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         * Constructor
  84         * @param $request object - if this is an instance of FauxRequest, errors are thrown and no printing occurs
  85         * @param $enableWrite bool should be set to true if the api may modify data
  86         */
  87         public function __construct($request, $enableWrite = false) {
  88
  89                 $this->mInternalMode = ($request instanceof FauxRequest);
  90
  91                 // Special handling for the main module: $parent === $this
  92                 parent :: __construct($this, $this->mInternalMode ? 'main_int' : 'main');
  93
  94                 $this->mModules = self :: $Modules;
  95                 $this->mModuleNames = array_keys($this->mModules); // todo: optimize
  96                 $this->mFormats = self :: $Formats;
  97                 $this->mFormatNames = array_keys($this->mFormats); // todo: optimize
  98
  99                 $this->mResult = new ApiResult($this);
 100                 $this->mShowVersions = false;
 101                 $this->mEnableWrite = $enableWrite;
 102
 103                 $this->mRequest = & $request;
 104
 105                 $this->mSquidMaxage = 0;
 106         }
 107
 108         /**
 109          * Return the request object that contains client's request
 110          */
 111         public function getRequest() {
 112                 return $this->mRequest;
 113         }
 114
 115         /**
 116          * Get the ApiResult object asscosiated with current request
 117          */
 118         public function getResult() {
 119                 return $this->mResult;
 120         }
 121
 122         /**
 123          * This method will simply cause an error if the write mode was disabled for this api.
 124          */
 125         public function requestWriteMode() {
 126                 if (!$this->mEnableWrite)
 127                         $this->dieUsage('Editing of this site is disabled. Make sure the $wgEnableWriteAPI=true; ' .
 128                         'statement is included in the site\'s LocalSettings.php file', 'readonly');
 129         }
 130
 131         /**
 132          * Set how long the response should be cached.
 133          */
 134         public function setCacheMaxAge($maxage) {
 135                 $this->mSquidMaxage = $maxage;
 136         }
 137
 138         /**
 139          * Create an instance of an output formatter by its name
 140          */
 141         public function createPrinterByName($format) {
 142                 return new $this->mFormats[$format] ($this, $format);
 143         }
 144
 145         /**
 146          * Execute api request. Any errors will be handled if the API was called by the remote client.
 147          */
 148         public function execute() {
 149                 $this->profileIn();
 150                 if ($this->mInternalMode)
 151                         $this->executeAction();
 152                 else
 153                         $this->executeActionWithErrorHandling();
 154                 $this->profileOut();
 155         }
 156
 157         /**
 158          * Execute an action, and in case of an error, erase whatever partial results
 159          * have been accumulated, and replace it with an error message and a help screen.
 160          */
 161         protected function executeActionWithErrorHandling() {
 162
 163                 // In case an error occurs during data output,
 164                 // clear the output buffer and print just the error information
 165                 ob_start();
 166
 167                 try {
 168                         $this->executeAction();
 169                 } catch (Exception $e) {
 170                         //
 171                         // Handle any kind of exception by outputing properly formatted error message.
 172                         // If this fails, an unhandled exception should be thrown so that global error
 173                         // handler will process and log it.
