The createDocumentFragment method creates an empty DocumentFragment object. Creating an instance of this object does not automatically include it in the XML Document tree, and so its parentNode property is set to null. In order for it to be included you must use one of the node insertion methods: insertBefore, replaceChild or appendChild.

To demonstrate this method, we shall create a DocumentFragment for the 'names.xml' file to which we shall add three child nodes consisting of new 'name' elements. The whole entity will then be inserted into an appropriate place among the children of the document's root element. Finally the values of all the 'name' elements will be displayed. (The code uses a user-defined function to create and add the child nodes to the DocumentFragment.)

XML:
<names>
   <name>Alice</name>
   <name>Bert</name>
   <name>Charlie</name>
   <name>Diane</name>
   <name>Eric</name>
</names>

Code (JavaScript):
xml_doc = new ActiveXObject("Microsoft.XMLDOM");
xml_doc.async = false;
xml_doc.load("names.xml");

function add_elem(frag, elem, text)
{
   var new_elem = xml_doc.createElement(elem);
   var new_text = xml_doc.createTextNode(text);
   new_elem.appendChild(new_text);
   frag.appendChild(new_elem);
}

doc_frag = xml_doc.createDocumentFragment();

add_elem(doc_frag, "name", "Billy");
add_elem(doc_frag, "name", "Bobby");
add_elem(doc_frag, "name", "Bonnie");

root = xml_doc.documentElement;
root.insertBefore(doc_frag, root.childNodes.item(2));

names = xml_doc.getElementsByTagName("name");
n_names = names.length;
for (i = 0; i < n_names; i++)
   document.write(names[i].firstChild.nodeValue + "<br>");

Output:
Alice
Bert
Billy
Bobby
Bonnie
Charlie
Diane
Eric