ng2-translate file loader for Angular Universal (server side)

translateUniversalLoader.ts

import {TranslateLoader} from "ng2-translate/ng2-translate";
import {Observable} from "rxjs/Observable";
import fs = require('fs');

export class TranslateUniversalLoader implements TranslateLoader {
    constructor(private prefix: string = 'i18n', private suffix: string = '.json') {}

    /**
     * Gets the translations from the server
     * @param lang
     * @returns {any}
     */
    public getTranslation(lang: string): Observable<any> {
        return Observable.create(observer => {
            observer.next(JSON.parse(fs.readFileSync(`${this.prefix}/${lang}${this.suffix}`, 'utf8')));
            observer.complete();
        });
    }
}