Drupal 8's theming layer is complemented by Twig, a component of the Symfony framework. Twig is a template language that uses a syntax similar to Django and Jinja templates. The preceding version of Drupal used PHPTemplate, which required frontend developers to have a rudimentary understanding of PHP.
In this recipe, we will override the Twig template to provide customizations for the email form element. We will use the basic Twig syntax to add a new class and provide a default placeholder.
This recipe assumes that you have already created a custom theme, such as the one you created in the first recipe. When you see mythemein
in the following recipe, use the machine name of the theme you created.