eyegorweb

var traverse = function(o, fn) {
  for (var i in o) {
    fn.apply(this,[i,o[i]]);  
    if (o[i] !== null && typeof(o[i])=="object") {
      traverse(o[i], fn);
    }
  }
}

// usage

eyegorweb

/**
 * Perform a deeply recursive reduce on a set of JSON, or a JSON-encodable Object hierarchy.
 *
 * @param  {Array|Object} collection
 * @param  {Function}     fn
 * @param  {*}            memo
 * @return {*}
 */
function deepReduce(collection, fn, memo) {

eyegorweb

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.

Element

Box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent
• elem.clientLeft, elem.clientTop, elem.clientWidth, elem.clientHeight
• elem.getClientRects(), elem.getBoundingClientRect()