JSON.Net: Convert JSON string from XML string to instance issue

Question

I have the following function:

public static T GetInstance<T>(string xmlString)
{
   var xmlDoc = new XmlDocument();
   xmlDoc.Load(new StringReader(xmlString));
   string jsonString = JsonConvert.SerializeXmlNode(xmlDoc.DocumentElement);
   T instance = JsonConvert.DeserializeObject(jsonString, typeof(T)) as T;
   return instance;
}

It works fine for normal XML strings. However, if the input XML string contains comments such as :

....
<!-- some comments ... 
-->
....

Then the function call to JsonConvert.DeserializeObject() will throw an exception:

Newtonsoft.Json.JsonSerializationException was unhandled
Message="Unexpected token when deserializing object: Comment"
Source="Newtonsoft.Json"
StackTrace:
   at Newtonsoft.Json.JsonSerializer.PopulateObject(Object newObject, JsonReader reader, Type objectType)
   ....

Either I have to trim out all the comments in the XML string, or if I can use any option settings in JsonConvert to ignore comments.

For the first option, if I have to take all the comments out by using XmlDocument, is there any options in XmlDocument available to convert an XML string to nodes-only XML string?

For the second option, I prefer, if there is any option in Json.Net to ignore comments when desialize to object?

Answer 1

I think the best way for me right now is to remove all the comment nodes from the xml string first.

public static string RemoveComments(
        string xmlString,
        int indention)
{
   XmlDocument xDoc = new XmlDocument();
   xDoc.PreserveWhitespace = false;
   xDoc.LoadXml(xmlString);
   XmlNodeList list = xDoc.SelectNodes("//comment()");

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

   string xml;
   using (StringWriter sw = new StringWriter())
   {
      using (XmlTextWriter xtw = new XmlTextWriter(sw))
      {
        if (indention > 0)
        {
          xtw.IndentChar = ' ';
          xtw.Indentation = indention;
          xtw.Formatting = System.Xml.Formatting.Indented;
        }

        xDoc.WriteContentTo(xtw);
        xtw.Close();
        sw.Close();
      }
      xml = sw.ToString();
    }

  return xml;
  }

And this is my function to get instance from xml string:

public static T GetInstance<T>(string xmlString)
{
  srring xml = RemoveComments(xmlString);
  var xmlDoc = new XmlDocument();
  xmlDoc.Load(new StringReader(xml));
  string jsonString = JsonConvert.SerializeXmlNode(xmlDoc.DocumentElement);
  T instance = JsonConvert.DeserializeObject(jsonString, typeof(T)) as T;
  return instance;
}