代码很简单，如下：

var pro = window.HTMLElement.prototype;

pro.__defineGetter__("outerHTML", function(){

var str = "<" + this.tagName;

var a = this.attributes;

for(var i = 0, len = a.length; i < len; i++){

if(a[i].specified){

str += " " + a[i].name + '="' + a[i].value + '"';

}

}

if(!this.canHaveChildren){

return str + " />";

}

return str + ">" + this.innerHTML + "</" + this.tagName + ">";

});

pro.__defineSetter__("outerHTML", function(s){

var r = this.ownerDocument.createRange();

r.setStartBefore(this);

var df = r.createContextualFragment(s);

this.parentNode.replaceChild(df, this);

return s;

});

pro.__defineGetter__("canHaveChildren", function(){

return !/^(area|base|basefont|col|frame|hr|img|br|input|isindex|link|meta|param)$/.test(this.tagName.toLowerCase());

});