Kotlin Multi-Platform TodoMVC

This is a multiplatform Kotlin project implementing a subset of the TodoMVC application. While it is not intended to showcase an MV* framework per se, it should provide a starting point for setting up multi-platform projects with the Kotlin toolchain. Please note, that most of the toolchain and frameworks used in this project are still pre-release at the time of writing.

This project was created as demo for our talk at Kotlin Vienna, which will be available online soon.

Overview

The project consists of three modules:

• domain: Common code that is required by both other modules. It builds on kotlin-platform-common, which only allows platform-independent implementations based on kotlin-stdlib-common. Specifically, it provides the Todo domain class so it can be shared between server and client.
• backend: The server-portion of the TodoMVC example. It builds on kotlin-platform-jre8 and Spring Boot. Additionally, it implements domain for the JVM.
• frontend: The client-portion of the TodoMVC example. It builds on kotlin-platform-js and kotlinx-html-js. Additionally, it implements domain for the browser.

Development

This project follows the standard gradle workflow. To build and run use ./gradlew or ./gradlew.bat on *nix systems and Windows, respectively. The relevant targets are:

• backend:bootRun starts the Spring Boot web server and exposes its API for the frontend.
• frontend:build builds the JavaScript bundle and places an index.html file in the output folder. Open that file, usually located in frontend/build/resources/main/index.html to open the Todo list.

Sadly, the IntelliJ IDEA import does not work yet. The fixing commit has already landed in the Kotlin Plugin master, so it is just a matter of time.

Useful Resources

• Kotlin Frontend Plugin: Use npm, webpack and karma in a convenient way during the gradle build process.
• ts2kt: Convert typescript definitions to kotlin bindings.
• Coroutines: Utilities and convenience functions to handle coroutines more easily.
• Kotlin DCE: Dead code elimination to reduce the file size of the kotlin library's kotlin.js.