $vers[] = ApiQueryBase :: getBaseVersion();
 422                 $vers[] = ApiFormatFeedWrapper :: getVersion(); // not accessible with format=xxx
 423                 return $vers;
 424         }
 425 }
 426
 427 /**
 428  * This exception will be thrown when dieUsage is called to stop module execution.
 429  * The exception handling code will print a help screen explaining how this API may be used.
 430  *
 431  * @addtogroup API
 432  */
 433 class UsageException extends Exception {
 434
 435         private $mCodestr;
 436
 437         public function __construct($message, $codestr, $code = 0) {
 438                 parent :: __construct($message, $code);
 439                 $this->mCodestr = $codestr;
 440         }
 441         public function getCodeString() {
 442                 return $this->mCodestr;
 443         }
 444         public function __toString() {
 445                 return "{$this->getCodeString()}: {$this->getMessage()}";
 446         }
 447 }
 448 ?>