API: Making a bunch of state-changing modules require POST requests.
[lhc/web/wiklou.git] / includes / api / ApiMain.php
index 3f1ae8b..4c294a4 100644 (file)
@@ -1,12 +1,11 @@
 <?php
 
-
 /*
  * Created on Sep 4, 2006
  *
  * API for MediaWiki 1.8+
  *
- * Copyright (C) 2006 Yuri Astrakhan <FirstnameLastname@gmail.com>
+ * Copyright (C) 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -29,9 +28,18 @@ if (!defined('MEDIAWIKI')) {
        require_once ('ApiBase.php');
 }
 
-
 /**
- * This is the main API class, used for both external and internal processing. 
+ * This is the main API class, used for both external and internal processing.
+ * When executed, it will create the requested formatter object,
+ * instantiate and execute an object associated with the needed action,
+ * and use formatter to print results.
+ * In case of an exception, an error message will be printed using the same formatter.
+ *
+ * To use API from another application, run it using FauxRequest object, in which
+ * case any internal exceptions will not be handled but passed up to the caller.
+ * After successful execution, use getResult() for the resulting data.   
+ *  
+ * @addtogroup API
  */
 class ApiMain extends ApiBase {
 
@@ -44,11 +52,26 @@ class ApiMain extends ApiBase {
         * List of available modules: action name => module class
         */
        private static $Modules = array (
-               'help' => 'ApiHelp',
                'login' => 'ApiLogin',
+               'logout' => 'ApiLogout',
+               'query' => 'ApiQuery',
+               'expandtemplates' => 'ApiExpandTemplates',
+               'parse' => 'ApiParse',
                'opensearch' => 'ApiOpenSearch',
                'feedwatchlist' => 'ApiFeedWatchlist',
-               'query' => 'ApiQuery'
+               'help' => 'ApiHelp',
+       );
+       
+       private static $WriteModules = array (
+               'rollback' => 'ApiRollback',
+               'delete' => 'ApiDelete',
+               'undelete' => 'ApiUndelete',
+               'protect' => 'ApiProtect',
+               'block' => 'ApiBlock',
+               'unblock' => 'ApiUnblock',
+               'move' => 'ApiMove',
+               #'changerights' => 'ApiChangeRights'
+               # Disabled for now
        );
 
        /**
@@ -57,71 +80,130 @@ class ApiMain extends ApiBase {
        private static $Formats = array (
                'json' => 'ApiFormatJson',
                'jsonfm' => 'ApiFormatJson',
-               'raw' => 'ApiFormatJson',
-               'rawfm' => 'ApiFormatJson',
+               'php' => 'ApiFormatPhp',
+               'phpfm' => 'ApiFormatPhp',
+               'wddx' => 'ApiFormatWddx',
+               'wddxfm' => 'ApiFormatWddx',
                'xml' => 'ApiFormatXml',
                'xmlfm' => 'ApiFormatXml',
                'yaml' => 'ApiFormatYaml',
-               'yamlfm' => 'ApiFormatYaml'
+               'yamlfm' => 'ApiFormatYaml',
+               'rawfm' => 'ApiFormatJson'
        );
 
        private $mPrinter, $mModules, $mModuleNames, $mFormats, $mFormatNames;
-       private $mResult, $mShowVersions, $mEnableWrite, $mRequest, $mInternalMode;
+       private $mResult, $mAction, $mShowVersions, $mEnableWrite, $mRequest, $mInternalMode, $mSquidMaxage;
 
        /**
-       * Constructor
+       * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
+       *
        * @param $request object - if this is an instance of FauxRequest, errors are thrown and no printing occurs
        * @param $enableWrite bool should be set to true if the api may modify data
        */
        public function __construct($request, $enableWrite = false) {
+
+               $this->mInternalMode = ($request instanceof FauxRequest);
+
                // Special handling for the main module: $parent === $this
-               parent :: __construct($this, 'main');
+               parent :: __construct($this, $this->mInternalMode ? 'main_int' : 'main');
+
+               if (!$this->mInternalMode) {
+                       
+                       // Impose module restrictions.
+                       // If the current user cannot read, 
+                       // Remove all modules other than login
+                       global $wgUser;
+                       if (!$wgUser->isAllowed('read')) {
+                               self::$Modules = array(
+                                       'login'  => self::$Modules['login'],
+                                       'logout' => self::$Modules['logout'],
+                                       'help'   => self::$Modules['help'],
+                                       ); 
+                       }
+               }
+
+               global $wgAPIModules, $wgEnableWriteAPI; // extension modules
+               $this->mModules = $wgAPIModules + self :: $Modules;
+               if($wgEnableWriteAPI)
+                       $this->mModules += self::$WriteModules;
+
+               $this->mModuleNames = array_keys($this->mModules); // todo: optimize
+               $this->mFormats = self :: $Formats;
+               $this->mFormatNames = array_keys($this->mFormats); // todo: optimize
 
