Javacript DOM编程

1.Create Node

var anchor = document.createElement("a"); // Create an <a> node
anchor.setAttribute("name", "TOC"); // Give it a name
toc.appendChild(anchor); // Insert it
anchor.appendChild(document.createTextNode("Table Of Contents"));

2.Search Node

function countTags(n) { // n is a Node
var numtags = 0; // Initialize the tag counter
if (n.nodeType == 1 /*Node.ELEMENT_NODE*/) // Check if n is an Element
numtags++; // Increment the counter if so
var children = n.childNodes; // Now get all children of n
for(var i=0; i < children.length; i++) { // Loop through the children
numtags += countTags(children[i]); // Recurse on each one
}
return numtags; // Return the total number of tags
}

3.Node Type

Common node types

Interface	nodeType constant	nodeType value
Element	Node.ELEMENT_NODE	1
Text	Node.TEXT_NODE	3
Document	Node.DOCUMENT_NODE	9
Comment	Node.COMMENT_NODE	8
DocumentFragment	Node.DOCUMENT_FRAGMENT_NODE	11
Attr	Node.ATTRIBUTE_NODE	2

4.Modify Node

function reverse(n) { // Reverse the order of the children of Node n
var kids = n.childNodes; // Get the list of children
var numkids = kids.length; // Figure out how many children there are
for(var i = numkids-1; i >= 0; i--) { // Loop backward through the children
var c = n.removeChild(kids[i]); // Remove a child
n.appendChild(c); // Put it back at its new position
}
}

5.Replace Node

function embolden(node) {
var bold = document.createElement("b"); // Create a new <b> element
var parent = node.parentNode; // Get the parent of the node
parent.replaceChild(bold, node); // Replace the node with the <b> tag
bold.appendChild(node); // Make the node a child of the <b> tag
}