Functional Kotlin

How Observable works

As we stated earlier, an Observable value has the following three most important events/methods:

• onNext: The Observable interface passes all the items one by one to this method
• onComplete: When all the items have gone through the onNext method, the Observable calls the onComplete method
• onError: When the Observable faces any error, it calls the onError method to deal with the error, if defined

One thing to note here is that the item in Observable that we are talking about can be anything; it is defined as Observable<T>, where T can be any class. Even an array/list can be assigned as Observable.

Let's look at the following diagram:

Here's a code example to understand it better:

fun main(args: Array<String>) { val observer ...