<copy-of> XLST tag not being applied consistently in different processors

Question

EDIT:

This is the smallest test case in lxml that I can come up with (written totally in Python)

from lxml import etree

xslt_tree = etree.XML('''\
<?xml version="1.0" encoding="UTF-8"?>
<MD_Metadata xmlns="http://www.isotc211.org/2005/gmd" xmlns:gco="http://www.isotc211.org/2005/gco">
  <language/>
  <characterSet/>
  </MD_Metadata>''')

doc = etree.XML('''\
  <xsl:stylesheet version="1.0"
     xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:gmd="http://www.isotc211.org/2005/gmd" >

<!-- This adds the contact tag if it doesn't exist -->
  <xsl:template match="/gmd:MD_Metadata">
     <xsl:copy-of select="*"/>
     <xsl:message>
     Worked
     </xsl:message>
  </xsl:template>
  </xsl:stylesheet>''')

transform = etree.XSLT(doc)

result = transform(xslt_tree)
print transform.error_log
print (etree.tostring(result,pretty_print=True))

This outputs

<language xmlns="http://www.isotc211.org/2005/gmd" xmlns:gco="http://www.isotc211.org/2005/gco"/>

when surely it should output

<MD_Metadata xmlns="http://www.isotc211.org/2005/gmd" xmlns:gco="http://www.isotc211.org/2005/gco">
  <language/>
  <characterSet/>
  </MD_Metadata>

Any ideas why?

---

OLD QUESTION

I have an xml file like this:

    <?xml version="1.0" encoding="UTF-8"?>
<MD_Metadata xmlns="http://www.isotc211.org/2005/gmd">
  <language>
  <LanguageCode codeList="http://www.loc.gov/standards/iso639-2/php/code_list.php" codeListValue="eng" codeSpace="ISO639-2">eng</LanguageCode>
  </language>
  <characterSet>
   <MD_CharacterSetCode codeList="http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#MD_CharacterSetCode" codeListValue="utf8" codeSpace="ISOTC211/19115">utf8</MD_CharacterSetCode>
  </characterSet>
 .... etc
 </MD_Metadata>

and an xlt file as follows:

 <xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

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

<!-- This adds the contact tag if it doesn't exist -->
  <xsl:template match="/gmd:MD_Metadata">
     <xsl:copy-of select="@*|node()">
          <xsl:if test="not(/gmd:MD_Metadata/gmd:contact)">
      <xsl:element name="contact" namespace="http://www.isotc211.org/2005/gmd">
            </xsl:element>
          </xsl:if>
     </xsl:copy-of>
  </xsl:template>

  </xsl:stylesheet>

When I run it in lxml in Python, I get the MD_Metadata element and the first child, returned. However, when I run this in Eclipse WTP (Eclipse XSL Tools) using either the default Java processor or Xalan, I get all elements returned from the MD_Metadata tag, including characterSet and elements afterwards. For me, the latter was the expected behaviour due to the tag. I can't see anything I am doing in calling the transform in Python, but just in case:

xslt_root = lxml.etree.parse("XSLFile")
transform = lxml.etree.XSLT(xslt_root)
result_tree = transform(doc)
print (etree.tostring(result_tree,pretty_print=True))

Is there a substantial difference between the two processors I am using or is there another explanation?

Answer 1

The reason you are getting odd behaviour is that xsl:copy-of should be an empty element. I can only presume that some engines are "helpfully" trying to interpret the xsl:if in some undefined way that is causing the trouble.

Remove the elements causing the undefined behaviour and it should be consistant across the different engines again.

Answer 2

Ah, it was the XPath.

I think I should have used <xsl:copy-of select="self::*"/>. I thought * selected all the current node as well as its children.

Thanks for help