Piwik\Plugin\Manager::makePluginClass PHP Method

    protected function makePluginClass($pluginName)
    {
        $pluginFileName = sprintf("%s/%s.php", $pluginName, $pluginName);
        $pluginClassName = $pluginName;
        if (!$this->isValidPluginName($pluginName)) {
            throw new \Exception(sprintf("The plugin filename '%s' is not a valid plugin name", $pluginFileName));
        }
        $path = self::getPluginsDirectory() . $pluginFileName;
        if (!file_exists($path)) {
            // Create the smallest minimal Piwik Plugin
            // Eg. Used for Morpheus default theme which does not have a Morpheus.php file
            return new Plugin($pluginName);
        }
        require_once $path;
        $namespacedClass = $this->getClassNamePlugin($pluginName);
        if (!class_exists($namespacedClass, false)) {
            throw new \Exception("The class {$pluginClassName} couldn't be found in the file '{$path}'");
        }
        $newPlugin = new $namespacedClass();
        if (!$newPlugin instanceof Plugin) {
            throw new \Exception("The plugin {$pluginClassName} in the file {$path} must inherit from Plugin.");
        }
        return $newPlugin;
    }