Kotlin-Multiplatform (Android, iOS, JS & JVM Desktop App)

<a target="_blank" href="https://androidweekly.net/issues/issue-397"><img src="https://androidweekly.net/issues/issue-397/badge"></a> <a target="_blank" href="https://androidweekly.net/issues/issue-380"><img src="https://androidweekly.net/issues/issue-380/badge"></a>

This example shows how to create a simple Android/iOS/JVM/JS project sharing some Kotlin code. This app saves on a local database your favourites locations and get the current weather of them from OpenWeatherMap.

In this app we share common code for both platforms (Android/iOS) to get data from an API (in this case OpenWeatherMap). The libraries that we use are:

• KTOR: to make HTTP requests
• Serialization: to De/Serializing JSON
• SqlDelight: Local database shared between Android & iOS

Tests:

• MockK: mocking library for Kotlin

<img src="https://github.com/jarroyoesp/KotlinMultiPlatform/blob/master/images/GetLocationDiagram.png">

Android App - Master Branch

With this app you can get the weather of your locations using KTor:

<img src="https://github.com/jarroyoesp/KotlinMultiPlatform/blob/master/images/AndroidCaptureWeather.png" width="200">

And add and save on SQLDelight database your favourite locations:

<img src="https://github.com/jarroyoesp/KotlinMultiPlatform/blob/master/images/AndroidCaptureLocationList.png" width="200">

iOS App

Open XCode and select the project:

<img src="https://github.com/jarroyoesp/KotlinMultiPlatform/blob/master/images/iOS_App.png" width="200">

JVM - Desktop App

To execute this version as desktop app, you have to execute this code on your console:

./gradlew JavaFxApp:run

By default the JDBC SQLite is created in memory. If you want to persist your database in your disk, you have to indicate the path when you create the database driver:

SQLDriver.kt
JdbcSqliteDriver("jdbc:sqlite:$your_database_path")

<img src="https://github.com/jarroyoesp/KotlinMultiPlatform/blob/master/images/JVMApp.png" width="800">

JS App

If you want to launch a web to get the weather you can try executing the next commands:

./gradlew JsApp:run
./gradlew BackEnd:run
--> localhost:8080

Current weather is not shown when you launch the browser? If you have this problem (Module not found: Error: Can't resolve 'core-js/features/object/assign') try to reinstall the node module core-js:

npm install core-js

<img src="https://github.com/jarroyoesp/KotlinMultiPlatform/blob/master/images/jsApp.png" width="400">

I have followed these examples:

https://kotlinlang.org/docs/tutorials/native/mpp-ios-android.html

https://www.raywenderlich.com/1022411-kotlin-multiplatform-project-for-android-and-ios-getting-started

https://proandroiddev.com/kotlin-multiplatform-very-beginners-guide-part-3-database-e34c92daf41c