What is Koin?

A pragmatic lightweight dependency injection framework for Kotlin developers. Written in pure Kotlin using functional resolution only: no proxy, no code generation, no reflection!

Koin is a DSL, a lightweight container and a pragmatic API.

Get started Setup

Actual Version - 1.0.1

repositories {
  jcenter()    
}
dependencies {
    // Koin for Kotlin
    compile 'org.koin:koin-core:1.0.1'
}

repositories {
  jcenter()    
}
dependencies {
    // Koin for Android
    compile 'org.koin:koin-android:1.0.1'
    // or Koin for Lifecycle scoping
    compile 'org.koin:koin-android-scope:1.0.1'
    // or Koin for Android Architecture ViewModel
    compile 'org.koin:koin-android-viewmodel:1.0.1'
}

repositories {
  jcenter()    
}
dependencies {
    // Koin for Android
    compile 'org.koin:koin-android:1.0.1'
    // or Koin for Lifecycle scoping
    compile 'org.koin:koin-androidx-scope:1.0.1'
    // or Koin for Android Architecture ViewModel
    compile 'org.koin:koin-androidx-viewmodel:1.0.1'
}

repositories {
  jcenter()    
}
dependencies {
    // Koin for SparkKotlin
    compile 'org.koin:koin-spark:1.0.1'
}

repositories {
  jcenter()    
}
dependencies {
    // Koin for Ktor
    compile 'org.koin:koin-ktor:1.0.1'
}

// Given some classes class Controller(val service : BusinessService) class BusinessService() // just declare it val myModule = module { single { Controller(get()) } single { BusinessService() } }

// Just inject in a simple Activity class MyActivity() : AppCompatActivity() { // lazy inject BusinessService into property val service : BusinessService by inject() override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) // or directly get any instance val service : BusinessService = get() } }

// Injected by constructor class MyViewModel(val repo : MyRepository) : ViewModel() // declared ViewModel using the viewModel keyword val myModule : Module = module { viewModel { MyViewModel(get()) } single { MyRepository() } } // Just get it class MyActivity() : AppCompatActivity() { // lazy inject MyViewModel val vm : MyViewModel by viewModel() }

// Just tag your class with KoinTest to unlick your testing power class SimpleTest : KoinTest { // lazy inject BusinessService into property val service : BusinessService by inject() @Test fun myTest() { // You can start your Koin configuration startKoin(myModules) // or directly get any instance val service : BusinessService = get() // Don't forget to close it at the end stopKoin() } }

What is Koin?

Declare a module

Start Koin

Inject in Android

Inject by Constructor

Ready for ViewModel

Easy testing