diff options
Diffstat (limited to 'lib/gitlab/markdown/filter/table_of_contents_filter.rb')
-rw-r--r-- | lib/gitlab/markdown/filter/table_of_contents_filter.rb | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/lib/gitlab/markdown/filter/table_of_contents_filter.rb b/lib/gitlab/markdown/filter/table_of_contents_filter.rb new file mode 100644 index 00000000000..bbb3bf7fc8b --- /dev/null +++ b/lib/gitlab/markdown/filter/table_of_contents_filter.rb @@ -0,0 +1,63 @@ +require 'gitlab/markdown' +require 'html/pipeline/filter' + +module Gitlab + module Markdown + # HTML filter that adds an anchor child element to all Headers in a + # document, so that they can be linked to. + # + # Generates the Table of Contents with links to each header. See Results. + # + # Based on HTML::Pipeline::TableOfContentsFilter. + # + # Context options: + # :no_header_anchors - Skips all processing done by this filter. + # + # Results: + # :toc - String containing Table of Contents data as a `ul` element with + # `li` child elements. + class TableOfContentsFilter < HTML::Pipeline::Filter + PUNCTUATION_REGEXP = /[^\p{Word}\- ]/u + + def call + return doc if context[:no_header_anchors] + + result[:toc] = "" + + headers = Hash.new(0) + + doc.css('h1, h2, h3, h4, h5, h6').each do |node| + text = node.text + + id = text.downcase + id.gsub!(PUNCTUATION_REGEXP, '') # remove punctuation + id.gsub!(' ', '-') # replace spaces with dash + id.squeeze!('-') # replace multiple dashes with one + + uniq = (headers[id] > 0) ? "-#{headers[id]}" : '' + headers[id] += 1 + + if header_content = node.children.first + href = "#{id}#{uniq}" + push_toc(href, text) + header_content.add_previous_sibling(anchor_tag(href)) + end + end + + result[:toc] = %Q{<ul class="section-nav">\n#{result[:toc]}</ul>} unless result[:toc].empty? + + doc + end + + private + + def anchor_tag(href) + %Q{<a id="#{href}" class="anchor" href="##{href}" aria-hidden="true"></a>} + end + + def push_toc(href, text) + result[:toc] << %Q{<li><a href="##{href}">#{text}</a></li>\n} + end + end + end +end |