Microsoft Access XML - Lesson 37: Operations on XML Elements

	Operations on XML Elements

Creating an XML Element

Introduction

The IXMLDOMNode interface provides the properties and methods used to perform most routine operations of an XML document. The operations include locating a node, adding a new node, or deleting an element.

Before performing an operation, you will usually need to decide in what section of the document you want the action to be applied. As it happens, you have the root node, a particular node inside the document, the parent of a node, the sibling of a node, etc. To get to a node, you will usually first get a reference to its IXMLDOMNode object. To do this, you can declare an IXMLDOMNode variable, call a method that returns that reference, and initialize the variable with it. You can get a reference when creating an element. Here is an example:

Private Sub cmdCreate_Click()
    Dim docXMLDOM  As DOMDocument
    Dim nodElement As IXMLDOMElement
    
    Set docXMLDOM = New DOMDocument
    
    Set nodElement = docXMLDOM.createElement("videos")
    Set docXMLDOM.documentElement = nodElement
    
    docXMLDOM.Save "C:\Exercises\videos2.xml"
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0"?>
<videos></videos>

You can also get a reference after locating the desired element.

Appending an Element

We already saw that, to let you create a new element, the DOMDocument class provides the createElement() method. Using this method, to create a new element, call it and pass it the name of the element. We already know that the createElement() method belongs to the DOMDocument class. To let you create an element as either a child of the root node or a child of any other element, the IXMLDOMNode interface is equipped with a method named appendChild. The syntax of the IXMLDOMNode.appendChild() method is:

Public Function appendChild(ByVal newChild As IXMLDOMNode) As IXMLDOMNode

When calling this method, pass an IXMLDOMNode object you would have previously created. Here is an example:

Private Sub cmdAppendElement_Click()
    Dim docXMLDOM  As DOMDocument
    Dim nodElement As IXMLDOMElement
    Dim nodChild As IXMLDOMElement
    
    Set docXMLDOM = New DOMDocument
    
    Set nodElement = docXMLDOM.createElement("videos")
    Set docXMLDOM.documentElement = nodElement
    
    Set nodChild = docXMLDOM.createElement("video")
    nodElement.appendChild nodChild

    docXMLDOM.Save "C:\Exercises\videos3.xml"
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0"?>
<videos>
  <video></video>
</videos>

In the same way, you can create other child nodes of the root. Simply use a combination of calling the DOMDocument.createElement() method that initializes IXMLDOMElement element you want to create, and calling the IXMLDOMNode.appendChild() method to which you pass a reference of the IXMLDOMElement variable. Here are examples:

Private Sub cmdAppendElement_Click()
    Dim docXMLDOM  As DOMDocument
    Dim nodElement As IXMLDOMElement
    Dim nodChild As IXMLDOMElement
    
    Set docXMLDOM = New DOMDocument
    
    Set nodElement = docXMLDOM.createElement("Videos")
    Set docXMLDOM.documentElement = nodElement
    
    Set nodChild = docXMLDOM.createElement("Video")
    nodElement.appendChild nodChild

    Set nodChild = docXMLDOM.createElement("Video")
    nodElement.appendChild nodChild
    Set nodChild = docXMLDOM.createElement("Video")
    nodElement.appendChild nodChild

    docXMLDOM.Save "C:\Exercises\videos4.xml"
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0"?>
<Videos>
  <Video></Video> 
  <Video></Video> 
  <Video></Video> 
</Videos>

Notice that, if you simply call the IXMLDOMNode.appendChild() method to create an element, the newly added element is empty. If you want the new node to have a value, assign the desired string to its Text property. Here is an example:

Private Sub cmdAppendElement_Click()
    Dim docXMLDOM  As DOMDocument
    Dim nodChild As IXMLDOMElement
    Dim nodElement As IXMLDOMElement
    
    Set docXMLDOM = New DOMDocument

    Set nodElement = docXMLDOM.createElement("Videos")
    Set docXMLDOM.documentElement = nodElement
    
    Set nodChild = docXMLDOM.createElement("Video")
    nodChild.Text = "Basic Instinct"

    nodElement.appendChild nodChild
    
    docXMLDOM.Save "C:\Exercises\videos5.xml"
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0"?>
<Videos>
  <Video>Basic Instinct</Video> 
</Videos>

In the same way, you can add a value to any other element you are creating. If you want to create a processing instruction, declare its variable, call the DOMDocument.createProcessingInstruction() method, then call the DOMDocument.appendChild() method. Here is an example:

Private Sub cmdCreateElement_Click()
    Dim docXMLDOM  As Object
    Dim nodElement As Object
    Dim piDeclaration As Object
    
    Set docXMLDOM = CreateObject("MSXML2.DOMDocument.3.0")
    
    Set piDeclaration = docXMLDOM.createProcessingInstruction("xml", "version='1.0'")
    docXMLDOM.appendChild piDeclaration
    
    Set nodElement = docXMLDOM.createElement("houses")
    Set docXMLDOM.documentElement = nodElement

    docXMLDOM.Save "C:\Exercises\Houses2.xml"
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0"?>
<houses></houses>

Creating Root Child Nodes

One one hand, the DOMDocument.createElement() method is used to start a new node. On the other hand, the IXMLDOMNode.appendChild() method is used to add a child node to an element. Also, the call to IXMLDOMNode.appendChild() produces a reference to the new child node. If you want to create a child of that new node, after declaring an IXMLDOMElement variable, initialize it with a call to DOMDocument.createElement(). Then call the IXMLDOMNode.appendChild() method of its parent and pass your new node as argument. Here is an example:

Private Sub cmdCreateChildNodes_Click()
    Dim docXMLDOM As DOMDocument
    Dim nodElement As IXMLDOMElement
    Dim nodChild As IXMLDOMElement
    Dim nodGrandChild As IXMLDOMElement
    
    Set docXMLDOM = New DOMDocument
    
    Set nodElement = docXMLDOM.createElement("Videos")
    Set docXMLDOM.documentElement = nodElement
    
    Set nodChild = docXMLDOM.createElement("video")
    nodElement.appendChild nodChild
    
