How to combine existing async requests with RxAndroid or using Kotlin coroutines?

Issue

Here is my code. I have async request which is implemented in SDK . I am using it, I have implemented it simple way calling login providing callback for that async request. My question is it possible if to combine this Async request using RxAndroid or Kotlin Coroutines? As I am going to have a lot of callback chains to avoid it I am thinking to combine with RxJava or Kotlin Coroutines. Any hints of referening to a sample could be goodl

private fun automaticLogin() {
    UserAction(username, password).login(AutomaticUserLoginRequest(this))
}


class AutomaticUserLoginRequest()
    : UserLoginRequest( object : ILoginResultHandler {
    override fun onSuccess(session: ISession) {
    }

    override fun onError(error: Error) {
    }
  })```

Solution

You may do something like with the suspendCoroutine function:

suspend fun automaticUserLoginRequest(): ISession {
  return suspendCoroutine<ISession> { cont ->
    callUserLoginRequest(object : ILoginResultHandler {
      override fun onSuccess(session: ISession) {
         cont.resume(session)
      }

      override fun onError(error: Error) {
         cont.resumeWithException(error)
      }
    }
  }
}

You may execute the suspend function from a coroutine. The kotlinx.coroutines-android provides the Dispatchers.UI for that:

fun someFunction() {
   //starts a coroutine, not waiting fro result
   launch(Dispatchers.UI) {

     val session = automaticUserLoginRequest()

     //the execution will resume here once login is done, it can be an exception too
     updateUI(session)
    }
}

https://github.com/Kotlin/kotlinx.coroutines/blob/master/ui/kotlinx-coroutines-android/README.md

Answered By - Eugene Petrenko