Angular 2/4:从单独的文件中加载所有文本，以便于修改、测试和国际化

{
  "welcomeMessage": "Welcome to my app!",
  "buttonText": "Click me"
}

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';

@Injectable()
export class TextService {
  private textsUrl = 'assets/texts.json';

  constructor(private http: HttpClient) { }

  getTexts() {
    return this.http.get(this.textsUrl);
  }
}

import { Component, OnInit } from '@angular/core';
import { TextService } from './text.service';

@Component({
  selector: 'app-my-component',
  template: `
    <h1>{{ texts?.welcomeMessage }}</h1>
    <button>{{ texts?.buttonText }}</button>
  `
})
export class MyComponent implements OnInit {
  texts: any;

  constructor(private textService: TextService) { }

  ngOnInit() {
    this.textService.getTexts().subscribe((data: any) => {
      this.texts = data;
    });
  }
}