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Read the Styling examples on how to include styles and a theme. This section is about how theming works and how to actually create a custom theme.

How Themes are built

By default, all the HTML Elements (components) are built by separating the "visual styling" parts from the "functional layout" parts. This way we can create new custom visual styles.

Of course, we can still overwrite the functional layout properties to customize our theme even further.

The easy way

Simply do not import dnb-theme-ui and create your own visual styles for every component you use in your App.

Using postcss-replace

If your applications only need new colors or other CSS properties, you could simply replace all the properties with postcss-replace using this config scheme:

resolve: 'gatsby-plugin-postcss',
options: {
postCssPlugins: [
pattern: /#([A-Fa-f0-9]+)/,
data: {
'007272': '#YOUR_COLOR' // sea-green

Using CSS (vars) Custom Properties

This is for sure a very nice and powerful solution, but lacks Internet Explorer support.

The hard way

Maybe the most common ways would be:

  • Make a Fork of Eufemia and go from there
  • Submit a request of creating a theme inside the main Eufemia repository so everyone can get access to it.

Technical aspects

The included themes are built using SASS. Simply because we can reuse the @mixin's and variables from SASS.

We have the Main Theming File, which is located here: dnb-ui-lib/src/style/themes/dnb-theme-[THEME].scss

From here, we "can" reuse some default theming mechanism, just to have a fallback:

@import '../theme-ui/dnb-theme-ui.scss';

All the additional sub theming files (for every component) are automatically added to the Main Theming File by running $ yarn build. More on that further down.

If we need a custom theming file for one or more components, we can do so by creating dnb-ui-lib/src/components/[COMPONENT]/style/dnb-button-theme-[THEME].scss.

Local Theming setup

There are several solutions to create a new theme. One of which is by using the linking feature of Yarn.

Method: yarn link and SASS

Make sure Your project can handle *.scss files.

1. make a copy of the repository. Place it somewhere locally on your machine

2. change your command line (Terminal) directory to the sub package dnb-ui-lib (eufemia/packages/dnb-ui-lib)

3. make the package ready for development by running:

$ yarn install && yarn build && yarn link

4. on your application root directory, run:

$ yarn link "dnb-ui-lib"

5. That's it. Now you can use (import/require) the NPM module in your application like:

import { Button } from 'dnb-ui-lib/components'
import 'dnb-ui-lib/style/components'
// See the "src" in the path?
import 'dnb-ui-lib/src/style/themes/dnb-theme-[MY THEME].scss'

6. Don't forget to add "dnb-ui-lib": "*" with the respective version (alongside React) to your dependencies:

"dependencies": {
"dnb-ui-lib": "*",
"react": "^16",
"react-dom": "^16",

7. Note: Every time you create a new theme file, you have to run yarn build again. This way the new theme file gets added/bundled to the Main Theming File.