appendChild()

set objXMLDOMNode = objDOMDocument.appendChild(objNewChildNode)

This method's function is to append (add) a new child Node to the end of a Node.

Before we can append a new Node (element, attribute, etc.), we need to first create this Node. Then once we have a reference to this Node, we can append it to the current parentNode by passing the parameter (objNewChildNode), which is the newly created Node. This new child will be added to the end of the list of children on this parentNode.

The child (objXMLDOMNode) will be returned if it is successfully added. It will be set to nothing if it fails.

Appending to the root (DOMDocument)

If you recall, we mentioned that the DOMDocument root could only have the following child Nodes:

Of these child Nodes, the only one that you cannot currently add to the DOMDocument is a DocumentType (DTD).

Before we can append a child Node, we need to fist create a Node of whichever type you want (attribute, element, etc.) and set a few properties to it if needed. This example creates a new DOMDocument, and then the documentElement gets added to it:

Dim objDOMDocument As DOMDocument

Dim objPeople As IXMLDOMNode

Dim objNode As IXMLDOMNode

Set objDOMDocument = new DOMDocument

Set objPeople = objDOMDocument.createElement("People")

Set objNode = objDOMDocument.appendChild (objPeople)

Consider the following code:

Set objNode = objDOMDocument.appendChild (objPeople)

If you want to check that this Node was created properly. You could just say:

objDOMDocument.appendChild objPeople

Appending to the root element (documentElement)

If you try to add a second element- type Node to the DOMDocument, you'll get a run- time error-because the DOMDocument only allows one root element.

How do you go about adding more data to your DOMDocument?

No matter how many levels deep your tree goes, you need to add your first branch, which is your documentElement. Thereafter you need to append (add) the rest of the XML data.

The following steps show the sequence for adding data to your XML code, starting with adding the root Node.

Step 1:

<PEOPLE>

....

</PEOPLE>

Then you need to add your next level branch, which will be the your first subelement of the root Node.

Step 2:

<PEOPLE>

<PERSON>

...

</PERSON>

</PEOPLE>

To this subelement we can then add the elements (data).

Step 3:

<PEOPLE>

<PERSON>

<NAME>Mark Wilson</NAME>

<ADDRESS>911 Somewhere Circle, Canberra, Australia</ADDRESS>

<TEL>(++612) 12345</TEL>

<FAX>(++612) 12345</FAX>

<EMAIL>markwilson@somewhere.com</EMAIL>

</PERSON>

</PEOPLE>

You now need to append the root element. The following code shows Step 2 and Step 3 added to the XML code in VB. (See createElement() to create the element.)

Dim objPerson As IXMLDOMNode

Dim objChild As IXMLDOMNode

Set objPerson = objDOMDocument.createElement("PERSON")

objDOMDocument.documentElement.appendChild objPerson

Set objChild = objDOMDocument.createElement("NAME")

objChild.Text = "Monty Python"

objPerson.appendChild objChild

objDOMDocument.save

To actually add any new change to the DOMDocument, you need to save the DOMDocument.

Note

The Node may be added to the instantiated DOMDocument, but it is not added to the actual XML file until you have called the save() method.

In Line 2 above we could also say:

objPeople.appendChild objPerson

Either method is fine. Both objPeople and objDOMDocument.documentElement refer to the Document Element.

This manuscript is an abridged version of a chapter from the Manning Publications book XML Programming with VB and ASP. This chapter looks at the Microsoft DOM objects. NOTE: Most images have been removed to increase speed and many of the code comments have also been removed for presentation. Please purchase the book to enjoy the full experience of all the chapters with images and code comments!