Roger Liu Digiogior

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.

Element

Box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent
elem.clientLeft, elem.clientTop, elem.clientWidth, elem.clientHeight
elem.getClientRects(), elem.getBoundingClientRect()

	import json

	json_data = open('filename').read()

	data = json.loads(json_data)

	for item in data:
	print(item)

	import csv

	csvfile = open('filename', 'r')
	reader = csv.DictReader(csvfile)

	for row in reader:
	print(row)

	import csv

	csvfile = open('filename', 'r')
	reader = csv.reader(csvfile)

	for row in reader:
	print(row)

	<!doctype html>
	<html lang="en-US">
	<head>
	<title></title>
	<meta charset="UTF-8" />
	</head>
	<body>

	</body>
	</html>