module Kramdown::Converter::SyntaxHighlighter::Rouge

Uses Rouge which is CSS-compatible to Pygments to highlight code blocks and code spans.

Constants

AVAILABLE

Highlighting via Rouge is available if this constant is true.

Public Class Methods

call(converter, text, lang, type, call_opts) click to toggle source
   # File lib/kramdown/converter/syntax_highlighter/rouge.rb
23 def self.call(converter, text, lang, type, call_opts)
24   opts = options(converter, type)
25   call_opts[:default_lang] = opts[:default_lang]
26   return nil unless lang || opts[:default_lang] || opts[:guess_lang]
27 
28   lexer = ::Rouge::Lexer.find_fancy(lang || opts[:default_lang], text)
29   return nil if opts[:disable] || !lexer || (lexer.tag == "plaintext" && !opts[:guess_lang])
30 
31   opts[:css_class] ||= 'highlight' # For backward compatibility when using Rouge 2.0
32   formatter = formatter_class(opts).new(opts)
33   formatter.format(lexer.lex(text))
34 end
formatter_class(opts = {}) click to toggle source
   # File lib/kramdown/converter/syntax_highlighter/rouge.rb
67 def self.formatter_class(opts = {})
68   case formatter = opts[:formatter]
69   when Class
70     formatter
71   when /\A[[:upper:]][[:alnum:]_]*\z/
72     ::Rouge::Formatters.const_get(formatter, false)
73   else
74     # Available in Rouge 2.0 or later
75     ::Rouge::Formatters::HTMLLegacy
76   end
77 rescue NameError
78   # Fallback to Rouge 1.x
79   ::Rouge::Formatters::HTML
80 end
normalize_keys(hash) click to toggle source
   # File lib/kramdown/converter/syntax_highlighter/rouge.rb
59 def self.normalize_keys(hash)
60   return if hash.empty?
61 
62   hash.keys.each do |k|
63     hash[k.kind_of?(String) ? Kramdown::Options.str_to_sym(k) : k] = hash.delete(k)
64   end
65 end
options(converter, type) click to toggle source
   # File lib/kramdown/converter/syntax_highlighter/rouge.rb
36 def self.options(converter, type)
37   prepare_options(converter)
38   converter.data[:syntax_highlighter_rouge][type]
39 end
prepare_options(converter) click to toggle source
   # File lib/kramdown/converter/syntax_highlighter/rouge.rb
41 def self.prepare_options(converter)
42   return if converter.data.key?(:syntax_highlighter_rouge)
43 
44   cache = converter.data[:syntax_highlighter_rouge] = {}
45 
46   opts = converter.options[:syntax_highlighter_opts].dup
47 
48   span_opts = opts.delete(:span)&.dup || {}
49   block_opts = opts.delete(:block)&.dup || {}
50   normalize_keys(span_opts)
51   normalize_keys(block_opts)
52 
53   cache[:span] = opts.merge(span_opts)
54   cache[:span][:wrap] = false
55 
56   cache[:block] = opts.merge(block_opts)
57 end