These tutorials target Micronaut Framework 3. Read, Guides for Micronaut Framework 4.

Turbo Native Demo with iOS/Android and a Micronaut Backend

Run the Turbo Native Demo with a Micronaut application as the backend.

Authors: Sergio del Amo, Tim Yates

Micronaut Version: 3.9.2

1. What you will need

To complete this guide, you will need the following:

  • Some time on your hands

  • A decent text editor or IDE

  • JDK 1.8 or greater installed with JAVA_HOME configured appropriately

2. Download

The complete application can be downloaded from the following link.

3. Getting Started

This guide provides the Micronaut version, written in Kotlin, of Hotwire’s Node small app. It demonstrates how to use Turbo with a native (iOS or Android) app.

3.1. What is Hotwire?

Hotwire is an umbrella for trio frameworks that implement the HTML-over-the-wire approach to building modern web applications. At its heart is Turbo, which gives you techniques for bringing the speed of a single-page application without writing a lick of JavaScript.

Turbo integration is part of the micronaut-views module.

To run the Android application, install Android Studio.

To run the iOS application, install XCode.

4. Running the Application

To run the application, use the ./gradlew run command, which starts the application on port 8080.

5. Android Demo App

Once the Micronaut application is running, you just need to change demo/src/main/kotlin/dev/hotwire/turbo/demo/util/Constants.kt. Set the BASE_URL to the URL of the Micronaut application.

If you’re running your Micronaut application locally without HTTPS, you’ll need to adjust your android:usesCleartextTraffic settings in the AndroidManifest.xml (or use an Android Network security configuration) and target 10.0.2.2 instead of localhost.
demo/src/main/kotlin/dev/hotwire/turbo/demo/util/Constants.kt
package dev.hotwire.turbo.demo.util

const val BASE_URL = "http://10.0.2.2:8080"
const val HOME_URL = BASE_URL
const val SIGN_IN_URL = "$BASE_URL/signin"
const val NUMBERS_URL = "$BASE_URL/numbers"
demo/src/main/AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:tools="http://schemas.android.com/tools"
    package="dev.hotwire.turbo.demo"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:usesCleartextTraffic="true"
...

Once you run the app on an emulator or on a real device, you will see the results:

Android demo app

5.1. Android Demo Screencast

There is a screencast which shows this in action

6. iOS Demo App

Once the Micronaut application is running, point to the local version of the demo by changing Demo.current to use local in Demo/Demo.swift. Then edit the port to match the port used by the Micronaut application.

...
struct Demo {
    ...
    static let local = URL(string: "http://localhost:8080")!
    static let turbolinks5Local = URL(string: "http://localhost:8080?turbolinks=1")!

    static var current: URL {
        local
    }
}
Ensure the URL does not end with a slash.

You will then be able to run this app locally (or on a real device) and see the results:

iOS demo app

6.1. iOS Demo Screencast

There is a screencast which shows this in action

7. Next steps

Explore more features with Micronaut Guides.

Read more about Turbo.

Read more about Micronaut Views.

8. Help with the Micronaut Framework

The Micronaut Foundation sponsored the creation of this Guide. A variety of consulting and support services are available.