README

react-native-css-transformer

Use CSS to style your React Native apps.

Behind the scenes the .css files are transformed to react native style objects (look at the examples).

This transformer can be used together with React Native CSS modules.

How does it work?

Your App.css file might look like this:

.myClass {
  color: blue;
}
.myOtherClass {
  color: red;
}
.my-dashed-class {
  color: green;
}

When you import your stylesheet:

import styles from "./App.css";

Your imported styles will look like this:

var styles = {
  myClass: {
    color: "blue"
  },
  myOtherClass: {
    color: "red"
  },
  "my-dashed-class": {
    color: "green"
  }
};

You can then use that style object with an element:

Plain React Native:

<MyElement style={styles.myClass} />

<MyElement style={styles["my-dashed-class"]} />

React Native CSS modules using className property:

<MyElement className={styles.myClass} />

<MyElement className={styles["my-dashed-class"]} />

React Native CSS modules using styleName property:

<MyElement styleName="myClass my-dashed-class" />

Installation and configuration

Step 1: Install

yarn add --dev react-native-css-transformer

Step 2: Configure the react native packager

For React Native v0.57 or newer / Expo SDK v31.0.0 or newer

Add this to metro.config.js in your project's root (create the file if it does not exist already):

const { getDefaultConfig } = require("metro-config");

module.exports = (async () => {
  const {
    resolver: { sourceExts }
  } = await getDefaultConfig();
  return {
    transformer: {
      babelTransformerPath: require.resolve("react-native-css-transformer")
    },
    resolver: {
      sourceExts: [...sourceExts, "css"]
    }
  };
})();

If you are using Expo, you also need to add this to app.json:

{
  "expo": {
    "packagerOpts": {
      "config": "metro.config.js"
    }
  }
}

For React Native v0.56 or older

If you are using React Native without Expo, add this to rn-cli.config.js in your project's root (create the file if you don't have one already):

module.exports = {
  getTransformModulePath() {
    return require.resolve("react-native-css-transformer");
  },
  getSourceExts() {
    return ["js", "jsx", "css"];
  }
};

For Expo SDK v30.0.0 or older

If you are using Expo, instead of adding the rn-cli.config.js file, you need to add this to app.json:

{
  "expo": {
    "packagerOpts": {
      "sourceExts": ["js", "jsx", "css"],
      "transformer": "node_modules/react-native-css-transformer/index.js"
    }
  }
}

Dependencies

This library has the following Node.js modules as dependencies:

Usage no npm install needed!