Jeremy Brown notmessenger

Do not use forEach with async-await

TLDR: Use for...of instead of forEach() in asynchronous code.

For legacy browsers, use for(...;...;...) or [].reduce()

To execute the promises in parallel, use Promise.all([].map(...))

The problem

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

Folder Structure

Please note

While this gist has been shared and followed for years, I regret not giving more background. It was originally a gist for the engineering org I was in, not a "general suggestion" for any React app.

Typically I avoid folders altogether. Heck, I even avoid new files. If I can build an app with one 2000 line file I will. New files and folders are a pain.

Data Down / Actions Up
- http://emberjs.jsbin.com/nayaho/edit?html,js - Interdependent select boxes. No observers.
- http://ember-twiddle.com/2d7246875098d0dbb4a4 - One Way Input
Plain JSBin's
- http://rwjblue.jsbin.com/pixeki/edit?html,js,output
Ember Version Base JSBin's
- 1.0 - http://emberjs.jsbin.com/juluje/edit?html,js,output
1.1 - http://emberjs.jsbin.com/cofufo/edit?html,js,output

	const MESSAGES = {
	400(foo) {
	// stuff
	},
	404(foo) {
	// stuff
	},
	500(foo) {
	// stuff
	}

	/**
	* `Ember.MergedArray` is an array that observes multiple other arrays (called source arrays) for changes and includes
	* all items from all source arrays in an efficient way.
	*
	* Usage:
	*
	* ```javascript
	* var obj = Ember.Object.create({
	* people: [
	* {