nathansmith

/*
  // Used like so…
  <Render if={isUserAuthenticated}>
    <p>
      Super secret UI.
    </p>
  </Render>
*/

import React from 'react';

Rich-Harris

Stuff I wish I'd known sooner about service workers

I recently had several days of extremely frustrating experiences with service workers. Here are a few things I've since learned which would have made my life much easier but which isn't particularly obvious from most of the blog posts and videos I've seen.

I'll add to this list over time – suggested additions welcome in the comments or via twitter.com/rich_harris.

Use Canary for development instead of Chrome stable

Chrome 51 has some pretty wild behaviour related to console.log in service workers. Canary doesn't, and it has a load of really good service worker related stuff in devtools.

Restuta

/*  Sometimes it's pretty easy to run ito troubles with React ES6 components.
    Consider the following code: */

class EventStub extends Component {
  componentDidMount() {
    window.addEventListener('resize', this.onResize.bind(this)); //notice .bind
  }
  
  componentWillUnmount() {
    window.removeEventListener('resize', this.onResize.bind(this));

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

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;

cmod

/*  

  Minimal Facebook Messenger 
  ==========================
  
  1. Make a Fluid (http://fluidapp.com/) instance of https://facebook.com/messages/
  1. a. (You need to buy the paid version of Fluid to modify UserStyles)
  2. Apply the below CSS as a Userstyles stylesheet
  3. Like magic, you can now message without all the cruft of Full Facebook
  

jelmerdemaat

<a href="javascript:(function(){window.open('//developers.google.com/speed/pagespeed/insights/?url='+window.location);})()">
  Check page in Google PageSpeed
</a>

davatron5000

Make it useful

• Install Package Control. For SublimeText 2, paste the following in Terminal:

import urllib2,os; pf='Package Control.sublime-package'; ipp = sublime.installed_packages_path(); os.makedirs( ipp ) if not os.path.exists(ipp) else None; urllib2.install_opener( urllib2.build_opener( urllib2.ProxyHandler( ))); open( os.path.join( ipp, pf), 'wb' ).write( urllib2.urlopen( 'http://sublime.wbond.net/' +pf.replace( ' ','%20' )).read()); print( 'Please restart Sublime Text to finish installation')

From here on out, use Package Control to install everything. ⌘+Shift+P, then type Install to get a list of installable packages you can 'livesearch through. After installing plugins, they should be running.

jelmerdemaat

@mixin keyframes( $animationName ) {
    @-webkit-keyframes $animationName {
        @content;
    }
    @-moz-keyframes $animationName {
        @content;
    }
    @-o-keyframes $animationName {
        @content;
    }

bjankord

Creating a new element named picture or pic that mirrors the img element would allow for an easier responsive image element to polyfill.

When polyfilling srcN paired with the image element, legacy browsers which don't support srcN would download the image from the src attr and the matching srcN attr. This would result in dual downloads in legacy browser which need the srcN polyfill. These "legacy browsers" are every browser today.

A few ways around this would be to leave the img src attr empty. Or remove it all togher.

From Riloadr docs, Túbal Martín has some concerning notes about leaving the src attr empty on img elements.

Warning!: >Do not set an empty string for the value of src src="".