rx-example.js

/* global document Rx*/

const link = document.querySelector('.nav-link');
const link$ = Rx.Observable.fromEvent(link, 'click');

const observer = {
  next(event) {
    console.log(event);
  },
  error(err) {
    console.error(err);
  },
  complete() {
    document.createElement('p').innerHTML = JSON.stringify(event.target.value);
  }
};

link$.subscribe(observer);