 174                         //
 175
 176                         // Error results should not be cached
 177                         $this->setCacheMaxAge(0);
 178
 179                         // Printer may not be initialized if the extractRequestParams() fails for the main module
 180                         if (!isset ($this->mPrinter)) {
 181                                 $this->mPrinter = $this->createPrinterByName(self :: API_DEFAULT_FORMAT);
 182                                 if ($this->mPrinter->getNeedsRawData())
 183                                         $this->getResult()->setRawMode();
 184                         }
 185
 186                         if ($e instanceof UsageException) {
 187                                 //
 188                                 // User entered incorrect parameters - print usage screen
 189                                 //
 190                                 $errMessage = array (
 191                                 'code' => $e->getCodeString(), 'info' => $e->getMessage());
 192                                 ApiResult :: setContent($errMessage, $this->makeHelpMsg());
 193
 194                         } else {
 195                                 //
 196                                 // Something is seriously wrong
 197                                 //
 198                                 $errMessage = array (
 199                                         'code' => 'internal_api_error',
 200                                         'info' => "Exception Caught: {$e->getMessage()}"
 201                                 );
 202                                 ApiResult :: setContent($errMessage, "\n\n{$e->getTraceAsString()}\n\n");
 203                         }
 204
 205                         $headerStr = 'MediaWiki-API-Error: ' . $errMessage['code'];
 206                         if ($e->getCode() === 0)
 207                                 header($headerStr, true);
 208                         else
 209                                 header($headerStr, true, $e->getCode());
 210
 211                         // Reset and print just the error message
 212                         ob_clean();
 213                         $this->getResult()->reset();
 214                         $this->getResult()->addValue(null, 'error', $errMessage);
 215
 216                         // If the error occured during printing, do a printer->profileOut()
 217                         $this->mPrinter->safeProfileOut();
 218                         $this->printResult(true);
 219                 }
 220
 221                 // Set the cache expiration at the last moment, as any errors may change the expiration.
 222                 // if $this->mSquidMaxage == 0, the expiry time is set to the first second of unix epoch
 223                 $expires = $this->mSquidMaxage == 0 ? 1 : time() + $this->mSquidMaxage;
 224                 header('Expires: ' . wfTimestamp(TS_RFC2822, $expires));
 225                 header('Cache-Control: s-maxage=' . $this->mSquidMaxage . ', must-revalidate, max-age=0');
 226
 227                 if($this->mPrinter->getIsHtml())
 228                         echo wfReportTime();
 229
 230                 ob_end_flush();
 231         }
 232
 233         /**
 234          * Execute the actual module, without any error handling
 235          */
 236         protected function executeAction() {
 237                 $action = $format = $version = null;
 238                 extract($this->extractRequestParams());
 239                 $this->mShowVersions = $version;
 240
 241                 // Instantiate the module requested by the user
 242                 $module = new $this->mModules[$action] ($this, $action);
 243
 244                 if (!$this->mInternalMode) {
 245
 246                         // See if custom printer is used
 247                         $this->mPrinter = $module->getCustomPrinter();
 248                         if (is_null($this->mPrinter)) {
 249                                 // Create an appropriate printer
 250                                 $this->mPrinter = $this->createPrinterByName($format);
 251                         }
 252
 253                         if ($this->mPrinter->getNeedsRawData())
 254                                 $this->getResult()->setRawMode();
 255                 }
 256
 257                 // Execute
 258                 $module->profileIn();
 259                 $module->execute();
 260                 $module->profileOut();
 261
 262                 if (!$this->mInternalMode) {
 263                         // Print result data
 264                         $this->printResult(false);
 265                 }
 266         }
 267
 268         /**
 269          * Print results using the current printer
 270          */
 271         protected function printResult($isError) {
 272                 $printer = $this->mPrinter;
 273                 $printer->profileIn();
 274                 $printer->initPrinter($isError);
 275                 $printer->execute();
 276                 $printer->closePrinter();
 277                 $printer->profileOut();
 278         }
 279
 280         /**
 281          * See ApiBase for description.
 282          */
 283         protected function getAllowedParams() {
 284                 return array (
 285                         'format' => array (
 286                                 ApiBase :: PARAM_DFLT => ApiMain :: API_DEFAULT_FORMAT,
 287                                 ApiBase :: PARAM_TYPE => $this->mFormatNames
 288                         ),
 289                         'action' => array (
 290                                 ApiBase :: PARAM_DFLT => 'help',
 291                                 ApiBase :: PARAM_TYPE => $this->mModuleNames
 292                         ),
 293                         'version' => false
 294                 );
 295         }
 296
 297         /**
 298          * See ApiBase for description.
 299          */
 300         protected function getParamDescription() {
 301                 return array (
 302                         'format' => 'The format of the output',
 303                         'action' => 'What action you would like to perform',
 304                         'version' => 'When showing help, include version for each module'
 305                 );
 306         }
 307
 308         /**
 309          * See ApiBase for description.