    Set nodGrandChild = docXMLDOM.createElement("title")
    nodChild.appendChild nodGrandChild

    docXMLDOM.Save "C:\Exercises\videos6.xml"
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0"?>
<videos>
  <video>
    <title></title>
  </video>
</videos>

Creating Other Child Nodes

In the same way, you can create other child nodes of an element. Here are examples:

Private Sub cmdCreateChildNodes_Click()
    Dim docXMLDOM As DOMDocument
    Dim nodElement As IXMLDOMElement
    Dim nodChild As IXMLDOMElement
    Dim nodGrandChild As IXMLDOMElement
    
    Set docXMLDOM = New DOMDocument
    
    Set nodElement = docXMLDOM.createElement("Videos")
    Set docXMLDOM.documentElement = nodElement
    
    Set nodChild = docXMLDOM.createElement("Video")
    nodElement.appendChild nodChild
    
    Set nodGrandChild = docXMLDOM.createElement("Title")
    nodChild.appendChild nodGrandChild
    Set nodGrandChild = docXMLDOM.createElement("Director")
    nodChild.appendChild nodGrandChild
    
    Set nodChild = docXMLDOM.createElement("Video")
    nodElement.appendChild nodChild
    
    Set nodGrandChild = docXMLDOM.createElement("Director")
    nodChild.appendChild nodGrandChild
    Set nodGrandChild = docXMLDOM.createElement("Length")
    nodChild.appendChild nodGrandChild
    Set nodGrandChild = docXMLDOM.createElement("Rating")
    nodChild.appendChild nodGrandChild
    Set nodGrandChild = docXMLDOM.createElement("Title")
    nodChild.appendChild nodGrandChild
    
    Set nodChild = docXMLDOM.createElement("Video")
    nodElement.appendChild nodChild
    Set nodGrandChild = docXMLDOM.createElement("Rating")
    nodChild.appendChild nodGrandChild

    docXMLDOM.Save "C:\Exercises\videos7.xml"
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<Videos>
  <Video>
    <Title></Title> 
    <Director></Director> 
  </Video>
  <Video>
    <Director></Director> 
    <Length></Length> 
    <Rating></Rating> 
    <Title></Title> 
  </Video>
  <Video>
    <Rating></Rating> 
  </Video>
</Videos>

In the same way, you can create grand child nodes nested in child nodes of elements. Here are examples:

Private Sub cmdCreateChildNodes_Click()
    Dim docXMLDOM As DOMDocument
    Dim nodElement As IXMLDOMElement
    Dim nodChild As IXMLDOMElement
    Dim nodGrandChild As IXMLDOMElement
    Dim nodGreatGrandChild As IXMLDOMElement
    Dim nodGreatGreatGrandChild As IXMLDOMElement
    
    Set docXMLDOM = New DOMDocument
    
    Set nodElement = docXMLDOM.createElement("Videos")
    Set docXMLDOM.documentElement = nodElement
    
    Set nodChild = docXMLDOM.createElement("Video")
    nodElement.appendChild nodChild
    
    Set nodGrandChild = docXMLDOM.createElement("Title")
    nodChild.appendChild nodGrandChild
    Set nodGreatGrandChild = docXMLDOM.createElement("CastMembers")
    nodGrandChild.appendChild nodGreatGrandChild
    
    Set nodGrandChild = docXMLDOM.createElement("Director")
    nodChild.appendChild nodGrandChild
    
    Set nodChild = docXMLDOM.createElement("Video")
    nodElement.appendChild nodChild
    
    Set nodGrandChild = docXMLDOM.createElement("Director")
    nodChild.appendChild nodGrandChild
    Set nodGrandChild = docXMLDOM.createElement("Length")
    nodChild.appendChild nodGrandChild
    Set nodGrandChild = docXMLDOM.createElement("Rating")
    nodChild.appendChild nodGrandChild
    Set nodGrandChild = docXMLDOM.createElement("Title")
    nodChild.appendChild nodGrandChild
    Set nodGreatGrandChild = docXMLDOM.createElement("Actors")
    nodGrandChild.appendChild nodGreatGrandChild
    Set nodGreatGreatGrandChild = docXMLDOM.createElement("Actor")
    nodGreatGrandChild.appendChild nodGreatGreatGrandChild
    Set nodGreatGreatGrandChild = docXMLDOM.createElement("Actor")
    nodGreatGrandChild.appendChild nodGreatGreatGrandChild
    
    Set nodChild = docXMLDOM.createElement("Video")
    nodElement.appendChild nodChild
    Set nodGreatGrandChild = docXMLDOM.createElement("TechnicalTeam")
    nodGrandChild.appendChild nodGreatGrandChild
    Set nodGreatGreatGrandChild = docXMLDOM.createElement("LineProducer")
    nodGreatGrandChild.appendChild nodGreatGreatGrandChild
    Set nodGreatGreatGrandChild = docXMLDOM.createElement("FirstAssistantDirector")
    nodGreatGrandChild.appendChild nodGreatGreatGrandChild
    Set nodGreatGreatGrandChild = docXMLDOM.createElement("SecondAssistantDirector")
    nodGreatGrandChild.appendChild nodGreatGreatGrandChild
    Set nodGrandChild = docXMLDOM.createElement("Rating")
    nodChild.appendChild nodGrandChild

    docXMLDOM.Save "C:\Exercises\videos8.xml"
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<Videos>
  <Video>
    <Title>
      <CastMembers></CastMembers> 
    </Title>
    <Director></Director> 
  </Video>
  <Video>
    <Director></Director> 
    <Length></Length> 
    <Rating></Rating> 
    <Title>
    <Actors>
      <Actor></Actor> 
      <Actor></Actor> 
    </Actors>
    <TechnicalTeam>
      <LineProducer></LineProducer> 
      <FirstAssistantDirector></FirstAssistantDirector> 
      <SecondAssistantDirector></SecondAssistantDirector> 
    </TechnicalTeam>
    </Title>
  </Video>
  <Video>
    <Rating></Rating> 
  </Video>
</Videos>

Remember that, to specify the value of a node, assign the desired string to its Text property. Here are examples:

