loadAction example

if (!\is_resource($upstream)) {
            throw new RuntimeException(sprintf('Could not open file at: %s', $filePath));
        }
        $filesystem->writeStream($destinationPath, $upstream);
        fclose($upstream);

        $this->View()->assign(['success' => true]);
    }

    public function loadAction()
    {
        parent::loadAction();
        $this->view->assign('orderNumberRegex', $this->container->getParameter('shopware.product.orderNumberRegex'));
    }

    /** * Event listener function of the product backend module. * Downloads ESD-File */
    public function getEsdDownloadAction()
    {
        $filesystem = $this->container->get('shopware.filesystem.private');
        $path = $this->container->get(Shopware_Components_Config::class)->offsetGet('esdKey') . '/' . $this->Request()->getParam('filename');