Example of Swift enum with allValues array containing constructors for cases with associated values

value-enumerable.swift

protocol ValueEnumerable {
    static var allValues: [Any] { get }
}

enum ColorScheme: ValueEnumerable {
    typealias SchemeTuple = (name: String, background: UIColor, foreground: UIColor, border: UIColor)

    case Light
    case Dark
    case custom(SchemeTuple)

    var schemeData: SchemeTuple {
        switch self {
        case Light:
            return ("Light", UIColor.whiteColor(), UIColor.blackColor(), UIColor.redColor())
        case Dark:
            return ("Dark", UIColor.blackColor(), UIColor.whiteColor(), UIColor.redColor())
        case custom(let name, let background, let foreground, let border):
            return (name, background, foreground, border)
        }
    }

    // placeholder for what would be implemented in Swift
    static var allValues: [Any] {
        return [Light, Dark, custom]
    }

    static var userSchemeData: [SchemeTuple] {
        // here you would pull data from however you want to persist the user themes
        // but manually providing a sample of what it could look like
        return [
            ("Some Custom Theme", UIColor.clearColor(), UIColor.clearColor(), UIColor.clearColor()),
            ("Another Custom Theme", UIColor.clearColor(), UIColor.clearColor(), UIColor.clearColor())
        ]
    }

    static var availableSchemes: [ColorScheme] {
        return allValues.reduce([ColorScheme]()) { schemes, schemeCase in
            var schemes = schemes

            switch schemeCase {
            case let instance as ColorScheme:
                schemes.append(instance)
            case let constructor as SchemeTuple -> ColorScheme:
                for userScheme in userSchemeData {
                    schemes.append(constructor(userScheme))
                }
            default:
                break
            }

            return schemes
        }
    }
}


let names = ColorScheme.availableSchemes.map { $0.schemeData.name }
names // ["Light", "Dark", "Some Custom Theme", "Another Custom Theme"]


let builtInValues = ColorScheme.allValues.flatMap { $0 as? ColorScheme }
builtInValues // ["Light", "Dark"]