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