Dripsy

A dead-simple, responsive design system for Expo / React Native Web. Heavily inspired by React’s theme-ui.

Style once, run anywhere.

<Text
  sx={{
    fontSize: [14, 16, 20], // 14 on mobile, 16 on tablet, 20 on desktop
    color: ['primary', null, 'accent'], // `primary` on mobile & tablet, `accent` on desktop
  }}
>
  Responsive font size?? 🤯
</Text>

Features

Responsive styles
Universal (Android, iOS, Web)
Works with Expo
Works with Next.js / server-side rendering
Full theme support
Custom theme variants
TypeScript support (TypeScript theme support is in the works too)
Insanely simple API (themed, responsive designs in one line!)
Works with Animated/Reanimated values
Dark mode / custom color modes

🤔 Why?

Build once, deploy everywhere, is a great philosophy made possible by Expo Web/React Native Web. A large impediment is responsive design.

React Native doesn’t have media queries for styles, and trying to micmick it with JS turns into useState hell with a ton of conditionals (as you’ll see below.)

While React Native has some great component libraries, it lacks a good design system that is responsive and themed.

No longer. The goal of Dripsy is to let you go from idea to universal, themed styles without much effort.

There is no shortage of discussion about what responsive design should look like in React Native.

After trying many, many different ways, I’m convinced this approach is the answer. I’m curious to see if you’ll think the same.

🙉 Installation

yarn add dripsy

# or
npm i dripsy

If you’re using Next.js or another SSR app, scroll down to see how to configure.

🛠 Set up

Technically, you don’t have to do anything else!

However, you’ll likely want to create a custom theme.

Custom theme

Wrap your entire app with the DripsyProvider, and pass it a theme object. Make sure you create your theme outside of the component to avoid re-renders.

If you’re using Next.js, this goes in pages/_app.js.

App.js

import { DripsyProvider } from 'dripsy'

const theme = {
  colors: {
    text: '#000',
    background: '#fff',
    primary: 'tomato',
  },
  fonts: {
    body: 'system-ui, sans-serif',
    heading: '"Avenir Next", sans-serif',
  },
  spacing: [10, 12, 14],
}

export default function App() {
  return (
    <DripsyProvider theme={theme}>
      {/* Your app code goes here! */}
    </DripsyProvider>
  )
}

Follow the docs from theme-ui to see how to theme your app – we use the same API as them.

My personal preference is to have the entire theme object in one file.

All theme values are optional. You don’t have to use them if you don’t want.

For SSR apps (Next.js, Gatsby, etc.)

If you are not using Next.js, skip down to #3 below.

Steps 1 & 2 are required for Next.js apps (for example, if you’re using Expo + Next.js.)

1. Install dependencies

yarn add next-compose-plugins next-transpile-modules

2. Edit your next.config.js file to look like this:

const withPlugins = require('next-compose-plugins')
const withTM = require('next-transpile-modules')([
  'dripsy',
  // you can add other packages here that need transpiling
])

const { withExpo } = require('@expo/next-adapter')

module.exports = withPlugins(
  [withTM],
  withExpo({
    projectRoot: __dirname,
  })
)

Add SSRStyleReset to the top of your body

Import SSRStyleReset and inject it at the top of your body HTML tag.

import { SSRStyleReset } from 'dripsy'

<body>
  <SSRStyleReset />
  <YourApp />
</body>

If you’re using Next.js, this should go in pages/_document.js.

Your pages/_document.js should look something like this.

We’ll add other library examples here too, such as Gatsby.

That’s it! Btw, if you’re using Expo + Next.js, check out my library, expo-next-react-navigation to help with navigation.

👀 What does Dripsy look like?

