android-mvi-sample

Example MVI implementation, based off of Google's architectural samples.

Description

This is a sample implementation of the Model View Intent pattern. Full Android examples for MVI are hard to find.

Target audience include, but not limited to:

• Developers making the pivot from an imperative to declarative style of programming.
• Developers looking for working example of functional or reactive programming on Android.

Here are some articles/examples explaining the core principles of MVI and unidirectional flow:

• http://hannesdorfmann.com/android/model-view-intent
• https://cycle.js.org/model-view-intent.html
• http://thenewstack.io/developers-need-know-mvi-model-view-intent/
• http://blog.danlew.net/2017/07/27/an-introduction-to-functional-reactive-programming/
• https://proandroiddev.com/mvi-a-new-member-of-the-mv-band-6f7f0d23bc8a

Key Application Components

• ModelStore.kt: a generic Model Store inspired by Redux
• Intent.kt: basic DSL for building Intents and Reducers for generic types.
• TaskEditorState.kt: sealed class + reducer based state machine.

Stack

One goal of this repo is to keep things as light as possible. The core libraries used are:

• Kotlin
• RxJava 2
• RxBindings
• RxRelay
• Retrofit
• Toothpick DI

If you require a very lightweight project, and still want to do MVI, it's not unreasonable to think you could do without RxJava. As of writing, RxJava dependencies weighs in at about ~2MB.

Once you grasp the basics, I suggest you explore the following existing libraries:

• https://github.com/airbnb/MvRx
• https://github.com/badoo/MVICore
• https://github.com/freeletics/RxRedux
• https://github.com/groupon/grox
• https://github.com/spotify/mobius
• https://github.com/Tinder/StateMachine