How to change localization on the fly SwiftUI

Question

How can I change the localization of the App on the fly in SwiftUI?

I think we can use below code, but we should find SwiftUI approach.

func localized(_ lang:String) -> String {

    let path = Bundle.main.path(forResource: lang, ofType: "lproj")
    let bundle = Bundle(path: path!)

    return NSLocalizedString(self, tableName: nil, bundle: bundle!, value: "", comment: "")
}}

Answer 1

First of all, we should create 2 Localizable.strings files, in my case it's en and ru.

And we should store our current language object, I choose store it property in UserSettings like ObservableObject

class UserSettings: ObservableObject {

    @Published var lang: String = "ru"

    var bundle: Bundle? {
        let b = Bundle.main.path(forResource: lang, ofType: "lproj")!
        return Bundle(path: b)
    }
}

We can use this settings object like .environmentObject() in SceneDelegate.swift, so every view in hierarchy will be updated.

var settings = UserSettings()
// ...
= UIHostingController(rootView: contentView.environmentObject(settings))

In View we can get desirable behaviour, note we should specify bundle in Text initialization.

struct ContentView: View {

    @EnvironmentObject var settings: UserSettings

    var body: some View {
        VStack {
            Text("App", bundle: settings.bundle)
        }
    }
}

And now I can change the language on someplace in the app, here is just sample loop example, you can call this function changeLanguage() in the of scene(_ scene:, willConnectTo:, options connectionOptions:) and every 3 seconds language will be changed.

func changeLanguage() {
    print(#function)
    DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
        self.settings.lang = self.settings.lang == "ru" ? "en" : "ru"
        self.changeLanguage()
    }
}