Salesforce Lightning Design System

Welcome to the Salesforce Lightning Design System brought to you by Salesforce UX.

• Tailored for building Salesforce apps: Using the Lightning Design System markup and CSS framework results in UIs that reflect the Salesforce Lightning look and feel.
• Continuously updated: As long as you’re using the latest version of the Lightning Design System, your pages are always up to date with Salesforce UI changes.

Quick start

1. Clone the project with git clone https://github.com/salesforce-ux/design-system.git
2. Run npm install in the root design-system folder.
3. Run npm start to launch the Previewer.
4. Visit http://localhost:3003/local/preview

Having trouble getting these steps to work on your machine? Follow the troubleshooting guide below.

Previewer

The previewer is an interactive tool for creating components.

It runs at the designated url on startup and is the primary means of viewing your work - it will live update as you make changes.

You can choose the component, variant, and modifiers to preview as well as background color and screen size. It also previews the sass docs.

Everything in the design system is driven by annotations and the previewer is no different. To see any work in the previewer, you must add annotations to your code.

Annotations

Annotations are the metadata that describe the entire system.

The most intriguing part is the @selector/@restrict pair. Each CSS selector should have a corresponding selector describing where it can be applied. Both are normal CSS selectors that will behave like a DOM query.

For example:

/**
 * @selector .slds-button
 * @restrict button, a, span
 */
.slds-button {
  ...
}

/**
 * @selector .slds-button_brand
 * @restrict .slds-button
 */
.slds-button_brand {
  ...
}

In this example we can see that .slds-button_brand must be applied to a .slds-button, which, in turn, must be applied to a button, a, span.

It's important to know that slds-button_brand will only be associated to the button component via this @restrict chain. Each rule uses its @restrict to declare its place in the hierarchy - it is not the the file that tells us to which component a selector belongs

For a more complex example, see: https://github.com/salesforce-ux/design-system-internal/blob/summer-17/ui/components/combobox/base/_index.scss

While there is a handful of annotations used throughout the codebase, you'll only need to know a few to get started:

• @base: creates a new component
• @variant: a component implementation with corresponding markup
• @modifier: a class that alters appearance when applied to existing markup

The markup for a @variant will be required from the /ui/:component/:variant/example.jsx.

For example:

/**
 * @name advanced
 * @selector .slds-table_fixed-layout
 * @restrict .slds-table
 * @variant
 */

Folder Structure:

ui/
└── components/
    └── data-tables/
        ├── _doc.scss
        ├── _doc.mdx
        └── advanced/
            └── example.jsx
            └── _index.scss

All other selectors which are not @base/@variant/@modifier are considered child elements of a component.

For more information see the Full annotation docs

Tasks

Install gulp globally:

npm install --global gulp

npm start

Start the Lightning Design System preview app.

gulp lint

Lint the code base for syntax and stylistic errors.

# Lint indentation, Sass, JavaScript files
gulp lint

# Lint languages independently
gulp lint:sass
gulp lint:js
gulp lint:js:test
gulp lint:spaces
gulp lint:html

# HTML5 validation
gulp lint:vnu
# HTML5 validation on comma separated component names
gulp lint:vnu --components button, path, trees

gulp a11y

Run aXe Core against the components for Accessibility issues

# All components
gulp a11y
# Comma separated list of components
gulp a11y --components button, path, trees

Compilation

npm run build && npm run dist

Generate the Lightning Design System into the .dist directory.

gulp styles

Compile Sass to CSS into .assets/styles.

gulp clean

Delete temporary build and local files.

Stats

npm run stats: Useful stats about the project's deliverables.

Tests

npm test: run all tests

Troubleshooting

npm and Node.js

The Salesforce Lightning Design System uses npm to manage dependencies. Please install Node.js, and try running npm install again.

If Node.js is already installed, make sure you’re running v6 or up.

JavaScript and compilation issues

JavaScript dependencies sometimes get out of sync and inexplicable bugs start to happen. Follow these steps to give a fresh start to your development environment:

1. The installed npm version must be at least v3.10. You can update your npm with: npm install npm -g (sudo may be required).
2. Re-install dependencies: rm -Rf node_modules && npm install
3. npm start

If this did not work, try running npm cache clean and repeat the above steps.

Contributing to the code base

See CONTRIBUTING.md.

Licenses

• Source code is licensed under BSD 3-Clause
• All icons and images are licensed under Creative Commons Attribution-NoDerivatives 4.0
• The Salesforce Sans font is licensed under our font license

Got feedback?

Please open a new GitHub Issue.