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how do you rename an xml nodfe in .c# 2005

how do you rename an xml node in .c# 2005?
kind regards
Peter

I want
<ReturnData>
    <SomeNode></SomeNode
</ReturnData>

to be...

<PassedInData>
    <SomeNode></SomeNode
</PassedInData>
0
peter3244
Asked:
peter3244
  • 4
  • 2
1 Solution
 
tetorvikCommented:
You could try something like in the snippet below:
            XmlDocument doc = new XmlDocument();
            //TODO: load your document here
 
            string newName = "newName";
            XmlElement newElement = doc.CreateElement(newName); //create new element
            XmlElement oldElement = null; // TODO:!! get reference to the element replaced here.
 
            while (oldElement.HasAttributes) //copy attributes
                newElement.SetAttributeNode(oldElement.RemoveAttributeNode(oldElement.Attributes[0]));
 
            while (oldElement.HasChildNodes) //copy child nodes
                newElement.AppendChild(oldElement.FirstChild);
 
            if (oldElement.ParentNode != null) //replace node
                oldElement.ParentNode.ReplaceChild(newElement, oldElement);

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peter3244Author Commented:
Hi, i Have this solution under another post which seems easier. It you use a n XSLT file and do a transform. Although I'll kepp you posted on whether it works! I'll keep you posted


<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
	<!-- identity transform -->
	<xsl:template match="@* | node()">
		<xsl:copy>
			<xsl:apply-templates select="@* | node()"/>
		</xsl:copy>
	</xsl:template>
	<!-- rename all nodes called OldName -->
	<xsl:template match="ReturnData">
		<PassedInData>
			<xsl:apply-templates/>
		</PassedInData>
	</xsl:template>
</xsl:stylesheet>

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abelCommented:
The most obvious way of transforming from one XML format to another. However, when it is really only one element that needs renaming, it isn't that much work using C#. Here's how I would do it with an XmlTextReader. The good news is: you do not have to load the DOM (which is slow, but insignificant if your documents are < 1MB).
 
 You already have a working solution above, here's my solution with XmlTextReader/Writer, which is faster then either XSLT or DOM, and doesn't consume any significant memory. Note that extension method, I needed that because the most obvious of all generic WriteXXX methods is not available, so I rolled my own:

// the method for reading / writing, note that the while-loop is all you need:
private void Q24416860_Click(object sender, EventArgs e)
{
    // create your xmlReader. You can use a file on disk, of course
    XmlTextReader xmlReader = new XmlTextReader(new StringReader(
            @"<ReturnData>
                <SomeNode></SomeNode>
            </ReturnData>"));
 
    // replace the .Create() with a filename in the argument to save it to disk
    StringBuilder xmlSB = new StringBuilder();
    XmlTextWriter xmlWriter = new XmlTextWriter(new StringWriter(xmlSB));
 
    while (xmlReader.Read())
    {
        if (xmlReader.NodeType == XmlNodeType.Element && xmlReader.Name == "ReturnData")
            xmlWriter.WriteStartElement("PassedInData");
        else
            xmlWriter.WriteCurrent(xmlReader);
        
    }
    xmlWriter.Flush();
    Debug.WriteLine(xmlSB.ToString());
}

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abelCommented:
Aha, I see you found out about XSLT yourself as well! Good, I love XSLT ;-)

There's a small error in your code, which with your current sample wouldn't matter, but if you would have attribute nodes (or processing instructions, or comments) on that very same element you wanted to rename you would be in trouble, they would get lost. It is a tiny difference, here you go:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
   <!-- identity transform -->
   <xsl:template match="@* | node()">
       <xsl:copy>
           <xsl:apply-templates select="@* | node()"/>
       </xsl:copy>
   </xsl:template>
 
   <!-- rename all nodes called OldName -->
   <xsl:template match="ReturnData">
       <PassedInData>
           <xsl:apply-templates select="@* | node()" />
       </PassedInData>
   </xsl:template>
</xsl:stylesheet>

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abelCommented:
And, in my enthusiasm to help you with the XSLT part, I totally forget to add the extension method. Here you are, just place it somewhere and make sure you "using" it on top of your class if you put it in a separate class (the code is not complete, but it serves 99% of all cases well):


public static class XmlWriterExtensions
{
    /// <summary>
    /// Writes the current information only (not the contents of the node,
    /// use WriteNode for that).
    /// </summary>
    /// <param name="writer">any XmlWriter</param>
    /// <param name="reader">the reader in Read state (Interactive ReadState)</param>
    public static void WriteCurrent(this XmlWriter writer, XmlReader reader)
    {
        switch (reader.NodeType)
        {
            case XmlNodeType.EndElement:
                writer.WriteEndElement();
                break;
            case XmlNodeType.Element:
                writer.WriteStartElement(reader.Name, reader.NamespaceURI);
                break;
            case XmlNodeType.Comment:
                writer.WriteComment(reader.Value);
                break;
            case XmlNodeType.CDATA:
                writer.WriteCData(reader.Value);
                break;
            case XmlNodeType.Attribute:
                writer.WriteAttributeString(reader.Name, reader.NamespaceURI, reader.Value);
                break;
            case XmlNodeType.Document:
                writer.WriteStartDocument();
                break;
            case XmlNodeType.Text:
                writer.WriteString(reader.Value);
                break;
            case XmlNodeType.Whitespace:
                writer.WriteWhitespace(reader.Value);
                break;
            default:
                break;
        }
    }
}

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peter3244Author Commented:
Many thanks, as I have put the code in a utilities class this will help in the future.
0
 
abelCommented:
> Many thanks, as I have put the code in a utilities class this will help in the future.
good to hear that and glad it all works now :)
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