handle_events7.js

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addLoadListener(initEvents);

function initEvents()
{
  var mylink = document.getElementById("mylink");

  attachEventListener(mylink, "click", engage, false);

  return true;
}

function engage(event)
{
  if (typeof event == "undefined")
  {
    event = window.event;
  }

  var target = getEventTarget(event);

  while(target.nodeName.toLowerCase() != "a")
  {
    target = target.parentNode;
  }

  var href = target.getAttribute("href");

  alert("Engage: " + href);

  return true;
}

function getEventTarget(event)
{
  var targetElement = null;

  if (typeof event.target != "undefined")
  {
    targetElement = event.target;
  }
  else
  {
    targetElement = event.srcElement;
  }

  while (targetElement.nodeType == 3 && targetElement.parentNode != null)
  {
    targetElement = targetElement.parentNode;
  }

  return targetElement;
}

function attachEventListener(target, eventType, functionRef, capture)
{
  if (typeof target.addEventListener != "undefined")
  {
    target.addEventListener(eventType, functionRef, capture);
  }
  else if (typeof target.attachEvent != "undefined")
  {
    target.attachEvent("on" + eventType, functionRef);
  }
  else
  {
    eventType = "on" + eventType;

    if (typeof target[eventType] == "function")
    {
      var oldListener = target[eventType];

      target[eventType] = function()
      {
        oldListener();

        return  functionRef();
      }
    }
    else
    {
      target[eventType] = functionRef;
    }
  }

  return true; 
}

function addLoadListener(fn)
{
  if (typeof window.addEventListener != 'undefined')
  {
    window.addEventListener('load', fn, false);
  }
  else if (typeof document.addEventListener != 'undefined')
  {
    document.addEventListener('load', fn, false);
  }
  else if (typeof window.attachEvent != 'undefined')
  {
    window.attachEvent('onload', fn);
  }
  else
  {
    var oldfn = window.onload;
    if (typeof window.onload != 'function')
    {
      window.onload = fn;
    }
    else
    {
      window.onload = function()
      {
        oldfn();
        fn();
      };
    }
  }
}