Preprocessor that extract AsciiDoc (Asciidoctor) metadata

nanoc-asciidoctor-preprocessor.rb

preprocess do
  @items.each do |item|
    case item[:extension]
    when 'adoc', 'asciidoc'
      Asciidoctor::Document.new(item.raw_content).attributes.each_pair do |k,v|
        item[k.to_sym] = v
      end
    end
  end
end

# Now you can access e.g. @item[:author] and @item[:revdate]! :D