README.md

@ngx-translate/http-loader

A loader for ngx-translate that loads translations using http.

Get the complete changelog here: https://github.com/ngx-translate/http-loader/releases

• Installation
• Usage

Installation

We assume that you already installed ngx-translate.

Now you need to install the npm module for TranslateHttpLoader:

npm install @ngx-translate/http-loader --save

if you're still on Angular <4.3, please use Http from @angular/http with http-loader@0.1.0.

If you're still using Angular v5, please use ngx-translate 9.x and http-loader 2.x, version 3 and above are only compatible with Angular v6. If you need to use RxJS 5, update to 5.6 and use the rxjs-compat library (see the RxJS update guide).

Usage

1. Setup the TranslateModule to use the TranslateHttpLoader:

The TranslateHttpLoader uses HttpClient to load translations, which means that you have to import the HttpClientModule from @angular/common/http before the TranslateModule:

import {NgModule} from '@angular/core';
import {BrowserModule} from '@angular/platform-browser';
import {HttpClientModule, HttpClient} from '@angular/common/http';
import {TranslateModule, TranslateLoader} from '@ngx-translate/core';
import {TranslateHttpLoader} from '@ngx-translate/http-loader';
import {AppComponent} from "./app";

// AoT requires an exported function for factories
export function HttpLoaderFactory(http: HttpClient) {
    return new TranslateHttpLoader(http);
}

@NgModule({
    imports: [
        BrowserModule,
        HttpClientModule,
        TranslateModule.forRoot({
            loader: {
                provide: TranslateLoader,
                useFactory: HttpLoaderFactory,
                deps: [HttpClient]
            }
        })
    ],
    bootstrap: [AppComponent]
})
export class AppModule { }

The TranslateHttpLoader also has two optional parameters:

• prefix: string = "/assets/i18n/"
• suffix: string = ".json"

By using those default parameters, it will load your translations files for the lang "en" from: /assets/i18n/en.json.

You can change those in the HttpLoaderFactory method that we just defined. For example if you want to load the "en" translations from /public/lang-files/en-lang.json you would use:

export function HttpLoaderFactory(http: HttpClient) {
    return new TranslateHttpLoader(http, "/public/lang-files/", "-lang.json");
}

For now this loader only support the json format.

Angular CLI/Webpack TranslateLoader Example

If you are using Angular CLI (uses webpack under the hood) you can write your own TranslateLoader that always loads the latest translation file available during your application build.

// webpack-translate-loader.ts
import { TranslateLoader } from '@ngx-translate/core';
import { Observable } from 'rxjs/Observable';

export class WebpackTranslateLoader implements TranslateLoader {
  getTranslation(lang: string): Observable<any> {
    return Observable.fromPromise(System.import(`../assets/i18n/${lang}.json`));
  }
}

Cause System will not be available you need to add it to your custom typings.d.ts:

declare var System: System;
interface System {
  import(request: string): Promise<any>;
}

Now you can use the WebpackTranslateLoader with your app.module:

@NgModule({
  bootstrap: [AppComponent],
  imports: [
    TranslateModule.forRoot({
      loader: {
        provide: TranslateLoader,
        useClass: WebpackTranslateLoader
      }
    })
  ]
})
export class AppModule { }

The disadvantage of this solution is that you have to rebuild the application everytime your translate files has changes.