Vladimir Jimenez allejo

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

	@function mapReverse ($map) {
	$result: null;

	@if type-of($map) == "map" {
	$keys: map-keys($map);
	$map-reversed: ();

	@for $i from length($keys) through 1 {
	$map-reversed: map-merge(
	$map-reversed,

	var HelloMessage = React.createClass({
	render: function() {
	return <div tabIndex="1" onBlur={this.onBlur}>
	Hello <input type="text" value="wat"/>
	</div>;
	},

	onBlur: function(e) {
	var currentTarget = e.currentTarget;