Plugin\Install\PublicController::index PHP Метод

    public function index()
    {
        $this->init();
        if (isset($_GET['step'])) {
            $step = (int) $_GET['step'];
        } else {
            $step = Helper::$firstStep;
        }
        if ($step < Helper::$firstStep) {
            $step = Helper::$firstStep;
        }
        // going to the last step
        if (!Helper::isInstallAvailable() || $step > Helper::$lastStep) {
            $step = Helper::$lastStep;
        }
        switch ($step) {
            case '1':
                $response = $this->configuration();
                break;
            case '2':
                $response = $this->systemCheck();
                break;
            case '3':
                $response = $this->database();
                break;
            case '4':
                $response = $this->finish();
                break;
            default:
                $response = new LayoutResponse();
        }
        return $response;
    }