['html']] // Reference: https://twig.symfony.com/doc/2.x/advanced.html#automatic-escaping new TwigFilter('filter_name', [$this, 'doSomething']), ]; } public function getFunctions(): array { return [ new TwigFunction('function_name', [$this, 'doSomething']), ]; } public function doSomething($value) { // ... } }