How to change language (localisation) within the app in swift 5? - ios

Question

I am trying to localise iOS app which is developed in Swift 5. I have done with all localisation things in code as well as in storyboard. But I am not sure how to change language within the app when i click on Language Button.
Is this possible to change app language within app? if yes How?
Please suggest best possible way to do same

Answer 1

I just did a similar implementation. Glad you asked and I saw this. Here is my implementation. You can modify.
enum Language: String, CaseIterable {
case english, german
var code: String {
switch self {
case .english: return "en"
case .german: return "de"
}
}
static var selected: Language {
set {
UserDefaults.standard.set([newValue.code], forKey: "AppleLanguages")
UserDefaults.standard.set(newValue.rawValue, forKey: "language")
}
get {
return Language(rawValue: UserDefaults.standard.string(forKey: "language") ?? "") ?? .english
}
}
static func switchLanguageBetweenEnglishAndGerman() {
selected = selected == .english ? .german : .english
}
}
Now you just need to call Language.selected == .german and reload the views.

Answer 2

To change localization throughout the app. For that, You need to follow the below step.
Create a Parent class of every UIViewController and define setupLocasitation method for further usage.
ParentViewController.swift
class ParentViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
func setupLocasitation(){
}
}
All other class of UIViewController should be a subclass of ParentViewController and override setupLocasitation method
ViewController1.swift
class ViewController1: ParentViewController {
override func viewDidLoad() {
super.viewDidLoad()
setupLocasitation()
}
override func setupLocasitation() {
super.setupLocasitation()
print("Your localisation specifi code here...")
}
}
ViewController2.swift
class ViewController2: ParentViewController {
override func viewDidLoad() {
super.viewDidLoad()
setupLocasitation()
}
override func setupLocasitation() {
super.setupLocasitation()
print("Your localisation specifi code here...")
}
}
ChangeLanguageVC.swift
You need to grab all instances of ParentViewController and force-fully call the setupLocasitation method.
class ChangeLanguageVC: ParentViewController {
override func viewDidLoad() {
super.viewDidLoad()
setupLocasitation()
}
#IBAction func btnChangeLanguageTap(){
//Code for your language changes here...
let viewControllers = self.navigationController?.viewControllers ?? []
for vc in viewControllers{
if let parent = vc as? ParentViewController{
parent.setupLocasitation()
}
}
}
}

Answer 3

//
// LanguageExtensions.swift
// Flourish
//
// Created by Janko on 11/11/2020.
//
import Foundation
import UIKit
let languageKey = "languageKey"
var language : Int {
switch UserDefaults.standard.string(forKey: languageKey) {
case "en":
return 0
case "dutch":
return 1
default:
return 0
}
}
extension String {
func localizedLanguage()->String?{
var defaultLanguage = "en"
if let selectedLanguage = UserDefaults.standard.string(forKey: languageKey){
defaultLanguage = selectedLanguage
}
return NSLocalizedString(self, tableName: defaultLanguage, comment: "")
}
}
class LanguageLabel: UILabel{
required init?(coder: NSCoder) {
super.init(coder: coder)
NotificationCenter.default.addObserver(self, selector: #selector(updateUI), name: AppNotification.changeLanguage, object: nil)
}
#IBInspectable var localizedLanguage: String? {
didSet{
updateUI()
}
}
#objc func updateUI(){
if let string = localizedLanguage {
text = string.localizedLanguage()
}
}
}
class LanguageButton: UIButton{
required init?(coder: NSCoder) {
super.init(coder: coder)
NotificationCenter.default.addObserver(self, selector: #selector(updateUI), name: AppNotification.changeLanguage, object: nil)
}
#IBInspectable var localizedLanguage: String? {
didSet{
updateUI()
}
}
#objc func updateUI(){
if let string = localizedLanguage {
setTitle(string.localizedLanguage(), for: .normal)
}
}
}
struct AppNotification{
static let changeLanguage = Notification.Name("changeLanguage")
}
extension UIViewController{
func changeLanguage(){
let alert = UIAlertController(title: "Change Language", message: "Change it", preferredStyle: .alert)
let actionEnglish = UIAlertAction(title: "English", style: .default) { (action) in
UserDefaults.standard.setValue("en", forKey: languageKey)
NotificationCenter.default.post(name: AppNotification.changeLanguage , object: nil)
}
let actionMontenegrin = UIAlertAction(title: "Montenegrinish", style: .default) { (action) in
UserDefaults.standard.setValue("dutch", forKey: languageKey)
NotificationCenter.default.post(name: AppNotification.changeLanguage , object: nil)
}
alert.addAction(actionEnglish)
alert.addAction(actionMontenegrin)
present(alert, animated: true, completion: nil)
}
}