Cleaner localized strings with Swift protocols and enums.

localized.swift

import Foundation

// Localized string struct that has single static method which accepts a `Localizeable` value.

struct LocalizedString {
    
    // Usage: LocalizedString.localizedStringForValue(NavBarTitle.Home)
    
    static func localizedStringForValue<T: Localizeable>(localizeableValue: T) -> String {
        return NSLocalizedString(localizeableValue.localizedString, comment: localizeableValue.localizedStringComment)
    }
}

protocol Localizeable {
    var localizedStringComment: String { get }
    var localizedString: String { get }
}

enum NavBarTitle: Localizeable {
    case Home, NewOffer, Search
    
    var localizedStringComment: String {
        get {
            switch self {
            case .Home:
                return "Navigation bar home title"
            case .NewOffer:
                return "Some comment"
            case .Search:
                return "Some comment"
            }
        }
    }
    
    var localizedString: String {
        get {
            switch self {
            case .Home:
                return "navbar.home.title"
            case .NewOffer:
                return "navbar.newoffer.title"
            case .Search:
                return "navbar.search.title"
            }
        }
    }
}