localization - localizeWithFormat and variadic arguments in Swift

Question

I am trying to create a String extension to do something like that

"My name is %@. I am %d years old".localizeWithFormat("John", 30)

which looks like this

extension String {
  func localizeWithFormat(arguments: CVarArgType...) -> String {
    return String.localizedStringWithFormat(
      NSLocalizedString(self,
        comment: ""), getVaList(arguments))
  }
}

it give me the following compilation error

Type CVaListPointer does not conform to protocol CVargType

Anyone knows how to work aroundthis compilation error?

Answer 1

This should be pretty simple just change your parameters as follow:

extension String {
    func localizeWithFormat(name:String,age:Int, comment:String = "") -> String {
        return String.localizedStringWithFormat( NSLocalizedString(self, comment: comment), name, age)
    }
}

"My name is %@. I am %d years old".localizeWithFormat("John", age: 30)  // "My name is John. I am 30 years old"

init(format:locale:arguments:)

extension String {
    func localizeWithFormat(args: CVarArgType...) -> String {
        return String(format: self, locale: nil, arguments: args)
    }
    func localizeWithFormat(local:NSLocale?, args: CVarArgType...) -> String {
        return String(format: self, locale: local, arguments: args)
    }
}
let myTest1 = "My name is %@. I am %d years old".localizeWithFormat(NSLocale.currentLocale(), args: "John",30)
let myTest2 = "My name is %@. I am %d years old".localizeWithFormat("John",30)