JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/5.0.1/Rx.js"></script>
<h1>請點擊</h1>

CSS

html, body {
  height: 100%;
  background-color: tomato;
}

JavaScript

function getPostData() {
    return fetch('https://jsonplaceholder.typicode.com/posts/1')
    .then(res => res.json())
}
var source = Rx.Observable.fromEvent(document.body, 'click');

var example = source.concatMap(
                e => Rx.Observable.from(getPostData()), 
                (e, res, eIndex, resIndex) => res.title);

example.subscribe({
    next: (value) => { console.log(value); },
    error: (err) => { console.log('Error: ' + err); },
    complete: () => { console.log('complete'); }
});