Angular2 and webpack - i18n plugin vs ng2-translate

Question

I want to build a web-application with angular2 and bundle this with webpack. What is the best way for providing multiple languages:

i18n-plugin: https://github.com/webpack/i18n-webpack-plugin

or

ng2-translate: https://github.com/ocombe/ng2-translate

Solution 1

If you are using angular-cli you can follow these steps:

Be aware that your app must be AOT compatibe, so you should be able to build it with --aot switch:

ng build --aot

1. Extract messages with ng xi18n command with location for translation file given:

   ng xi18n --output-path src/i18n
   

2. You will get src/i18n/messages.xlf file. Copy this file and translate messages to languages you need:

   src/i18n/messages.en.xlf
   src/i18n/messages.pl.xlf
   

3. Serve/build your app with ng serve / ng build command (change locale accordingly):

   ng serve --i18n-file=src/i18n/messages.en.xlf --locale=en --i18n-format=xlf --aot
   

Solution 2

in case someone still wondering how to use angular 2 localization with webpack loader, i have modified the provider angular 2 cookbook provided;

First create i18n.provider.ts

import { TRANSLATIONS, TRANSLATIONS_FORMAT, LOCALE_ID } from '@angular/core';
import { Observable } from "rxjs/Rx";
export function getTranslationProviders(): Promise<Object[]> {


  // Get the locale id from the global
  const locale = document['locale'] as string;
  // return no providers if fail to get translation file for locale
  const noProviders: Object[] = [];
  // No locale or U.S. English: no translation providers
  if (!locale || locale === 'en') {
    return Promise.resolve(noProviders);
  }
  // Ex: 'locale/messages.fr.xlf`
  const translationFile = `./src/app/localezation/messages.${locale}.xlf`;
  var provider = getTranslationsWithSystemJs(translationFile)
    .then((translations: string) => [
      { provide: TRANSLATIONS, useValue: translations },
      { provide: TRANSLATIONS_FORMAT, useValue: 'xlf' },
      { provide: LOCALE_ID, useValue: locale }
    ])
    .catch(() => noProviders); // ignore if file not found

  debugger;
  return provider;
}
declare var System: any;
function getTranslationsWithSystemJs(file: string) {
// changes Start here 
  var text = "";
  var fileRequest = new XMLHttpRequest();
  fileRequest.open("GET", file, false);
  fileRequest.onerror = function (err) {
    console.log(err);
  }
  fileRequest.onreadystatechange = function () {
    if (fileRequest.readyState === 4) {
      if (fileRequest.status === 200 || fileRequest.status == 0) {
        text = fileRequest.responseText;
      }
    }
  }
  fileRequest.send()
  var observable = Observable.of(text);
  var prom = observable.toPromise();
  return prom; 
}

notice the changes are :

1. i used jxjs library to create observable/ promise
2. i used XMLHttpRequest to get the localezation files

Second in the main.ts files change the bootstrapping the same as mentioned in angular cookbook

getTranslationProviders().then(providers => {
  const options = { providers };
  platformBrowserDynamic().bootstrapModule(AppModule, options);
});

Solution 3

Angular 2 Final release has i18n native support https://angular.io/docs/ts/latest/cookbook/i18n.html

Check another answer https://stackoverflow.com/a/39004058/1267942 with example and some details about usage.

ng2-translate is too verbose comparing to the native implementation. Also the author of ng2-translate is a big contributor to angular 2 i18n documentation

Comments

[lyessmecano]

But this cookbook still refers to SystemJS as an integration mechanism instead of Webpack. How do we integrate the XLIFF file into compilation with Webpack?

[circy]

What is the most profitable difference to the i18n plugin from webpack?

[Spock]

@Sebastien If you don't want to do it in a separate process, you can use the AoT Webpack plugin from npmjs.com/package/@ngtools/webpack

[gkri]

and how can you change the language of the app within the app? This is my main problem and the reason why I want to do this with JIT instead of AOT, but I can find no help for this

[lukk]

unfortunately, you have to make separate build for each language and provide correct routing on the server side eg. using custom url localhost:8080/webapp/en

[Davor]

@lukk - holy shit, that's such a bad design. Who in the world decided that, was everyone in Google high that day? I think I'll try my luck with ng2-translate first...

[IrishDubGuy]

For anyone who has come from AngularJS's angular-translate, the i18n native support seems like a bizarre approach. It requires the app to be completely rebuilt and separately deployed for each language. I can't imagine what the admin overhead on this is like when you get into 4/5/6 languages which would be typical on an internal business app. At first glance it looks like ngx-translate is closer to angular-translate in that it can set up language from the server on startup, switch languages on the fly etc.