ng2-translate

An implementation of angular translate for Angular 2.

Simple examples using ng2-translate:

• with ng2-play: https://github.com/ocombe/ng2-play/tree/ng2-translate
• with angular2-seed: https://github.com/ocombe/angular2-seed/tree/ng2-translate

Installation

First you need to install the npm module:

npm install ng2-translate --save

If you use SystemJS to load your files, you might have to update your config with this if you don't use defaultJSExtensions: true:

System.config({
    packages: {
        "/ng2-translate": {"defaultExtension": "js"}
    }
});

Finally, you can use ng2-translate in your Angular 2 project (make sure that you've loaded the angular2/http bundle as well). It is recommended to instantiate TranslateService in the bootstrap of your application and to never add it to the "providers" property of your components, this way you will keep it as a singleton. If you add it to the "providers" property of a component it will instantiate a new instance of the service that won't be initialized.

import {HTTP_PROVIDERS} from 'angular2/http';
import {Component, Injectable} from 'angular2/core';
import {TranslateService, TranslatePipe} from 'ng2-translate/ng2-translate';
import {bootstrap} from 'angular2/platform/browser';

bootstrap(AppComponent, [
    HTTP_PROVIDERS,
    TranslateService // not required, but recommended to have 1 unique instance of your service
]);

@Injectable()
@Component({
    selector: 'app',
    template: `
        <div>{{ 'HELLO' | translate:{value: param} }}</div>
    `,
    pipes: [TranslatePipe]
})
export class AppComponent {
    param: string = "world";
    
    constructor(translate: TranslateService) {
        var userLang = navigator.language.split('-')[0]; // use navigator lang if available
        userLang = /(fr|en)/gi.test(userLang) ? userLang : 'en';
        
         // this language will be used as a fallback when a translation isn't found in the current language
        translate.setDefaultLang('en');
        
         // the lang to use, if the lang isn't available, it will use the current loader to get them
        translate.use(userLang);
    }
}

For now, only the static loader is available. You can configure it like this:

var prefix = 'assets/i18n/';
var suffix = '.json';
translate.useStaticFilesLoader(prefix, suffix);

Then put your translations in a json file that looks like this (for en.json):

{
    "HELLO": "hello {{value}}"
}

An then you can get new translations like this:

    translate.getTranslation(userLang);

But you can also define your translations manually instead of using getTranslation:

translate.setTranslation('en', {
    "HELLO": "hello {{value}}"
});

API

TranslateService

Properties:

• currentLang: The lang currently used

• currentLoader: An instance of the loader currently used (static loader by default)

• onLangChange: An EventEmitter to listen to lang changes events

  example:

   onLangChange.subscribe((params: {lang: string, translations: any}) => {
     // do something
   });

Methods:

• useStaticFilesLoader(): Use a static files loader
• setDefaultLang(lang: string): Sets the default language to use as a fallback
• use(lang: string): Observable<any>: Changes the lang currently used
• getTranslation(lang: string): Observable<any>: Gets an object of translations for a given language with the current loader
• setTranslation(lang: string, translations: Object): Manually sets an object of translations for a given language
• getLangs(): Returns an array of currently available langs
• get(key: string|Array<string>, interpolateParams?: Object): Observable<string|Object>: Gets the translated value of a key (or an array of keys)
• set(key: string, value: string, lang?: string):

TranslatePipe

You can call the TranslatePipe with some optional parameters that will be transpolated into the translation for the given key.

Example:

<p>Say {{ 'HELLO' | translate:{value: "world"} }}</p>

With the given translation: "HELLO": "hello {{value}}".

Parser

Methods:

• interpolate(expr: string, params?: any): string: Interpolates a string to replace parameters.

  This is a {{ key }} ==> This is a value with params = { key: "value" }

• flattenObject(target: Object): Object: Flattens an object { key1: { keyA: 'valueI' }} ==> { 'key1.keyA': 'valueI' }