Private Sub cmdCreate_Click()
    Dim docXMLDOM As DOMDocument
    Dim nodElement As IXMLDOMElement
    Dim nodChild As IXMLDOMElement
    Dim nodGrandChild As IXMLDOMElement
    Dim nodGreatGrandChild As IXMLDOMElement
    Dim nodGreatGreatGrandChild As IXMLDOMElement
    
    Set docXMLDOM = New DOMDocument
    
    Set nodElement = docXMLDOM.createElement("Videos")
    Set docXMLDOM.documentElement = nodElement
    
    Set nodChild = docXMLDOM.createElement("Video")
    nodElement.appendChild nodChild
    
    Set nodGrandChild = docXMLDOM.createElement("Title")
    nodChild.appendChild nodGrandChild
    Set nodGreatGrandChild = docXMLDOM.createElement("CastMembers")
    nodGrandChild.appendChild nodGreatGrandChild
    
    Set nodGrandChild = docXMLDOM.createElement("Director")
    nodChild.appendChild nodGrandChild
    
    Set nodChild = docXMLDOM.createElement("Video")
    nodElement.appendChild nodChild
    
    Set nodGrandChild = docXMLDOM.createElement("Director")
    nodChild.appendChild nodGrandChild
    nodGrandChild.Text = "Jonathan Lynn"
    Set nodGrandChild = docXMLDOM.createElement("Length")
    nodGrandChild.Text = "112 Minutes"
    nodChild.appendChild nodGrandChild
    Set nodGrandChild = docXMLDOM.createElement("Rating")
    nodGrandChild.Text = "R"
    nodChild.appendChild nodGrandChild
    Set nodGrandChild = docXMLDOM.createElement("Title")
    nodGrandChild.Text = "The Distinguished Gentleman"
    nodChild.appendChild nodGrandChild
    Set nodGreatGrandChild = docXMLDOM.createElement("Actors")
    nodGrandChild.appendChild nodGreatGrandChild
    Set nodGreatGreatGrandChild = docXMLDOM.createElement("Actor")
    nodGreatGreatGrandChild.Text = "Eddie Murphy"
    nodGreatGrandChild.appendChild nodGreatGreatGrandChild
    Set nodGreatGreatGrandChild = docXMLDOM.createElement("Actor")
    nodGreatGreatGrandChild.Text = "Lane Smith"
    nodGreatGrandChild.appendChild nodGreatGreatGrandChild
    Set nodGreatGreatGrandChild = docXMLDOM.createElement("Actor")
    nodGreatGreatGrandChild.Text = "Sheryl Lee Ralph"
    nodGreatGrandChild.appendChild nodGreatGreatGrandChild
    
    Set nodChild = docXMLDOM.createElement("Video")
    nodElement.appendChild nodChild
    Set nodGreatGrandChild = docXMLDOM.createElement("TechnicalTeam")
    nodGrandChild.appendChild nodGreatGrandChild
    Set nodGreatGreatGrandChild = docXMLDOM.createElement("LineProducer")
    nodGreatGrandChild.appendChild nodGreatGreatGrandChild
    Set nodGreatGreatGrandChild = docXMLDOM.createElement("FirstAssistantDirector")
    nodGreatGrandChild.appendChild nodGreatGreatGrandChild
    Set nodGreatGreatGrandChild = docXMLDOM.createElement("SecondAssistantDirector")
    nodGreatGrandChild.appendChild nodGreatGreatGrandChild
    Set nodGrandChild = docXMLDOM.createElement("Rating")
    nodChild.appendChild nodGrandChild

    docXMLDOM.Save "C:\Exercises\videos9.xml"
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<Videos>
  <Video>
    <Title>
      <CastMembers></CastMembers> 
    </Title>
    <Director></Director> 
  </Video>
  <Video>
    <Director>Jonathan Lynn</Director> 
    <Length>112 Minutes</Length> 
    <Rating>R</Rating> 
    <Title>The Distinguished Gentleman</Title>
    <Actors>
      <Actor>Eddie Murphy</Actor> 
      <Actor>Lane Smith</Actor> 
      <Actor>Sheryl Lee Ralph</Actor> 
    </Actors>
    <TechnicalTeam>
      <LineProducer></LineProducer> 
      <FirstAssistantDirector></FirstAssistantDirector> 
      <SecondAssistantDirector></SecondAssistantDirector> 
    </TechnicalTeam>
    </Title>
  </Video>
  <Video>
    <Rating></Rating> 
  </Video>
</Videos>

Consider the following XML document:

<?xml version="1.0" encoding="utf-8"?>
<videos>
  <video>
    <title>The Distinguished Gentleman</title>
  </video>
  <video>
    <title>Basic Instinct</title>
  </video>
</videos>

If you want to add a new node to the root of such an element, first get a reference to the root node using the documentElement property of the root node. To create the new element, call the DOMDocument.createElement() method to create the start tag. Then call the IXMLDOMNode.appendChild() method on the root node. Here is an example::

Private Sub cmdCreate_Click()
    Dim docXMLDOM As DOMDocument
    Dim nodRoot As IXMLDOMElement
    Dim nodElement As IXMLDOMElement
    
    Set docXMLDOM = New DOMDocument
    docXMLDOM.Load "C:\Exercises\Videos10.xml"
    
    Set nodRoot = docXMLDOM.documentElement
    Set nodElement = docXMLDOM.createElement("video")
    nodRoot.appendChild nodElement
    
    docXMLDOM.Save "C:\Exercises\videos10.xml"
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0" encoding="utf-8" ?> 
<videos>
  <video>
    <title>The Distinguished Gentleman</title> 
  </video>
  <video>
    <title>Basic Instinct</title> 
  </video>
  <Video></Video>
</videos>

The call to IXMLDOMNode.appendChild() produces a reference to the new child node. If you want to create a child of that new node, after declaring an IXMLDOMElement variable, initialize it with a call to DOMDocument.createElement(). Then call theIXMLDOMNode.appendChild() method of its parent and pass your new node as argument.Here is an example of how you would do this:

Private Sub cmdCreate_Click()
    Dim docXMLDOM As DOMDocument
    Dim nodRoot As IXMLDOMElement
    Dim nodElement As IXMLDOMElement
    Dim nodChild As IXMLDOMElement
    
    Set docXMLDOM = New DOMDocument
    docXMLDOM.Load "C:\Exercises\videos10.xml"
    
