How can I store a Swift enum value in NSUserDefaults

Question

I have an enum like this:

enum Environment {
    case Production
    case Staging
    case Dev
}

And I\'d like to save an instance in NSUserDef

Answer 1

Here is another alternative that can be be easily used with enums based on types (like String, Int etc) that can be stored by NSUserDefaults.

@propertyWrapper
struct StoredProperty {
    let key: String
    let defaultValue: T

    init(_ key: String, defaultValue: T) {
        self.key = key
        self.defaultValue = defaultValue
    }

    var wrappedValue: T {
        get {
            guard let rawValue = UserDefaults.standard.object(forKey: key) as? T.RawValue, let value = T(rawValue: rawValue) else {
                 return defaultValue
            }
            return value
        }
        set {
            UserDefaults.standard.set(newValue.rawValue, forKey: key)
        }
    }
}

Example usage:

enum Environment: String {
    case Production
    case Staging
    case Dev
}

@StoredProperty("Environment", defaultValue: .Dev)
var storedProperty: Environment