Android Rxjava subscribe to a variable change

Question

I am learning Observer pattern, I want my observable to keep track of a certain variable when it changes it\'s value and do some operations, I\'ve done something like :

Answer 1

If interested here a Kotlin version of Variable class, which lets subscribers to be updated after every variable change.

class Variable(private val defaultValue: T) {
var value: T = defaultValue
    set(value) {
        field = value
        observable.onNext(value)
    }
val observable = BehaviorSubject.createDefault(value)
}

Usage:

val greeting = Variable("Hello!")
greeting.observable.subscribe { Log.i("RxKotlin", it) }
greeting.value = "Ciao!"
greeting.value = "Hola!"

This will print:

"Hello!"
"Ciao!"
"Hola!"