How do I put child nodes into their own parent node?

Question

I have the following XML input:

<init>
   <options>
      <option>1</option>
      <option>2</option>
      <option>3</option>
   </options>
</init>

I would like to transform this into the following output XML:

<init>
    <options>
       <option>1</option>
    </options>
    <options>
       <option>2</option>
    </options>
    <options>
       <option>3</option>
    </options>
</init>

So instead of one <options> tag, I want to create multiple <options> tags based on the amount of child nodes within the input XML.

I'm using XmlDocument in C# .NET.

What is the easiest way to do this?

Answer 1

Assuming the format exactly you have provided

var xmlStr = @"<init>
                  <options>
                     <option>1</option>
                     <option>2</option>
                     <option>3</option>
                  </options>
               </init>";
        var xmlDoc = new XmlDocument();
        xmlDoc.LoadXml(xmlStr);

        var resultDoc = new XmlDocument();
        resultDoc.LoadXml("<init></init>");
        XmlElement elem;

        foreach (XmlElement node in xmlDoc.FirstChild.FirstChild.ChildNodes)
        {
            elem = resultDoc.CreateElement("options");
            resultDoc.FirstChild.AppendChild(elem);

            elem = resultDoc.CreateElement("option");
            elem.InnerText = node.InnerText;
            resultDoc.FirstChild.LastChild.AppendChild(elem);
        }

Console.WriteLine(resultDoc.InnerXml);

Edit: Instead of creating new XmlDocument, you can use the same document and reorder your elements. I hope this is what you meant.

xmlDoc.LoadXml(xmlStr);

xmlDoc.FirstChild.InnerXml = string.Join("", 
    xmlDoc.SelectNodes("//option")
    .Cast<XmlNode>()
    .Select(n => n.OuterXml));

XmlElement elem;
foreach (XmlElement node in xmlDoc.SelectNodes("//init//option"))
{
    xmlDoc.FirstChild.RemoveChild(node);
    elem = xmlDoc.CreateElement("options");
    elem.AppendChild(node);
    xmlDoc.FirstChild.AppendChild(elem);
}