Parsing XSLT 2.0 and 3.0 files

[frantisekrokusek]

What problem are you trying to solve?
We are trying to validate .xml files with 2.0 XSLT schemas.
Here are the schemas in question.
https://github.com/ConnectingEurope/eInvoicing-EN16931/blob/master/cii/xslt/EN16931-CII-validation.xslt

From what I understand is that nokogiri is compiled with libxml2 and libxslt that can only handle version 1 XSLTs ?

Is there a possibility to be able to parse also 2.0 and 3.0 versions ?

Please show your code!

Here is the code to reproduce.

#! /usr/bin/env ruby

require 'nokogiri'

Nokogiri::XSLT.parse(File.read("/Users/frantisekrokusek/Downloads/EN16931-CII-validation.xslt"))
# fails with error
# RuntimeError: compilation error: element stylesheet
# xsl:version: only 1.1 features are supported
# and more lines

Environment

# Nokogiri (1.16.7)
    ---
    warnings: []
    nokogiri:
      version: 1.16.7
      cppflags:
      - "-I/Users/frantisekrokusek/.asdf/installs/ruby/3.3.4/lib/ruby/gems/3.3.0/gems/nokogiri-1.16.7-arm64-darwin/ext/nokogiri"
      - "-I/Users/frantisekrokusek/.asdf/installs/ruby/3.3.4/lib/ruby/gems/3.3.0/gems/nokogiri-1.16.7-arm64-darwin/ext/nokogiri/include"
      - "-I/Users/frantisekrokusek/.asdf/installs/ruby/3.3.4/lib/ruby/gems/3.3.0/gems/nokogiri-1.16.7-arm64-darwin/ext/nokogiri/include/libxml2"
      ldflags: []
    ruby:
      version: 3.3.4
      platform: arm64-darwin23
      gem_platform: arm64-darwin-23
      description: ruby 3.3.4 (2024-07-09 revision be1089c8ec) [arm64-darwin23]
      engine: ruby
    libxml:
      source: packaged
      precompiled: true
      patches:
      - 0001-Remove-script-macro-support.patch
      - 0002-Update-entities-to-remove-handling-of-ssi.patch
      - 0003-libxml2.la-is-in-top_builddir.patch
      - '0009-allow-wildcard-namespaces.patch'
      - 0010-update-config.guess-and-config.sub-for-libxml2.patch
      - 0011-rip-out-libxml2-s-libc_single_threaded-support.patch
      memory_management: ruby
      iconv_enabled: true
      compiled: 2.12.9
      loaded: 2.12.9
    libxslt:
      source: packaged
      precompiled: true
      patches:
      - 0001-update-config.guess-and-config.sub-for-libxslt.patch
      datetime_enabled: true
      compiled: 1.1.39
      loaded: 1.1.39
    other_libraries:
      zlib: 1.3.1
      libiconv: '1.17'
      libgumbo: 1.0.0-nokogiri

Thank you very much for your help 🙏

[flavorjones]

Thanks for asking about this. Nokogiri currently relies on libxml2, libxslt, and libexslt for XSLT functionality. These libraries do not currently support anything beyond XSLT 1.1.

I'm not necessarily an expert in libxslt, but my understanding is that the XSLT 2.0 spec was partly based on XPath 2.0, so adding XPath 2.0 support to libxml2 is probably a prerequisite for adding XSLT 2.0 support to libxslt.

The last time I remember the upstream maintainers talking about XPath 2.0 was in this thread from 2007:

https://www.mail-archive.com/xml@gnome.org/msg04082.html

If this is something you'd like to see, it would be valuable to open an issue upstream and ask the question. There's a new maintainer of libxml2/libxslt since ~2020 (Nick Wellnhof) who's been very responsive and has been willing to make significant changes and improvements to the codebase.

[frantisekrokusek]

Thanks a lot @flavorjones 🙏
Helps a lot, will have a look this way and will keep you posted 😉

[frantisekrokusek]

Issue created on GNOME side https://gitlab.gnome.org/GNOME/libxml2/-/issues/814