# -*- coding: utf-8; frozen_string_literal: true -*-
#
#--
# Copyright (C) 2009-2019 Thomas Leitner <t_leitner@gmx.at>
#
# This file is part of kramdown which is licensed under the MIT.
#++
#
require 'kramdown/parser'
require 'kramdown/converter'
require 'kramdown/utils'
module Kramdown
module Converter
# Converts a Kramdown::Document to HTML.
#
# You can customize the HTML converter by sub-classing it and overriding the +convert_NAME+
# methods. Each such method takes the following parameters:
#
# [+el+] The element of type +NAME+ to be converted.
#
# [+indent+] A number representing the current amount of spaces for indent (only used for
# block-level elements).
#
# The return value of such a method has to be a string containing the element +el+ formatted as
# HTML element.
class Html < Base
include ::Kramdown::Utils::Html
include ::Kramdown::Parser::Html::Constants
# The amount of indentation used when nesting HTML tags.
attr_accessor :indent
# Initialize the HTML converter with the given Kramdown document +doc+.
def initialize(root, options)
super
@footnote_counter = @footnote_start = @options[:footnote_nr]
@footnotes = []
@footnotes_by_name = {}
@footnote_location = nil
@toc = []
@toc_code = nil
@indent = 2
@stack = []
end
# The mapping of element type to conversion method.
DISPATCHER = Hash.new {|h, k| h[k] = "convert_#{k}" }
# Dispatch the conversion of the element +el+ to a +convert_TYPE+ method using the +type+ of
# the element.
def convert(el, indent = -@indent)
send(DISPATCHER[el.type], el, indent)
end
# Return the converted content of the children of +el+ as a string. The parameter +indent+ has
# to be the amount of indentation used for the element +el+.
#
# Pushes +el+ onto the @stack before converting the child elements and pops it from the stack
# afterwards.
def inner(el, indent)
result = +''
indent += @indent
@stack.push(el)
el.children.each do |inner_el|
result << send(DISPATCHER[inner_el.type], inner_el, indent)
end
@stack.pop
result
end
def convert_blank(_el, _indent)
"\n"
end
def convert_text(el, _indent)
escape_html(el.value, :text)
end
def convert_p(el, indent)
if el.options[:transparent]
inner(el, indent)
elsif el.children.size == 1 && el.children.first.type == :img &&
el.children.first.options[:ial]&.[](:refs)&.include?('standalone')
convert_standalone_image(el.children.first, indent)
else
format_as_block_html(el.type, el.attr, inner(el, indent), indent)
end
end
# Helper method used by +convert_p+ to convert a paragraph that only contains a single :img
# element.
def convert_standalone_image(el, indent)
attr = el.attr.dup
figure_attr = {}
figure_attr['class'] = attr.delete('class') if attr.key?('class')
figure_attr['id'] = attr.delete('id') if attr.key?('id')
body = "#{' ' * (indent + @indent)}<img#{html_attributes(attr)} />\n" \
"#{' ' * (indent + @indent)}<figcaption>#{attr['alt']}</figcaption>\n"
format_as_indented_block_html("figure", figure_attr, body, indent)
end
def convert_codeblock(el, indent)
attr = el.attr.dup
lang = extract_code_language!(attr)
hl_opts = {}
highlighted_code = highlight_code(el.value, el.options[:lang] || lang, :block, hl_opts)
if highlighted_code
add_syntax_highlighter_to_class_attr(attr, lang || hl_opts[:default_lang])
"#{' ' * indent}<div#{html_attributes(attr)}>#{highlighted_code}#{' ' * indent}</div>\n"
else
result = escape_html(el.value)
result.chomp!
