ericelliott

ES6 Defaults / Overrides Pattern

Combine default parameters and destructuring for a compact version of the defaults / overrides pattern.

function foo ({
    bar = 'no',
    baz = 'works!'
  } = {}) {

chantastic

Hi Nicholas,

I saw you tweet about JSX yesterday. It seemed like the discussion devolved pretty quickly but I wanted to share our experience over the last year. I understand your concerns. I've made similar remarks about JSX. When we started using it Planning Center, I led the charge to write React without it. I don't imagine I'd have much to say that you haven't considered but, if it's helpful, here's a pattern that changed my opinion:

The idea that "React is the V in MVC" is disingenuous. It's a good pitch but, for many of us, it feels like in invitation to repeat our history of coupled views. In practice, React is the V and the C. Dan Abramov describes the division as Smart and Dumb Components. At our office, we call them stateless and container components (view-controllers if we're Flux). The idea is pretty simple: components can't

ericelliott

React Reusable Component Factory

'use strict';

const ENTER_KEY = 13;

const emailFactory = function ({
  React,
  setEmail,

jlongster

// Have some complicated non-React widgets that manipulate DOM?
// Do they manage a list of DOM elements? Here's how to wrap it
// into a React component so you can "constantly rerender" it.

// A dumb non-react widget that manually manage some DOM node that
// represent a list of items
function NonReactWidget(node) {
  this.node = node;
}

paulirish

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

gaearon

function mapValues(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {
    result[key] = fn(obj[key], key);
    return result;
  }, {});
}

function pick(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {
    if (fn(obj[key])) {

joepie91

Don't use VPN services.

No, seriously, don't. You're probably reading this because you've asked what VPN service to use, and this is the answer.

Note: The content in this post does not apply to using VPN for their intended purpose; that is, as a virtual private (internal) network. It only applies to using it as a glorified proxy, which is what every third-party "VPN provider" does.

• A Russian translation of this article can be found here, contributed by Timur Demin.
• A Turkish translation can be found here, contributed by agyild.
• There's also this article about VPN services, which is honestly better written (and has more cat pictures!) than my article.

bahmutov

# See list of docker virtual machines on the local box
$ docker-machine ls
NAME      ACTIVE   URL          STATE     URL                         SWARM   DOCKER   ERRORS
default   *        virtualbox   Running   tcp://192.168.99.100:2376           v1.9.1 

# Note the host URL 192.168.99.100 - it will be used later!

# Build an image from current folder under given image name
$ docker build -t gleb/demo-app .

vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

gaearon

// While I claim this is a drop-in replacement, it is a little bit slower.
// If you have hundreds of links, you might spend a few more milliseconds rendering the page on transitions.

// KNOWN ISSUES WITH THIS APPROACH:

// * This doesn't work great if you animate route changes with <TransitionGroup>
//   because the links are going to get updated immediately during the animation.
// * This might still not update the <Link> correctly for async routes,
//   as explained in https://github.com/reactjs/react-router/issues/470#issuecomment-217010985.