    Set nodRoot = docXMLDOM.documentElement
    Set nodElement = docXMLDOM.createElement("Video")
    nodRoot.appendChild nodElement
    
    Set nodChild = docXMLDOM.createElement("Title")
    nodElement.appendChild nodChild
    
    docXMLDOM.Save "C:\Exercises\Videos10.xml"
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0" encoding="utf-8" ?> 
<videos>
  <video>
    <title>The Distinguished Gentleman</title> 
    </video>
  <video>
    <title>Basic Instinct</title> 
  </video>
  <Video>
    <Title></Title>
  </Video>
</videos>

By now, you should know how easy it is to specify the value of an element: assign the desired string to its Text property. Just in case, here is an example:

Private Sub cmdCreate_Click()
    Dim docXMLDOM As DOMDocument
    Dim nodRoot As IXMLDOMElement
    Dim nodElement As IXMLDOMElement
    Dim nodChild As IXMLDOMElement
    
    Set docXMLDOM = New DOMDocument
    docXMLDOM.Load "C:\Exercises\videos10.xml"
    
    Set nodRoot = docXMLDOM.documentElement
    Set nodElement = docXMLDOM.createElement("Video")
    nodRoot.appendChild nodElement

    Set nodChild = docXMLDOM.createElement("Title")
    nodChild.Text = "Her Alibi"
    nodElement.appendChild nodChild
    
    docXMLDOM.Save "C:\Exercises\Videos10.xml"
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0" encoding="utf-8"?>
<videos>
  <video>
    <title>The Distinguished Gentleman</title>
  </video>
  <video>
    <title>Basic Instinct</title>
  </video>
  <video>
    <title>Her Alibi</title>
  </video>
</videos>

In the same way, you can create child and grant-child (and great-grand child) nodes.

Locating an Element

Introduction

In some cases, you may want to perform an operation on an existing and particular node. For example, you may want to change the value of a node, you may want to add a new child node to an existing node, etc. Before taking any of these actions, you must be able to locate or identify the desired element.

Locating an element consists of looking for a particular node among the nodes. To do this, you must start somewhere. Obviously, the first node you can identify is the root. Once you get the root, you can then get a collection of its children. After getting a collection of the children of the root, you can locate a node in the collection. If the node you are looking for is a child of that first collection, you can then get a collection of the child nodes of that node and proceed.

Locating an Element Using its Index

Consider the following XML file named videos12.xml:

<?xml version="1.0" encoding="utf-8"?>
<videos>
    <video>
	<title>The Distinguished Gentleman</title>
	<director>Jonathan Lynn</director>
	<length>112 Minutes</length>
	<format>DVD</format>
	<rating>R</rating>
    </video>
    <video>
	<title>Her Alibi</title>
	<director>Bruce Beresford</director>
	<length>94 Minutes</length>
	<format>DVD</format>
	<rating>PG-13</rating>
    </video>
    <video>
	<title>The Day After Tomorrow</title>
	<director>Roland Emmerich</director>
	<length>124 Minutes</length>
	<format>DVD</format>
	<rating>PG-13</rating>
    </video>
    <video>
	<title>Other People's Money</title>
	<director>Alan Brunstein</director>
	<length>114 Minutes</length>
	<format>VHS</format>
	<rating>PG-13</rating>
    </video>
</videos>

We saw that the IXMLDOMNodeList interface is equipped with an indexed property named Item. That member allows you to access an element based on its index. Here are examples:

Private Sub cmdLocate_Click()
    Dim docXMLDOM As DOMDocument
    Dim nodRoot As IXMLDOMElement
    Dim lstVideos As IXMLDOMNodeList
    
    Set docXMLDOM = New DOMDocument
    docXMLDOM.Load "C:\Exercises\videos12.xml"
    
    Set nodRoot = docXMLDOM.documentElement
    Set lstVideos = nodRoot.childNodes
    
    MsgBox lstVideos(0).Text
    MsgBox lstVideos(0).XML
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

Videos

Locating an Element Using its Index

You can use this characteristic to locate a node. Because XML is very flexible with the names (you can have two child nodes that have the same name) and values (you can have two child nodes that have the same value) of nodes, when creating an XML file, it is your responsibility to create a scheme that would eventually allow you to uniquely identify each element.

Locating an Element Using a Tag Name

To assist you with finding a node, the DOMDocument class is equipped with a method named getElementByTagName. Its syntax is:

Public Function getElementsByTagName(ByVal tagName As String) As IXMLDOMNodeList

This method takes as argument the name of a node as a string. If at least one node that holds that name exists in the document, this method returns a collection of the nodes with that name. If there is no node with that name, the collection is returned empty. Here is an example of calling the method:

Private Sub cmdLocate_Click()
    Dim docXMLDOM As DOMDocument
    Dim nodRoot As IXMLDOMElement
    Dim lstVideos As IXMLDOMNodeList
    
    Set docXMLDOM = New DOMDocument
    docXMLDOM.Load "C:\Exercises\videos12.xml"
    
    Set nodRoot = docXMLDOM.documentElement
    Set lstVideos = nodRoot.getElementsByTagName("title")
    
    Set docXMLDOM = Nothing
End Sub

Once you have a list of the nodes of a particular criterion, you can then act as you see fit. For example, For example, you can look for a particular node that holds a text of your choice.

