Remove Table of Contents From a Jekyll RSS Feed

Note from the Editor: The following method will only work if you self-host your Jekyll site. GitHub Pages doesn’t allow custom plugins.

As you may have noticed, I added table of contents to appropriate posts. If you hadn’t noticed, take a look at the release notes from the latest version.

Having a table of contents on longer posts is awesome. Some of the longer reviews and development articles are much easier to consume by knowing what’s in the article. Adding a table of contents to a Jekyll post is a piece of cake with Kramdown:

* table of contents
{:toc}

All was fine and dandy with the new table of contents till I realized that they were being output in the RSS feed. 🤦🏽‍ I didn’t want that! After searching the vast internet cosmos for more than an hour, I wasn’t finding what I needed. Shocked and disappointed thinking that no one had written about this, I almost gave up.

Then, finally, I found it. Well… not really. The article is about removing footnotes from excerpts in Jekyll with the help of the nokogiri gem. This wasn’t what I was trying to do, but close enough that I could modify and make it work.

The Solution

Create a Jekyll Plugin

Go to your _plugins folder and create a new Ruby file. You can call it whatever you’d like, I called mine stripTOC.rb

# stripTOC.rb

require 'nokogiri'

module Jekyll
  module StripTocFilter

    def strip_toc(raw)
      doc = Nokogiri::HTML.fragment(raw.encode('UTF-8', :invalid => :replace, :undef => :replace, :replace => ''))

      for block in ['ul'] do
        doc.css(block).each do |ele|
          ele.remove if (ele['id'] == 'markdown-toc')
        end
      end

      doc.inner_html

    end
  end
end

Liquid::Template.register_filter(Jekyll::StripTocFilter)

This code creates a new filter that we can use to remove the table of contents from our RSS feed. If you noticed, we’re telling it to find any element with the #markdown-toc id. This is the id assigned to it by Kramdown.

Filtering Our RSS Feed

Now we want to open up our feed and use the filter. Mine is called atom.xml.

<!-- atom.xml -->
<content type="html">
  <![CDATA[
    {{ post.content | strip_toc }}
  ]]>
</content>

Now your table of contents is present on your articles, but doesn’t clutter up the RSS feed.