XML —

XMLDOMNodeList Object

The XMLDOMNodeList object is a collection of node objects. It is primarily used to iterate through the element nodes. This object implements the IXMLDOMNodeList interface. The IXMLDOMNodeList interface reflects the current state of the nodes in the document, so a change in the nodes will be immediately reflected in the object. The property and methods of IXMLDOMNodeList are as follows:

IXMLDOMNodeList Property

Name Description
length Returns the number of nodes that are contained in the node list.

IXMLDOMNodeList Methods

Name Description
item (index) Returns the node located at position index in the node list. The first node is indexed as 0.
nextNode()* Returns the next node object in the node list. If there are no more nodes, it returns null.
reset()* Resets the pointer so that it points before the first node element.

For an example of the IXMLDOMNodeList interface, you can add an attribute to the XML document and another command button to the frmDOMTest form. To do so, follow these steps:

  1. Open the XML document Books.xml and change the title element to the following:

  2.   <title language="English">Number, the Language of Science
  </title>
  3. Add another command button to the frmDOMTest form called cmdNodeList with the caption NodeList.
  4. Add the following code to the click event handler of the cmdNodeList button:

  5.   Private Sub cmdNodeList_Click()
      Dim objNodeList As IXMLDOMNodeList
      Dim objXMLDoc As DOMDocument
      Set objXMLDoc = New DOMDocument
      objXMLDoc.async = False
      objXMLDoc.Load ("c:\Books.xml")
      Set objNodeList = _
           objXMLDoc.documentElement.firstChild.childNodes
      Debug.Print "The second item's basename is: " & _
           objNodeList.Item(2).baseName
      Debug.Print "The number of nodes are: " & objNodeList.length
      Debug.Print "The first node xml is: " & vbCrLf & _
           objNodeList.nextNode.xml
      Debug.Print "The second node xml is: " & _
           objNodeList.nextNode.xml
      Debug.Print "The third node xml is: " & _
          objNodeList.nextNode.xml
          objNodeList.Reset
      Debug.Print "After reset, the first node xml is: " & _
          vbCrLf & objNodeList.nextNode.xml
      Dim intNodeCounter As Integer
      For intNodeCounter = 0 To objNodeList.length - 1
          Debug.Print "The " & "xml of node" & _
          Str(intNodeCounter + 1) & " is: " & vbCrLf & _
          objNodeList.Item(intNodeCounter).xml
      Next
      Set objNodeList = Nothing
      Set objXMLDoc = Nothing
  End Sub

Notice that, once again, we first get a reference to the document object. Once we have this reference, we can get a reference to the IXMLDOMNodeList interface. Then we use the item, nextNode, and reset methods of the IXMLDOMNodeList interface to navigate the document. Last, we print all the nodes in the collection with a loop. When you run this updated application and click the NodeList button, the results are as follows:

  The second item's basename is: price
  The number of nodes are: 4
  The first node xml is:
  <title language="English">Number, the Language of Science</title>
  The second node xml is: <author>Danzig</author>
  The third node xml is: <price>5.95</price>
  After reset, the first node xml is:
  <title language="English">Number, the Language of Science</title>
  The xml of node 1 is:
  <title language="English">Number, the Language of Science</title>
  The xml of node 2 is:
  <author>Danzig</author>
  The xml of node 3 is:
  <price>5.95</price>
  The xml of node 4 is:
  <quantity>3</quantity>

Notice that the attribute node was not included in the results. We will need to use the IXMLDOMNamedNodeMap interface to get a reference to attribute nodes.