RxSwift，MVVM，Alamofire / Moya。 使用间隔更新股票行情

Question

Currently learning RxSwift (Rx in general). I want to update a UILabel regularly with the latest ticker price.

How can .interval and the updateTicker function every period and then update the UILabel accordingly.

ViewController.swift

class ViewController: UIViewController {
    private let disposeBag = DisposeBag()

    // Dependencies
    private var viewModel = ViewModel()

    // Outlets
    @IBOutlet var tickerLabel: UILabel!

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

    func setupViewModel() {        
        self.viewModel.ticker.asObservable()
        .bind(to: self.tickerLabel.rx.text)
        .addDisposableTo(self.disposeBag)
    }
}

ViewModel.swift

struct ViewModel {
    private let disposeBag = DisposeBag()

    let provider = RxMoyaProvider<StockAPI>()

    var ticker = Variable<String>("")

    init() {
        startTimer()
        // ???
    }


    func startTimer() -> Observable<Int> {
        return Observable<Int>.interval(5, scheduler: MainScheduler.instance)
    }

    func updateTicker() {
        _ = self.provider.request(.ticker(symbol: "AAPL")).subscribe { (event) in
        switch event {
        case .next(let response):
            print(response)
        // do something with the data
        case .error(let error):
            // handle the error
            print(error)
            break
        default:
            break
        }
    }
}

Answer 1

Maybe something like this

var ticker = Observable.just("")

func startTimer() {
    self.ticker = Observable<Int>.interval(1, scheduler: MainScheduler.instance)
        .map({ _ in self.updateTicker() })
}

The func updateTicker will need return a String.