if el.attr['class'].to_s =~ /\bshow-whitespaces\b/
result.gsub!(/(?:(^[ \t]+)|([ \t]+$)|([ \t]+))/) do |m|
suffix = ($1 ? '-l' : ($2 ? '-r' : ''))
m.scan(/./).map do |c|
case c
when "\t" then "<span class=\"ws-tab#{suffix}\">\t</span>"
when " " then "<span class=\"ws-space#{suffix}\">⋅</span>"
end
end.join('')
end
end
code_attr = {}
code_attr['class'] = "language-#{lang}" if lang
"#{' ' * indent}<pre#{html_attributes(attr)}>" \
"<code#{html_attributes(code_attr)}>#{result}\n</code></pre>\n"
end
end
def convert_blockquote(el, indent)
format_as_indented_block_html(el.type, el.attr, inner(el, indent), indent)
end
def convert_header(el, indent)
attr = el.attr.dup
if @options[:auto_ids] && !attr['id']
attr['id'] = generate_id(el.options[:raw_text])
end
@toc << [el.options[:level], attr['id'], el.children] if attr['id'] && in_toc?(el)
level = output_header_level(el.options[:level])
format_as_block_html("h#{level}", attr, inner(el, indent), indent)
end
def convert_hr(el, indent)
"#{' ' * indent}<hr#{html_attributes(el.attr)} />\n"
end
def convert_ul(el, indent)
if !@toc_code && (el.options[:ial][:refs].include?('toc') rescue nil)
@toc_code = [el.type, el.attr, (0..128).to_a.map { rand(36).to_s(36) }.join]
@toc_code.last
elsif !@footnote_location && el.options[:ial] && (el.options[:ial][:refs] || []).include?('footnotes')
@footnote_location = (0..128).to_a.map { rand(36).to_s(36) }.join
else
format_as_indented_block_html(el.type, el.attr, inner(el, indent), indent)
end
end
alias convert_ol convert_ul
def convert_dl(el, indent)
format_as_indented_block_html(el.type, el.attr, inner(el, indent), indent)
end
def convert_li(el, indent)
output = ' ' * indent << "<#{el.type}" << html_attributes(el.attr) << ">"
res = inner(el, indent)
if el.children.empty? || (el.children.first.type == :p && el.children.first.options[:transparent])
output << res << (res =~ /\n\Z/ ? ' ' * indent : '')
else
output << "\n" << res << ' ' * indent
end
output << "</#{el.type}>\n"
end
alias convert_dd convert_li
def convert_dt(el, indent)
attr = el.attr.dup
@stack.last.options[:ial][:refs].each do |ref|
if ref =~ /\Aauto_ids(?:-([\w-]+))?/
attr['id'] = "#{$1}#{basic_generate_id(el.options[:raw_text])}".lstrip
break
end
end if !attr['id'] && @stack.last.options[:ial] && @stack.last.options[:ial][:refs]
format_as_block_html(el.type, attr, inner(el, indent), indent)
end
def convert_html_element(el, indent)
res = inner(el, indent)
if el.options[:category] == :span
"<#{el.value}#{html_attributes(el.attr)}" + \
(res.empty? && HTML_ELEMENTS_WITHOUT_BODY.include?(el.value) ? " />" : ">#{res}</#{el.value}>")
else
output = +''
if @stack.last.type != :html_element || @stack.last.options[:content_model] != :raw
output << ' ' * indent
end
output << "<#{el.value}#{html_attributes(el.attr)}"
if el.options[:is_closed] && el.options[:content_model] == :raw
output << " />"
elsif !res.empty? && el.options[:content_model] != :block
output << ">#{res}</#{el.value}>"
elsif !res.empty?
output << ">\n#{res.chomp}\n" << ' ' * indent << "</#{el.value}>"
elsif HTML_ELEMENTS_WITHOUT_BODY.include?(el.value)
output << " />"
else
output << "></#{el.value}>"
end
output << "\n" if @stack.last.type != :html_element || @stack.last.options[:content_model] != :raw
output
end
end
def convert_xml_comment(el, indent)
if el.options[:category] == :block &&
(@stack.last.type != :html_element || @stack.last.options[:content_model] != :raw)
' ' * indent << el.value << "\n"
else
el.value
end
end
alias convert_xml_pi convert_xml_comment
def convert_table(el, indent)
format_as_indented_block_html(el.type, el.attr, inner(el, indent), indent)
end
alias convert_thead convert_table
alias convert_tbody convert_table
