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# -*- coding: utf-8; frozen_string_literal: true -*-
#
#--
# Copyright (C) 2019 Thomas Leitner <t_leitner@gmx.at>
#
# This file is part of kramdown-parser-gfm which is licensed under the MIT.
#++
#
require 'kramdown/options'
require 'kramdown/parser/kramdown'
require_relative 'gfm/options'
module Kramdown
module Parser
# This class provides a parser implementation for the GFM dialect of Markdown.
class GFM < Kramdown::Parser::Kramdown
VERSION = '1.1.0'
attr_reader :paragraph_end
def initialize(source, options)
super
@options[:auto_id_stripping] = true
@id_counter = Hash.new(-1)
@span_parsers.delete(:line_break) if @options[:hard_wrap]
@span_parsers.delete(:typographic_syms) if @options[:gfm_quirks].include?(:no_auto_typographic)
if @options[:gfm_quirks].include?(:paragraph_end)
atx_header_parser = :atx_header_gfm_quirk
@paragraph_end = self.class::PARAGRAPH_END_GFM
else
atx_header_parser = :atx_header_gfm
@paragraph_end = self.class::PARAGRAPH_END
end
{codeblock_fenced: :codeblock_fenced_gfm,
atx_header: atx_header_parser}.each do |current, replacement|
i = @block_parsers.index(current)
@block_parsers.delete(current)
@block_parsers.insert(i, replacement)
end
i = @span_parsers.index(:escaped_chars)
@span_parsers[i] = :escaped_chars_gfm if i
@span_parsers << :strikethrough_gfm
@hard_line_break = "#{@options[:hard_wrap] ? '' : '\\'}\n"
end
def parse
super
update_elements(@root)
end
def update_elements(element)
element.children.map! do |child|
if child.type == :text && child.value.include?(@hard_line_break)
update_text_type(element, child)
elsif child.type == :html_element
child
elsif child.type == :header && @options[:auto_ids] && !child.attr.key?('id')
child.attr['id'] = generate_gfm_header_id(child.options[:raw_text])
child
else
update_elements(child)
child
end
end.flatten!
end
# Update the raw text for automatic ID generation.
def update_raw_text(item)
raw_text = +''
append_text = lambda do |child|
case child.type
when :text, :codespan, :math
raw_text << child.value
when :entity
raw_text << child.value.char
when :smart_quote
raw_text << ::Kramdown::Utils::Entities.entity(child.value.to_s).char
when :typographic_sym
raw_text << case child.value
when :laquo_space
"« "
when :raquo_space
" »"
else
::Kramdown::Utils::Entities.entity(child.value.to_s).char
end
else
child.children.each { |c| append_text.call(c) }
end
end
append_text.call(item)
item.options[:raw_text] = raw_text
end
NON_WORD_RE = /[^\p{Word}\- \t]/.freeze
def generate_gfm_header_id(text)
result = text.downcase
result.gsub!(NON_WORD_RE, '')
result.tr!(" \t", '-')
@id_counter[result] += 1
counter_result = @id_counter[result]
result << "-#{counter_result}" if counter_result > 0
@options[:auto_id_prefix] + result
end
ATX_HEADER_START = /^(?<level>\#{1,6})[\t ]+(?<contents>.*)\n/.freeze
define_parser(:atx_header_gfm, ATX_HEADER_START, nil, 'parse_atx_header')
define_parser(:atx_header_gfm_quirk, ATX_HEADER_START)
# Copied from kramdown/parser/kramdown/header.rb, removed the first line
def parse_atx_header_gfm_quirk
text, id = parse_header_contents
text.sub!(/[\t ]#+\z/, '') && text.rstrip!
return false if text.empty?
add_header(@src["level"].length, text, id)
true
end
FENCED_CODEBLOCK_START = /^[ ]{0,3}[~`]{3,}/.freeze
FENCED_CODEBLOCK_MATCH = /^[ ]{0,3}(([~`]){3,})\s*?((\S+?)(?:\?\S*)?)?\s*?\n(.*?)^[ ]{0,3}\1\2*\s*?\n/m.freeze
define_parser(:codeblock_fenced_gfm, FENCED_CODEBLOCK_START, nil, 'parse_codeblock_fenced')
STRIKETHROUGH_DELIM = /~~/.freeze
STRIKETHROUGH_MATCH = /#{STRIKETHROUGH_DELIM}(?!\s|~).*?[^\s~]#{STRIKETHROUGH_DELIM}/m.freeze
define_parser(:strikethrough_gfm, STRIKETHROUGH_MATCH, '~~')
def parse_strikethrough_gfm
line_number = @src.current_line_number
@src.pos += @src.matched_size
el = Element.new(:html_element, 'del', {}, category: :span, line: line_number)
@tree.children << el
env = save_env
reset_env(src: Kramdown::Utils::StringScanner.new(@src.matched[2..-3], line_number),
text_type: :text)
parse_spans(el)
restore_env(env)
el
end
LIST_TYPES = [:ul, :ol].freeze
# To handle task-lists we override the parse method for lists, converting matching text into
# checkbox input elements where necessary (as well as applying classes to the ul/ol and li
# elements).
def parse_list
super
current_list = @tree.children.select { |element| LIST_TYPES.include?(element.type) }.last
is_tasklist = false
box_unchecked = '<input type="checkbox" class="task-list-item-checkbox" disabled="disabled" />'
box_checked = '<input type="checkbox" class="task-list-item-checkbox" ' \
'disabled="disabled" checked="checked" />'
current_list.children.each do |li|
list_items = li.children
next unless !list_items.empty? && list_items[0].type == :p
# li -> p -> raw_text
descendant = list_items[0].children[0].value
checked = descendant.gsub!(/\A\s*\[ \]\s+/, box_unchecked)
unchecked = descendant.gsub!(/\A\s*\[x\]\s+/i, box_checked)
is_tasklist ||= checked || unchecked
li.attr['class'] = 'task-list-item' if is_tasklist
end
current_list.attr['class'] = 'task-list' if is_tasklist
true
end
ESCAPED_CHARS_GFM = /\\([\\.*_+`<>()\[\]{}#!:\|"'\$=\-~])/.freeze
define_parser(:escaped_chars_gfm, ESCAPED_CHARS_GFM, '\\\\', :parse_escaped_chars)
PARAGRAPH_END_GFM = Regexp.union(
LAZY_END, LIST_START, ATX_HEADER_START, DEFINITION_LIST_START,
BLOCKQUOTE_START, FENCED_CODEBLOCK_START
)
private
def update_text_type(element, child)
children = []
lines = child.value.split(@hard_line_break, -1)
omit_trailing_br = (lines[-1].empty? && Kramdown::Element.category(element) == :block &&
element.children[-1] == child)
lines.each_with_index do |line, index|
new_element_options = {location: child.options[:location] + index}
children << Element.new(:text, (index > 0 ? "\n#{line}" : line), nil, new_element_options)
if index < lines.size - 2 || (index == lines.size - 2 && !omit_trailing_br)
children << Element.new(:br, nil, nil, new_element_options)
end
end
children
end
end
end
end
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