[코드리뷰쇼] #1. Relay 5개라굽쇼?

ViewController.swift

import RxCocoa
import RxSwift
import UIKit

class ViewController: UIViewController {
    enum SortType {
        case none, newest, oldest
    }

    enum MonthType {
        case none, one, three, six
    }

    let sortRelay = BehaviorRelay(value: SortType.none) // 정렬기준
    let monthRelay = BehaviorRelay(value: MonthType.none) // 기간설정

    var disposeBag = DisposeBag()

    override func viewDidLoad() {
        super.viewDidLoad()
        binding()
    }

    private func binding() {
        // sort
        Observable.merge(
            optionSortNewest.rx.tap.map { SortType.newest },
            optionSortOldest.rx.tap.map { SortType.oldest }
        )
        .bind(to: sortRelay)
        .disposed(by: disposeBag)

        sortRelay.flatMap { [weak self] in
            Observable.from([
                ($0 == .newest, self?.optionSortNewest),
                ($0 == .oldest, self?.optionSortOldest),
            ])
        }
        .asDriver(onErrorJustReturn: (false, nil))
        .drive(onNext: { selected, button in
            button?.isSelected = selected
        })
        .disposed(by: disposeBag)

        // month
        Observable.merge(
            optionTermOneMonth.rx.tap.map { MonthType.one },
            optionTermThreeMonth.rx.tap.map { MonthType.three },
            optionTermSixMonth.rx.tap.map { MonthType.six }
        )
        .bind(to: monthRelay)
        .disposed(by: disposeBag)

        monthRelay.flatMap { [weak self] in
            Observable.from([
                ($0 == .one, self?.optionTermOneMonth),
                ($0 == .three, self?.optionTermThreeMonth),
                ($0 == .six, self?.optionTermSixMonth),
            ])
        }
        .asDriver(onErrorJustReturn: (false, nil))
        .drive(onNext: { selected, button in
            button?.isSelected = selected
        })
        .disposed(by: disposeBag)

        // confirm button
        Observable.combineLatest(
            sortRelay.map { $0 != .none },
            monthRelay.map { $0 != .none }
        ) { $0 && $1 }
            .bind(to: confirmButton.rx.isEnabled)
            .disposed(by: disposeBag)
    }

    // MARK: - UI

    @IBOutlet var optionSortNewest: UIButton!
    @IBOutlet var optionSortOldest: UIButton!

    @IBOutlet var optionTermOneMonth: UIButton!
    @IBOutlet var optionTermThreeMonth: UIButton!
    @IBOutlet var optionTermSixMonth: UIButton!

    @IBOutlet var confirmButton: UIButton!

    @IBAction func onCancel(sender: Any) {
        dismiss(animated: true, completion: nil)
    }

    @IBAction func onOK(sender: Any) {
        dismiss(animated: true, completion: nil)
    }
}

YouTube 코드리뷰 SHOW @곰튀김
Relay에는 어떤 데이터를 취급해야 올바르게 사용하는 것일까요?