Kotlin Multiplatform is a framework of Kotlin that allows for sharing of a single codebase for business logic across different targets/platforms. Some of the targets supported by kotlin are: Android, iOS, Kotlin/JVM, Kotlin/JS, Android NDK, Windows, Linux, macOS etc.
Compose Multiplatform is a UI framework mabe by Jetbrains that allow for simple and accelerated desktop application and web development using compose. Compose multiplatform also allows sharing compose UI code between diffrent platforms. eg android, desktop(Windows, Linux, MacOS) and web.
In order to be able to build the application you'll need to change the api key in
gradle.properties. First and formost you need to generate your own api key by creating a TMDB account and generating an api key.
Koltin Multiplatform is still in alpha phase at the time of writting this however it's still being used by some well known companies around the world.
Kotlin multiplatform and Compose multiplatform are two diffrent concepts that aim to so achieve multiplatform programming. Kotlin multiplatform is all about sharing business logic(at times presentation logic too but only "viewmodels") across diffrent platforms while compose multiplatform is about using/sharing compose UI across diffrent platforms.
When starting out a KMP/KMM project some knownledge of Clean Architecture or similar design patterns, SOLID principles, separation of concern and modularization might go a long way into reducing the learning curve. i have discussed the usage of above concepts in a previous iteration of this project.
Kotlin multiplatform and compose multiplatform have limited learning resources and a relatively small community at the time of writting. However learning resources have been attached at the end of this doc and you can find a fast diverse Kotlin community on Kotlin Official slack or Android254 twitter.
The project currently has 3 main modules:
This module contains the android application's UI built using Jetpack compose.
This module contains the desktop application's UI built using Compose Multiplatform.
This module contains shared code that holds the domain and data layers and some part of the presentation logic ie.shared viewmodels
This is the core layer of the application. The
domain layer is independent of any other layers this means that changes in other layers will have no effect on domain layer eg. screen UI (presentation layer) or changing database (data layer) will not result in any code change withing domain layer.
Components of domain layer include:
Models: Defines the core structure of the data that will be used within the application.
Repositories: Interfaces used by the use cases. Implemented in the data layer.
data layer is responsibile for selecting the proper data source for the domain layer. It contains the implementations of the repositories declared in the domain layer.
Components of data layer include:
-Dto Models: Defines POJO of network responses.
-Entity Models: Defines the schema of the database.
Mappers: They perform data transformation between
Network: This is responsible for performing network operations eg. defining API endpoints using Ktor.
Cache: This is responsible for performing caching operations using Realm.
Data Sources: Responsible for deciding which data source (network or cache) will be used when fetching data and presenting the data to viewmodels.
In this section I've included some resources ie. articles and GitHub reposirtories that i used to learn about kotlin mutltiplatform mobile:
In this section I've included resources that are not related to kotin multiplatform mobile but were really helpful in learning other android components and tools: