Angular4: Locale for a user

I followed the answer from this thread and I have the following solution:

import { LOCALE_ID } from '@angular/core';@NgModule({  // ...  providers: [...     {provide: LOCALE_ID,      deps: [SettingsService],      // some service handling global settings      useFactory: getLanguage  // returns locale string    }  ]  // ...})export class AppModule { }// the following function is required (for Angular 4.1.1!!!)export function getLanguage(settingsService: SettingsService) {  return settingsService.getLanguage();}

Note: The usage of an extra function prevents the error Function calls are not supported. Consider replacing the function or lambda with a reference to an exported function !!!!

and I create the class

import { Injectable } from '@angular/core';@Injectable()export class SettingsService {  currentLang: string;  constructor() {    this.currentLang = 'en';  }  setLanguage(lang: string) {    this.currentLang = lang;  }  getLanguage() {    return this.currentLang;  }}

which changes the LOCALE_ID on the fly :-)

How about this?

• use local storage to store the locale (eg. 'fr')
• load the associated translation file in main.ts (eg. messages.fr.xlf)
• set the LOCALE_ID in app.module.ts

To change the locale

• set the new locale in local storage
• refresh the app

main.ts

declare const require;const locale = localStorage.getItem('locale');const translation = require(`raw-loader!./locale/messages.${locale}.xlf`)platformBrowserDynamic().bootstrapModule(AppModule, {  providers: [    {provide: TRANSLATIONS, useValue: translation},    {provide: TRANSLATIONS_FORMAT, useValue: 'xlf'}  ]});

app.module.ts

@NgModule({  providers: [    {provide: LOCALE_ID, useValue: localStorage.getItem('locale')}  ]})export class AppModule { }

What you're doing in app.module.ts is the right way to do this and for the whole app:

@NgModule({  // ...  providers: [    { provide: LOCALE_ID, useValue: 'de-DE'}  ]  // ...})export class AppModule { }

But unfortunately I don't think that it's possible to change it on the fly.