 310          */
 311         protected function getDescription() {
 312                 return array (
 313                         '',
 314                         'This API allows programs to access various functions of MediaWiki software.',
 315                         'For more details see API Home Page @ http://www.mediawiki.org/wiki/API',
 316                         '',
 317                         'Status: ALPHA -- all features shown on this page should be working,',
 318                         '                 but the API is still in active development, and  may change at any time.',
 319                         '                 Make sure you monitor changes to this page, wikitech-l mailing list,',
 320                         '                 or the source code in the includes/api directory for any changes.',
 321                         ''
 322                 );
 323         }
 324
 325         /**
 326          * Returns an array of strings with credits for the API
 327          */
 328         protected function getCredits() {
 329                 return array(
 330                         'This API is being implemented by Yuri Astrakhan [[User:Yurik]] / <Firstname><Lastname>@gmail.com',
 331                         'Please leave your comments and suggestions at http://www.mediawiki.org/wiki/API'
 332                 );
 333         }
 334
 335         /**
 336          * Override the parent to generate help messages for all available modules.
 337          */
 338         public function makeHelpMsg() {
 339
 340                 // Use parent to make default message for the main module
 341                 $msg = parent :: makeHelpMsg();
 342
 343                 $astriks = str_repeat('*** ', 10);
 344                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 345                 foreach( $this->mModules as $moduleName => $unused ) {
 346                         $msg .= "* action=$moduleName *";
 347                         $module = new $this->mModules[$moduleName] ($this, $moduleName);
 348                         $msg2 = $module->makeHelpMsg();
 349                         if ($msg2 !== false)
 350                                 $msg .= $msg2;
 351                         $msg .= "\n";
 352                 }
 353
 354                 $msg .= "\n$astriks Formats  $astriks\n\n";
 355                 foreach( $this->mFormats as $formatName => $unused ) {
 356                         $msg .= "* format=$formatName *";
 357                         $module = $this->createPrinterByName($formatName);
 358                         $msg2 = $module->makeHelpMsg();
 359                         if ($msg2 !== false)
 360                                 $msg .= $msg2;
 361                         $msg .= "\n";
 362                 }
 363
 364                 $msg .= "\n*** Credits: ***\n   " . implode("\n   ", $this->getCredits()) . "\n";
 365
 366
 367                 return $msg;
 368         }
 369
 370         private $mIsBot = null;
 371
 372         /**
 373          * Returns true if the currently logged in user is a bot, false otherwise
 374          */
 375         public function isBot() {
 376                 if (!isset ($this->mIsBot)) {
 377                         global $wgUser;
 378                         $this->mIsBot = $wgUser->isAllowed('bot');
 379                 }
 380                 return $this->mIsBot;
 381         }
 382
 383         public function getShowVersions() {
 384                 return $this->mShowVersions;
 385         }
 386
 387         /**
 388          * Returns the version information of this file, plus it includes
 389          * the versions for all files that are not callable proper API modules
 390          */
 391         public function getVersion() {
 392                 $vers = array ();
 393                 $vers[] = __CLASS__ . ': $Id$';
 394                 $vers[] = ApiBase :: getBaseVersion();
 395                 $vers[] = ApiFormatBase :: getBaseVersion();
 396                 $vers[] = ApiQueryBase :: getBaseVersion();
 397                 $vers[] = ApiFormatFeedWrapper :: getVersion(); // not accessible with format=xxx
 398                 return $vers;
 399         }
 400 }
 401
 402 /**
 403  * This exception will be thrown when dieUsage is called to stop module execution.
 404  * The exception handling code will print a help screen explaining how this API may be used.
 405  *
 406  * @addtogroup API
 407  */
 408 class UsageException extends Exception {
 409
 410         private $mCodestr;
 411
 412         public function __construct($message, $codestr, $code = 0) {
 413                 parent :: __construct($message, $code);
 414                 $this->mCodestr = $codestr;
 415         }
 416         public function getCodeString() {
 417                 return $this->mCodestr;
 418         }
 419         public function __toString() {
 420                 return "{$this->getCodeString()}: {$this->getMessage()}";
 421         }
 422 }
 423 ?>