Techniques of Creating Elements

Adding an Element as a Child

Consider the following document from a file named videos13.xml file:

<?xml version="1.0" encoding="utf-8"?>
<videos>
    <video>
	<title>The Distinguished Gentleman</title>
	<director>Jonathan Lynn</director>
	<length>112 Minutes</length>
	<format>DVD</format>
	<rating>R</rating>
    </video>
    <video>
	<title>Her Alibi</title>
	<director>Bruce Beresford</director>
	<length>94 Minutes</length>
	<format>DVD</format>
	<rating>PG-13</rating>
    </video>
    <video>
	<title>The Day After Tomorrow</title>
	<director>Roland Emmerich</director>
	<length>124 Minutes</length>
	<format>DVD</format>
	<rating>PG-13</rating>
    </video>
    <video>
	<title>Other People's Money</title>
	<director>Alan Brunstein</director>
	<length>114 Minutes</length>
	<format>VHS</format>
	<rating>PG-13</rating>
    </video>
</videos>

Imagine you want to create a new node as a child of one of the elements. The first action to take is to locate the element that will act as the parent. If/since you know the element, you can locate it using its name by calling the DOMDocument.getElementsByTagName() method applied to a collection of nodes. From that list of nodes, you can look for the node whose value you know. Once you have found this element, get a reference to its parent. Then add the new node as a child to its parent. This can be done as follows:

Private Sub cmdInsertElement_Click()
    Dim Found As Boolean
    Dim docXMLDOM As DOMDocument
    Dim nodChild As IXMLDOMElement
    Dim nodParent As IXMLDOMElement
    Dim nodElement As IXMLDOMElement
    Dim lstVideos As IXMLDOMNodeList
    
    Found = False
    Set docXMLDOM = New DOMDocument
    docXMLDOM.Load "C:\Exercises\videos13.xml"
    
    Set lstVideos = docXMLDOM.getElementsByTagName("title")
    
    For Each nodElement In lstVideos
        If nodElement.Text = "Her Alibi" Then
            Set nodChild = docXMLDOM.createElement("actors")
            Set nodParent = nodElement.parentNode
            nodParent.appendChild nodChild
    
            docXMLDOM.Save "C:\Exercises\Videos13.xml"
            Found = True
        End If
    Next
    
    If Found = False Then
        MsgBox "There is no element with that value", _
               vbOKOnly Or vbInformation, _
               "Extensible Markup Language"
    End If
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0" encoding="utf-8"?>
<videos>
  . . .
  <video>
    <title>Her Alibi</title>
    <director>Bruce Beresford</director>
    <length>94 Minutes</length>
    <format>DVD</format>
    <rating>PG-13</rating>
    <actors></actors>
  </video>
  . . .
</videos>

This code creates an empty element. You may already know how to specify the value of an element: by assigning a string to its Text property. Here is an example:

Private Sub cmdInsertElement_Click()
    Dim Found As Boolean
    Dim docXMLDOM As DOMDocument
    Dim nodChild As IXMLDOMElement
    Dim nodParent As IXMLDOMElement
    Dim nodElement As IXMLDOMElement
    Dim lstVideos As IXMLDOMNodeList
    
    Found = False
    Set docXMLDOM = New DOMDocument
    docXMLDOM.Load "C:\Exercises\videos13.xml"
    
    Set lstVideos = docXMLDOM.getElementsByTagName("title")
    
    For Each nodElement In lstVideos
        If nodElement.Text = "The Day After Tomorrow" Then
            Set nodChild = docXMLDOM.createElement("category")
            nodChild.Text = "Drama - Environment"
            Set nodParent = nodElement.parentNode
            nodParent.appendChild nodChild
    
            docXMLDOM.Save "C:\Exercises\Videos13.xml"
            Found = True
        End If
    Next
    
    If Found = False Then
        MsgBox "There is no element with that value", _
               vbOKOnly Or vbInformation, _
               "Extensible Markup Language"
    End If
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0" encoding="utf-8" ?> 
<videos>
  . . .
  <video>
    <title>The Day After Tomorrow</title> 
    <director>Roland Emmerich</director> 
    <length>124 Minutes</length> 
    <format>DVD</format> 
    <rating>PG-13</rating> 
    <category>Drama - Environment</category> 
  </video>
  . . .
</videos>

Creating an Element After a Node

MSXML makes it possible to programmatically add a new element based on the position of another. For example, you can create a new node before an existing one. To support this operation, the IXMLDOMNodeList interface is equipped with a method named insertBefore. Its syntax is:

public Function insertBefore(ByVal newChild As IXMLDOMNodeList, _
			    ByVal refChild As IXMLDOMNodeList) As IXMLDOMNodeList

This method takes two arguments. The first argument is the element you want to create. The second argument is the node that will precede the one you are creating. Consider the following XML file named videos.xml:

<?xml version="1.0" encoding="utf-8"?>
<videos>
    <video>
	<title>The Distinguished Gentleman</title>
	<director>Jonathan Lynn</director>
	<length>112 Minutes</length>
	<format>DVD</format>
	<rating>R</rating>
    </video>
    <video>
	<title>Her Alibi</title>
	<director>Bruce Beresford</director>
	<length>94 Minutes</length>
	<format>DVD</format>
	<rating>PG-13</rating>
    </video>
</videos>

Imagine you want to add a new element before the second one. Here is an example of how this can be done:

Private Sub cmdInsertElement_Click()
    Dim Found As Boolean
    Dim docXMLDOM As DOMDocument
    Dim nodRoot As IXMLDOMElement
    Dim nodElement As IXMLDOMElement
    Dim lstVideos As IXMLDOMNodeList
    Dim nodNewElement As IXMLDOMElement
    Dim nodReference As IXMLDOMElement
    
    ' Initialize the document model
    Set docXMLDOM = New DOMDocument
    ' Open the XML document
    docXMLDOM.Load "C:\Exercises\videos14.xml"
    ' Get a list of nodes based on the director element
    Set lstVideos = docXMLDOM.getElementsByTagName("title")
    
    ' Check the list of all nodes
    For Each nodElement In lstVideos
        ' If you find a video titled Her Alibi, ...
        If nodElement.Text = "Her Alibi" Then
            ' ... get a reference to that video
            Set nodReference = nodElement
            ' Let the interpreter know that we found a match
            Found = True
            ' Get out of the For loop (no need to look further)
            Exit For
        End If
    Next
    
    ' Since the video was found
    If Found = True Then
        ' Get a reference to the root node
        Set nodRoot = docXMLDOM.documentElement
        ' ... start a new node named video
        Set nodNewElement = docXMLDOM.createElement("video")
        ' Add the new node before the element titled video
        nodRoot.insertBefore nodNewElement, nodReference.parentNode
            
        ' Save the file
        docXMLDOM.Save "C:\Exercises\Videos14.xml"
    End If

    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0" encoding="utf-8" ?> 
<videos>
  <video>
    <title>The Distinguished Gentleman</title> 
    <director>Jonathan Lynn</director> 
    <length>112 Minutes</length> 
    <format>DVD</format> 
    <rating>R</rating> 
  </video>
  <video></video>
  <video>
    <title>Her Alibi</title> 
    <director>Bruce Beresford</director> 
    <length>94 Minutes</length> 
    <format>DVD</format> 
    <rating>PG-13</rating> 
  </video>
</videos>

