(Visual Basic) Compress XML Tree

Demonstrates how to compress and restore the entire subtree rooted at an XML node.

The input XML, available at http://www.chilkatsoft.com/data/compress2.xml, is this:

<root>
    <lazydog>
        <fox>The quick brown fox jumps over the lazy dog</fox>
    </lazydog>
    <fox>The quick brown fox jumps over the lazy dog</fox>
    <child>
        <grandchild>The quick brown fox jumps over the lazy dog</grandchild>
    </child>
    <child>
        <grandchild>The quick brown fox jumps over the lazy dog</grandchild>
    </child>
</root>

Download Chilkat XML ActiveX

Dim xml As New ChilkatXml

Dim success As Long
'  The sample input XML is available at http://www.chilkatsoft.com/data/compress2.xml
success = xml.LoadXmlFile("compress2.xml")
If (success <> 1) Then
    Text1.Text = Text1.Text & xml.LastErrorText & vbCrLf
    Exit Sub
End If

'  Zip compress the root node's entire subtree:
xml.ZipTree 

'  Examine the new XML document:
Text1.Text = Text1.Text & xml.GetXml() & vbCrLf

'  This is the XML w/ the compressed subtree in Base64 encoded format:
'  
<root><![CDATA[4+WyKcrPL7Hj5VIAApucxKrKlPx0KBcslJZfYReSkapQWJqZnK2QVJRfnqcAFFPIKs0tKFbIL0st
UigBSoN0KgC12uiDNECN00c1jyKzkjMyc1KQHZZelJiXAhElyUwkfTBnovDoYZGNPjTUAQ==
]]></root>


'  Now uncompress and show that the original subtree was restored:
xml.UnzipTree 
Text1.Text = Text1.Text & xml.GetXml() & vbCrLf