Question

A surprisingly simple question this time! 🙂 There’s an XML file like this:

<xml>
  <data> </data>
</xml>

Now I need to read exactly whatever is in the <data> element. Be it a single whitespace like U+0020. My naive guess:

XmlDocument xd = new XmlDocument();
xd.Load(fileName);
XmlNode xn = xd.DocumentElement.SelectSingleNode("data");
string data = xn.InnerText;

But that returns an empty string. The white space got lost. Any other data can be read just fine.

What do I need to do to get my space character here?

After browsing the web for a while, I tried reading the XML file with an XmlReader that lets me set XmlReaderSettings.IgnoreWhitespace = false but that didn’t help.

Answer 1

You must use xml:space="preserve" in your XML, according to the W3C standards and the MSDN docs.

The W3C standards dictate that white space be handled differently
depending on where in the document it occurs, and depending on the
setting of the xml:space attribute. If the characters occur within the
mixed element content or inside the scope of the xml:space=”preserve”,
they must be preserved and passed without modification to the
application. Any other white space does not need to be preserved. The
XmlTextReader only preserves white space that occurs within an
xml:space=”preserve” context.

        XmlDocument xd = new XmlDocument();
        xd.LoadXml(@"<xml xml:space=""preserve""><data> </data></xml>");
        XmlNode xn = xd.DocumentElement.SelectSingleNode("data");
        string data = xn.InnerText; // data == " "
        Console.WriteLine(data == " "); //True

Tested HERE.