Forwarding parameters

Koin 0.9.0 is really great Thanks for the parameter support when injecting dependencies. It is working great.

I have a small optimization for injecting with parameters. It would be fantastic if we can forward this parameter map.

e.g.

class MyActivity : Activity() {
   val presenter: MyPresenter by inject(parameters = mapOf("activity" to this)
}

class MyPresenter(navigator: Navigator) {

}

class Navigator(activity: Activity) {

}

and the module looks like this

val myModule: Module = applicationContext {
   context("Screen") {
      bean { params -> MyPresenter(get()) }  // here we have the params with the activity 
      bean { params -> Navigator(params["activity"]) }  // BUT the activity is needed here (and here are params null)
   }
}

can you provide us with the possibillty to forward these params in the get() method, e.g

val myModule: Module = applicationContext {
   context("Screen") {
      bean { params -> MyPresenter(get(params)) }  // forward params in get(params)
      bean { params -> Navigator(params["activity"]) }  // so we can access the params here
   }
}

looking at the get() functions it should be possible in the current version 0.9.0 you pass an emptyMap to the resolve functions.

inline fun <reified T : Any> get(): T = koinContext.resolveByClass(emptyMap())
inline fun <reified T : Any> get(name: String): T = koinContext.resolveByName(name, emptyMap())

maybe we can do something like this:

inline fun <reified T : Any> get(parameters: ParameterMap = emptyMap()): T = koinContext.resolveByClass(parameters)
inline fun <reified T : Any> get(name: String, parameters: ParameterMap = emptyMap()): T = koinContext.resolveByName(name, parameters)

What do you think about this?

[z3ntu]

I’ve got it working now by using

single { params -> provideRetrofit(get { params }, params.component1()) }

Such an example should still be put on the website though. Thanks for creating Koin!

[z3ntu]

Hello. (while waiting for my kotlin slack invitation I’m writing here)

I have the following module defined:

val nextNewsModule = module {
    single { (acc: SingleSignOnAccount) -> provideAuthenticationInterceptor(acc) }
    single { params -> provideHttpClient(get { params }) }
    single { (acc: SingleSignOnAccount) -> provideRetrofit(get { params }, acc) }
    single { params -> provideNewsService(get { params }) }
    single<NewsRepository> { params -> NewsRepositoryImpl(get { params }) }
    viewModel { params -> NewsViewModel(get { params }) }
}

and getting called by

private val vm: NewsViewModel by viewModel { parametersOf(SingleSignOnAccount("a", "b", "c", "d")) }

The problem before adding all the params -> was that the “downstream dependencies” didn’t get the required SingleSignOnAccount instance and Koin failed to inject. Now I think I just need to pass the params object through the provideRetrofit line (so it reaches the provideAuthenticationInterceptor) but with the extra (acc: SingleSignOnAccount) parameter I don’t know the syntax to make this working.

I got the params -> ... get { params } from here and it would also be nice if such an example was on the website.