Back in the Drupal 7 days (aka last year), we came across some pretty large, hard-to-maintain Drupal 7 sites. The theme was often responsible for a lot of the cruft. We saw themes with excess code, too many template files, and not enough documentation.

The Drupal 8 theme layer provides new features like libraries and Twig blocks that can help us to build cleaner, better-organized themes. So now is a good time for themers to re-visit which theming techniques to use to create themes that are smaller, maintainable, and well organized.

In this session, we’ll cover some of these features and look at specific examples of how to apply them in real-world themes:

Creating libraries to load CSS and JS in different contexts
Extending existing libraries
Using breakpoints consistently
When to use view modes
How to use Twig blocks to reduce template code
When to use templates vs. preprocess functions
Why/how to use theme settings