Saxon Prematurely Evalutes xsl:attribute-set

Question

This relates to schema-aware validation of inputs into an XSLT transformation using latest Saxon EE 9.8.

My XSLT file contains the following.

A namespace and associated schema defined as such:

<xsl:import-schema namespace="http://www.fpml.org/2005/FpML-4-2" schema-location="/path/to/some_swbml.xsd"/>

A result document conforming to the above schema:

<xsl:result-document method="xml" href="{$file}" format="swbml-format" validation="strict">
    <SWBML xmlns="http://www.fpml.org/2005/FpML-4-2" xsl:use-attribute-sets="ir">
        GENERATE SOME MORE XML TO BE VALIDATED BY THE XSD
    </SWBML>
 </xsl:result-document>

You will note that the parent tag in the result document <SWBML> uses an attrribute set xsl:use-attribute-sets="ir".

The attribute set is defined as per below:

<xsl:stylesheet version="3.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <xsl:attribute-set name="ir">
        <xsl:attribute name="version">4-2</xsl:attribute>
    </xsl:attribute-set>
</xsl:stylesheet>

This is a toy-example, the boilerplate isn't justified above!

This works fine when I use it with:

 java net.sf.saxon.Transform -sa -ext:on -it -o:output.xml -xsl:example.xslt

This is expected because "-sa" will only check the outputed XML document, as I understand it.

This doesn't work:

java net.sf.saxon.Transform -val:lax -ext:on -it -o:output.xml -xsl:example.xslt

Giving:

FORG0001: Attribute @xsl:use-attribute-sets is not allowed on element <SWBML>

My question is - shouldn't the validator process the attribute sets before trying validate the <SWBML>? It looks to me like it's complaining that an XSLT instruction is not permitted in the output XML document, which is of course true, but it seems to be checking prematurely.

The resulting XML is valid:

<SWBML xmlns="http://www.fpml.org/2005/FpML-4-2" version="4_2">

As demonstrated by transforming with the "-sa" option.

I'm not sure if this is a limitation of XSLT, or a bug in Saxon processing? It feels like I should be able to do this to me!

Any ideas?

score 4 · Accepted Answer · answered May 23 '18 at 17:38

4

I haven't been able to reproduce this.

I ran this stylesheet:

<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  exclude-result-prefixes="#all"
  version="3.0">

  <xsl:import-schema namespace="http://www.fpml.org/2005/FpML-4-2">
    <xs:schema targetNamespace="http://www.fpml.org/2005/FpML-4-2">
      <xs:element name="SWBML">
        <xs:complexType>
          <xs:simpleContent>
            <xs:extension base="xs:string">
              <xs:attribute name="version" type="xs:decimal"/>
            </xs:extension>
          </xs:simpleContent>
        </xs:complexType>
      </xs:element>
    </xs:schema>
  </xsl:import-schema>

  <xsl:template name="xsl:initial-template">
    <xsl:result-document method="xml" validation="strict">
      <SWBML xmlns="http://www.fpml.org/2005/FpML-4-2" xsl:use-attribute-sets="ir">
        GENERATE SOME MORE XML TO BE VALIDATED BY THE XSD
      </SWBML>
    </xsl:result-document>
  </xsl:template> 

    <xsl:attribute-set name="ir">
      <xsl:attribute name="version">4.2</xsl:attribute>
    </xsl:attribute-set>


</xsl:transform>

using the command line options:

-xsl:test.xsl -sa -val:lax -it -t

and it ran fine.

It looks to me as if for some reason you are validating the stylesheet itself. Perhaps the stylesheet uses the construct document("") to read its own source code, in which case lax validation will kick in and cause this failure. If that's not the explanation, please provide more detail of exactly what you are doing.

answered May 23 '18 at 17:38

Michael Kay

156,231
11
92
164

1

Thanks vm for the clue - buried elsewhere in the XSLT was a self look-up of the SWBML namespace ``. – Phil May 23 '18 at 21:39
Just for clarification is there any way around this short of removing the `document('')`? It looks to me that by design the answer is "no", but was wondering if there is a way of saying "do not validate" for a given document? – Phil May 24 '18 at 14:49
1

You can use the saxon:doc() function which has a second argument that can be used to set validation (and other) options. But is document('') good practice anyway, it really shouldn't be necessary with XSLT 3.0, and it means the stylesheet can only be executed if the source code is available which limits deployment options. – Michael Kay May 24 '18 at 15:18
To change I replaced document with `` then set the SWBML namespace off that. I replace `` with ``.... this breaks - `Static error at swbBrokerTradeId on line` and then `XTTE1510: Element swbHeader is not permitted in the content model of the complex type Q{http://www.fpml.org/2005/FpML-4-2}SWBML`. swbHeader is a child of SWBML, and swbBrokerTradeId a child of swbHeader . – Phil May 24 '18 at 15:28
If I replace `` with `` it works fine. I'm obviously missing a trick here! – Phil May 24 '18 at 15:55
1

Sorry, I think this is a supplementary question. Packing supplementary questions into comments isn't good practice; comments are too restricted to present the information clearly. Raise a new question. – Michael Kay May 24 '18 at 15:58

Saxon Prematurely Evalutes xsl:attribute-set

1 Answers1

Linked