handle_events.js

来自「《JavaScript精粹》 源文件下载」· JavaScript 代码 · 共 49 行

addLoadListener(initEvents);

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

  mylink.onclick = engage;
  
  return true;
}

function engage()
{
  alert("Engage!");

  return false;
}

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();
      };
    }
  }
}