Is there a way to check if a specific Node from a XML-File contains a comment and if it does to read the comment?

Question

I want to read all comments from specific Nodes and put them into a List in C#.

My Code is:

List<string> keyList = new List<string>();
List<string> valueList= new List<string>();

var xmldoc = new XmlDocument();
xmldoc.Load("xmlfile.xml");

var result = xmldoc.SelectNodes(/manuel/chapter-ref/chapter/chapter-ref/chapter/block/procedure/step/action/table/tgroup/tbody/row/entry/p/formfield/@field_id);

foreach(XmlNode item in result){
keyList.Add(item.Value)
}

This way I can get every field_id from the formfields and put them into the keyList. Some formfields contain a comment and some don't. I want to add those comments into the list valueList and if the formfield doesn't contain a comment I want to add "no value" into the list. Is there a way to do so?

Answer 1

Select comments in XPath using foo/bar/comment()

Since you already call SelectNodes towards the formfield I suggest changing the XPath and add an if statement checking for the comment node.

List<string> keyList = new List<string>();
List<string> valueList= new List<string>();

var xmldoc = new XmlDocument();
xmldoc.Load("xmlfile.xml");

// Removed '/@field_id'
var result = xmldoc.SelectNodes("/manuel/chapter-ref/chapter/chapter-ref/chapter/block/procedure/step/action/table/tgroup/tbody/row/entry/p/formfield");

foreach(XmlElement item in result)
{
    var nd = item.SelectSingleNode("comment()");
    if (nd != null) valueList.Add(nd.InnerText);
    else valueList.Add("no val");

    keyList.Add(item.GetAttribute("field_id")); // Changed to GetAttribute
}