null, 'postflight' => function () { /** @var VersionUpdate $this */ try { // Keep old defaults for backwards compatibility. $yaml = YamlUpdater::instance(GRAV_ROOT . '/user/config/system.yaml'); $yaml->define('twig.autoescape', false); $yaml->define('strict_mode.yaml_compat', true); $yaml->define('strict_mode.twig_compat', true); $yaml->define('strict_mode.blueprint_compat', true); $yaml->save(); } catch (\Exception $e) { throw new InstallException('Could not update system configuration to maintain backwards compatibility', $e); } } ];