Book Image

Modernizing Drupal 10 Theme Development

By : Luca Lusso
4 (1)
Book Image

Modernizing Drupal 10 Theme Development

4 (1)
By: Luca Lusso

Overview of this book

Working with themes in Drupal can be challenging, given the number of layers and APIs involved. Modernizing Drupal 10 Theme Development helps you explore the new Drupal 10’s theme layer in depth. With a fully implemented Drupal website on the one hand and a set of Storybook components on the other, you’ll begin by learning to create a theme from scratch to match the desired final layout. Once you’ve set up a local environment, you’ll get familiarized with design systems and learn how to map them to the structures of a Drupal website. Next, you’ll bootstrap your new theme and optimize Drupal’s productivity using tools such as webpack, Tailwind CSS, and Browsersync. As you advance, you’ll delve into all the theme layers in a step-by-step way, starting from how Drupal builds an HTML page to where the template files are and how to add custom CSS and JavaScript. You’ll also discover how to leverage all the Drupal APIs to implement robust and maintainable themes without reinventing the wheel, but by following best practices and methodologies. Toward the end, you’ll find out how to build a fully decoupled website using json:api and Next.js. By the end of this book, you’ll be able to confidently build custom Drupal themes to deliver state-of-the-art websites and keep ahead of the competition in the modern frontend world.
Table of Contents (21 chapters)
1
Part 1 – Styling Drupal
12
Part 2 – Advanced Topics
17
Part 3 – Decoupled Architectures

Defining a new field formatter

Looking at the full version of a trip node, you’ll see that field_lat_lng is a little bit ugly. It prints the raw values for the latitude and longitude. It should be way better to have a geographical map with a marker on it. We can implement this directly in a Twig template, but this solution has a couple of drawbacks:

  • Twig is quite limited when it comes to data manipulation
  • If we need a similar field but with a different name, we have to duplicate the code

Providing a different way to render a field on the frontend is a task for a field formatter.

First of all, we need to define a new theme hook in a custom module:

function alps_base_theme(): array {
  return [
    'alps_base_lat_lng' => [
      'variables' => [
        'lat' => '',
       ...