I know there's the `get` from `KoinJavaComponent` ...

# koin

[Matthew Laser]

I know there's the get from KoinJavaComponent , but not sure if that is the preferred method for getting on demand instances in Kotlin code

[arnaud.giuliani]

don’t use KoinJavaComponent if you don’t need Java compat

[Michael Pohl]

I usually prefer injecting in the constructor, imho makes things easier to test and makes your class independent of Koin. Not sure if that’s actually what you’re asking about, something very basic like this:

val myModule = module {
    single { SomeClass() }
}

class MyClass(val someClass: SomeClass) {
    // someClass will be injected
}

I rarely ever use get, but rather lazy injection (if I have to or I get a benefit out of doing it lazily) like

class someClass() : KoinComponent { 
    val myInjectedProperty: SomeType by inject()
}

[Matthew Laser]

yeah that is what I normally do as well @Michael Pohl - thats a good point

@arnaud.giuliani agreed, trying to avoid this. I am just fundamentally confused whether extending KoinComponent is required for injection into Kotlin classes, because the identically named API (get) of course works via KoinJavaComponent without the use of additional interfaces

[Michael Pohl]

That’s how I understand the docs at least - unless you pass the injected properties in through the constructor.
Since Koin does everything at runtime and (afaik) there’s no reflection used, the functionalities for field injection have to be present in your classes, hence the requirement to extend KoinComponent . That’s at least how I understand it. Never used KoinJavaComponent , but @arnaud.giuliani’s point is valid.