ViewController.swift

func setupObserving() {
    currentWeatherView.reactive.weatherFeatures <~ viewModel.weatherFeatures
    loadingIndicator.reactive.isAnimating <~ viewModel.isLoading

    segmentedControl.reactive.isEnabled <~ viewModel.isEnabledControl(for: Set([.turnCurrent, .turnForecast]))

    reactive.title <~ viewModel.title
    reactive.rightBarButtonItem <~ viewModel.isLoading.map { [weak self] (isLoading) -> UIBarButtonItem? in
        return isLoading ? self?.loadingBarButtonItem : self?.refreshBarButtonItem
    }

    leftBarButtonItem.reactive.pressed = CocoaAction(viewModel.createButtonAction(for: .turnLeft))
    rightBarButtonItem.reactive.pressed = CocoaAction(viewModel.createButtonAction(for: .turnRight))
    refreshBarButtonItem.reactive.pressed = CocoaAction(viewModel.reloadAction)
    locateBarButtonItem.reactive.pressed = CocoaAction(viewModel.locateAction)

    let action = viewModel.uiAction
    segmentedControl.reactive.controlEvents(.valueChanged)
        .map { $0.selectedSegmentIndex == 0 ? UIEvent.turnCurrent : UIEvent.turnForecast }
        .observeValues { action.apply($0).start() }
}