protected function getPreviewRouteParameters()
    {
        $previewPath = sprintf('/%s/preview/{url}', $this->adminKey);
        $previewDefaults = array(
            '_controller' => 'KunstmaanNodeBundle:Slug:slug',
            'preview' => true,
            'url' => '',
            '_locale' => $this->getDefaultLocale(),
        );
        $previewRequirements = array(
            'url' => $this->getSlugPattern(),
        );

        if ($this->isMultiLanguage()) {
            $previewPath = '/{_locale}' . $previewPath;
            unset($previewDefaults['_locale']);
            $previewRequirements['_locale'] = $this->getEscapedLocales($this->getBackendLocales());
        }

        return array(
            'path' => $previewPath,
            'defaults' => $previewDefaults,
            'requirements' => $previewRequirements,
        );
    }