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# frozen_string_literal: true
HTML::Pipeline.require_dependency('escape_utils', 'TableOfContentsFilter')
module HTML
class Pipeline
# HTML filter that adds an 'id' attribute to all headers
# in a document, so they can be accessed from a table of contents.
#
# Generates the Table of Contents, with links to each header.
#
# Examples
#
# TocPipeline =
# HTML::Pipeline.new [
# HTML::Pipeline::TableOfContentsFilter
# ]
# # => #<HTML::Pipeline:0x007fc13c4528d8...>
# orig = %(<h1>Ice cube</h1><p>is not for the pop chart</p>)
# # => "<h1>Ice cube</h1><p>is not for the pop chart</p>"
# result = {}
# # => {}
# TocPipeline.call(orig, {}, result)
# # => {:toc=> ...}
# result[:toc]
# # => "<ul class=\"section-nav\">\n<li><a href=\"#ice-cube\">...</li><ul>"
# result[:output].to_s
# # => "<h1>\n<a id=\"ice-cube\" class=\"anchor\" href=\"#ice-cube\">..."
class TableOfContentsFilter < Filter
PUNCTUATION_REGEXP = RUBY_VERSION > '1.9' ? /[^\p{Word}\- ]/u : /[^\w\- ]/
# The icon that will be placed next to an anchored rendered markdown header
def anchor_icon
context[:anchor_icon] || '<span aria-hidden="true" class="octicon octicon-link"></span>'
end
def call
result[:toc] = String.new('')
headers = Hash.new(0)
doc.css('h1, h2, h3, h4, h5, h6').each do |node|
text = node.text
id = ascii_downcase(text)
id.gsub!(PUNCTUATION_REGEXP, '') # remove punctuation
id.tr!(' ', '-') # replace spaces with dash
uniq = headers[id] > 0 ? "-#{headers[id]}" : ''
headers[id] += 1
if header_content = node.children.first
result[:toc] << %(<li><a href="##{id}#{uniq}">#{CGI.escape_html(text)}</a></li>\n)
header_content.add_previous_sibling(%(<a id="#{id}#{uniq}" class="anchor" href="##{id}#{uniq}" aria-hidden="true">#{anchor_icon}</a>))
end
end
result[:toc] = %(<ul class="section-nav">\n#{result[:toc]}</ul>) unless result[:toc].empty?
doc
end
if RUBY_VERSION >= '2.4'
def ascii_downcase(str)
str.downcase(:ascii)
end
else
def ascii_downcase(str)
str.downcase
end
end
end
end
end
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