layouts

One of the great additions to Drupal 8 theming is the layouts file. Previously adding layout options to a Drupal 7 site required the Display Suite module, creating folders for each layout then creating 2-3 files per template option/folder. Now the DS module is still required, however the templating control is all within the theme, specifically the theme.layouts.yml file.

Each layout requires a minimum of 6 items:

1. layout machine name
2. layout ui label
3. category template
4. location
5. css
6. available regions:
   1. region machine name...