判断元素是否为HTMLElement元素【转载】

地址：http://www.cnblogs.com/snandy/archive/2011/03/12/1981516.html

我们经常使用nodeType==1判断元素是否是一个HMTLElement元素。页面上的元素都是节点(Node)，有元素节点(Element Node)、属性节点(Attribute Node)、文本节点(Text Node)等。w3c nodeType 的定义如下

const unsigned short ELEMENT_NODE = 1;
const unsigned short ATTRIBUTE_NODE = 2;
const unsigned short TEXT_NODE = 3;
const unsigned short CDATA_SECTION_NODE = 4;
const unsigned short ENTITY_REFERENCE_NODE = 5;
const unsigned short ENTITY_NODE = 6;
const unsigned short PROCESSING_INSTRUCTION_NODE = 7;
const unsigned short COMMENT_NODE = 8;
const unsigned short DOCUMENT_NODE = 9;
const unsigned short DOCUMENT_TYPE_NODE = 10;
const unsigned short DOCUMENT_FRAGMENT_NODE = 11;
const unsigned short NOTATION_NODE = 12;

 

但如果我们自定义的对象也包含nodeType属性呢？如

view sourceprint?

1	var obj = {nodeType:1};

2	function isHTMLElement(obj){

3	if(obj.nodeType){

4	return obj.nodeType==1;

5

}

6

}

7	isHTMLElement(obj);//true

以上isHTMLElement(obj)返回true，但obj明显不是一个HTML节点元素。下面通过对象特性及try-catch语句来判断。

view sourceprint?

01	function isHTMLElement(obj){

02	var d = document.createElement("div");

03

try{

04	d.appendChild(obj.cloneNode(true));

05	return obj.nodeType==1?true:false;

06	}catch(e){

07	return false;

08

}

09

}

10	var obj1 = {nodeType:1};

11	var obj2 = document.createTextNode("hello");

12	var obj2 = document.createElement("p");

13	isHTMLElement(obj1);//false

14	isHTMLElement(obj2);//false

15	isHTMLElement(obj3);//true

对于window和document还要特别处理下

view sourceprint?

01	function isHtmlControl(obj) {

02

03	var d = document.createElement("div");

04

try{

05	d.appendChild(obj.cloneNode(true));

06	return obj.nodeType==1 ? true : false;

07	}catch(e){

08	return obj==window || obj==document;

09

}

10

}