NotesDOMParser 全攻略 — XML 整棵樹載入記憶體、14 個 Node 類別、走訪／修改／序列化

<library>
    <book id="b1">
        <title>The Hobbit</title>
        <author>Tolkien</author>
    </book>
    <book id="b2">
        <title>Dune</title>
    </book>
</library>

Document（root，NotesDOMDocumentNode）
└─ library（Element）
   ├─ book（Element，attribute id="b1"）
   │  ├─ title（Element）
   │  │  └─ "The Hobbit"（TextNode）
   │  └─ author（Element）
   │     └─ "Tolkien"（TextNode）
   └─ book（Element，attribute id="b2"）
      └─ title（Element）
         └─ "Dune"（TextNode）

Dim session As New NotesSession
Dim domParser As NotesDOMParser
Dim xml_in As NotesStream
Dim xml_out As NotesStream

Set xml_in = session.CreateStream
Call xml_in.Open("c:\data\library.xml")

Set xml_out = session.CreateStream
Call xml_out.Open("c:\data\library_modified.xml")
Call xml_out.Truncate

Set domParser = session.CreateDOMParser(xml_in, xml_out)
Call domParser.Process()   ' 開始 parse — 把整份載入記憶體蓋 tree

Sub Initialize
    Dim session As New NotesSession
    Dim domParser As NotesDOMParser
    Dim xml_in As NotesStream, xml_out As NotesStream

    Set xml_in = session.CreateStream
    If Not xml_in.Open("c:\data\library.xml") Then
        Print "Cannot open input" : Exit Sub
    End If

    Set xml_out = session.CreateStream
    Call xml_out.Open("c:\data\library_modified.xml")
    Call xml_out.Truncate

    Set domParser = session.CreateDOMParser(xml_in, xml_out)
    domParser.ExitOnFirstFatalError = True
    Call domParser.Process()

    ' 拿到 root
    Dim docNode As NotesDOMDocumentNode
    Set docNode = domParser.Document

    ' 走訪、改 title 大寫
    Call WalkAndModify(docNode)

    ' 序列化回 XML 檔
    Call domParser.Serialize()
    Call xml_out.Close()

    Print "Done — output at c:\data\library_modified.xml"
End Sub

Sub WalkAndModify(node As NotesDOMNode)
    If node Is Nothing Then Exit Sub

    ' Element 處理
    If node.NodeType = DOMNODETYPE_ELEMENT_NODE Then
        Dim elem As NotesDOMElementNode
        Set elem = node    ' downcast

        If elem.TagName = "title" Then
            ' 改 title 的 text 為大寫
            If elem.HasChildNodes Then
                Dim textNode As NotesDOMNode
                Set textNode = elem.FirstChild
                If textNode.NodeType = DOMNODETYPE_TEXT_NODE Then
                    textNode.NodeValue = UCase(textNode.NodeValue)
                End If
            End If
        ElseIf elem.TagName = "book" Then
            ' 加新 attribute
            Call elem.SetAttribute("modified", "true")
        End If
    End If

    ' 遞迴 children
    Dim child As NotesDOMNode
    Set child = node.FirstChild
    Do Until child Is Nothing
        Call WalkAndModify(child)
        Set child = child.NextSibling
    Loop
End Sub

' ❌ 錯
Print elem.Text     ' 沒有這個 property

' ✅ 對 — 取 child TextNode
Dim t As NotesDOMNode
Set t = elem.FirstChild
If t.NodeType = DOMNODETYPE_TEXT_NODE Then
    Print t.NodeValue
End If

Set child = elem.FirstChild
Do Until child Is Nothing
    If child.NodeType = DOMNODETYPE_TEXT_NODE And Trim(child.NodeValue) = "" Then
        ' skip whitespace
    Else
        ' 真實處理
    End If
    Set child = child.NextSibling
Loop

Function FindByTagName(node As NotesDOMNode, tagName As String) As NotesDOMElementNode
    If node.NodeType = DOMNODETYPE_ELEMENT_NODE Then
        Dim e As NotesDOMElementNode
        Set e = node
        If e.TagName = tagName Then
            Set FindByTagName = e
            Exit Function
        End If
    End If
    Dim child As NotesDOMNode
    Set child = node.FirstChild
    Do Until child Is Nothing
        Dim found As NotesDOMElementNode
        Set found = FindByTagName(child, tagName)
        If Not found Is Nothing Then
            Set FindByTagName = found
            Exit Function
        End If
        Set child = child.NextSibling
    Loop
End Function