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acceptNode

NodeFilter

object has only one method:

acceptNode()

, which returns

NodeFilter.FILTER_ACCEPT

if the given node should be visited or

NodeFilter.FILTER_REJECT

if the given node should not be vis-

ited. However, you cannot create an object using the class

NodeFilter

because it is an abstract class. In

Java or other languages, you must define a new subclass of

NodeFilter

, but because this is JavaScript

you can’t do that.

Instead, you just create an object with an

acceptNode()

method and pass that to the

createNodeIterator()

method, like this:

var oFilter = new Object;

oFilter.acceptNode = function (oNode) {

//filter logic goes here

};

To disallow

<p/>

element nodes, you just check the

tagName

property and return

NodeFilter.

FILTER_REJECT

if it’s equal to

“P”

var oFilter = new Object;

oFilter.acceptNode = function (oNode) {

return (oNode.tagName == “P”) ? NodeFilter.FILTER_REJECT :

NodeFilter.FILTER_ACCEPT;

};

If you include this in the previous example, the code becomes the following:

<html>

<head>

<title>NodeIterator Example</title>

var iterator = null;

function makeList() {

var oDiv = document.getElementById(“div1”);

var oFilter = new Object;

oFilter.acceptNode = function (oNode) {

return (oNode.tagName == “P”) ?

NodeFilter.FILTER_REJECT : NodeFilter.FILTER_ACCEPT;

};

iterator = document.createNodeIterator(oDiv,

NodeFilter.SHOW_ELEMENT, oFilter, false);

var oOutput = document.getElementById(“text1”);

var oNode = iterator.nextNode();

while (oNode) {

oOutput.value += oNode.tagName + “\n”;

oNode = iterator.nextNode();

}

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