Observables, Subjects and EventEmitters are amazing, I love them. But they have a common problem: what if you subscribe to one of them when the event has been already emitted? You would lose it!
RxJS Observables, compared to the old Promises in Angular 1, seem to be more complicated to understand, but they are far more flexible. Let’s see how we can combine and chain them, in order to merge multiple Http streams of data and get what we need.