rails/guides/rails_guides/markdown.rb
2015-09-18 17:05:05 +09:00

166 lines
4.7 KiB
Ruby

require 'redcarpet'
require 'nokogiri'
require 'rails_guides/markdown/renderer'
module RailsGuides
class Markdown
def initialize(view, layout)
@view = view
@layout = layout
@index_counter = Hash.new(0)
@raw_header = ''
@node_ids = {}
end
def render(body)
@raw_body = body
extract_raw_header_and_body
generate_header
generate_title
generate_body
generate_structure
generate_index
render_page
end
private
def dom_id(nodes)
dom_id = dom_id_text(nodes.last.text)
# Fix duplicate node by prefix with its parent node
if @node_ids[dom_id]
if @node_ids[dom_id].size > 1
duplicate_nodes = @node_ids.delete(dom_id)
new_node_id = "#{duplicate_nodes[-2][:id]}-#{duplicate_nodes.last[:id]}"
duplicate_nodes.last[:id] = new_node_id
@node_ids[new_node_id] = duplicate_nodes
end
dom_id = "#{nodes[-2][:id]}-#{dom_id}"
end
@node_ids[dom_id] = nodes
dom_id
end
def dom_id_text(text)
escaped_chars = Regexp.escape('\\/`*_{}[]()#+-.!:,;|&<>^~=\'"')
text.downcase.gsub(/\?/, '-questionmark')
.gsub(/!/, '-bang')
.gsub(/[#{escaped_chars}]+/, ' ').strip
.gsub(/\s+/, '-')
end
def engine
@engine ||= Redcarpet::Markdown.new(Renderer, {
no_intra_emphasis: true,
fenced_code_blocks: true,
autolink: true,
strikethrough: true,
superscript: true,
tables: true
})
end
def extract_raw_header_and_body
if @raw_body =~ /^\-{40,}$/
@raw_header, _, @raw_body = @raw_body.partition(/^\-{40,}$/).map(&:strip)
end
end
def generate_body
@body = engine.render(@raw_body)
end
def generate_header
@header = engine.render(@raw_header).html_safe
end
def generate_structure
@headings_for_index = []
if @body.present?
@body = Nokogiri::HTML.fragment(@body).tap do |doc|
hierarchy = []
doc.children.each do |node|
if node.name =~ /^h[3-6]$/
case node.name
when 'h3'
hierarchy = [node]
@headings_for_index << [1, node, node.inner_html]
when 'h4'
hierarchy = hierarchy[0, 1] + [node]
@headings_for_index << [2, node, node.inner_html]
when 'h5'
hierarchy = hierarchy[0, 2] + [node]
when 'h6'
hierarchy = hierarchy[0, 3] + [node]
end
node[:id] = dom_id(hierarchy)
node.inner_html = "#{node_index(hierarchy)} #{node.inner_html}"
end
end
end.to_html
end
end
def generate_index
if @headings_for_index.present?
raw_index = ''
@headings_for_index.each do |level, node, label|
if level == 1
raw_index += "1. [#{label}](##{node[:id]})\n"
elsif level == 2
raw_index += " * [#{label}](##{node[:id]})\n"
end
end
@index = Nokogiri::HTML.fragment(engine.render(raw_index)).tap do |doc|
doc.at('ol')[:class] = 'chapters'
end.to_html
@index = <<-INDEX.html_safe
<div id="subCol">
<h3 class="chapter"><img src="images/chapters_icon.gif" alt="" />Chapters</h3>
#{@index}
</div>
INDEX
end
end
def generate_title
if heading = Nokogiri::HTML.fragment(@header).at(:h2)
@title = "#{heading.text} — Ruby on Rails Guides"
else
@title = "Ruby on Rails Guides"
end
end
def node_index(hierarchy)
case hierarchy.size
when 1
@index_counter[2] = @index_counter[3] = @index_counter[4] = 0
"#{@index_counter[1] += 1}"
when 2
@index_counter[3] = @index_counter[4] = 0
"#{@index_counter[1]}.#{@index_counter[2] += 1}"
when 3
@index_counter[4] = 0
"#{@index_counter[1]}.#{@index_counter[2]}.#{@index_counter[3] += 1}"
when 4
"#{@index_counter[1]}.#{@index_counter[2]}.#{@index_counter[3]}.#{@index_counter[4] += 1}"
end
end
def render_page
@view.content_for(:header_section) { @header }
@view.content_for(:page_title) { @title }
@view.content_for(:index_section) { @index }
@view.render(:layout => @layout, :text => @body)
end
end
end