How to ignore comments when reading a XML file into a XmlDocument?

Question

I am trying to read a XML document with C#, I am doing it this way:

XmlDocument myData = new XmlDocument();
myData.Load("datafile.xml");

anyway, I sometimes get comments when reading XmlNode.ChildNodes.

For the benefit of who's experiencing the same requirement, here's how I did it at the end:

/** Validate a file, return a XmlDocument, exclude comments */
private XmlDocument LoadAndValidate( String fileName )
{
    // Create XML reader settings
    XmlReaderSettings settings = new XmlReaderSettings();
    settings.IgnoreComments = true;                         // Exclude comments
    settings.ProhibitDtd = false;                           
    settings.ValidationType = ValidationType.DTD;           // Validation

    // Create reader based on settings
    XmlReader reader = XmlReader.Create(fileName, settings);

    try {
        // Will throw exception if document is invalid
        XmlDocument document = new XmlDocument();
        document.Load(reader);
        return document;
    } catch (XmlSchemaException) {
        return null;
    }
}

Thank you
Tommaso

Solution 1

You can use an XmlReader with XmlReaderSettings.IgnoreComments set to true:

XmlReaderSettings readerSettings = new XmlReaderSettings();
readerSettings.IgnoreComments = true;
using (XmlReader reader = XmlReader.Create("input.xml", readerSettings))
{
    XmlDocument myData = new XmlDocument();
    myData.Load(reader);
    // etc...
}

(Found from here by searching for XmlDocument ignore comments)

Solution 2

foreach(XmlNode node in nodeList)
  if(node.NodeType != XmlNodeType.Comment)
     ...

Solution 3

You could simply add filter on your ChildNodes. E.g.

var children = myNode.ChildNodes.Cast<XmlNode>().Where(n => n.NodeType != XmlNodeType.Comment);

Alternatively, you could load the XmlDocument passing in an XmlReader with settings such that XmlReaderSettings.IgnoreComments is true.

using (var file = File.OpenRead("datafile.xml"))
{
    var settings = new XmlReaderSettings() { IgnoreComments = true, IgnoreWhitespace = true };
    using (var xmlReader = XmlReader.Create(file, settings))
    {
        var document = new XmlDocument();
        document.Load(xmlReader);

        // Process document nodes...
    }
}

Solution 4

use XmlReaderSettings

XmlReaderSettings readerSettings = new XmlReaderSettings();
readerSettings.IgnoreComments = true;
XmlReader reader = XmlReader.Create(sourceFilePath, readerSettings);
XmlDocument myXmlDoc = new XmlDocument();
myXmlDoc.Load(reader);

Solution 5

Dim pattern As String = String.Empty
Dim xDoc As XmlDocument = New XmlDocument()

xDoc.Load(path)

''Pattern of comments
pattern = "(<!--.*?--\>)"
xDoc.InnerXml = Regex.Replace(xDoc.InnerXml, pattern, String.Empty, RegexOptions.Singleline)

<!--aftr this run ur code-->

View more solutions

Comments

[Curt Nichols]

Alternatively, hoist the filter out of the loop for readability: foreach(XmlNode node in nodeList.Where(node => node.NodeType != XmlNodeType.Comment)) ...

[bkovacic]

this excludes <!-- --> comments, but not /* */ which are also valid XML comments (checked with w3c validator)...