govuk-react

An implementation of the GOV.UK Design System in React using CSSinJS using Object notation (with styled-components).

We aim to track the following projects (in priority order) as to which components to implement and how they should look/behave. Where possible we are using the existing CSS as a guide. When we need to modify to suit custom markup, we aim to provide a comment in our code as to why this was done.

• GOV.UK Frontend
• GOV.UK Design System (source)
• GOV.UK Design System Backlog (where there are open tickets in the backlog that reference patterns/components in existing govuk sites)
• GOV.UK/elements
• GOV.UK Publishing Components
• Any other established govuk pattern

Usage

npm install govuk-react styled-components --save

import { Button } from 'govuk-react'

const MyComponent = ({title}) => (<div>
  <h1>{title}</h1>
  <Button />
</div>)

See the Storybook for examples of all available components.

Also see the example project for basic usage.

Using Link with a Router Link

We provide a Link component which creates an element styled as a GDS link. As we are using styled-components it is possible to apply that style to an existing component using the as prop. Other props will be passed through.

For example;

import { BrowserRouter, Link as RouterLink } from 'react-router';
import { Link } from '@govuk-react/link';

const MyComponent = () => (
  <nav>
    <BrowserRouter>
      <Link as={RouterLink} to="https://example.com">example</Link>
    </BrowserRouter>
  </nav>
);

Assumptions

Use of these components assumes the following from the peer project:

• Either normalize.css or sanitize.css is used as a CSS reset.
• The GDS Transport font face is included (for gov.uk domains only)
• Other than the reset, no other styles affecting generic elements (without classes, IDs etc) are present in the CSS.

Why CSS-in-JS?

See A Unified Styling Language.

This project is part of a larger initiative to componetise large scale React applications. Using CSSinJS allows us to include styles inside a module bundle that can be published (using npm publish) and consumed by a peer application, without putting dependencies on the peer application to implement a specific CSS build system.

We are expecting to use Interoperable Style Transfer Format (ISTF) once it is finalised and compatible with a CSSinJS library, which would allow us to distribute CSSinJS stylesheets without a runtime.

Why not use GDS styles/classes directly

1. We want to be free to write different DOM structure and/or CSS that is more in keeping with a React and bem-ish architecture. (e.g. in React you often don't need to specify IDs for field inputs, and can wrap inputs with labels so that they are automatically associated. We want to leave the decision of whether to use input IDs to the parent project. GDS styles don't wrap inputs with labels and require IDs and for attributes).
2. We want a parent project to not have to worry about a specific build system (e.g. for handling import styles.css, particularly if you want universal support) or including certain CSS files. We want a simple npm install govuk-react to be enough to get govuk styled components on to your page, irrespective of your build system.
3. We want to distribute React applications as modules that have self contained styles. CSS in JS allows all styles to be contained in distributable JS modules that can be ported across projects.

About the GDS font

Unfortuantely the GDS transport font has a relatively restrictive license described on the gov.uk blog. We are investigating rendering an elegant alternative before falling back to Arial on issue 272.

Related sites and projects

GOV.UK

• govuk-elements (source)
• govuk_frontend_toolkit
• govuk-frontend
• govuk_template (source)
• GOV.UK Design Patterns

Other React component libraries

• Auth0 Cosmos
• Shopify Polaris
• Zendesk Garden
• Atlassian Atlaskit
• Carbon Design System
• Material UI
• Rebass

Acknowledgements

We use Chromaticqa for visual regression testing and it is awesome, you should too!

Contributors

• Alasdair McLeay
• David Murdoch
• Gavin Orland
• Mark Chambers
• Steve Sims
• Taran Chauhan
• Toby Brancher

Want to contribute? Checkout our Contributing page.