caridy

// default exports
export default 42;
export default {};
export default [];
export default foo;
export default function () {}
export default class {}
export default function foo () {}
export default class foo {}

akras14

Git Cheat Sheet

Commands

Getting Started

git init

or

nolanlawson

// Promise.all is good for executing many promises at once
Promise.all([
  promise1,
  promise2
]);

// Promise.resolve is good for wrapping synchronous code
Promise.resolve().then(function () {
  if (somethingIsNotRight()) {
    throw new Error("I will be rejected asynchronously!");

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

0bie

const overlay = (element) => {
  const newElement = document.createElement(element);
  newElement.style.height = '100vh';
  return newElement;
};

const onEvent = (inputType, DOMElement, callback) => {
  if (DOMElement.addEventListener){
    DOMElement.addEventListener(inputType, callback);
  }

acdlite

// getComponent is a function that returns a promise for a component
// It will not be called until the first mount
function asyncComponent(getComponent) {
  return class AsyncComponent extends React.Component {
    static Component = null;
    state = { Component: AsyncComponent.Component };

    componentWillMount() {
      if (!this.state.Component) {
        getComponent().then(Component => {

nrollr

Install MySQL on macOS Sierra

This procedure explains how to install MySQL using Homebrew on macOS Sierra 10.12

Install Homebrew

• Installing Homebrew is effortless, open Terminal and enter :
  $ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
• Note: Homebrew will download and install Command Line Tools for Xcode 8.0 as part of the installation process.

Install MySQL

At this time of writing, Homebrew has MySQL version 5.7.15 as default formulae in its main repository :

ljharb

Array Iteration

https://gist.github.com/ljharb/58faf1cfcb4e6808f74aae4ef7944cff

While attempting to explain JavaScript's reduce method on arrays, conceptually, I came up with the following - hopefully it's helpful; happy to tweak it if anyone has suggestions.

Intro

JavaScript Arrays have lots of built in methods on their prototype. Some of them mutate - ie, they change the underlying array in-place. Luckily, most of them do not - they instead return an entirely distinct array. Since arrays are conceptually a contiguous list of items, it helps code clarity and maintainability a lot to be able to operate on them in a "functional" way. (I'll also insist on referring to an array as a "list" - although in some languages, List is a native data type, in JS and this post, I'm referring to the concept. Everywhere I use the word "list" you can assume I'm talking about a JS Array) This means, to perform a single operation on the list as a whole ("atomically"), and to return a new list - thus making it mu

datchley

React/Redux Style Guide

Table of Contents:

• React/Redux Style Guide
  • React Guidelines
    • Organization
    • Components
• Container Components

heygrady

Redux containers: mapDispatchToProps

This document details some tips and tricks for creating redux containers. Specifically, this document is looking at the mapDispatchToProps argument of the connect function from [react-redux][react-redux]. There are many ways to write the same thing in redux. This gist covers the various forms that mapDispatchToProps can take.