alias convert_tfoot convert_table
alias convert_tr convert_table
ENTITY_NBSP = ::Kramdown::Utils::Entities.entity('nbsp') # :nodoc:
def convert_td(el, indent)
res = inner(el, indent)
type = (@stack[-2].type == :thead ? :th : :td)
attr = el.attr
alignment = @stack[-3].options[:alignment][@stack.last.children.index(el)]
if alignment != :default
attr = el.attr.dup
attr['style'] = (attr.key?('style') ? "#{attr['style']}; " : '') + "text-align: #{alignment}"
end
format_as_block_html(type, attr, res.empty? ? entity_to_str(ENTITY_NBSP) : res, indent)
end
def convert_comment(el, indent)
if el.options[:category] == :block
"#{' ' * indent}<!-- #{el.value} -->\n"
else
"<!-- #{el.value} -->"
end
end
def convert_br(_el, _indent)
"<br />"
end
def convert_a(el, indent)
format_as_span_html(el.type, el.attr, inner(el, indent))
end
def convert_img(el, _indent)
"<img#{html_attributes(el.attr)} />"
end
def convert_codespan(el, _indent)
attr = el.attr.dup
lang = extract_code_language(attr)
hl_opts = {}
result = highlight_code(el.value, lang, :span, hl_opts)
if result
add_syntax_highlighter_to_class_attr(attr, hl_opts[:default_lang])
else
result = escape_html(el.value)
end
format_as_span_html('code', attr, result)
end
def convert_footnote(el, _indent)
repeat = ''
name = @options[:footnote_prefix] + el.options[:name]
if (footnote = @footnotes_by_name[name])
number = footnote[2]
repeat = ":#{footnote[3] += 1}"
else
number = @footnote_counter
@footnote_counter += 1
@footnotes << [name, el.value, number, 0]
@footnotes_by_name[name] = @footnotes.last
end
"<sup id=\"fnref:#{name}#{repeat}\">" \
"<a href=\"#fn:#{name}\" class=\"footnote\">" \
"#{number}</a></sup>"
end
def convert_raw(el, _indent)
if !el.options[:type] || el.options[:type].empty? || el.options[:type].include?('html')
el.value + (el.options[:category] == :block ? "\n" : '')
else
''
end
end
def convert_em(el, indent)
format_as_span_html(el.type, el.attr, inner(el, indent))
end
alias convert_strong convert_em
def convert_entity(el, _indent)
entity_to_str(el.value, el.options[:original])
end
TYPOGRAPHIC_SYMS = {
mdash: [::Kramdown::Utils::Entities.entity('mdash')],
ndash: [::Kramdown::Utils::Entities.entity('ndash')],
hellip: [::Kramdown::Utils::Entities.entity('hellip')],
laquo_space: [::Kramdown::Utils::Entities.entity('laquo'),
::Kramdown::Utils::Entities.entity('nbsp')],
raquo_space: [::Kramdown::Utils::Entities.entity('nbsp'),
::Kramdown::Utils::Entities.entity('raquo')],
laquo: [::Kramdown::Utils::Entities.entity('laquo')],
raquo: [::Kramdown::Utils::Entities.entity('raquo')],
} # :nodoc:
def convert_typographic_sym(el, _indent)
if (result = @options[:typographic_symbols][el.value])
escape_html(result, :text)
else
TYPOGRAPHIC_SYMS[el.value].map {|e| entity_to_str(e) }.join('')
end
end
def convert_smart_quote(el, _indent)
entity_to_str(smart_quote_entity(el))
end
def convert_math(el, indent)
if (result = format_math(el, indent: indent))
result
else
attr = el.attr.dup
attr['class'] = "#{attr['class']} kdmath".lstrip
if el.options[:category] == :block
format_as_block_html('div', attr, "$$\n#{el.value}\n$$", indent)
else
format_as_span_html('span', attr, "$#{el.value}$")
end
end
end
def convert_abbreviation(el, _indent)
title = @root.options[:abbrev_defs][el.value]
attr = @root.options[:abbrev_attr][el.value].dup
attr['title'] = title unless title.empty?
format_as_span_html("abbr", attr, el.value)
end
def convert_root(el, indent)
result = inner(el, indent)
if @footnote_location
result.sub!(/#{@footnote_location}/, footnote_content.gsub(/\\/, "\\\\\\\\"))
else
result << footnote_content
end
if @toc_code
toc_tree = generate_toc_tree(@toc, @toc_code[0], @toc_code[1] || {})
text = if !toc_tree.children.empty?