-               $this->mModules =& self::$Modules;
-               $this->mModuleNames = array_keys($this->mModules);      // todo: optimize
-               $this->mFormats =& self::$Formats;
-               $this->mFormatNames = array_keys($this->mFormats);      // todo: optimize
-               
                $this->mResult = new ApiResult($this);
                $this->mShowVersions = false;
                $this->mEnableWrite = $enableWrite;
-               
-               $this->mRequest =& $request;
 
-               $this->mInternalMode = ($request instanceof FauxRequest);
+               $this->mRequest = & $request;
+
+               $this->mSquidMaxage = 0;
+       }
+
+       /**
+        * Return true if the API was started by other PHP code using FauxRequest
+        */
+       public function isInternalMode() {
+               return $this->mInternalMode;
        }
 
-       public function & getRequest() {
+       /**
+        * Return the request object that contains client's request
+        */
+       public function getRequest() {
                return $this->mRequest;
        }
 
-       public function & getResult() {
+       /**
+        * Get the ApiResult object asscosiated with current request
+        */
+       public function getResult() {
                return $this->mResult;
        }
 
+       /**
+        * This method will simply cause an error if the write mode was disabled for this api.
+        */
        public function requestWriteMode() {
                if (!$this->mEnableWrite)
                        $this->dieUsage('Editing of this site is disabled. Make sure the $wgEnableWriteAPI=true; ' .
-                       'statement is included in the site\'s LocalSettings.php file', 'readonly');
+                       'statement is included in the site\'s LocalSettings.php file', 'noapiwrite');
        }
-       
+
+       /**
+        * Set how long the response should be cached.
+        */
+       public function setCacheMaxAge($maxage) {
+               $this->mSquidMaxage = $maxage;
+       }
+
+       /**
+        * Create an instance of an output formatter by its name
+        */
        public function createPrinterByName($format) {
                return new $this->mFormats[$format] ($this, $format);
        }
 
+       /**
+        * Execute api request. Any errors will be handled if the API was called by the remote client. 
+        */
        public function execute() {
                $this->profileIn();
-               if($this->mInternalMode)
+               if ($this->mInternalMode)
                        $this->executeAction();
                else
                        $this->executeActionWithErrorHandling();
                $this->profileOut();
        }
-       
+
+       /**
+        * Execute an action, and in case of an error, erase whatever partial results
+        * have been accumulated, and replace it with an error message and a help screen.
+        */
        protected function executeActionWithErrorHandling() {
 
                // In case an error occurs during data output,
-               // this clear the output buffer and print just the error information
+               // clear the output buffer and print just the error information
                ob_start();
 
