Return Observable From Inside Nested Callbacks Functions

Good afternoon! I'm currently developing a web app in Angular2/4 and I have a problem with Observables. The goal is, inside a component, to call a function and when that function f

Solution 1:

What You are looking for is switchMap or mergeMap. switch map is better it will cancel previous request if new comes out.

myFunc1(): Observable<Status> {
    // some code and then call of myFunc2()
    return this.myService2.myFunc2()
      .switchMap(data => {
       // do some staff here and then call of myFunc3()
       return this.myService3.myFunc3()
      }).switchMap(data2 => {
          // do some other staff and then call of myFunc4()
          return this.myService4.myFunc4()
      }).switchMap(data3 => {
             // do staff and then return program flow into the Component
             return Observable.of<Status>({status: 'ok'});
          });
       });
    });
}