Create a theme!

export default {
  colors: {
    text: '#000',
    background: '#fff',
    primary: 'tomato',
  },
  spacing: [10, 12, 14],
  fontSizes: [16, 20, 24],
  text: {
    h1: {
      fontSize: 3, // this is 24px, taken from `fontSize` above
    },
    p: {
      fontSize: 1, // & this is 16px, taken from `fontSize` above
    },
  },
}

…and build a beautiful, responsive UI

<Text
  sx={{
    color: 'primary',
    padding: [1, 3], // [10px, 14px] from theme!
  }}
>
  Themed color!
</Text>

…you can even use “HTML” elements

import { H1, H2, P } from 'dripsy'

<H1
  sx={{
    color: 'text', // #000 from theme!
    fontSize: 2    // 24px from theme!
  }}
>

</H1>

Credit to Evan Bacon for @expo/html-elements, used above!

Todo: make the theme values show up in TS types for intelliesense.

Usage

Dripsy is an almost-drop-in replacement for React Native’s UI components.

Change your imports from react-native to dripsy

- import { View, Text } from 'react-native'
+ import { View, H1, P } from 'dripsy'

Use the sx prop instead of style to use themed and responsive styles:

<View
  sx={{
    height: [100, 400],
    backgroundColor: 'primary',
    marginX: 10,
  }}
/>

Also, instead of marginHorizontal, use marginX or mx, as seen on the theme-ui docs.

Animated Values

To use an animated view, simple use the as prop.

import { View } from 'dripsy'
import Animated from 'react-native-reanimated'
import { useValue } from 'react-native-redash'

function App() {
  const height = useValue(0)

  return <View as={Animated.View} sx={{ height }} />
}

🏆 Before & After

Before Dripsy ☹️

This is what it took to make one responsive style without Dripsy…

import { useState } from 'react'
import { View } from 'react-native'

const ResponsiveBox = () => {
  const [screenWidth, setScreenWidth] = useState(Dimensions.get('window').width)

  useEffect(() => {
    const onResize = event => {
      setScreenWidth(event.window.width)
    }
    Dimensions.addEventListener('change', onResize)

    return () => Dimensions.removeEventListener('change', onResize)
  }, [])

  let width = '100%'
  if (screenWidth > 700) {
    width = '50%'
  }

  return <View style={{ width }} />
}

A big issue with using JS-only breakpoints like that is that it won’t work on SSR apps using Expo + Next.js. The “solution” would be to lazy load the component, but then you lose the SEO benefits of Next.js. With Dripsy, SSR works fine!

With Dripsy 🤩

import { View } from 'dripsy'

const ResponsiveBox = () => {
  return <View sx={{ width: ['100%', '50%'] }} />
}

API

🚨 More docs coming here!!!

`styled`

import { View } from 'react-native'
import { styled } from 'dripsy' 

const StyledView = styled(View)({
  flex: 1,
  bg: 'primary'
})

// This uses the theme.layout.container styles!
const StyledView2 = styled(View, { themeKey: 'layout', defaultVariant: 'container' })({
  flex: 1,
  bg: 'primary'
})

`createThemedComponent`

Prefer styled.

Currently, a bunch of the React Native components are supported. That said, I haven’t added them all. If you want to add one, go to src/components and add one and submit a PR.

Or, you can use the createThemedComponent function in your own app.

import { createThemedComponent } from 'dripsy'
import { View } from 'react-native'

const CustomView = createThemedComponent(View, {
  defaultStyle: {
    flex: 1,
  },
})

How it works

First, this library is super inspired by theme-ui, and uses many of its low-level functions and methodologies.

Practically speaking, this library uses the Dimensions api on Android & iOS, and uses actual CSS breakpoints on web. The CSS breakpoints are made possible by @artsy/fresnel. This means that you get actually-native web breakpoints. That matters, because server-size rendered apps will have startup issues if you use JS-based media queries that require React to rehydrate on when it opens.

On Native, there is nothing too fancy going on. We track the screen width, generate styles based on the current width using a mobile-first approach, and return the regular React Native components. But it just feels like magic!

Contributing

This is a really new project. I’d love your help and contributions.

Download Details:

Author: nandorojo

Source Code: https://github.com/nandorojo/dripsy

#react-native #react #mobile-apps

A simple, responsive design system for Expo + React Native Web