pebble/devsite/lib/toc_generator.rb
2025-02-24 18:58:29 -08:00

81 lines
2.1 KiB
Ruby

# Copyright 2025 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
require 'redcarpet'
require 'nokogiri'
module Pebble
class TocGenerator
def initialize(max_depth=-1)
@max_depth = max_depth
@markdown = TocMarkdown.new()
@redcarpet = Redcarpet::Markdown.new(@markdown,
fenced_code_blocks: true,
autolink: true,
tables: true,
no_intra_emphasis: true,
strikethrough: true,
highlight: true)
end
def generate(content)
@redcarpet.render(content)
page_toc = @markdown.get_toc
toc_array(toc_normalised(page_toc))
end
private
# Convert the ToC array of hashes into an array of array so that it can
# be used in the Liquid template.
def toc_array(array)
array.map { |entry| [ entry[:id], entry[:title], entry[:level] ] }
end
# Normalised the ToC array by ensuring that the smallest level number is 1.
def toc_normalised(array)
min_level = 100
array.each { |entry| min_level = [ min_level, entry[:level] ].min }
level_offset = min_level - 1
array.map { |entry| entry[:level] -= level_offset; entry }.select do |entry|
@max_depth == -1 || entry[:level] <= @max_depth
end
end
end
class TocMarkdown < Redcarpet::Render::HTML
def initialize()
@toc = Array.new
@depth = 0
super()
end
def get_toc()
@toc
end
def header(text, header_level)
text = Nokogiri::HTML(text).text if text.include?('<')
entry = { title: text, id: text.slugize, level: header_level }
@toc << entry
""
end
end
end