If you want, you can then populate the new node with a value and/or child nodes. Here are examples from the original videos14.xml file:

Private Sub cmdInsertElement_Click()
    Dim docXMLDOM As DOMDocument
    Dim nodRoot As IXMLDOMElement
    Dim nodChild As IXMLDOMElement
    Dim nodElement As IXMLDOMElement
    Dim lstVideos As IXMLDOMNodeList
    Dim nodReference As IXMLDOMElement
    Dim nodNewElement As IXMLDOMElement
    
    ' Initialize the document model
    Set docXMLDOM = New DOMDocument
    ' Open the XML document
    docXMLDOM.Load "C:\Exercises\videos14.xml"
    ' Get a list of nodes based on the director element
    Set lstVideos = docXMLDOM.getElementsByTagName("title")
    
    ' Check the list of all nodes
    For Each nodElement In lstVideos
        ' If you find a video titled Her Alibi, ...
        If nodElement.Text = "Her Alibi" Then
            ' ... get a reference to that video
            Set nodReference = nodElement
            
            ' Get a reference to the root node
            Set nodRoot = docXMLDOM.documentElement
            ' ... start a new node named video
            Set nodNewElement = docXMLDOM.createElement("video")
            ' Specify some value for the element
            nodNewElement.Text = "The video is provided in Blu-ray/DVD Combo."
            ' Add some child nodes to the new element
            Set nodChild = docXMLDOM.createElement("title")
            nodChild.Text = "A Good Day to Die Hard"
            nodNewElement.appendChild nodChild
            Set nodChild = docXMLDOM.createElement("director")
            nodChild.Text = "John Moore"
            nodNewElement.appendChild nodChild
            Set nodChild = docXMLDOM.createElement("length")
            nodChild.Text = "98 minutes"
            nodNewElement.appendChild nodChild

            ' Add the new node before the referenced element
            nodRoot.insertBefore nodNewElement, nodReference.parentNode
            
            ' Save the file
            docXMLDOM.Save "C:\Exercises\Videos14.xml"
            ' Get out of the For loop (no need to look further)
            Exit For
        End If
    Next

    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0" encoding="utf-8" ?> 
<videos>
  <video>
    <title>The Distinguished Gentleman</title> 
    <director>Jonathan Lynn</director> 
    <length>112 Minutes</length> 
    <format>DVD</format> 
    <rating>R</rating> 
  </video>
  <video>The video is provided in Blu-ray/DVD Combo. 
    <title>A Good Day to Die Hard</title> 
    <director>John Moore</Director> 
    <length>98 minutes</length> 
  </video>
  <video>
    <title>Her Alibi</title> 
    <director>Bruce Beresford</director> 
    <length>94 Minutes</length> 
    <format>DVD</format> 
    <rating>PG-13</rating> 
  </video>
</videos>

Of course, you can also add an element before a node that is a child node. Here is an example:

Private Sub cmdInsertElement_Click()
    Dim docXMLDOM As DOMDocument
    Dim nodElement As IXMLDOMElement
    Dim lstVideos As IXMLDOMNodeList
    Dim nodNewElement As IXMLDOMElement
    
    ' Initialize the document model
    Set docXMLDOM = New DOMDocument
    ' Open the XML document
    docXMLDOM.Load "C:\Exercises\videos14.xml"
    ' Get a list of nodes based on the director element
    Set lstVideos = docXMLDOM.getElementsByTagName("director")
    
    ' Check the list of all nodes
    For Each nodElement In lstVideos
        ' If you find a director named Jonathan Lynn, ...
        If nodElement.Text = "Jonathan Lynn" Then
            ' ... start a new node named actors
            Set nodNewElement = docXMLDOM.createElement("actors")
            ' Add the new node before the element named director
            nodElement.parentNode.insertBefore nodNewElement, nodElement
    
            ' Save the file
            docXMLDOM.Save "C:\Exercises\Videos14.xml"
            Exit For
        End If
    Next
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0" encoding="utf-8" ?> 
<videos>
  <video>
    <title>The Distinguished Gentleman</title> 
    <actors></actors>
    <director>Jonathan Lynn</director> 
    <length>112 Minutes</length> 
    <format>DVD</format> 
    <rating>R</rating> 
  </video>
  <video>
    <title>Her Alibi</title> 
    <director>Bruce Beresford</director> 
    <length>94 Minutes</length> 
    <format>DVD</format> 
    <rating>PG-13</rating> 
  </video>
</videos>

Remember that you can specify the value of an element by assigning a string to its Text property. You can also add child nodes to the new element.

Replacing a Child Node of an Element

If you have an existing node but that has a wrong child node (probably the name of the child node is wrong) or a child node has a wrong value, you can edit the child node or change the value of the child node(s). This is done by creating a new value and replacing the existing one. To support this operation, the IXMLDOMNodeList interface is equipped with a method named replaceChild. Its syntax is:

Public Function replaceChild(ByVal newChild As IXMLDOMNode, _
			     ByVal oldChild As IXMLDOMNode) As IXMLDOMNode

This mehod takes as arguments the new child node that will replace the existing element. Consider the following XML file named videos15.xml

<?xml version="1.0" encoding="utf-8" ?> 
<videos>
  <video>
    <title>The Distinguished Gentleman</title> 
    <director>Jonathan Lynn</director> 
    <length>112 Minutes</length> 
    <format>DVD</format> 
    <rating>R</rating> 
  </video>
  <video>The video is provided in Blu-ray/DVD Combo. 
    <title>A Good Day to Die Hard</title> 
    <director>John Moore</Director> 
    <length>98 minutes</length> 
  </video>
  <video>
    <title>Her Alibi</title> 
    <director>Bruce Beresford</director> 
    <length>94 Minutes</length> 
    <format>DVD</format>
    <rating>PG-13</rating> 
  </video>
</videos>

Imagine you want to completely replace the video in the middle: A Good Day to Die Hard. Here is an example that replaces an existing node with a new one:

