Nikita NikitaIT

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

Technical overview

A basic `Option` type

// Option.ts

// definition
export class None {
  readonly tag: 'None' = 'None'


	import { PublicFormContext, SubmissionHandler } from "vee-validate";

	export function createSubmitHandler<
	TValues extends Record<string, any> = Record<string, any>,
	TContext extends Omit<PublicFormContext<TValues>, "handleSubmit"> = Omit<
	PublicFormContext<TValues>,
	"handleSubmit"
	>
	>(


	// Available variables:
	// - Machine
	// - interpret
	// - assign
	// - send
	// - sendParent
	// - spawn
	// - raise
	// - actions


	// Available variables:
	// - Machine
	// - interpret
	// - assign
	// - send
	// - sendParent
	// - spawn
	// - raise
	// - actions


	// Available variables:
	// - Machine
	// - interpret
	// - assign
	// - send
	// - sendParent
	// - spawn
	// - raise
	// - actions

	{
	country: [
	[0, "Любая"],
	[1, "Россия"],
	[2, "Украина"],
	[3, "Беларусь"],
	[4, "Казахстан"],
	[5, "Азербайджан"],
	[6, "Армения"],
	[7, "Грузия"],