                try {
@@ -132,99 +214,164 @@ class ApiMain extends ApiBase {
                        // If this fails, an unhandled exception should be thrown so that global error
                        // handler will process and log it.
                        //
-                       
+
+                       $errCode = $this->substituteResultWithError($e);
+
+                       // Error results should not be cached
+                       $this->setCacheMaxAge(0);
+
+                       $headerStr = 'MediaWiki-API-Error: ' . $errCode;
+                       if ($e->getCode() === 0)
+                               header($headerStr, true);
+                       else
+                               header($headerStr, true, $e->getCode());
+
+                       // Reset and print just the error message
+                       ob_clean();
+
+                       // If the error occured during printing, do a printer->profileOut()
+                       $this->mPrinter->safeProfileOut();
+                       $this->printResult(true);
+               }
+
+               // Set the cache expiration at the last moment, as any errors may change the expiration.
+               // if $this->mSquidMaxage == 0, the expiry time is set to the first second of unix epoch
+               $expires = $this->mSquidMaxage == 0 ? 1 : time() + $this->mSquidMaxage;
+               header('Expires: ' . wfTimestamp(TS_RFC2822, $expires));
+               header('Cache-Control: s-maxage=' . $this->mSquidMaxage . ', must-revalidate, max-age=0');
+
+               if($this->mPrinter->getIsHtml())
+                       echo wfReportTime();
+
+               ob_end_flush();
+       }
+
+       /**
+        * Replace the result data with the information about an exception.
+        * Returns the error code 
+        */
+       protected function substituteResultWithError($e) {
+       
                        // Printer may not be initialized if the extractRequestParams() fails for the main module
                        if (!isset ($this->mPrinter)) {
-                               $this->mPrinter = $this->createPrinterByName(self :: API_DEFAULT_FORMAT);
+                               // The printer has not been created yet. Try to manually get formatter value.
+                               $value = $this->getRequest()->getVal('format', self::API_DEFAULT_FORMAT);
+                               if (!in_array($value, $this->mFormatNames))
+                                       $value = self::API_DEFAULT_FORMAT;
+
+                               $this->mPrinter = $this->createPrinterByName($value);
+                               if ($this->mPrinter->getNeedsRawData())
+                                       $this->getResult()->setRawMode();
                        }
-                       
+
                        if ($e instanceof UsageException) {
                                //
                                // User entered incorrect parameters - print usage screen
                                //
                                $errMessage = array (
-                                       'code' => $e->getCodeString(),
-                                       'info' => $e->getMessage()
-                               );
-                               ApiResult :: setContent($errMessage, $this->makeHelpMsg());
-               
+                               'code' => $e->getCodeString(),
+                               'info' => $e->getMessage());
+                               
+                               // Only print the help message when this is for the developer, not runtime
+                               if ($this->mPrinter->getIsHtml() || $this->mAction == 'help')
+                                       ApiResult :: setContent($errMessage, $this->makeHelpMsg());
+
                        } else {
                                //
                                // Something is seriously wrong
                                //
                                $errMessage = array (
-                                       'code' => 'internal_api_error',
+                                       'code' => 'internal_api_error_'. get_class($e),
                                        'info' => "Exception Caught: {$e->getMessage()}"
                                );
                                ApiResult :: setContent($errMessage, "\n\n{$e->getTraceAsString()}\n\n");
                        }
-                       
-                       $headerStr = 'MediaWiki-API-Error: ' . $errMessage['code'];
-                       if ($e->getCode() === 0)
-                               header($headerStr, true);
-                       else
-                               header($headerStr, true, $e->getCode());
 
-                       // Reset and print just the error message
-                       ob_clean();
-                       $this->mResult->Reset();
-                       $this->mResult->addValue(null, 'error', $errMessage);
+                       $this->getResult()->reset();
+                       $this->getResult()->addValue(null, 'error', $errMessage);
 
-                       // If the error occured during printing, do a printer->profileOut()
-                       $this->mPrinter->safeProfileOut();
-                       $this->printResult(true);
-               }
-               
-               ob_end_flush();
+               return $errMessage['code'];
        }
 
        /**
         * Execute the actual module, without any error handling
         */
        protected function executeAction() {
-               $action = $format = $version = null;
-               extract($this->extractRequestParams());
-               $this->mShowVersions = $version;
 
-               // Instantiate the module requested by the user
-               $module = new $this->mModules[$action] ($this, $action);
+               $params = $this->extractRequestParams();
 
+               $this->mShowVersions = $params['version'];
+               $this->mAction = $params['action'];
+
+               // Instantiate the module requested by the user
+               $module = new $this->mModules[$this->mAction] ($this, $this->mAction);
+               
+               if( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
+                       // Check for maxlag
+                       global $wgLoadBalancer, $wgShowHostnames;
+                       $maxLag = $params['maxlag'];
+                       list( $host, $lag ) = $wgLoadBalancer->getMaxLag();
+                       if ( $lag > $maxLag ) {
+                               if( $wgShowHostnames ) {
+                                       ApiBase :: dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
+                               } else {
+                                       ApiBase :: dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
+                               }
+                               return;
+                       }
+               }
+               
                if (!$this->mInternalMode) {
-                       
+                       // Ignore mustBePosted() for internal calls
+                       if($module->mustBePosted() && !$this->mRequest->wasPosted())
+                               $this->dieUsage("The {$this->mAction} module requires a POST request", 'mustbeposted');
+
                        // See if custom printer is used
-                       $this->mPrinter = $module->getCustomPrinter();                          
-                       
+                       $this->mPrinter = $module->getCustomPrinter();
                        if (is_null($this->mPrinter)) {
                                // Create an appropriate printer
-                               $this->mPrinter = $this->createPrinterByName($format);
+                               $this->mPrinter = $this->createPrinterByName($params['format']);
                        }
+
+                       if ($this->mPrinter->getNeedsRawData())
+                               $this->getResult()->setRawMode();
                }
-               
+
                // Execute
                $module->profileIn();
                $module->execute();
                $module->profileOut();
-               
+
                if (!$this->mInternalMode) {
                        // Print result data
                        $this->printResult(false);
                }
        }
-       
+
        /**
-        * Internal printer
+        * Print results using the current printer
         */
        protected function printResult($isError) {
                $printer = $this->mPrinter;
                $printer->profileIn();
+       
+               /* If the help message is requested in the default (xmlfm) format,
+                * tell the printer not to escape ampersands so that our links do
+                * not break. */
+               $params = $this->extractRequestParams();
+               $printer->setUnescapeAmps ( ( $this->mAction == 'help' || $isError ) 
+                               && $params['format'] == ApiMain::API_DEFAULT_FORMAT );
+
                $printer->initPrinter($isError);
-               if (!$printer->getNeedsRawData())
-                       $this->getResult()->SanitizeData();
+
                $printer->execute();
                $printer->closePrinter();
                $printer->profileOut();
        }
 
