XPath Result Serializer

A standard XSLT module intended to help with XSLT/XPath debugging in combination with the xsl:message instruction and trace() function.

Provides four main utility XSLT functions:

• print()
• println()
• trace()
• log()

1. The print() and println() functions are for use inside <xsl:message> instructions.
2. The trace() and log() functions are for use inside XPath expressions

Note: The standard fn:serialize() function, using the 'adaptive' output method, provides similar functionality:
fn:serialize($n, map{'method':'adaptive'})
The XSLT functions here enhance output specifically to improve human readability.
Unlike fn:serialize(), the output from these functions is not intended to be parsed.

---

Sample Usage of ext:print()

    <xsl:message expand-text="yes">
      ==== Root element ====
      languages-count:  {node-name() => ext:print(9,'  ')}
      colorNodes:  {ext:print((*,*/@*),9,'  ')}
      
    </xsl:message>
    <xsl:copy>    
      <xsl:message expand-text="yes">
        ==== data====
        context:     {ext:print(.,10,'  ')}
        language:    {ext:print($langItems,10,'  ')}
      </xsl:message>

Screenshot from the xsl:message output shown above in the VS Code terminal using ext:print() and ext:println():

Key Resource Files

• Source XSLT: src/xpath-result-serializer.xsl (import this if you want standard output)
• Source XSLT: src/xpath-result-serializer-color.xsl (import this if you colorized output)
• Sample: sample/test-serializer.xsl

Colorising of xsl:message Output with Saxon

When using src/xpath-result-serializer.xsl, ANSI escape codes will only be included in the outputs to provide colorisation if you're using a Saxon version that supports ANSI escape codes in xsl:message output.

The src/xpath-result-serializer-color.xsl stylesheeet is a thin wrapper that forces colorising using ANSI escape codes regardless of Saxon version.

ANSI escape codes are normally serialized as XML character references by SaxonJ (Java) in the output. In SaxonJ, prior to v9.9.0.2, the command-line option -m:net.sf.saxon.serialize.TEXTEmitter can be used to prevent this XML escaping so xsl:message colors can be seen as intended.

SaxonJ Command-line Wrapper

If you want color output with SaxonJ versions after 9.9.0.1 then you need use the API to add a simple messageListener to ouput text-only. Thin wrappers for the SaxonJ command-line-interface that implement this are maintained on GitHub. There are different branches for Saxon 9.9, 10.0, 11.0 and 12.0.