npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

fela

v12.2.1

Published

State-Driven Styling in JavaScript

Downloads

234,764

Vulnerabilities

Powered byPowered by Snyk
  • 0High
  • 0Medium
  • 0Low

Links

Git

Maintainers

rofrischmannrofrischmanntxhawkstxhawks

Keywords

feladynamic stylingstylesheetcssstylingfunctional stylingfunctional cssatomic cssstate-drivenatomic designstate-driven stylingcssinjs

Readme

Fela is a small, high-performant and framework-agnostic toolbelt to handle state-driven styling in JavaScript. It is dynamic by design and renders your styles depending on your application state.

It generates atomic CSS and supports all common CSS features such as media queries, pseudo classes, keyframes and font-faces. Fela ships with a powerful plugin API adding e.g. vendor prefixing or fallback value support.

Fela can be used with React or with any other view library. It even supports React Native.

Support Us

Support Robin Weser's work on Fela and its ecosystem directly via GitHub Sponsors.

Benefits

  • Predictable Styling
  • Scoped Atomic CSS
  • Minimal Bundle Size
  • No Specificity Issues
  • No Naming Conflicts
  • Framework-Agnostic
  • Huge Ecosystem
  • RTL Support

Read more about the benefits!

The Gist

Fela's core principle is to consider style as a function of state. The whole API and all plugins and bindings are built on that idea. It is reactive and auto-updates once registered to the DOM.

The following example illustrates the key parts of Fela though it only shows the very basics.

import { createRenderer } from 'fela'

// a simple style rule is a pure function of state
// that returns an object of style declarations
const rule = (state) => ({
  textAlign: 'center',
  padding: '5px 10px',
  // directly use the state to compute style values
  fontSize: state.fontSize + 'pt',
  borderRadius: 5,
  // deeply nest media queries and pseudo classes
  ':hover': {
    fontSize: state.fontSize + 2 + 'pt',
    boxShadow: '0 0 2px rgb(70, 70, 70)',
  },
})

const renderer = createRenderer()

// fela generates atomic CSS classes in order to achieve
// maximal style reuse and minimal CSS output
const className = renderer.renderRule(rule, {
  fontSize: 14,
}) // =>  a b c d e f

The generated CSS output would look like this:

.a { text-align: center }
.b { padding: 5px 10px }
.c { font-size: 14pt }
.d { border-radius: 5px }
.e:hover { font-size: 16pt }
.f:hover { box-shadow: 0 0 2px rgb(70, 70, 70) }

Primitive Components

If you're using Fela, you're most likely also using React. Using the React bindings, you get powerful APIs to create primitive components.

Read: Usage with React for a full guide.

import * as React from 'react'
import { useFela } from 'react-fela'

const rule = ({ fontSize }) => ({
  textAlign: 'center',
  padding: '5px 10px',
  // directly use the props to compute style values
  fontSize: fontSize + 'pt',
  borderRadius: 5,
  ':hover': {
    fontSize: fontSize + 2 + 'pt',
    boxShadow: '0 0 2px rgb(70, 70, 70)',
  },
})

function Button({ fontSize, children }) {
  const { css } = useFela({ fontSize })

  return <button className={css(rule)}>{children}</button>
}

Check this example on CodeSandbox

Examples

Documentation

Workshop

If you are coming from CSS and want to learn JavaScript Styling with Fela, there is a full-feature fela-workshop which demonstrates typical Fela use cases. It teaches all important parts, step by step with simple examples. If you already know other CSS in JS solutions and are just switching to Fela, you might not need to do the whole workshop, but it still provides useful information to get started quickly.

Talks

Posts

Ecosystem

There are tons of useful packages maintained within this repository including plugins, enhancers, bindings and tools that can be used together with Fela. Check the Ecosystem documentation for a quick overview.

Community

Apart from all the packages managed within this repository, there are many community third-party projects that are worth mentioning:

Support

Got a question? Come and join us on Spectrum! We'd love to help out. We also highly appreciate any feedback. Don't want to miss any update? Follow us on Twitter.

Who's using Fela?

Your company is using Fela, but is not listed yet? Add your company / organisation

Contributing

This project exists thanks to all the people who contribute.

We highly appreciate any contribution. For more information follow the contribution guide. Also, please read our code of conduct.

License

Fela is licensed under the MIT License. Documentation is licensed under Creative Commons License. Created with ♥ by @robinweser and all the great contributors.