Scala.js + Slinky Expo Template

This template sets up a simple React Native application written in Scala through Scala.js, Slinky, and Expo.

Installation

On macOS will need to install XCode for this if you haven't already.

Install the Expo CLI:

$ npm install -g expo-cli

Use the template

$ expo init --template expo-template-scala

Prepare react-native

$ npm install react-native

Building Apps

Once you've created your project, first compile your Scala code to JavaScript by running

$ sbt fastOptJS

Then, launch the app with Expo

$ npm start

Production Bundles

To create a minified app, first build an optimized Scala.js bundle

$ sbt fullOptJS

Then, go to App.js and uncomment app = require("./target/scala-2.13/app-opt.js").app; in order to enable the production bundle. Finally, switch Expo to production mode to load your production app.

Ejecting

If you need to develop your app without depending on Expo, you can eject at any time by running npm run eject. This gives you the option to either eject to a "bare" project that uses React Native's build tooling or to an unmanaged ExpoKit project that still uses Expo but lets you add in custom native dependencies.