XML Programming Information for VB

See UPS OnLine Tools Developer's Guide for tool specific Xpaths and options for formatting XML Requests.

Building XML

Creating an XML Document

A document can be created using the MSXML3 Dom object. After the document has been created the node can added by calling the addNode function. To build an XML Document the AddNode function takes the tag of the parent node and generates a child then appends the child node to the parent node using calls to the DOM object.

Code Example

The following code example illustrates creating an XML document:

Public Function createXMLDocument(rootname As String, xml As MSXML2.DOMDocument30) As Boolean

On Error GoTo ErrHand

Dim docXML As New MSXML2.DOMDocument30

Dim parentNode As IXMLDOMNode

Dim root As IXMLDOMElement

Dim Prop As MSXML2.IXMLDOMProcessingInstruction

docXML.async = False

Set root = docXML.createElement(rootname)

docXML.loadXML root.xml

Set parentNode = root

Set Prop = docXML.createProcessingInstruction("xml", "version = '1.0'")

docXML.loadXML (Prop.xml & root.xml)

Set xml = docXML

createXMLDocument = True

Exit Function

ErrHand:

createXMLDocument = False

End Function

Adding a Node

The Parent node and the newTagName are required for the AddNode subroutine. If the textString is passed then the node is added to the parentnode with textString as the node value. If the "EMPTY_NODE" tag is passed in the textString field then a container node (newTagName) is added to the parent node. If the textString field is empty and the attrName and attrValue the attribute is added the parentnode. Otherwise no node is added.

Code Example

The following code example illustrates adding a node:

Public Function AddNode(doc As MSXML2.DOMDocument30, strParentTag As String, newTagName As String, _

textString As String, attrName As String, AttrValue As String)

On Error GoTo ErrHand

Dim Item As MSXML2.IXMLDOMElement

Dim root As MSXML2.IXMLDOMElement

Dim oAttr As MSXML2.IXMLDOMAttribute

Dim parentTag As MSXML2.IXMLDOMNode

Dim Node As MSXML2.IXMLDOMNode

Dim pNode As MSXML2.IXMLDOMNode

Dim child As MSXML2.IXMLDOMNode

Dim ThisNode As MSXML2.IXMLDOMText

AddNode = True

' we are getting a nodelist because it allows us to specify the parent element

' by its string name; that way, we don't have to pass Elements around

Dim N1 As MSXML2.IXMLDOMNodeList

Set parentTag = doc

Set N1 = doc.getElementsByTagName(strParentTag)

If N1.length > 0 Then

Set Parent = N1.Item(N1.length - 1)

Else

Set Parent = parentTag

End If

If Not (StrComp(textString, "") = 0) Then

Set Node = doc.createNode(NODE_ELEMENT, newTagName, "")

If Not (StrComp(textString, "EMPTY_NODE") = 0) Then

Node.nodeTypedValue = textString

End If

Parent.appendChild Node

AddNode = True

Else

If Not (((StrComp(attrName, "") = 0) Or (StrComp(AttrValue, "") = 0))) Then

Set oAttr = doc.createAttribute(attrName)

Parent.setAttribute attrName, AttrValue

AddNode = True

Else

AddNode = False

End If

Exit Function

ErrHand:

AddNode = False

End Function

Parsing XML

Parsing XML with VB6. The DOM Object parses the document when it is loaded. If the document is not valid then the appropriate DOM Exception is returned. The "getElementsByTagName()" function can be used to access nodes within the Document as shown below.

Code Example

The following code example illustrates parsing an XML document:

Public Function FillXML(xnodes() As String, strXML As String) As String

'This method requires that the array size be greater than or equal to the amount 'of "writable" nodes in the XML document. Also, the order of the values in the 'array should sync up with the order of their respective "writable" nodes in the 'XML document.

On Error GoTo ErrFill

Dim I As Integer

Dim str As String

Dim objXMl As DOMDocument30

Dim objXMLList As IXMLDOMNodeList

Set objXMl = New DOMDocument30

objXMl.loadXML strXML

Set objXMLList = objXMl.getElementsByTagName("*")

t = 0

MaxNodes = objXMl.getElementsByTagName("*").length

For I = 0 To MaxNodes - 1

'Here we make a list of child nodes for every element in the list.

Set ElementList = objXMLList.Item(I).childNodes

'If there is only one child in the list then we write the value in the array to 'that node.

If ElementList.length = 1 Then

objXMl.getElementsByTagName("*").Item(I).Text = xnodes(t)

t = t + 1

End If

Next I

FillXML = True

strXML = objXMl.xml

Exit Function

ErrFill:

FillXML = False

End Function

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