jsbin/public/js/runner/utils.js

/**
 * Utilities & polyfills
 */

var prependChild = function(elem, child) { elem.insertBefore(child, elem.firstChild); };

var addEvent = function(elem, event, fn) {
  if (elem.addEventListener) {
    elem.addEventListener(event, fn, false);
  } else {
    elem.attachEvent("on" + event, function() {
      // set the this pointer same as addEventListener when fn is called
      return(fn.call(elem, window.event));
    });
  }
};

if (!window.location.origin) window.location.origin = window.location.protocol+"//"+window.location.host;

var throttle = function (fn, delay) {
  var timer = null;
  var throttled = function () {
    var context = this, args = arguments;
    throttled.cancel();
    throttled.timer = setTimeout(function () {
      fn.apply(context, args);
    }, delay);
  };

  throttled.cancel = function () {
    clearTimeout(throttled.timer);
  };

  return throttled;
};

var cleanse = function (s) {
  return (s||'').replace(/[<&]/g, function (m) { return {'&':'&amp;','<':'&lt;'}[m];});
};

var getIframeWindow = function (iframeElement) {
    return iframeElement.contentWindow || iframeElement.contentDocument.parentWindow;
};