Welcome to BrownBag!

Ahem.. is this thing on??

Building a Component Library

What's the point of this talk?

• Explain the what and why of component libs

• Explain the process of building a library

• Encourage you build and publish your own libs

What is a component library?

• a collection of reusable and extensible UI bits

Some Examples

• Usually more than standalone component libs

Why Build My Own?

• Keep UI consistent across multiple applications

• Build once, reuse often

• Leverage predictable and reliable UI

• Version control with npm

• Strengthen your frontend skillset 💪

Why Build My Own?

meme credit here

Why React?

• Component-based structure

• Testability

• Portability

Initial Setup

• Initialize git and npm

• Dependency management and .npmignore

• Use Babel to compile ES2015 (and JSX)

• Add linting and testing

• Add helpful documentation & a CoC

Want more details?

I wrote an article with detailed steps on this setup here.

I also gave a talk on publishing to npm, & the slides are here.

Here's an example starter repo.

Script Overview

  // package.json

  ...
  "main": "build/index.js",
  ...
  "scripts": {
    "build": "babel lib -d build",
    "build:watch": "babel lib -w -d build",
    "lint": "eslint lib/**; exit 0",
    "lint:watch": "esw -w lib/**",
    "prepublish": "npm run build",
    "test": "mocha --compilers js:babel-core/register ./test/**/*.spec.js",
    "test:watch": "npm test -- --watch"
  },
  ...

File Structure

Using Styled Components 💅

• Bundles our CSS with our JS

• Write real CSS 🎊

• Styles are predictable and reliable

• Users don't need to install additional deps

• Server-side rendering (if needed)

• Theming becomes a lot simpler

Looking for other alternatives?

Check out Glamor & Glamorous!

Also check out Aphrodite & Radium!

Applying Atomic Design

Want to know more?

You can read more or buy Brad Frost's book here.

A Few Modifications

• Atoms => Elements

(spans, buttons, etc.)

• Molecules => Components

(search field, dropdown, etc.)

• Organisms, Templates, & Pages

Adding a Button

import styled from 'styled-components';

const Button = styled.button`
  background: #1FB6FF;
  border: none;
  border-radius: 2px;
  color: #FFFFFF;
  cursor: pointer;
  display: inline-block;
  font-size: 16px;
  line-height: 40px;
  font-weight: 200;
  margin: 8px 0;
  outline: none;
  padding: 0 12px;
  text-transform: uppercase;
  transition: all 300ms ease;
  &:hover {
    background: #009EEB;
  }
`;

export default Button;

Updating index.js

// lib/index.js

import Button from './elements/Button’;

module.exports = {
  Button,
};

Publish! ... right?

Well, it would be nice to test it locally first though...

Development Workflow

// from the root of your component library
$ npm link

// set up a playground app for testing our library

$ git clone git@github.com:alanbsmith/component-lib-playground.git
$ cd component-lib-playground
$ npm install

// link our local module
$ npm link name-of-your-lib

// fire up the app
$ npm run dev

Create a symlink of our module

Add a playground

Hot Updates

// from the root of your component library
$ npm run build:watch

// update our button color to purple

const Button = styled.button`
  background: #7E5BEF;
  ...
  &:hover {
    background: #592DEA;
  }
`;

Run `build:watch` script

Making an update to our lib

This is cool, but...

It would be nice if our users had more control

Things to think about

• Balancing convention and customization

• What use-cases to cover

• Where is our greatest need? (for internal use)

Add a Color Palette

* This palette is from Marvel's Styleguide, which you can find here.

Updating our Button

Ok... now publish!?!

Well, hold on for a second...

Setting Button Sizes

Helpful Hints

• Adopt a grid system
• Think a lot about consistent size and space

• Keep base styles simple

• Adapt styles through prop modifiers

Publishing

// from the root of your component library
$ npm login
// enter your credentials
$ npm publish

// NOTE: your email address is public
$ npm set init.author.name "Your Name"
$ npm set init.author.email "you@example.com"
$ npm set init.author.url "http://yourblog.com"
$ npm adduser
$ npm publish

Already have an account with npm? Run:

New to npm? Run:

Thanks!

RESOURCES
• Example Component Library Starter
• Component Library Playground

• Styled-Components

• Atomic Design

• MarvelApp Styleguide

• Using `npm link`

• Publishing Packages

• Accompanying blogpost(s)

• Contributor Code of Conduct