react-native-workers

Spin worker threads and run CPU intensive tasks in the background. Bonus point on Android you can keep a worker alive even when a user quit the application :fireworks:

Features

• JS web workers for iOS and Android
• access to native modules (network, geolocation, storage ...)
• Android Services in JS :tada:

Installation

npm install react-native-workers --save

Automatic setup

simply rnpm link react-native-workers and you'r good to go.

Manual setup

iOS

1. Open your project in XCode, right click on Libraries and click Add Files to "Your Project Name". Look under node_modules/react-native-workers/ios and add Workers.xcodeproj
2. Add libWorkers.a to Build Phases -> Link Binary With Libraries

Android

in android/settings.gradle

 include ':app', ':react-native-workers'
 project(':react-native-workers').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-workers/android')

in android/app/build.gradle add:

dependencies {
   ...
   compile project(':react-native-workers')
}

and finally, in your MainApplication.java add:

import co.apptailor.Worker.WorkerPackage; // <--- This!

public class MainApplication extends Application implements ReactApplication {

private final ReactNativeHost mReactNativeHost = new ReactNativeHost(this) {
    @Override
    protected boolean getUseDeveloperSupport() {
      return BuildConfig.DEBUG;
    }

    @Override
    protected List<ReactPackage> getPackages() {
      return Arrays.<ReactPackage>asList(
          new MainReactPackage(),
          new WorkerPackage() // <--- and this
      );
    }
  };

  @Override
  public ReactNativeHost getReactNativeHost() {
      return mReactNativeHost;
  }
}

Note: only the official react native modules are available from your workers (vibration, fetch, etc...). To include additional modules in your workers add them to the WorkerPackage constructor. Like this:

new WorkerPackage(new MyAwesomePackage(), new MyAmazingPackage())`

JS API

From your application:

import { Worker } from 'react-native-workers';

/* start worker */
const worker = new Worker("path/to/worker.js");

/* post message to worker. String only ! */
worker.postMessage("hello from application");

/* get message from worker. String only ! */
worker.onmessage = (message) => {

}

/* stop worker */
worker.terminate();

From your worker js file:

import { self } from 'react-native-workers';

/* get message from application. String only ! */
self.onmessage = (message) => {
}

/* post message to application. String only ! */
self.postMessage("hello from worker");

Lifecycle

• the workers are paused when the app enters in the background
• the workers are resumed once the app is running in the foreground
• During development, when you reload the main JS bundle (shake device -> Reload) the workers are killed

Todo

• [x] Android - download worker files from same location as main bundle
• [x] iOS - download worker files from same location as main bundle
• [ ] script to package worker files for release build
• [x] load worker files from disk if not debug