How to make a synchronous call in angular 5?

Question

So, I was trying to get the solution of this problem. But, somehow I am unable to do so, May be because of the lack of knowledge in angular 5. This is my service:

Answer 1

To make sure async calls are executed before processing response you may use Observable.forkJoin() from ReactiveX.

import {Observable} from 'rxjs/Observable';
import 'rxjs/add/observable/forkJoin';

Observable.forkJoin(
    this.http.get('/links.json').map((response:Response) => response.json()),
    this.http.get('/bookmarks.json').map((response:Response) => response.json())
).subscribe(
    data => {
      this.links = data[0]
      this.bookmarks = data[1]
    },
    error => console.error(error)
);

subscribe() function's onNext handler will execute when all HTTP requests complete successfully.