harinathsrinivasan / kotlin-mpp-angular

Experimental Kotlin Multiplatform with Gradle sub-projects and Angular

kotlin-multiplatform-angular

This project is a playground for exploring how to use Kotlin for building a multi-platform application that contains JVM and Angular UIs.

The domain logic calculates Fibonacci numbers and is by intention as simple as possible.

Links:

• Multiplatform setup: https://github.com/dhakehurst/example.kotlin.angular
• Kotlin and Typescript integration: https://www.itemis.com/en/kotlin-typescript-integration/

Environment

• Developement with IntelliJ IDEA 2019.3
• Gradle project with multiple subprojects
• Kotlin multiplatform setup for JVM and JS targets
• mockk for mocking in tests
• Entire domain logic written in Kotlin
• JVM Swing UI built with ShadowJar and started by gradle "run" task
• Angular UI using Kotlin domain logic in the browser

Usage

Run JVM application

In a console (using the built shadow JAR):

java -jar .gradle-build/ui/libs/ui-1.0.0-all.jar

Or with the gradle run task (also using the shadow JAR):

gradlew :ui:run

Or with an IntelliJ IDEA run configuration: Navigate in IntelliJ IDEA to ../ui/jvm/src/main/ch/flandreas/techstack/ui /FibonacciUI and execute "Run FibonacciUI" from the popup menu, which will generate a new run configuration.

Run Angular App

In a console:

cd ui/js/src/angular
ng serve --open

Solved issues

1. Resources are not part of IntelliJ Kotlin (JVM) run configuration classpath. See https://youtrack.jetbrains.com /issue/KT-24463. Use gradle task to copy the resources to the appropriate build directory.
2. The "application" plugin can't be used, because the "main" source set is hardcoded in ApplicationPlugin, but the source set of the artifact is "jvmMain". See gradle/gradle#8113. Hence, the ShadowJar plugin can't be used based on the application plugin, but must be configured separately. The same applies to running the Java application.

Open issues

• Feature: Build a combined JAR with all Java classes and resources (non-fat JAR)
• Bug: jvmJar contains Angular artifacts

Future extensions

1. Include backend REST endpoint