Change the node names in an XML file using C#

Question

I have a huge bunch of XML files with the following structure:

<Stuff1>
  <Content>someContent</name>
  <type>someType</type>
</Stuff1>
<Stuff2>
  <Content>someContent</name>
  <type>someType</type>
</Stuff2>
<Stuff3>
  <Content>someContent</name>
  <type>someType</type>
</Stuff3>
...
...

I need to change the each of the "Content" node names to StuffxContent; basically prepend the parent node name to the content node's name.

I planned to use the XMLDocument class and figure out a way, but thought I would ask if there were any better ways to do this.

Answer 1

(1.) The [XmlElement / XmlNode].Name property is read-only.

(2.) The XML structure used in the question is crude and could be improved.

(3.) Regardless, here is a code solution to the given question:

String sampleXml =
  "<doc>"+
    "<Stuff1>"+
      "<Content>someContent</Content>"+
      "<type>someType</type>"+
    "</Stuff1>"+
    "<Stuff2>"+
      "<Content>someContent</Content>"+
      "<type>someType</type>"+
    "</Stuff2>"+
    "<Stuff3>"+
      "<Content>someContent</Content>"+
      "<type>someType</type>"+
    "</Stuff3>"+
  "</doc>";

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml(sampleXml);

XmlNodeList stuffNodeList = xmlDoc.SelectNodes("//*[starts-with(name(), 'Stuff')]");

foreach (XmlNode stuffNode in stuffNodeList)
{
    // get existing 'Content' node
    XmlNode contentNode = stuffNode.SelectSingleNode("Content");

    // create new (renamed) Content node
    XmlNode newNode = xmlDoc.CreateElement(contentNode.Name + stuffNode.Name);

    // [if needed] copy existing Content children
    //newNode.InnerXml = stuffNode.InnerXml;

    // replace existing Content node with newly renamed Content node
    stuffNode.InsertBefore(newNode, contentNode);
    stuffNode.RemoveChild(contentNode);
}

//xmlDoc.Save

PS: I came here looking for a nicer way of renaming a node/element; I'm still looking.

Answer 2

I used this method to rename the node:

/// <summary>
/// Rename Node
/// </summary>
/// <param name="parentnode"></param>
/// <param name="oldname"></param>
/// <param name="newname"></param>
private static void RenameNode(XmlNode parentnode, string oldChildName, string newChildName)
{
    var newnode = parentnode.OwnerDocument.CreateNode(XmlNodeType.Element, newChildName, "");
    var oldNode = parentnode.SelectSingleNode(oldChildName);

    foreach (XmlAttribute att in oldNode.Attributes)
        newnode.Attributes.Append(att);
    foreach (XmlNode child in oldNode.ChildNodes)
        newnode.AppendChild(child);

    parentnode.ReplaceChild(newnode, oldNode);
}

Answer 3

The easiest way I found to rename a node is:

xmlNode.InnerXmL = newNode.InnerXml.Replace("OldName>", "NewName>")

Don't include the opening < to ensure that the closing </OldName> tag is renamed as well.

Answer 4

I am not an expert in XML, and in my case I just needed to make all tag names in a HTML file to upper case, for further manipulation in XmlDocument with GetElementsByTagName. The reason I needed upper case was that for XmlDocument the tag names are case sensitive (since it is XML), and I could not guarantee that my HTML-file had consistent case in the tag names.

So I solved it like this: I used XDocument as an intermediate step, where you can rename elements (i.e. the tag name), and then loaded that into a XmlDocument. Here is my VB.NET-code (the C#-coding will be very similar).

Dim x As XDocument = XDocument.Load("myFile.html")
For Each element In x.Descendants()
  element.Name = element.Name.LocalName.ToUpper()
Next
Dim x2 As XmlDocument = New XmlDocument()
x2.LoadXml(x.ToString())

For my purpose it worked fine, though I understand that in certain cases this might not be a solution if you are dealing with a pure XML-file.

Answer 5

I'll answer the higher question: why are you trying this using XmlDocument?

I Think the best way to accomplish what you aim is a simple XSLT file
that match the "CONTENTSTUFF" node and output a "CONTENT" node...

don't see a reason to get such heavy guns...

Either way, If you still wish to do it C# Style,
Use XmlReader + XmlWriter and not XmlDocument for memory and speed purposes. XmlDocument store the entire XML in memory, and makes it very heavy for Traversing once...

XmlDocument is good if you access the element many times (not the situation here).

Answer 6

Perhaps a better solution would be to iterate through each node, and write the information out to a new document. Obviously, this will depend on how you will be using the data in future, but I'd recommend the same reformatting as FlySwat suggested...

<stuff id="1">
    <content/>
</stuff>

I'd also suggest that using the XDocument that was recently added would be the best way to go about creating the new document.

Answer 7

Load it in as a string and do a replace on the whole lot..

    String sampleXml =
  "<doc>"+
    "<Stuff1>"+
      "<Content>someContent</Content>"+
      "<type>someType</type>"+
    "</Stuff1>"+
    "<Stuff2>"+
      "<Content>someContent</Content>"+
      "<type>someType</type>"+
    "</Stuff2>"+
    "<Stuff3>"+
      "<Content>someContent</Content>"+
      "<type>someType</type>"+
    "</Stuff3>"+
  "</doc>"; 

    sampleXml = sampleXml.Replace("Content","StuffxContent")

Answer 8

The XML you have provided shows that someone completely misses the point of XML.

Instead of having

<stuff1>
   <content/>
</stuff1>

You should have:/

<stuff id="1">
    <content/>
</stuff>

Now you would be able to traverse the document using Xpath (ie, //stuff[id='1']/content/) The names of nodes should not be used to establish identity, you use attributes for that.

To do what you asked, load the XML into an xml document, and simply iterate through the first level of child nodes renaming them.

PseudoCode:

foreach (XmlNode n in YourDoc.ChildNodes)
{        
    n.ChildNode[0].Name = n.Name + n.ChildNode[0].Name;
}

YourDoc.Save();

However, I'd strongly recommend you actually fix the XML so that it is useful, instead of wreck it further.