rename node name using xslt and c#

tsbalaji · March 24th, 2013, 01:42 AM

Hi,

I have an array of xml nodes in c# which i pass it to xslt along with newnodename. I need to rename all the oldnodename with newnodename.

Code:

 XmlReader oXmlReader = XmlReader.Create(new StringReader(xmlDoc.InnerXml.ToString()));
XPathDocument oXmlDoc = new XPathDocument(oXmlReader);
XPathNavigator oXmlNav = oXmlDoc.CreateNavigator();

XsltArgumentList argsList = new XsltArgumentList();
argsList.AddParam("newnodename", "", newName);
argsList.AddParam("oldnodename", "", oldNodeName);

XslCompiledTransform transform = new XslCompiledTransform(true);
transform.Load(Server.MapPath("~/App_Data/NodeRename.xslt"));

string outputpath = @"C:\test\output.xml";
using (StreamWriter sw1 = new StreamWriter(outputpath))
{
    transform.Transform(oXmlNav, argsList, sw1);
}

my xslt is something like this

Code:

 
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:msxsl="urn:schemas-microsoft-com:xslt" exclude-result-prefixes="msxsl">
<xsl:output method="xml" indent="yes"/>
  <xsl:param name="newnodename"/>
  <xsl:param name="oldnodename"/>
    <!-- identity transform -->
    <xsl:template match="@* | node()">
      <xsl:copy>
        <xsl:apply-templates select="@* | node()"/>
      </xsl:copy>
    </xsl:template>

    <!-- rename all nodes called oldnodename -->
    <xsl:template match="/">
      <xsl:choose>
        <xsl:when test="local-name()=@oldnodename">
          <xsl:element
               name="{@newnodename}">
            <xsl:apply-templates select="@*|node()"/>
          </xsl:element>
        </xsl:when>
        <xsl:otherwise>
          <xsl:element name="{name()}">
            <xsl:apply-templates select="@*|node()"/>
          </xsl:element>
        </xsl:otherwise>
      </xsl:choose>

    </xsl:template>
</xsl:stylesheet>

How do i loop xslt to rename all the oldnodenames?
Thank you,
balaji

mhkay · March 24th, 2013, 05:41 AM

You've started on the right lines by defining an identity template rule that copies nodes unchanged by default. Then you just need to add a rule for nodes that match oldname. In XSLT 2.0 you can write:

Code:

<xsl:template match="*[local-name()=$oldname]>
  <xsl:element name="$newname">
    <xsl:apply-templates select="@* | node()"/>
  </xsl:element>
</xsl:template>

Unfortunately Microsoft's XSLT processor doesn't support XSLT 2.0, and XSLT 1.0 doesn't allow variable references in match patterns. As Microsoft's XML technology is now years behind the latest standards you would be better off moving to third-party tools - both Saxon and XmlPrime support the 2.0 standard on .NET. But if you don't want to do that a workaround would be to define a key:

Code:

<xsl:key name="k" match="*[local-name()=$oldname]" use="1"/>

and then use the key in the match pattern:

Code:

<xsl:template match="key('k', 1)">

tsbalaji · March 29th, 2013, 04:49 AM

Quote:

Originally Posted by mhkay

You've started on the right lines by defining an identity template rule that copies nodes unchanged by default. Then you just need to add a rule for nodes that match oldname. In XSLT 2.0 you can write:

Code:

<xsl:template match="*[local-name()=$oldname]>
  <xsl:element name="$newname">
    <xsl:apply-templates select="@* | node()"/>
  </xsl:element>
</xsl:template>

Unfortunately Microsoft's XSLT processor doesn't support XSLT 2.0, and XSLT 1.0 doesn't allow variable references in match patterns. As Microsoft's XML technology is now years behind the latest standards you would be better off moving to third-party tools - both Saxon and XmlPrime support the 2.0 standard on .NET. But if you don't want to do that a workaround would be to define a key:

Code:

<xsl:key name="k" match="*[local-name()=$oldname]" use="1"/>

and then use the key in the match pattern:

Code:

<xsl:template match="key('k', 1)">

Thank you very much for the reply.As this method is consuming more time to process and my requirement is to rename all the node name which has _ in them to new name. Since passing a whole bunch of new name and old name is there any way i can strip the char right of _ present in a node name and leave the left side of the name as the new node name? e.g. abc_2013 to be renamed as abc. Can i ask a follow up question or need to post it separatly? Thank you once again.

mhkay · March 29th, 2013, 04:58 AM

Try xsl:element name="{substring-before(local-name(), '_'))"

But it won't be any faster!

I can't see any reason why there should be a performance problem for this kind of transformation - it should run at parsing speed.