daniellmb

window.onerror = function(message) {
  top.location.href = 'http://stackoverflow.com/search?q=' + 
    encodeURIComponent(message + ' [js]');
};

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

austinhyde

Observables

You don't really need a framework or fancy cutting-edge JavaScript features to do two-way data binding. Let's start basic - first and foremost, you need a way to tell when data changes. Traditionally, this is done via an Observer pattern, but a full-blown implementation of that is a little clunky for nice, lightweight JavaScript. So, if native getters/setters are out, the only mechanism we have are accessors:

var n = 5;
function getN() { return n; }
function setN(newN) { n = newN; }

console.log(getN()); // 5

setN(10);

dergachev

OS X Screencast to animated GIF

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

Instructions

To capture the video (filesize: 19MB), using the free "QuickTime Player" application: