User Language Preferences

Here’s a quick one. Google has a neat library for (among lots of other things) on-device translation, called ML Kit. I’m trying to implement it for a hackathon. Turns out (no surprise?) it’s written in Objective-C, and doesn’t really have great affordances to integrate with system libraries. In particular, the enum called TranslateLanguage doesn’t have an initializer that takes a language identifier or locale identifier. I went about this in what I thought was the obvious way, using Locale.current.languageCode to initialize a new TranslateLanguage. But of course the current locale isn’t necessarily the same as the language the user has chosen. For that, I found this to be the simplest way:

extension TranslateLanguage {
    init?() {
        guard let preferredLanguage = Locale.preferredLanguages.first,
              let languageCode = Locale(identifier: preferredLanguage)
              .languageCode else { return nil }
        self = .init(rawValue: languageCode)
    }
}