SwitchMap

one observable inside another

by Krishna Ananthi

HTML

<script src="https://unpkg.com/@reactivex/[email protected]/dist/global/Rx.js"></script>

<input type="text" id="input1">
<input type="text" id="input2">

<p>Combined value: <span></span></p>

JavaScript

var span = document.querySelector('span');
var o1= Rx.Observable.fromEvent(input1,'input');
var o2= Rx.Observable.fromEvent(input2,'input');

o1.switchMap(e=>{
     return o2.map(e1=> { console.log(e); return e1.target.value;} )
}).subscribe(c=> span.textContent = c);