Question

I’m trying to understand how schema-element() works when used as a SequenceType with literal result elements. This is my stylesheet

<xsl:stylesheet
  version="2.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  exclude-result-prefixes="xs">

  <xsl:import-schema>
    <xs:schema>
      <xs:element name="foo">
        <xs:complexType>
          <xs:attribute name="bar"/>
        </xs:complexType>
      </xs:element>
    </xs:schema>
  </xsl:import-schema>

  <xsl:variable name="test" as="schema-element(foo)">
    <foo bar="baz"/>
  </xsl:variable>

  <xsl:template match="/">
    <xsl:sequence select="$test"/>
  </xsl:template>

</xsl:stylesheet>

Saxon-EE 9.4.0.4 (in Oxygen 14.1) is giving me the following compilation error Required item type of value of variable $test is schema-element(foo); supplied value has item type element(foo, {http://www.w3.org/2001/XMLSchema}untyped)

According to XSLT 2.0 and XPath 2.0 Programmer’s Reference

When the construct «schema-element(N)» … is used in a SequenceType,
then N must be the name of a global element … declaration in an
imported schema.

elsewhere in the same source

«as=”schema-element(EVENT)”» indicates that [a parameter] must be an element node validated as being
either an EVENT or an element in the substitution group of EVENT.

It seems like <foo bar="baz"/> should validate as a foo element by the imported schema. @xsl:type seems like it would help, but only if I had a named complex type in my imported schema. What am I missing or doing wrong?

Answer 1

Have you tried to use <foo xsl:validation="strict" bar="baz"/>? The error message suggests the result element is created without type annotations so perhaps the validation needs to be requested explicitly, the as attribute might not suffice. But I am not too familiar with schema aware XSLT 2.0 so it is a suggestion for you to try.