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