RxJS formalism

Now, unlike YieldJS, RxJS is push-based. Here, the subscribers would automatically receive new values from the publisher. A subscriber or listener is denoted by the observer object, and the publisher (that pushes/publishes new values) is denoted by the Observable object. Just like the way we specified iterator methods (our future operators) to compose our generated sequences, we can efficiently do the same (transform, filter, and so on) for all the elements in the observable sequence.

Observables and observers

The generator becomes our observable, and the callback function, which would be interested in these sequences, becomes the observer. Having said this, creating Observables is pretty straightforward, as we saw in the earlier chapter with reactive extensions for .NET. The following code bares it all:

    var client = Rx.Observable.create(function (observer) { 
      observer.onNext('On Your Mark'); 
      observer.onNext('Get Set'); 
      observer...