File Structure

All files are within resources/:

  • Sass code, documentation and example markup is within /resources/styles/
  • JavaScript code is within /resources/js/

Style Structure

Within /resource/styles/, there are the following directories from Atomic Design:

  • atoms/
  • molecules/
  • organisms/
  • templates/
  • pages/

We also have three other directories:

  • docs/ - project specific, front end documentation (such as this.)
  • examples/ – project specific examples of groups of components assembled together.
  • utilities/ - utilities are lightweight components that add specific functionality and aren’t limited to one of the Atomic Design categories.

There’s also a handful of Sass files within this folder itself:

  • main.scss - This is the root file that Boilerplate compiles to main.css. It just contains @import statements.
  • _base.scss - Base styles, such as typography.
  • _colors.scss – A set of starter color scales.
  • _mixins.scss - contains Sass mixins and functions that don’t make sense to get their own folder.
  • _transitions.scs – css transitions.
  • _utilities.scss - contains Sass utilities that are too simple to define standalone.
  • _config.scss - contains Sass variables.

Component File Structure and Naming

Quick Reference

  • styles/<category>/<component-name>/<component-name>.scss
  • styles/<category>/<component-name>/<component-name>.twig
  • styles/<category>/<component-name>/
  • styles/<category>/<component-name>/<component-name>[–<variant-name>].twig
  • styles/<category>/<component-name>/<component-name>.js
  • styles/<category>/<component-name>/<component-name>.config.json


Components are first categorized and put in one of the following folders, based on Atomic Design principles: utilities/, atoms/, molecules/, organisms/, templates/, or pages/. Atomic Design is a methodology for breaking down and front end development into manageable, modular pieces that are easier to maintain. Boilerplate uses Atomic Design because it is useful, thought out, well documented, and has a strong community.

The notable addition to the typical Atomic Design categories is utilities/ (although Atomic Design doesn’t oppose this kind of category at all.) The utilities/ folder is meant for utilities - code that isn’t specific to a single component.

It’s okay for components to change categories during development. Whenever you’re trying to choose a category for a component, make your best guess, erring on making it smaller. For example, if you’re torn between something being an atom or a molecule, start with atom.

Each component should have its own folder. These folder names should use kebab-case. Within that folder, a component may contain the following:

  • A Sass file, with the same name as the folder, defining the styles for this component.
  • A Twig file, with the same name as the folder, containing example markup for this component.
  • Additional Twig files, showing additional examples markup (what Fractal calls Variants) for this component.
  • A, with additional, component specific documentation.
  • A JavaScript file, with the same name as the folder, meant to work with the example markup to render the component. Note that this isn’t meant to be the source code of a JavaScript plugin or library, but rather the code required to use on the example markup.
  • A Fractal configuration file, defining how to display this component within the pattern library.

For example, for buttons, we have the following:

  • atoms/button/
  • atoms/button/button.scss
  • atoms/button/button.twig
  • atoms/button/button–disabled.twig
  • atoms/button/button.config.json