public function getFilters()
    {
        $filters = [
            new Twig_SimpleFilter('app', [$this, 'appFilter'], ['is_safe' => ['html']]),
            new Twig_SimpleFilter('media', [$this, 'mediaFilter'], ['is_safe' => ['html']]),
        ];

        /*
         * Include extensions provided by plugins
         */
        $filters = $this->markupManager->makeTwigFilters($filters);

        return $filters;
    }