How to remove all comment tags from XmlDocument

Question

How would i go about to remove all comment tags from a XmlDocument instance?

Is there a better way than retrieving a XmlNodeList and iterate over those?

    XmlNodeList list = xmlDoc.SelectNodes("//comment()");

    foreach(XmlNode node in list)
    {
        node.ParentNode.RemoveChild(node);
    }

Answer 1

When you load the xml, you can use XmlReaderSettings

XmlReaderSettings settings = new XmlReaderSettings();
settings.IgnoreComments = true;
XmlReader reader = XmlReader.Create("...", settings);
xmlDoc.Load(reader);

On an existing instance, your solution looks good.

Answer 2

Nope thats about it, although I'd be inclind to place the nodes in a List first.

I'm not sure about the .NET implementation of XmlNodeList but I know that previous MSXML implementations loaded the list in lazy manner and code such as the above in the past would end up failing in some way as result of the DOM tree being modified as the List is enumerated.

 foreach (var node in xml.SelectNodes("//comment()").ToList())
   node.ParentNode.RemoveChild(node);

Answer 3

Today looking for the way how to extract <!-- --> from Visual Basic for Applications (not C#), I have found also nodeTypeString property, but it takes more space. Here is an example in VBA:

Dim xmldoc As New MSXML2.DOMDocument30
Dim oNodeList As IXMLDOMSelection
Dim node As IXMLDOMNode
Dim i As Long

Dim FileName As String, FileName1 As String

FileName = "..." ' Source
FileName2 = "..." ' Target

xmldoc.async = False ' ?
xmldoc.Load FileName
If (xmldoc.parseError.errorCode <> 0) Then Exit Sub ' or Function

Set oNodeList = xmldoc.selectNodes("//*") '' all nodes

For i = 0 To oNodeList.length - 1
With oNodeList(i)

     For Each node In .childNodes
         If node.nodeTypeString = "comment" Then .removeChild node
     Next

End With
Next

xmldoc.Save FileName2

Set oNodeList = Nothing ' ?
Set xmldoc = Nothing

It omitts document top parent comment nodes, but they can be retrieved somehow directly if needed, for example using With xmldoc.documentElement.childNodes.