Private Sub cmdReplaceElement_Click()
    Dim docXMLDOM As DOMDocument
    Dim nodRoot As IXMLDOMElement
    Dim nodChild As IXMLDOMElement
    Dim nodElement As IXMLDOMElement
    Dim lstVideos As IXMLDOMNodeList
    Dim nodReference As IXMLDOMElement
    Dim nodNewElement As IXMLDOMElement
    
    ' Initialize the document model
    Set docXMLDOM = New DOMDocument
    ' Open the XML document
    docXMLDOM.Load "C:\Exercises\videos15.xml"
    ' Get a list of nodes based on the director element
    Set lstVideos = docXMLDOM.getElementsByTagName("title")
    
    ' Check the list of all nodes
    For Each nodElement In lstVideos
        ' If you find a video titled Her Alibi, ...
        If nodElement.Text = "A Good Day to Die Hard" Then
            ' ... get a reference to that video
            Set nodReference = nodElement
            
            ' Get a reference to the root node
            Set nodRoot = docXMLDOM.documentElement
            ' ... start a new node named video
            Set nodNewElement = docXMLDOM.createElement("video")
            ' Add some child nodes to the new element
            Set nodChild = docXMLDOM.createElement("title")
            nodChild.Text = "Indiana Jones and the Kingdom of the Crystal Skull"
            nodNewElement.appendChild nodChild
            Set nodChild = docXMLDOM.createElement("director")
            nodChild.Text = "Stephen Sielvert"
            nodNewElement.appendChild nodChild
            Set nodChild = docXMLDOM.createElement("producers")
            nodChild.Text = "Kathleen Kennedy, George Lucas"
            nodNewElement.appendChild nodChild
            Set nodChild = docXMLDOM.createElement("rating")
            nodChild.Text = "PG-13"
            nodNewElement.appendChild nodChild

            ' Add the new node before the referenced element
            nodRoot.replaceChild nodNewElement, nodReference.parentNode
            
            ' Save the file
            docXMLDOM.Save "C:\Exercises\Videos15.xml"
            ' Get out of the For loop (no need to look further)
            Exit For
        End If
    Next

    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0" encoding="utf-8" ?> 
<videos>
  <video>
    <title>The Distinguished Gentleman</title> 
    <director>Jonathan Lynn</director> 
    <length>112 Minutes</length> 
    <format>DVD</format> 
    <rating>R</rating> 
  </video>
  <video>
    <title>Indiana Jones and the Kingdom of the Crystal Skull</title> 
    <director>Stephen Sielvert</director> 
    <producers>Kathleen Kennedy, George Lucas</producers> 
    <rating>PG-13</rating> 
  </video>
  <video>
    <title>Her Alibi</title> 
    <director>Bruce Beresford</director> 
    <length>94 Minutes</length>
    <format>DVD</format> 
    <rating>PG-13</rating> 
    </video>
</videos>

Now consider the following file named videos16.xml:

<?xml version="1.0" encoding="utf-8" ?> 
<videos>
  <video>
    <title>The Distinguished Gentleman</title> 
    <director>Jonathan Lynn</director> 
    <length>112 Minutes</length> 
    <format>DVD</format> 
    <rating>R</rating> 
  </video>
  <video>
    <title>Indiana Jones and the Kingdom of the Crystal Skull</title>
    <director>Stephen Sielvert</director> 
    <producers>Kathleen Kennedy, George Lucas</producers> 
    <rating>PG-13</rating> 
  </video>
  <video>
    <title>Her Alibi</title> 
    <director>Bruce Beresford</director> 
    <length>94 Minutes</length>
    <format>DVD</format> 
    <rating>PG-13</rating> 
    </video>
</videos>

Imagine that the name of the director in the second video as Stephen Sielvert is wrong and you want to edit/change/update it. To do that (programmatically), you would have to replace that string. To do this, you would have to locate the name and replace/change its value. Obviously there are different approaches you can use but the whole technique (of course not the only one) is to call the IXMLDOMNodeList.replaceChild() method after locating the video. Here is one way this can be done:

Private Sub cmdReplaceChild_Click()
    Dim docXMLDOM As DOMDocument
    Dim nodRoot As IXMLDOMElement
    Dim nodVideo As IXMLDOMElement
    Dim nodDirector As IXMLDOMElement
    Dim lstDirectors As IXMLDOMNodeList
    
    ' Initialize the document model
    Set docXMLDOM = New DOMDocument
    ' Open the XML document
    docXMLDOM.Load "C:\Exercises\videos16.xml"
    ' Get a list of nodes based on the director element
    Set lstDirectors = docXMLDOM.getElementsByTagName("director")
    
    ' Check the list of all nodes
    For Each nodVideo In lstDirectors
        ' If you find a video whose director is Stephen Sielvert, ...
        If nodVideo.Text = "Stephen Sielvert" Then
            ' Get a reference to the root
            Set nodRoot = docXMLDOM.documentElement
            ' Start creating a new node
            Set nodDirector = docXMLDOM.createElement("director")
            ' Specify its value
            nodDirector.Text = "Steven Spielberg"
            ' Use the new node in place of the old node
            nodVideo.parentNode.replaceChild nodDirector, nodVideo
            ' Save the file
            docXMLDOM.Save "C:\Exercises\Videos16.xml"
            ' Get out of the For loop (no need to look further)
            Exit For
        End If
    Next

    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0" encoding="utf-8" ?> 
<videos>
  <video>
    <title>The Distinguished Gentleman</title> 
    <director>Jonathan Lynn</director> 
    <length>112 Minutes</length> 
    <format>DVD</format> 
    <rating>R</rating>
  </video>
  <video>
    <title>Indiana Jones and the Kingdom of the Crystal Skull</title>
    <director>Steven Spielberg</director> 
    <producers>Kathleen Kennedy, George Lucas</producers> 
    <rating>PG-13</rating> 
  </video>
  <video>
    <title>Her Alibi</title> 
    <director>Bruce Beresford</director> 
    <length>94 Minutes</length> 
    <format>DVD</format> 
    <rating>PG-13</rating> 
  </video>
</videos>

Using the same approach, you can edit/update/change/replace any node or child node or grand-child and/or their values.

