Use %XML.Node to walk a DOM

The following code walks a DOM using %XML.Node. It also prevents %XML.Writer to change whitespace. Run the code using the class method "test":

Class objectscript.walkDOM Extends %Persistent
{
ClassMethod dfs(node As %XML.Node)
{
s entrynode=node.NodeId
do {
//element nodes with one whitespacetyped child are the ones we want to change
if (node.NodeType=$$$xmlELEMENTNODE){
s snode=node.NodeId

if (node.MoveToFirstChild())

{
i ('node.MoveToNextSibling()){
i (node.NodeType=$$$xmlWHITESPACENODE){
s node.NodeType=$$$xmlTEXTNODE
s node.NodeId=snode
}
}
}
s node.NodeId=snode

}

if (node.HasChildNodes()){
d node.MoveToFirstChild()
d ..dfs(node)
}
} while (node.NodeType'="" && node.MoveToNextSibling())
s node.NodeId=entrynode

}
 
ClassMethod test()
{
  set xml = "abcdefg"
 
  s reader=##class(%XML.Reader).%New()
  do reader.OpenString(xml)  
  set writer = ##class(%XML.Writer).%New()
  //do some magic
  d ..dfs(reader.Document)
   
  w !,"with indent=1:",!
  set writer.Indent = 1
  do writer.OutputToString()
  do writer.Document(reader.Document)
  w writer.GetXMLString()
  set writer.Indent = 0
  w !,"with indent=0:",!
  do writer.OutputToString()
  do writer.Document(reader.Document)
  w writer.GetXMLString()
}

}

Here's a link to the code on GitHub: https://github.com/intersystems-community/code-snippets/blob/master/src/cls/objectscript/walkDOM.cls