xslt to add an attribute

I need to add a namespace, and to add an attribute to certain nodes. With this input:

<root>
  <Node1>test</Node1>
  <DateTo />
</root>

I want this output:

<my:root xmlns:my="http://schemas.microsoft.com/office/infopath/2003/myXSD/2010-07-28T07:33:11">
  <my:Node1>test</my:Node1>
  <my:DateTo xsi:nil="true"/>
</my:root>

The DateTo node needs to have this attribute set.

I successfully added the namespace with this transform, but cannot get the attribute added.

<xsl:stylesheet xmlns:xsl='http://www.w3.org/1999/XSL/Transform' version='1.0'>
    <xsl:template match='*'>
        <xsl:element name='my:{local-name()}' namespace='http://schemas.microsoft.com/office/infopath/2003/myXSD/2010-07-28T07:33:11' >
            <xsl:apply-templates /&g开发者_开发百科t;
        </xsl:element>
    </xsl:template>
</xsl:stylesheet>"

I get this error "Attribute and namespace nodes cannot be added to the parent element after a text, comment, pi, or sub-element node has already been added." Be grateful for any help here.

You can try the following to insert the additional attribute:

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet xmlns:xsl='http://www.w3.org/1999/XSL/Transform'
                xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
                version='1.0'>
  <xsl:template match='*'>
    <xsl:element name='my:{local-name()}'
                 xmlns:my='http://schemas.microsoft.com/office/infopath/2003/myXSD/2010-07-28T07:33:11'>
      <xsl:if test="not(*) and not(normalize-space())">
        <xsl:attribute name="xsi:nil">
          <xsl:value-of select="true()"/>
        </xsl:attribute>
      </xsl:if>
      <xsl:apply-templates />
    </xsl:element>
  </xsl:template>
</xsl:stylesheet>