Hello guys, in our team we're tired of dagger 2 on...

# koin

[themishkun]

Hello guys, in our team we're tired of dagger 2 on android, that "rebuild all the things" and "wow much boilerplate, so verbose" stuff. I like koin it seems nice to me, but how can I do java interop with it? Any tips?

[leandrodev]

You can create an interface with a single method that provides a dependency. This method will lazily load it using Koin.

[leandrodev]

Kotlin code:

interface DependencyProvider<out T>: KoinComponent {
    fun provide(): T
}

fun <T: Any> provideDependency(clazz: KClass<T>): DependencyProvider<T> {
    return object: DependencyProvider<T> {
        override fun provide(): T {
            val koinContext = StandAloneContext.koinContext as KoinContext
            val resolver: () -> BeanDefinition<*> = { koinContext.beanRegistry.searchAll(clazz) }
            return koinContext.resolveInstance(clazz, resolver)
        }

    }
}

And the Java code:

public class JavaClass {
    private DependencyProvider<TasksDao> tasksDaoDependencyProvider = AppExecutorsKt.provideDependency(kotlin.jvm.JvmClassMappingKt.getKotlinClass(TasksDao.class));
}

[arnaud.giuliani]

@themishkun did you managed to bring Koin to your java app?

[themishkun]

@arnaud.giuliani Not yet, we are actively discussing it, examples above gave us some insights. We are practically 50/50 Java to Kotlin ratio right now, the project is rather old, so we need to figure out the way to migrate smoothly, not touching scary beasts hiding in legacy code

[themishkun]

@arnaud.giuliani maybe you know more pleasant way for Java interop?

[arnaud.giuliani]

@themishkun to be honest, Java interop was not in the 1st features to develop for Koin. We were focused on Kotlin feature and how to easily write things

[arnaud.giuliani]

But you can open an issue and we will see how we can help you - and if we need to patch Koin for your Java usage

[themishkun]

@arnaud.giuliani and it worked out well, I wish I could start from scratch and throw out all Java code just to write things easily

[arnaud.giuliani]

😄

[arnaud.giuliani]

I think you will have to describe your content with Kotlin Koin modules

[arnaud.giuliani]

the idea will be to try to use Your java classes to inject

[arnaud.giuliani]

but I never tested injection in activities/fragments without Kotlin

[arnaud.giuliani]

Do know yet the final syntax for java

[arnaud.giuliani]

@themishkun I think one strategy will be to write as much as possible in Kotlin

[arnaud.giuliani]

make all your DI in Kotlin

[arnaud.giuliani]

and for Java Android Components (Activities ...) write a dependency holder

[arnaud.giuliani]

this gists can help you : https://gist.github.com/arnaudgiuliani/446e0d8ee79f4bda38b3057b01098f2e