@startupjs/babel-plugin-rn-stylename-to-style

@startupjs/babel-plugin-rn-stylename-to-style

Transform JSX styleName property to style property in react-native. The styleName attribute and syntax are based on babel-plugin-react-css-modules.

Information

This is the fork of https://github.com/kristerkari/babel-plugin-react-native-stylename-to-style

The differences are:

1. Support resolving multi-class selectors in CSS:

import classnames from 'classnames'

function Button ({
  variant,  // [string] 'primary' | 'secondary'
  dark,     // [bool]
  disabled  // [bool]
}) {
  return (
    <Text
      styleName={classnames('button', [variant, { dark, disabled }])}
    >CLICK ME</Text>
  )
}

.button
  background-color: blue
  &.primary
    color: #ff0000
    &.disabled
      color: rgba(#ff0000, 0.5)
  &.secondary
    color: #00ff00
    &.disabled
      color: rgba(#00ff00, 0.5)
  &.disabled
    color: #777

.dark
  &.button
    background-color: purple
    &.primary
      color: white
      &.disabled
        color: #ddd
  &.disabled
    color: #eee

And what's important is that selectors` specificity is properly emulated. For example:

Styles for .button.primary.disabled (specificity 30) will override styles of .button.disabled (specificity 20), even though .button.disabled is written later in the CSS.

This simple change brings a lot more capabilities in theming your components for a dynamic look.

1. Convert any *StyleName attribute to the according *Style attribute. This is very useful for passing the sub-element styles (which are usually exposed by react-native libraries) directly from CSS.

2. If the styleName value is an object or an array, automatically pipe it through the classnames-like library.

3. Support for multiple named css file imports is removed

Usage

WARNING: This plugin is already built in into the babel-preset-startupjs and is included into the default StartupJS project.

If you want to use this plugin separately from StartupJS:

Step 1: Install

yarn add --dev @startupjs/babel-plugin-rn-stylename-to-style

or

npm install --save-dev @startupjs/babel-plugin-rn-stylename-to-style

Step 2: Configure .babelrc

You must give one or more file extensions inside an array in the plugin options.

{
  "presets": [
    "react-native"
  ],
  "plugins": [
    ["react-native-dynamic-stylename-to-style", {
      "extensions": ["css"]
    }]
  ]
}

Plugin Options

extensions

Required

List of css extensions to process (css, styl, sass, etc.)

useImport

Default: false

Whether to generate ESM import instead of CJS require.

parseJson

Default: false

Whether the imported css is expected to be a JSON string or an object. If this flag is specified then JSON string is expected and it will do JSON.parse on it.

Syntax

Anonymous reference

Anonymous reference can be used when there is only one stylesheet import.

Single class

import "./Button.css";

<View styleName="wrapper">
  <Text>Foo</Text>
</View>;

↓ ↓ ↓ ↓ ↓ ↓

import Button from "./Button.css";

<View style={Button.wrapper}>
  <Text>Foo</Text>
</View>;

Multiple classes

import "./Button.css";

<View styleName="wrapper red-background">
  <Text>Foo</Text>
</View>;

↓ ↓ ↓ ↓ ↓ ↓

import Button from "./Button.css";

<View style={[Button.wrapper, Button["red-background"]]}>
  <Text>Foo</Text>
</View>;

Expression

import "./Button.css";
const name = "wrapper";

<View styleName={name}>
  <Text>Foo</Text>
</View>;

↓ ↓ ↓ ↓ ↓ ↓

import Button from "./Button.css";
const name = "wrapper";

<View
  style={(name || "")
    .split(" ")
    .filter(Boolean)
    .map(function(name) {
      Button[name];
    })}
>
  <Text>Foo</Text>
</View>;

Expression with ternary

import "./Button.css";

const condition = true;
const name = "wrapper";

<View styleName={condition ? name : "bar"}>
  <Text>Foo</Text>
</View>;

↓ ↓ ↓ ↓ ↓ ↓

import Button from "./Button.css";

const condition = true;
const name = "wrapper";

<View
  style={((condition ? name : "bar") || "")
    .split(" ")
    .filter(Boolean)
    .map(function(name) {
      Button[name];
    })}
>
  <Text>Foo</Text>
</View>;

with styleName and style:

import "./Button.css";

<View styleName="wrapper" style={{ height: 10 }}>
  <Text>Foo</Text>
</View>;

↓ ↓ ↓ ↓ ↓ ↓

import Button from "./Button.css";

<View style={[Button.wrapper, { height: 10 }]}>
  <Text>Foo</Text>
</View>;

::part() selector

Preprocess part attribute.

• Each part gets its styles from the {part}Style prop.
• part='root' is magic -- it's linked to the pure style prop.

Here is an example <Card> component which specifies its root container, title and footer as stylizable parts:

// Card.js

function Card ({ title }) {
  return (
    <View part='root'>
      <Text part='header'>{title}</Text>
      <Text part='footer'>Copyright</Text>
    </View>
  )
}

↓ ↓ ↓ ↓ ↓ ↓

function Card ({ title, style, headerStyle, footerStyle }) {
  return (
    <View style={style}>
      <Text style={headerStyle}>{title}</Text>
      <Text style={footerStyle}>Copyright</Text>
    </View>
  )
}

Preprocess ::part() selector from CSS file to style any component which uses part attributes.

Following an example <Card> component above, we can call <Card> from the <App> and customize its parts styles:

// App.js

import Card from './Card'
import './index.styl'

function App ({ users }) {
  return users.map(user => (
    <Card styleName='user' title={user.name} />
  ))
}

// index.styl

.user
  margin-top 16px

  &:part(header)
    background-color black
    color white

  &:part(footer)
    font-weight bold