Piwik\Updater::getComponentUpdates PHP Method

    public function getComponentUpdates()
    {
        $componentsToCheck = array('core' => Version::VERSION);
        $manager = \Piwik\Plugin\Manager::getInstance();
        $plugins = $manager->getLoadedPlugins();
        foreach ($plugins as $pluginName => $plugin) {
            if ($manager->isPluginInstalled($pluginName)) {
                $componentsToCheck[$pluginName] = $plugin->getVersion();
            }
        }
        $columnsVersions = $this->columnsUpdater->getAllVersions($this);
        foreach ($columnsVersions as $component => $version) {
            $componentsToCheck[$component] = $version;
        }
        $componentsWithUpdateFile = $this->getComponentsWithUpdateFile($componentsToCheck);
        if (count($componentsWithUpdateFile) == 0) {
            $this->columnsUpdater->onNoUpdateAvailable($columnsVersions);
            if (!$this->hasNewVersion('core')) {
                return null;
            }
        }
        return $componentsWithUpdateFile;
    }

 public function dispatch()
 {
     $module = Common::getRequestVar('module', '', 'string');
     $action = Common::getRequestVar('action', '', 'string');
     if ($module == 'CoreUpdater' || $module == 'Proxy' || $module == 'Installation' || $module == 'LanguagesManager' && $action == 'saveLanguage') {
         return;
     }
     $updater = new PiwikCoreUpdater();
     $updates = $updater->getComponentsWithNewVersion(array('core' => Version::VERSION));
     if (!empty($updates)) {
         Filesystem::deleteAllCacheOnUpdate();
     }
     if ($updater->getComponentUpdates() !== null) {
         if (FrontController::shouldRethrowException()) {
             throw new Exception("Piwik and/or some plugins have been upgraded to a new version. \n" . "--> Please run the update process first. See documentation: http://piwik.org/docs/update/ \n");
         } elseif ($module === 'API') {
             $outputFormat = strtolower(Common::getRequestVar('format', 'xml', 'string', $_GET + $_POST));
             $response = new ResponseBuilder($outputFormat);
             $e = new Exception('Database Upgrade Required. Your Piwik database is out-of-date, and must be upgraded before you can continue.');
             echo $response->getResponseException($e);
             Common::sendResponseCode(503);
             exit;
         } else {
             Piwik::redirectToModule('CoreUpdater');
         }
     }
 }