+       /**
+        * See ApiBase for description.
+        */
        protected function getAllowedParams() {
                return array (
                        'format' => array (
@@ -235,24 +382,63 @@ class ApiMain extends ApiBase {
                                ApiBase :: PARAM_DFLT => 'help',
                                ApiBase :: PARAM_TYPE => $this->mModuleNames
                        ),
-                       'version' => false
+                       'version' => false,
+                       'maxlag'  => array (
+                               ApiBase :: PARAM_TYPE => 'integer'
+                       ),
                );
        }
 
+       /**
+        * See ApiBase for description.
+        */
        protected function getParamDescription() {
                return array (
                        'format' => 'The format of the output',
                        'action' => 'What action you would like to perform',
-                       'version' => 'When showing help, include version for each module'
+                       'version' => 'When showing help, include version for each module',
+                       'maxlag' => 'Maximum lag'
                );
        }
 
+       /**
+        * See ApiBase for description.
+        */
        protected function getDescription() {
                return array (
                        '',
-                       'This API allows programs to access various functions of MediaWiki software.',
-                       'For more details see API Home Page @ http://meta.wikimedia.org/wiki/API',
-                       ''
+                       '',
+                       '******************************************************************',
+                       '**                                                              **',
+                       '**  This is an auto-generated MediaWiki API documentation page  **',
+                       '**                                                              **',
+                       '**                  Documentation and Examples:                 **',
+                       '**               http://www.mediawiki.org/wiki/API              **',
+                       '**                                                              **',
+                       '******************************************************************',
+                       '',
+                       'Status:          All features shown on this page should be working, but the API',
+                       '                 is still in active development, and  may change at any time.',
+                       '                 Make sure to monitor our mailing list for any updates.',
+                       '',
+                       'Documentation:   http://www.mediawiki.org/wiki/API',
+                       'Mailing list:    http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
+                       'Bugs & Requests: http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
+                       '',
+                       '',
+                       '',
+                       '',
+                       '',
+               );
+       }
+       
+       /**
+        * Returns an array of strings with credits for the API
+        */
+       protected function getCredits() {
+               return array(
+                       'This API is being implemented by Yuri Astrakhan [[User:Yurik]] / <Firstname><Lastname>@gmail.com',
+                       'Please leave your comments and suggestions at http://www.mediawiki.org/wiki/API'
                );
        }
 
@@ -260,15 +446,17 @@ class ApiMain extends ApiBase {
         * Override the parent to generate help messages for all available modules.
         */
        public function makeHelpMsg() {
+               
+               $this->mPrinter->setHelp();
 
                // Use parent to make default message for the main module
                $msg = parent :: makeHelpMsg();
 
                $astriks = str_repeat('*** ', 10);
                $msg .= "\n\n$astriks Modules  $astriks\n\n";
-               foreach ($this->mModules as $moduleName => $moduleClass) {
-                       $msg .= "* action=$moduleName *";
+               foreach( $this->mModules as $moduleName => $unused ) {
                        $module = new $this->mModules[$moduleName] ($this, $moduleName);
+                       $msg .= self::makeHelpMsgHeader($module, 'action');
                        $msg2 = $module->makeHelpMsg();
                        if ($msg2 !== false)
                                $msg .= $msg2;
@@ -276,19 +464,37 @@ class ApiMain extends ApiBase {
                }
 
