Event Listener with destroyers.

addListener.js

function addListener(elem, evtName, listener) {
  elem.addEventListener(evtName, listener, false);
  oneTimeListener(document, "motiondestroy", function () {
    elem.removeEventListener(evtName, listener, false);
  });
}

oneTimeListener.js

function oneTimeListener(elem, evtName, listener) {
  elem.addEventListener(evtName, function callback() {
    listener.apply(this, arguments);
    elem.removeEventListener(evtName, callback, false);
  }, false);
}