February 9, 2002 - Adding A Comment to An XML Tree | WebReference

February 9, 2002 - Adding A Comment to An XML Tree

Yehuda Shiran February 9, 2002
Adding A Comment to An XML Tree
Tips: February 2002

Yehuda Shiran, Ph.D.
Doc JavaScript

You can add a comment node to an XML tree with the createComment() method. The syntax of the method is:

  createComment(data)
where data is a string specifying the new comment. This comment will be placed between <!-- and -->.

Let's look at an example. First, let's read in our mydvd XML file:

  var xmlDoc = new ActiveXObject("Msxml2.DOMDocument");
  xmlDoc.async = false;
  xmlDoc.load("mydvd.xml");
Now, find the root of the tree and create the new comment object:

  root = xmlDoc.documentElement;
  newComment = xmlDoc.createComment("That's all folks");
Append the new node as the last child of <sales>:

   root.appendChild(newComment);
Let's summarize the above calls in one function:

  function addComment() {
    var xmlDoc = new ActiveXObject("Msxml2.DOMDocument");
    var root;
    var newAtt;
    var namedNodeMap;
    xmlDoc.async = false;
    xmlDoc.load("mydvd.xml");
    alert(xmlDoc.documentElement.xml);
    root = xmlDoc.documentElement;
    newComment = xmlDoc.createComment("That's all folks");
    root.appendChild(newComment);
    alert(xmlDoc.documentElement.xml);
}
Try it now. The first alert box echoed the XML file before adding the comment node. The second alert box reflects the addition. Notice the <!--That's all folks--> comment as the last child of the <sales> tag.