外观模式

兼容方式

function addEvent(dom, type, fn) {
    if (dom.addEventListener) {
      dom.addEventListener(type, fn, false);
  } else if (dom.attachEvent) {
      dom.attchEvent('on' + type, fn);
  } else {
      dom['on' + type] = fn;
  }
}

// 获取事件对象
var getEvent = function(event) {
  return event || window.event;
}
// 获取元素
var getTarget = function() {
  var event = getEvent(event);
  return event.target || event.srcElement;
}
// 阻止默认行为
var preventDefault = function() {
  var event = getEvent(event);
  if (event.preventDefault) {
    event.preventDefault();
  } else {
    event.returnValue = false;
  }
}

小型属性样式方法库

var A = {
  g : function(id) {
    return documen.getElementById(id);
  },
  css : function(id, key, value) {
    return document.getELementById(id).style[key] = value;
  },
  attr : function(id, key, value) {
    return document.getElementById(id)[key] = value;
  },
  html : function(id, html) {
    return document.getElementById(id).innerHTML = html;
  },
  on : function(id, type, fn) {
    return document.getElementById['on' + type] = fn;
  }
};