How to declare a variable type depending on a ternary expression?

Question

I have this enum :

enum WeatherMapDisplayType {
    case temperature
    case wind
}

Can I declare a variable like this ?

let markerView: mode == .temperature ? WeatherMapItemTemp : WeatherMapItemWind = UIView.fromNib()

Knowing that mode is of type WeatherMapDisplayType

How can I handle this scenario in an elegant way ?

EDIT:

I want to be able to do something like this :

let markerView: WeatherMapItem = UIView.fromNib()
markerView.frame = CGRect(x: 0, y: 0, width: 80, height: 30)
markerView.setupWeatherInformations(mode: self.currentDisplayMode, forecast: forecasts)
marker.iconView = markerView

Previously I only had WeatherMapItem type.

Then I have been asked to add an other weather map item, that is why I have the WeatherMapItemTemp and WeatherMapItemWind now (also corresponding to my enum display type).

---

func setupWeatherInformations(forecast: Forecast.HourlyForecast)

This is a method in my custom classes in order to configure the outlets.

But I don't have access to this method if I init my custom view from frame, because it's of UIView type.

Answer 1

Add a common protocol to these views:

protocol WeatherMapItem where Self: UIView {
    func setupWeatherInformations()
}

class WeatherMapItemTemp: UIView, WeatherMapItem {
    func setupWeatherInformations() {
        // setup
    }
}

class WeatherMapItemWind: UIView, WeatherMapItem {
    func setupWeatherInformations() {
        // setup
    }
}

Add a computed variable to the enum:

enum WeatherMapDisplayType {
    case temperature
    case wind

    var view: (UIView & WeatherMapItem)? {
        var nibName: String? = nil
        switch self {
        case .temperature:
            nibName = "WeatherMapItemTemp"
        case .wind:
            nibName = "WeatherMapItemWind"
        }
        if let nibName = nibName, let views = Bundle.main.loadNibNamed(nibName, owner: nil), views.count > 0 {
            return views[0] as? UIView & WeatherMapItem
        }
        return nil
    }
}

Now you can generate a view like so:

// assuming mode is the variable of type WeatherMapDisplayType
let view = mode.view
view?.setupWeatherInformations()
return view