RxSwift: how to select one btn and unselect the rest?

Question

I have three btns, select one, and unselect the rest two.

The following RXSwift code is not very elegant.

twoBtn.isSelected = true

// the btns
let buttons = [oneBtn, twoBtn, threeBtn]

// find the selected btn we need
let selectedBtn : Observable<UIButton?> = Observable.from(buttons.map({ (button)  in
    return button!.rx.tap.map({
        return button
    })  
})).merge()


//  every btn subscribe to the selectedButton
for buttonPiece in buttons{
    selectedBtn.map { (btn) in
        return btn == buttonPiece
        }.bind(to: buttonPiece!.rx.isSelected).disposed(by: disposeBag)
}

The BehaviorSubject starts with an initial value, and they will replay the latest value or the initial value.

I think BehaviorSubject is proper here.

new to RxSwift, How to do it better?

Answer 1

Define a State struct with states of all buttons in it, modify it by using .scan() operator like let state: Observable<State> = events.scan(State()) { oldState, event) -> State in /* update and return state */ } and subscribe every button to it like state.map { $0.button1state }.