discourse/plugins/footnote/plugin.rb

# frozen_string_literal: true

# name: footnote
# about: Adds markdown.it footnote support to Discourse
# version: 1.0
# authors: Discourse Team
# meta_topic_id: 84533
# url: https://github.com/discourse/discourse/tree/main/plugins/footnote

enabled_site_setting :enable_markdown_footnotes

register_asset "vendor/javascripts/markdown-it-footnote.js", :vendored_pretty_text

register_asset "stylesheets/footnotes.scss"

register_svg_icon "ellipsis" if respond_to?(:register_svg_icon)

on(:before_post_process_cooked) do |doc, post|
  doc
    .css("a.footnote-backref")
    .each do |backref|
      href = backref["href"] || ""
      id = href[6..-1].to_i
      backref["href"] = "#footnote-ref-#{post.id}-#{id}"
    end

  doc
    .css("sup.footnote-ref a")
    .each do |ref|
      href = ref["href"] || ""
      id = href[3..-1].to_i
      ref["href"] = "#footnote-#{post.id}-#{id}"

      id = ref["id"] || ""
      id = id[5..-1].to_i
      ref["id"] = "footnote-ref-#{post.id}-#{id}"
    end

  doc
    .css("li.footnote-item")
    .each do |li|
      id = li["id"] || ""
      id = id[2..-1].to_i

      li["id"] = "footnote-#{post.id}-#{id}"
    end
end