Myndex

Let's Flip For Color

Q: I want my text color to switch to black or white, depending on the background color the user chooses. Just where is that flip point?

Short Answer:

Calculate the luminance (Y) of the given color, and flip the text either black or white based on a pre-determined middle contrast figure. For a typical sRGB display, flip to white when Y < 0.36 (i.e. 36%)

Longer Answer

First I want to acknowledge the massive amount of misinformation on the internet on this particular subject. The fact this field is still a subject of active research and unsettled science adds to the fun. I came to this conclusion as the result of the last few years of research into a new contrast prediction method for readability.

The field of visual perception is dense and abstract, as well as developing, so it is common for misunderstandings to exist. For instance, HSV and HSL are not even close to perceptually accurate. For that you need a perceptually uniform model such as CIELAB or CIELUV or CIECAM02 etc

Myndex

Where's The Luv?

An Examination of the CIELAB and CIELUV colorspaces.

It is exciting to see so many new color features for the CSS Color Module. There are nevertheless a couple items that resulted in a "raised eyebrow response". This Gist is mainly going to focus on one: the use of the LAB version of LCh instead of LUV LCh, which may be better suited for the task but appears to have been dismissed as if irrellevant.

I DISAGREE. Luv is in common use and very relevant, and LuvLCh or one of the several LuvLCh variants has distinct advantages over LabLCh for use cases such as choosing color for web content for displays.

Myth Destruction

modernserf

Simple value literals

Numbers

syntax	examples	languages
decimal literals	-123.45	(most languages)
scientific notation	1.23e-2
prefix hexadecimal	0xDEADBEEF
prefix binary	0b1110
prefix octal	0o777

jkrems

Modules - History & Future

History

• Early work by Ihab Awad (Google) and Kris Kowal (FastSoft)
  • https://twitter.com/kriskowal/status/943547614158450688
  • Hermetic eval presentation: https://docs.google.com/presentation/d/1KlPxgocvzpTq44KTF4xZ6TnzGRsy628hP5he7bXVB3I/edit#slide=id.i0
• 2009-09: 2nd draft of module strawman, still very close to "closures as modules", export x = 42
  • https://esdiscuss.org/topic/hermetic-evaluation-modules-strawman

• https://docs.google.com/document/u/1/pub?id=1hNv1SHh_v_6nD1QBd6pySUJ2U5roAELzW5cqD2tt_WM

wesbos

// 🔥 Node 7.6 has async/await! Here is a quick run down on how async/await works

const axios = require('axios'); // promised based requests - like fetch()

function getCoffee() {
  return new Promise(resolve => {
    setTimeout(() => resolve('☕'), 2000); // it takes 2 seconds to make coffee
  });
}

olivierlacan

This guide assumes that you recently run brew upgrade postgresql and discovered to your dismay that you accidentally bumped from one major version to another: say 9.3.x to 9.4.x. Yes, that is a major version bump in PG land.

First let's check something.

brew info postgresql

The top of what gets printed as a result is the most important:

jonathantneal

Local SSL websites on macOS Sierra

These instructions will guide you through the process of setting up local, trusted websites on your own computer.

These instructions are intended to be used on macOS Sierra, but they have been known to work in El Capitan, Yosemite, Mavericks, and Mountain Lion.

NOTE: You may substitute the edit command for nano, vim, or whatever the editor of your choice is. Personally, I forward the edit command to Sublime Text:

alias edit="/Applications/Sublime\ Text.app/Contents/SharedSupport/bin/subl"

nicoleslaw

Tiny Content Framework

About the project

This is a tiny content strategy framework focused on goals, messages, and branding. This is not a checklist. Use what you need and scrap the rest. Rewrite it or add to it. These topics should help you get to the bottom of things with clients and other people you work with.

Give me feedback on Twitter (@nicoleslaw) or by email (nicole@nicolefenton.com).

Contents

ShirtlessKirk

/**
 * Luhn algorithm in JavaScript: validate credit card number supplied as string of numbers
 * @author ShirtlessKirk. Copyright (c) 2012.
 * @license WTFPL (http://www.wtfpl.net/txt/copying)
 */
var luhnChk = (function (arr) {
    return function (ccNum) {
        var 
            len = ccNum.length,
            bit = 1,