atwong

/*
 * Extract multiple screenshots/frames from a video URL
 * Params
 *   - vidURL : video URL
 *   - frOffsets : array of timestamps
 *   - frameWidth : screenshot width (default: video width)
 * Returns
 *   - frames: object with offset => {imgUrl, blob}
 *
 * An multiple-frame extension of http://cwestblog.com/2017/05/03/javascript-snippet-get-video-frame-as-an-image/

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

tkadlec

(function () {
	var perfBar = function(budget) {

		window.onload = function() {
			window.performance = window.performance || window.mozPerformance || window.msPerformance || window.webkitPerformance || {};


			var timing = window.performance.timing,
			now = new Date().getTime(),
			output, loadTime;

paulirish

/* bling.js */

window.$ = document.querySelectorAll.bind(document);

Node.prototype.on = window.on = function (name, fn) {
  this.addEventListener(name, fn);
}

NodeList.prototype.__proto__ = Array.prototype;

bobbygrace

Hello, visitors! If you want an updated version of this styleguide in repo form with tons of real-life examples… check out Trellisheets! https://github.com/trello/trellisheets

---

Trello CSS Guide

“I perfectly understand our CSS. I never have any issues with cascading rules. I never have to use !important or inline styles. Even though somebody else wrote this bit of CSS, I know exactly how it works and how to extend it. Fixes are easy! I have a hard time breaking our CSS. I know exactly where to put new CSS. We use all of our CSS and it’s pretty small overall. When I delete a template, I know the exact corresponding CSS file and I can delete it all at once. Nothing gets left behind.”

You often hear updog saying stuff like this. Who’s updog? Not much, who is up with you?

hamstu

var ParallaxManager, ParallaxPart;

ParallaxPart = (function() {
  function ParallaxPart(el) {
    this.el = el;
    this.speed = parseFloat(this.el.getAttribute('data-parallax-speed'));
    this.maxScroll = parseInt(this.el.getAttribute('data-max-scroll'));
  }

  ParallaxPart.prototype.update = function(scrollY) {

p3t3r67x0

Styling native elements

Native HTML controls are a challenge to style. You can style any element in the web platform that uses Shadow DOM with a pseudo element ::pseudo-element or the /deep/ path selector.

video::webkit-media-controls-timeline {
  background-color: lime;
}

video /deep/ input[type=range] {

addyosmani

CSS Layout Debugger

A tweet-sized debugger for visualizing your CSS layouts. Outlines every DOM element on your page a random (valid) CSS hex color.

One-line version to paste in your DevTools

Use $$ if your browser aliases it:

~ 108 byte version

fta2012

var selector = 'img' // Replace this with the selector for the element you want to make transformable


jQuery.getScript('//ajax.googleapis.com/ajax/libs/jqueryui/1.10.3/jquery-ui.min.js', function() {
jQuery.getScript('//cdnjs.cloudflare.com/ajax/libs/numeric/1.2.6/numeric.min.js', function() {
  
(function() {
  var $, applyTransform, getTransform, makeTransformable;

  $ = jQuery;

aarongustafson

// Get the active Media Query as defined in the CSS
// Use the following format:
// #getActiveMQ-watcher { font-family: "default"; }
// @media only screen and (min-width:20em){ #getActiveMQ-watcher { font-family: "small"; } }
// etc.
window.getActiveMQ = function() {
      // Build the watcher
  var $watcher = document.createElement('div'),
      // alias getComputedStyle
      computed = window.getComputedStyle,