Deleting XML Elements

Deleting an Element

If you have a node you don't want or don't need anymore in your XML document, you can delete it. To support this operation, the IXMLDOMNode interface provides a method named removeChild. Its syntax is:

Public Function removeChild(ByVal node As IXMLDOMNode) As IXMLDOMNode

This method takes as argument the node to delete. If the node exists, it would be deleted and the method would return the node that was deleted. If the node does not exist, nothing would happen. To effectively use this method, you should first locate the particular node you want to delete. You can look for it using any of the logics we have applied so far. Once you find the node, you can then delete it. Consider the following file named videos17.xml:

<?xml version="1.0" encoding="utf-8" ?> 
<videos>
  <video>
    <title>The Distinguished Gentleman</title> 
    <director>Jonathan Lynn</director> 
    <length>112 Minutes</length> 
    <format>DVD</format> 
    <rating>R</rating> 
  </video>
  <video>The video is provided in Blu-ray/DVD Combo. 
    <title>A Good Day to Die Hard</title> 
    <director>John Moore</director> 
    <length>98 minutes</length> 
  </video>
  <video>
    <title>Indiana Jones and the Kingdom of the Crystal Skull</title> 
    <director>Steven Spielberg</director> 
    <producers>Kathleen Kennedy, George Lucas</producers> 
    <rating>PG-13</rating> 
  </video>
  <video>
    <title>Her Alibi</title> 
    <director>Bruce Beresford</director> 
    <length>94 Minutes</length> 
    <format>DVD</format> 
    <rating>PG-13</rating> 
  </video>
</videos>

Imagine you want to delete the video titled A Good Day to Die Hard. Here is an example of calling this method to perform the operation:

Private Sub cmdDeleteElement_Click()
    Dim docXMLDOM  As DOMDocument
    Dim nodRoot As IXMLDOMElement
    Dim nodElement As IXMLDOMElement
    Dim lstVideos As IXMLDOMNodeList
    
    Found = False
    Set docXMLDOM = New DOMDocument
    docXMLDOM.Load "C:\Exercises\videos17.xml"
    Set lstVideos = docXMLDOM.getElementsByTagName("title")
    
    For Each nodElement In lstVideos
        If nodElement.Text = "A Good Day to Die Hard" Then
            Set nodRoot = docXMLDOM.documentElement
            nodRoot.removeChild nodElement.parentNode

            docXMLDOM.Save "C:\Exercises\videos17.xml"
            Exit For
        End If
    Next
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0" encoding="utf-8" ?> 
<videos>
  <video>
    <title>The Distinguished Gentleman</title> 
    <director>Jonathan Lynn</director> 
    <length>112 Minutes</length> 
    <format>DVD</format> 
    <rating>R</rating> 
  </video>
  <video>
    <title>Indiana Jones and the Kingdom of the Crystal Skull</title> 
    <director>Steven Spielberg</director> 
    <producers>Kathleen Kennedy, George Lucas</producers> 
    <rating>PG-13</rating> 
  </video>
  <video>
    <title>Her Alibi</title> 
    <director>Bruce Beresford</director> 
    <length>94 Minutes</length> 
    <format>DVD</format> 
    <rating>PG-13</rating> 
  </video>
</videos>

Obviously, to delete the first or the last child node of an element, call either the firstChild() or the lastChild() method on the document element. Here is an example that deletes the first child node of the root element:

Private Sub cmdDeleteNode_Click()
    Dim docXMLDOM  As DOMDocument
    Dim nodRoot As IXMLDOMElement
    
    Set docXMLDOM = New DOMDocument
    docXMLDOM.Load "C:\Exercises\videos17.xml"

    ' Get a reference to the root element
    Set nodRoot = docXMLDOM.documentElement
    
    ' Delete the first child node of the root element
    nodRoot.removeChild nodRoot.firstChild

    docXMLDOM.Save "C:\Exercises\videos17.xml"
    
    Set docXMLDOM = Nothing
End Sub

Deleting a Child Node of an Element

Using any of these techniques, you can delete any node inside your XML document. Consider the above videos17.xml file. Imagine you want to delete a node named producers in the video titled Kathleen Kennedy, George Lucas. Here is how this can be done:

Private Sub cmdDeleteChildNode_Click()
    Dim docXMLDOM  As DOMDocument
    Dim nodProducer As IXMLDOMNode
    Dim nodVideo As IXMLDOMElement
    Dim lstVideos As IXMLDOMNodeList
    Dim lstProducers As IXMLDOMNodeList
    
    Set docXMLDOM = New DOMDocument
    docXMLDOM.Load "C:\Exercises\videos17.xml"
    
    ' Get a list of all elements named video
    Set lstVideos = docXMLDOM.getElementsByTagName("video")
    
    ' Visit each node under the root element
    For Each nodVideo In lstVideos
        ' Create a list of all nodes named producers in the current node
        Set lstProducers = nodVideo.getElementsByTagName("producers")
        ' Visit each producer node
        For Each nodProducer In lstProducers
            ' Look for a producer node whose value is Kathleen Kennedy, George Lucas
            If nodProducer.Text = "Kathleen Kennedy, George Lucas" Then
                ' Since we found such a node, delete it
                nodVideo.removeChild nodProducer
                ' Save the updated file
                docXMLDOM.Save "C:\Exercises\videos17.xml"
                ' Stop searching
                Exit For
            End If
        Next
    Next
    
    Set docXMLDOM = Nothing
End Sub

This would produce:

<?xml version="1.0" encoding="utf-8" ?> 
<videos>
  <video>
    <title>The Distinguished Gentleman</title>
    <director>Jonathan Lynn</director> 
    <length>112 Minutes</length> 
    <format>DVD</format> 
    <rating>R</rating> 
  </video>
  <video>
    <title>Indiana Jones and the Kingdom of the Crystal Skull</title>
    <director>Steven Spielberg</director> 
    <rating>PG-13</rating> 
  </video>
  <video>
    <title>Her Alibi</title> 
    <director>Bruce Beresford</director>
    <length>94 Minutes</length> 
    <format>DVD</format> 
    <rating>PG-13</rating> 
  </video>
</videos>

In the same way, you can delete a child of a child of a child node.