Adding element at different levels of hierarchy

ilyaz · February 16th, 2011, 04:11 PM

I need to transform a bunch of XMLs that have the following structure: each has an element called "container" of type "Box" which has a sub-element "container" of type "Folder" and it has another sub-element of type "Document". Each container has some properties, so a typical XML looks like this:

Code:

<?xml version="1.0" encoding="UTF-8"?>
<data>
<container type="Box" >
	<property name="BoxPrName1">BoxPrName1val</property>
	<property name="BoxPrName2">BoxPrName2val</property>
	<container type="Folder">
		<property name="FoldPrName1">FoldPrName1val</property>
		<property name="FoldPrName2">FoldPrName2val</property>
		<container type="Document">
			<property name="DocPrName1">DocPrName1val</property>
			<property name="DocPrName2">DocPrName2val</property>
		</container>
	</container>
</container>
</data>

In this example there is only one child for each parent but I can also have multiple folders in one box and multiple docs in one folder.

All I need is to add to each container a property called GUID. I know how to generate the GUID itself using a script, but I am having trouble modifying all the containers. Instead, I only modify the top one. So the result has to look like this:

Code:

<?xml version="1.0" encoding="UTF-8"?>
<data>
<container type="Box" >
	<property name="GUID">GUIDval1</property>
	<property name="BoxPrName1">BoxPrName1val</property>
	<property name="BoxPrName2">BoxPrName2val</property>
	<container type="Folder">
		<property name="GUID">GUIDval2</property>
		<property name="FoldPrName1">FoldPrName1val</property>
		<property name="FoldPrName2">FoldPrName2val</property>
		<container type="Document">
			<property name="GUID">GUIDval3</property>
			<property name="DocPrName1">DocPrName1val</property>
			<property name="DocPrName2">DocPrName2val</property>
		</container>
	</container>
</container>
</data>

I use the following stylesheet:

Code:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:msxsl="urn:schemas-microsoft-com:xslt"
  xmlns:user="urn:my-scripts">
  <msxsl:script language="C#" implements-prefix="user">
  <![CDATA[
  public string GetGUID(){
    return System.Guid.NewGuid().ToString();
  }
  ]]>
  </msxsl:script>
  <xsl:template match="data">
    <data>
      <xsl:for-each select="container">
        <container>
          <xsl:copy-of select="node()"/>
          <property name="GUID">
            <xsl:value-of select="user:GetGUID()"/>
          </property>
        </container>
      </xsl:for-each>
    </data>
  </xsl:template>
</xsl:stylesheet>

which only adds a GUID to the top Box, but ignores Folders and Documents. How do I have to modify it to get what I need? Thanks!

samjudson · February 17th, 2011, 06:57 AM

You best bet is rather than using xsl:for-each to write templates instead.

Start with the identity template:

Code:

<xsl:template match="@*|node()">
	<xsl:copy>
		<xsl:apply-templates select="@*|node()"/>
	</xsl:copy>
</xsl:template>

Then write another template to handle <container> elements:

Code:

<xsl:template match="container">
    <xsl:copy>
        <xsl:apply-templates select="@*"/>
        <property name="GUID"><xsl:value-of select="user:GetGUID()"/></property>
        <xsl:apply-templates/>
    </xsl:copy>
</xsl:template>

ilyaz · February 22nd, 2011, 05:03 PM

Sam, thanks, it mostly worked. Here's what my s/s looks like now:

Code:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:msxsl="urn:schemas-microsoft-com:xslt"
  xmlns:user="urn:my-scripts">
  <msxsl:script language="C#" implements-prefix="user">
  <![CDATA[
  public string GetGUID(){
    return System.Guid.NewGuid().ToString();
  }
  ]]>
  </msxsl:script>

  <xsl:template match="@*|node()">
	<xsl:copy>
		<xsl:apply-templates select="@*|node()"/>
	</xsl:copy>
</xsl:template>

<xsl:template match="container">
    <xsl:copy>
        <xsl:apply-templates select="@*"/>
        <property name="GUID"><xsl:value-of select="user:GetGUID()"/></property>
        <xsl:apply-templates/>
    </xsl:copy>
</xsl:template>

</xsl:stylesheet>

The resulting XML has all the pieces, but the GUID property has extra stuff in it that I do not need:

Code:

<data>
  <container type="Box">
    <property name="GUID" xmlns:msxsl="urn:schemas-microsoft-com:xslt" xmlns:user="urn:my-scripts">1a07c598-36d0-432e-a63b-607867ae720e</property>
...

How can the

Code:

xmlns:msxsl="urn:schemas...

be removed?

thanks much

samjudson · February 22nd, 2011, 05:10 PM

You'll want the exclude-prefixes attribute on the xsl:stylesheet element.