mirror of https://github.com/mastodon/mastodon
70 lines
1.5 KiB
Ruby
70 lines
1.5 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
class TOCGenerator
|
|
TARGET_ELEMENTS = %w(h1 h2 h3 h4 h5 h6).freeze
|
|
LISTED_ELEMENTS = %w(h2 h3).freeze
|
|
|
|
class Section
|
|
attr_accessor :depth, :title, :children, :anchor
|
|
|
|
def initialize(depth, title, anchor)
|
|
@depth = depth
|
|
@title = title
|
|
@children = []
|
|
@anchor = anchor
|
|
end
|
|
|
|
delegate :<<, to: :children
|
|
end
|
|
|
|
def initialize(source_html)
|
|
@source_html = source_html
|
|
@processed = false
|
|
@target_html = ''
|
|
@headers = []
|
|
@slugs = Hash.new { |h, k| h[k] = 0 }
|
|
end
|
|
|
|
def html
|
|
parse_and_transform unless @processed
|
|
@target_html
|
|
end
|
|
|
|
def toc
|
|
parse_and_transform unless @processed
|
|
@headers
|
|
end
|
|
|
|
private
|
|
|
|
def parse_and_transform
|
|
return if @source_html.blank?
|
|
|
|
parsed_html = Nokogiri::HTML.fragment(@source_html)
|
|
|
|
parsed_html.traverse do |node|
|
|
next unless TARGET_ELEMENTS.include?(node.name)
|
|
|
|
anchor = node['id'] || node.text.parameterize.presence || 'sec'
|
|
@slugs[anchor] += 1
|
|
anchor = "#{anchor}-#{@slugs[anchor]}" if @slugs[anchor] > 1
|
|
|
|
node['id'] = anchor
|
|
|
|
next unless LISTED_ELEMENTS.include?(node.name)
|
|
|
|
depth = node.name[1..-1]
|
|
latest_section = @headers.last
|
|
|
|
if latest_section.nil? || latest_section.depth >= depth
|
|
@headers << Section.new(depth, node.text, anchor)
|
|
else
|
|
latest_section << Section.new(depth, node.text, anchor)
|
|
end
|
|
end
|
|
|
|
@target_html = parsed_html.to_s
|
|
@processed = true
|
|
end
|
|
end
|