convert(toc_tree, 0)
else
''
end
result.sub!(/#{@toc_code.last}/, text.gsub(/\\/, "\\\\\\\\"))
end
result
end
# Format the given element as span HTML.
def format_as_span_html(name, attr, body)
"<#{name}#{html_attributes(attr)}>#{body}</#{name}>"
end
# Format the given element as block HTML.
def format_as_block_html(name, attr, body, indent)
"#{' ' * indent}<#{name}#{html_attributes(attr)}>#{body}</#{name}>\n"
end
# Format the given element as block HTML with a newline after the start tag and indentation
# before the end tag.
def format_as_indented_block_html(name, attr, body, indent)
"#{' ' * indent}<#{name}#{html_attributes(attr)}>\n#{body}#{' ' * indent}</#{name}>\n"
end
# Add the syntax highlighter name to the 'class' attribute of the given attribute hash. And
# overwrites or add a "language-LANG" part using the +lang+ parameter if +lang+ is not nil.
def add_syntax_highlighter_to_class_attr(attr, lang = nil)
(attr['class'] = (attr['class'] || '') + " highlighter-#{@options[:syntax_highlighter]}").lstrip!
attr['class'].sub!(/\blanguage-\S+|(^)/) { "language-#{lang}#{$1 ? ' ' : ''}" } if lang
end
# Generate and return an element tree for the table of contents.
def generate_toc_tree(toc, type, attr)
sections = Element.new(type, nil, attr.dup)
sections.attr['id'] ||= 'markdown-toc'
stack = []
toc.each do |level, id, children|
li = Element.new(:li, nil, nil, level: level)
li.children << Element.new(:p, nil, nil, transparent: true)
a = Element.new(:a, nil)
a.attr['href'] = "##{id}"
a.attr['id'] = "#{sections.attr['id']}-#{id}"
a.children.concat(fix_for_toc_entry(Marshal.load(Marshal.dump(children))))
li.children.last.children << a
li.children << Element.new(type)
success = false
until success
if stack.empty?
sections.children << li
stack << li
success = true
elsif stack.last.options[:level] < li.options[:level]
stack.last.children.last.children << li
stack << li
success = true
else
item = stack.pop
item.children.pop if item.children.last.children.empty?
end
end
end
until stack.empty?
item = stack.pop
item.children.pop if item.children.last.children.empty?
end
sections
end
# Fixes the elements for use in a TOC entry.
def fix_for_toc_entry(elements)
remove_footnotes(elements)
unwrap_links(elements)
elements
end
# Remove all link elements by unwrapping them.
def unwrap_links(elements)
elements.map! do |c|
unwrap_links(c.children)
c.type == :a ? c.children : c
end.flatten!
end
# Remove all footnotes from the given elements.
def remove_footnotes(elements)
elements.delete_if do |c|
remove_footnotes(c.children)
c.type == :footnote
end
end
# Obfuscate the +text+ by using HTML entities.
def obfuscate(text)
result = +''
text.each_byte do |b|
result << (b > 128 ? b.chr : sprintf("&#%03d;", b))
end
result.force_encoding(text.encoding)
result
end
FOOTNOTE_BACKLINK_FMT = "%s<a href=\"#fnref:%s\" class=\"reversefootnote\">%s</a>"
# Return a HTML ordered list with the footnote content for the used footnotes.
def footnote_content
ol = Element.new(:ol)
ol.attr['start'] = @footnote_start if @footnote_start != 1
i = 0
backlink_text = escape_html(@options[:footnote_backlink], :text)
while i < @footnotes.length
name, data, _, repeat = *@footnotes[i]
li = Element.new(:li, nil, 'id' => "fn:#{name}")
li.children = Marshal.load(Marshal.dump(data.children))
para = nil
if li.children.last.type == :p || @options[:footnote_backlink_inline]
parent = li
while !parent.children.empty? && ![:p, :header].include?(parent.children.last.type)
parent = parent.children.last
end
para = parent.children.last
insert_space = true
end
unless para
li.children << (para = Element.new(:p))
insert_space = false
end
unless @options[:footnote_backlink].empty?
nbsp = entity_to_str(ENTITY_NBSP)
value = sprintf(FOOTNOTE_BACKLINK_FMT, (insert_space ? nbsp : ''), name, backlink_text)
para.children << Element.new(:raw, value)
(1..repeat).each do |index|
value = sprintf(FOOTNOTE_BACKLINK_FMT, nbsp, "#{name}:#{index}",
"#{backlink_text}<sup>#{index + 1}</sup>")
para.children << Element.new(:raw, value)
end
end
ol.children << Element.new(:raw, convert(li, 4))
i += 1
end
if ol.children.empty?
''
else
format_as_indented_block_html('div', {class: "footnotes"}, convert(ol, 2), 0)
end
end
end
end
end