pietmau / IoC-Container

IoC Contanier

Contents

This repository contains two modules:

• the library itself;
• an Android demo application.

How to use it

Create the providers:

class CoffeeMakerProvider : Provider<CoffeeMaker> {

    override fun get(clazz: Class<CoffeeMaker>, injector: Injector): CoffeeMaker {
        var grinder = injector.get<CoffeeGrinder>()
        return CoffeeMaker(grinder)
    }
}

class CoffeeGrinderProvider : Provider<CoffeeGrinder> {

    override fun get(clazz: Class<CoffeeGrinder>, injector: Injector) = CoffeeGrinder()
}

Add the providers to the Injector:

 val injector = Injector(Providers())
 injector.addProvider(CoffeeMaker::class.java, CoffeeMakerProvider())
 injector.addProvider(CoffeeGrinder::class.java, CoffeeGrinderProvider())

Get the needed dependency:

 val coffeeMaker = injector.get<CoffeeMaker>()

Field injection for Android

Ideally I would implement constructor injection and use annotations.

For Android Activities, Fragments, Services, etc. is not possible to use constructor injection,

so I implemented a very simple field injection (also here I would use annotations):

first add the Providers (maybe in the Application Class)

Injector.addProvider(Model::class.java, ModelProvider())
Injector.addProvider(Presenter::class.java, PresenterProvider())

then in the Activity you can do:

class MainActivity : AppCompatActivity() {
    val presenter: Presenter by fieldInject()

    override fun onCreate(savedInstanceState: Bundle?) {
        ...
        presenter.run()
    }
}

this will lazily initialize the presenter.