# -*- coding: utf-8; frozen_string_literal: true -*- # #-- # Copyright (C) 2009-2019 Thomas Leitner # # This file is part of kramdown which is licensed under the MIT. #++ # module Kramdown::Converter::SyntaxHighlighter # Uses Rouge which is CSS-compatible to Pygments to highlight code blocks and code spans. module Rouge begin require 'rouge' # Highlighting via Rouge is available if this constant is +true+. AVAILABLE = true rescue LoadError, SyntaxError AVAILABLE = false # :nodoc: end def self.call(converter, text, lang, type, call_opts) opts = options(converter, type) call_opts[:default_lang] = opts[:default_lang] return nil unless lang || opts[:default_lang] || opts[:guess_lang] lexer = ::Rouge::Lexer.find_fancy(lang || opts[:default_lang], text) return nil if opts[:disable] || !lexer || lexer.tag == "plaintext" opts[:css_class] ||= 'highlight' # For backward compatibility when using Rouge 2.0 formatter = formatter_class(opts).new(opts) formatter.format(lexer.lex(text)) end def self.options(converter, type) prepare_options(converter) converter.data[:syntax_highlighter_rouge][type] end def self.prepare_options(converter) return if converter.data.key?(:syntax_highlighter_rouge) cache = converter.data[:syntax_highlighter_rouge] = {} opts = converter.options[:syntax_highlighter_opts].dup span_opts = (opts.delete(:span) || {}).dup block_opts = (opts.delete(:block) || {}).dup [span_opts, block_opts].each do |hash| hash.keys.each do |k| hash[k.kind_of?(String) ? Kramdown::Options.str_to_sym(k) : k] = hash.delete(k) end end cache[:span] = opts.merge(span_opts).update(wrap: false) cache[:block] = opts.merge(block_opts) end def self.formatter_class(opts = {}) case formatter = opts[:formatter] when Class formatter when /\A[[:upper:]][[:alnum:]_]*\z/ ::Rouge::Formatters.const_get(formatter) else # Available in Rouge 2.0 or later ::Rouge::Formatters::HTMLLegacy end rescue NameError # Fallback to Rouge 1.x ::Rouge::Formatters::HTML end end end