                $msg .= "\n$astriks Formats  $astriks\n\n";
-               foreach ($this->mFormats as $formatName => $moduleClass) {
-                       $msg .= "* format=$formatName *";
+               foreach( $this->mFormats as $formatName => $unused ) {
                        $module = $this->createPrinterByName($formatName);
+                       $msg .= self::makeHelpMsgHeader($module, 'format');
                        $msg2 = $module->makeHelpMsg();
                        if ($msg2 !== false)
                                $msg .= $msg2;
                        $msg .= "\n";
                }
+               
+               $msg .= "\n*** Credits: ***\n   " . implode("\n   ", $this->getCredits()) . "\n";
+               
 
                return $msg;
        }
 
+       public static function makeHelpMsgHeader($module, $paramName) {
+               $modulePrefix = $module->getModulePrefix();
+               if (!empty($modulePrefix))
+                       $modulePrefix = "($modulePrefix) "; 
+               
+               return "* $paramName={$module->getModuleName()} $modulePrefix*";
+       } 
+
        private $mIsBot = null;
+       private $mIsSysop = null;
+       private $mCanApiHighLimits = null;
+       
+       /**
+        * Returns true if the currently logged in user is a bot, false otherwise
+        * OBSOLETE, use canApiHighLimits() instead
+        */
        public function isBot() {
                if (!isset ($this->mIsBot)) {
                        global $wgUser;
@@ -296,25 +502,81 @@ class ApiMain extends ApiBase {
                }
                return $this->mIsBot;
        }
+       
+       /**
+        * Similar to isBot(), this method returns true if the logged in user is
+        * a sysop, and false if not.
+        * OBSOLETE, use canApiHighLimits() instead
+        */
+       public function isSysop() {
+               if (!isset ($this->mIsSysop)) {
+                       global $wgUser;
+                       $this->mIsSysop = in_array( 'sysop', $wgUser->getGroups());
+               }
+
+               return $this->mIsSysop;
+       }
+       
+       public function canApiHighLimits() {
+               if (!isset($this->mCanApiHighLimits)) {
+                       global $wgUser;
+                       $this->mCanApiHighLimits = $wgUser->isAllowed('apihighlimits');
+               }
+
+               return $this->mCanApiHighLimits;
+       }
 
        public function getShowVersions() {
                return $this->mShowVersions;
        }
 
+       /**
+        * Returns the version information of this file, plus it includes
+        * the versions for all files that are not callable proper API modules
+        */
        public function getVersion() {
                $vers = array ();
+               $vers[] = 'MediaWiki ' . SpecialVersion::getVersion();
                $vers[] = __CLASS__ . ': $Id$';
                $vers[] = ApiBase :: getBaseVersion();
                $vers[] = ApiFormatBase :: getBaseVersion();
                $vers[] = ApiQueryBase :: getBaseVersion();
-               $vers[] = ApiFormatFeedWrapper :: getVersion(); // not accessible with format=xxx
+               $vers[] = ApiFormatFeedWrapper :: getVersion(); // not accessible with format=xxx
                return $vers;
        }
+
+       /**
+        * Add or overwrite a module in this ApiMain instance. Intended for use by extending
+        * classes who wish to add their own modules to their lexicon or override the 
+        * behavior of inherent ones.
+        *
+        * @access protected
+        * @param $mdlName String The identifier for this module.
+        * @param $mdlClass String The class where this module is implemented.
+        */
+       protected function addModule( $mdlName, $mdlClass ) {
+               $this->mModules[$mdlName] = $mdlClass;
+       }
+
+       /**
+        * Add or overwrite an output format for this ApiMain. Intended for use by extending
+        * classes who wish to add to or modify current formatters.
+        *
+        * @access protected
+        * @param $fmtName The identifier for this format.
+        * @param $fmtClass The class implementing this format.
+        */
+       protected function addFormat( $fmtName, $fmtClass ) {
+               $this->mFormats[$fmtName] = $fmtClass;
+       }
 }
 
 /**
-* @desc This exception will be thrown when dieUsage is called to stop module execution.
-*/
+ * This exception will be thrown when dieUsage is called to stop module execution.
+ * The exception handling code will print a help screen explaining how this API may be used.
+ * 
+ * @addtogroup API
+ */
 class UsageException extends Exception {
 
        private $mCodestr;
@@ -330,4 +592,5 @@ class UsageException extends Exception {
                return "{$this->getCodeString()}: {$this->getMessage()}";
        }
 }
-?>
\ No newline at end of file
+
+