ng-2 angular lifecycle

ngOnInit() {
    ...
    this.getBooksAndMovies(); // <-- add this line
  }
 
  getBooksAndMovies() {
    Observable.forkJoin(
        this.http.get('/app/books.json').map((res:Response) => res.json()),
        this.http.get('/app/movies.json').map((res:Response) => res.json())
    ).subscribe(
      data => {
        this.books = data[0]
        this.movies = data[1]
      },
      err => console.error(err)
    );
  }