Anders D. Johnson AndersDJohnson

If you use server rendering, keep in mind that neither useLayoutEffect nor useEffect can run until the JavaScript is downloaded.

You might see a warning if you try to useLayoutEffect on the server. Here's two common ways to fix it.

Option 1: Convert to useEffect

If this effect isn't important for first render (i.e. if the UI still looks valid before it runs), then useEffect instead.

function MyComponent() {

Data Prefetching in Next.js

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

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

Description

This simple script will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.

The script is here:

#!/bin/bash
convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2"

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

	<script type="text/javascript">
	window.open ("popup.html","mywindow", "width=350,height=250");

	// Create IE + others compatible event handler

	#/usr/bin/env bash
	# MIT © Sindre Sorhus - sindresorhus.com
	# forked by Gianluca Guarini

	changed_files="$(git diff-tree -r --name-only --no-commit-id ORIG_HEAD HEAD)"

	check_run() {
	echo "$changed_files" \| grep -E --quiet "$1" && eval "$2"
	}

	#!/usr/bin/env bash
	# MIT © Sindre Sorhus - sindresorhus.com

	# git hook to run a command after `git pull` if a specified file was changed
	# Run `chmod +x post-merge` to make it executable then put it into `.git/hooks/`.

	changed_files="$(git diff-tree -r --name-only --no-commit-id ORIG_HEAD HEAD)"

	check_run() {
	echo "$changed_files" \| grep --quiet "$1" && eval "$2"

	var https = require('https'),
	user = process.argv[2],
	opts = parseOpts(process.argv.slice(3))

	request('/users/' + user, function (res) {
	if (!res.public_repos) {
	console.log(res.message)
	return
	}
	var pages = Math.ceil(res.public_repos / 100),

	#!/bin/sh

	# check for where the latest version of IDEA is installed
	IDEA=`ls -1d /Applications/IntelliJ\ * \| tail -n1`
	wd=`pwd`

	# were we given a directory?
	if [ -d "$1" ]; then
	# echo "checking for things in the working dir given"
	wd=`ls -1d "$1" \| head -n1`