createTreeWalker

Summary

Creates a TreeWalker object that you can use to traverse filtered lists of nodes or elements in a document.

Syntax

var treeWalker = document.createTreeWalker(rootNode, whatToShow, filter, entityReferenceExpansion);

Parameters

rootNode

Data-type: DOM Node

The root element or node to start traversing on.

whatToShow

Data-type: unsigned long

The type of nodes or elements to appear in the node list. For more information, see whatToShow.

filter

Data-type: DOM Node

A custom NodeFilter function to use. For more information, see filter, or null for none.

entityReferenceExpansion

Data-type: Boolean

Whether entity reference nodes are expanded. For more information, see expandEntityReferences.

Return Value

Returns an object of type DOM NodeDOM Node

A TreeWalker instance object.

Examples

The following code example shows how to use TreeWalker objects to find and remove references. The iterator returns all text nodes from the document body and searches for Monday in text and id attributes of parent nodes. The script matches text by using the wholeText property of the node.

<!DOCTYPE html>
<html>
 <head>
  <script>
function noMondays()
{
    var tw = document.createTreeWalker(document.body, NodeFilter.SHOW_TEXT, null, false);

    var textNode = tw.nextNode();
    while (textNode) {
        if (textNode.wholeText.match('Monday') ||
            textNode.parentNode.getAttribute('id') == 'Monday')
        {
            textNode.parentNode.removeChild(textNode);
        }
        textNode = tw.nextNode();
    }
}
function refresh()
{
    window.location.reload( false );    // Reload our page.
}
  </script>
 </head>
 <body>
    <p>Monday, Joe bought a turkey.</p>
    <p>Tuesday, Bill bought a pound of nails.</p>
    <div>Chuck called in sick Monday.</div>
    <p id="Monday">CALL supplier today!</p>
    <p>Wednesday's delivery was delayed.</p>
    <button onclick="refresh()">Reload</button>
    <button onclick="noMondays()">Lose Mondays</button>
 </body>
</html>

Usage

 Use the createTreeWalker method when you want to navigate a representation of the document's hierarchical structure. If you would rather traverse a sequence of nodes without regard to document structure, use createNodeIterator.

Related specifications

DOM Level 2 Traversal and Range: Recommendation

Attributions

Microsoft Developer Network: [Windows Internet Explorer API reference Article]