[Reactive Programming] Using an event stream of double clicks -- buffer()

See a practical example of reactive programming in JavaScript and the DOM. Learn how to detect double clicks with a few operators in RxJS.

<!DOCTYPE html>
<html>
<head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/2.3.22/rx.all.js"></script>
<meta charset="utf-8">
<title>JS Bin</title>
</head>
<body>
<div class="header">
<a href="#" class="button">BUTTON</a><h4>-</h4>
</div>
</body>
</html>
var button = document.querySelector('.button');
var h4 = document.querySelector('h4'); var clicks = Rx.Observable.fromEvent(button, 'click');
var doubleClicks = clicks
.buffer(() => clicks.throttle(250)) // buffer the events, for each event debounce 250ms and group together
.map(arr => arr.length) // for each group, count the lengh of event
.filter(x => x ===2); // only pick length === 2 which means double click var res = doubleClicks.subscribe( () => {
h4.textContent = "double click"
}); doubleClicks.throttle(1000).subscribe(() => {
h4.textContent = "-";
});
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