Angular 2.将事件数据从子组件传递给所有其他组件

Question

这个概念看起来很难看，与Angular相比1.我仍然无法得到如何通知我所有其他组件的变化。假设我有HeaderComponent，我将按钮更改语言属性从'en'到'de'。我在EventEmitter中绑定事件，但是如何在其他组件中获取新属性？

    import { Component, Output, EventEmitter, Input }          from '@angular/core'
    import { ROUTER_DIRECTIVES, Router }  from '@angular/router';
    import {Observable} from 'rxjs/Observable';

    @Component({
        selector: 'bp-header',
        templateUrl: 'app/header.component.html',
        directives: [ROUTER_DIRECTIVES]
    })
    export class HeaderComponent {
        isActive: number;
    language: string = "en";
    constructor(private dataService: DataService) {
  }
    ngOnInit() {
        this.isActive = 1;
    }
    public setLanguage = (language: string) => {
        if (this.language === language) { return }
        else { this.language = language };
        this.dataService.changeLanguage(language);
    }
    private setActive(active: number) {
        if (this.isActive === active) return;
        this.isActive = active;
    }
    }

这是另一个子组件。我是对的，输入应该听取变化吗？

import { Component, Input } from '@angular/core';
import { Person } from './data.person';
import { Article } from './data.article';
import { ROUTER_DIRECTIVES, Router }  from '@angular/router';

@Component({
    selector: 'bp-home',
    templateUrl: "app/home.component.html",
    directives: [ROUTER_DIRECTIVES]
})
export class HomeComponent {
        language: string;
article: Article;
persons: Person[];
subscription: Subscription;
constructor(private dataService: DataService) {
    this.subscription = dataService.languageChanged$.subscribe(
        language => {
            this.language = language;
        });
}
ngOnInit() {
    this.article = this.language == "ru" ? this.articleRu : this.articleEn;
    this.persons = this.language == "ru" ? this.personsRu : this.personsEn;
}
ngOnDestroy() {
    this.subscription.unsubscribe();
}
ngOnChanges() {
    this.article = this.language == "ru" ? this.articleRu : this.articleEn;
    this.persons = this.language == "ru" ? this.personsRu : this.personsEn;
}

这是数据服务：

import { Component, Injectable}          from '@angular/core';
import { Subject }    from 'rxjs/Subject';

@Injectable()
export class DataService {
  private language = new Subject<string>();
  languageChanged$ = this.language.asObservable();
  changeLanguage(language: string) {
    this.language.next(language);
  }
}