Enum with localized string in swift

I want to use enumeration with localized string, so I do like this, it works, but the problem of this solution is : I can't get easily enum value from localized string, I must have the key to do it :

let option = DietWithoutResidueOption(rawValue: "NoDiet")

If not I must to call dietWithoutResidueOptionWith method to get enum value... :/

There are a better solution to store directly localizedString and not keys in enum ?

Thanks

Enumeration

  enum DietWithoutResidueOption: String {
  case NoDiet = "NoDiet"
  case ThreeDays = "ThreeDays"
  case FiveDays  = "FiveDays"

  private func localizedString() -> String {
    return NSLocalizedString(self.rawValue, comment: "")
  }

  static func dietWithoutResidueOptionWith(#localizedString: String) -> DietWithoutResidueOption {
    switch localizedString {
    case DietWithoutResidueOption.ThreeDays.localizedString():
      return DietWithoutResidueOption.ThreeDays
    case DietWithoutResidueOption.FiveDays.localizedString():
      return DietWithoutResidueOption.FiveDays
    default:
      return DietWithoutResidueOption.NoDiet
    }
  }
}

Localizable.strings

"NoDiet" = "NON, JE N'AI PAS DE RÉGIME";
"ThreeDays" = "OUI, SUR 3 JOURS";
"FiveDays"  = "OUI, SUR 5 JOURS";

call

println(DietWithoutResidueOption.FiveDays.localizedString())

Solution

You can use any StringLiteralConvertible, Equatable type for RawValue type of enum.

So, how about:

import Foundation

struct LocalizedString: StringLiteralConvertible, Equatable {

    let v: String

    init(key: String) {
        self.v = NSLocalizedString(key, comment: "")
    }
    init(localized: String) {
        self.v = localized
    }
    init(stringLiteral value:String) {
        self.init(key: value)
    }
    init(extendedGraphemeClusterLiteral value: String) {
        self.init(key: value)
    }
    init(unicodeScalarLiteral value: String) {
        self.init(key: value)
    }
}

func ==(lhs:LocalizedString, rhs:LocalizedString) -> Bool {
    return lhs.v == rhs.v
}

enum DietWithoutResidueOption: LocalizedString {
    case NoDiet = "NoDiet"
    case ThreeDays = "ThreeDays"
    case FiveDays  = "FiveDays"

    var localizedString: String {
        return self.rawValue.v
    }

    init?(localizedString: String) {
        self.init(rawValue: LocalizedString(localized: localizedString))
    }
}

Using this, you can construct DietWithoutResidueOption by 3 ways:

let option1 = DietWithoutResidueOption.ThreeDays
let option2 = DietWithoutResidueOption(rawValue: "ThreeDays") // as Optional
let option3 = DietWithoutResidueOption(localizedString: "OUI, SUR 3 JOURS")  // as Optional

and extract the localized string with:

let localized = option1.localizedString