Class: Banzai::Filter::TableOfContentsFilter

Inherits:
HTML::Pipeline::Filter
  • Object
show all
Includes:
Gitlab::Utils::Markdown
Defined in:
lib/banzai/filter/table_of_contents_filter.rb

Overview

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.

Defined Under Namespace

Classes: HeaderNode

Constant Summary

Constants included from Gitlab::Utils::Markdown

Gitlab::Utils::Markdown::PRODUCT_SUFFIX, Gitlab::Utils::Markdown::PUNCTUATION_REGEXP

Instance Method Summary collapse

Methods included from Gitlab::Utils::Markdown

#string_to_anchor

Instance Method Details

#callObject


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# File 'lib/banzai/filter/table_of_contents_filter.rb', line 22

def call
  return doc if context[:no_header_anchors]

  result[:toc] = +""

  headers = Hash.new(0)
  header_root = current_header = HeaderNode.new

  doc.css('h1, h2, h3, h4, h5, h6').each do |node|
    if header_content = node.children.first
      id = string_to_anchor(node.text)

      uniq = headers[id] > 0 ? "-#{headers[id]}" : ''
      headers[id] += 1
      href = "#{id}#{uniq}"

      current_header = HeaderNode.new(node: node, href: href, previous_header: current_header)

      header_content.add_previous_sibling(anchor_tag(href))
    end
  end

  push_toc(header_root.children, root: true)

  doc
end