CODEWITHSUNDEEP
androidkotlinrx-java2behaviorsubject
saintjab
saintjab

Reputation: 1642

Observable subscribe not getting called on same value

I have a BehaviourSubject as a callback for my Retrofit method.

private val loadCompleted = BehaviourSubject.create<List<String>>()

Inside my retrofit OnResponse/onFailure, I call 

loadCompleted.onNext(myList) //inside retrofit onResponse and 
loadCompleted.onError("Error") // inside retrofit onFailure

I am subscribed to a function which returns loadCompleted. 

fun loadingCompleted() : Observable<List<String>>{return loadCompleted}

and then I subscribe to the loadingCompleted as

loadingCompleted.subscribe{list -> 
     //only called once
     anotherfun(list)
}

The first time my Retrofit function gets called, I am able to get my subscribe called but subsequent calls to the same function doesn't fire the subscribe. I am assuming the calls normally return the same value because it is just a refresh and the data might not have changed. However, I still need to get the subscribe called so I can react accordingly. I have tried both BS and ReplaySubject but the result is the same. How do I use an observable to ensure I always get the subscribe called whenever I call onNext(x)/onComplete(x) even though x might not have changed?

Upvotes: 0

Views: 1899

Answers (1)

Tuby
Tuby

Reputation: 3253

You are probably finishing your BehaviorSubject stream with onComplete/onError. If you don't want to do that, wrap x/error to some kind of Result which is sealed class and has Success and Failure subclasses. Then always use subject.onNext() to emit.

sealed class Result<T> {
    class Success<T>(val t: T) : Result<T>()
    class Failure<T>(val e: Throwable) : Result<T>()
}

class Test {
    val subject: BehaviorSubject<Result<List<String>>> = BehaviorSubject.create()

    fun call() {
        subject.onNext(Result.Success(listOf("example")))
        subject.onNext(Result.Failure(RuntimeException("error")))

        subject.subscribe{result->
            when(result){
                is Result.Success -> print(result.t)
                is Result.Failure -> print(result.e.message)
            }
        }
    }

}

Upvotes: 1

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