Adding An RSS Feed to a Jekyll Site

23 May 2013

Adding an RSS 2.0 feed to a Jekyll site is actually pretty simple.

First the required header and footer:

<?xml version="1.0" encoding="utf-8"?>
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
  <channel>
    <atom:link href="{{ site.url }}/feed.xml" rel="self" type="application/rss+xml" />
    <title>{{ site.name }}</title>
    <link>{{ site.url }}</link>
    <description>{{ site.description }}</description>
  </channel>
</rss>

Don’t forget to add a name, url and description to your configuration file.

url: http://kmikael.com

name: Mikael Konutgan
description: 'Thoughts on programming, Unix and technology'

We’ve got our XML boilerplate and then in the channel we need to add a title, a link and a description. The channel elements also has a few optional elements, which I haven’t included here.

The next step is to add the item’s. We iterate over the 20 latest posts and add them. Each item has a title, a link a guid (globally unique identifier), a pupDate and a description. The guid can be any string, here I just set it to the link of the post. isPermaLink="true" tells feed readers that they can assume the guid is a permalink.

Actually non of these are required, it’s the most minimal approach that makes sense in my opinion. To quote the spec:

An item may also be complete in itself, if so, the description contains the text (entity-encoded HTML is allowed), and the link and title may be omitted. All elements of an item are optional, however at least one of title or description must be present.

We use the date_to_rfc822 and xml_escape filters Jekyll adds to Liquid to comply with the specification.

{% for post in site.posts limit:20 %}
  <item>
    <title>{{ post.title }}</title>
    <link>{{ site.url }}{{ post.url }}</link>
    <guid isPermaLink="true">{{ site.url }}{{ post.url }}</guid>
    <pubDate>{{ post.date | date_to_rfc822 }}</pubDate>
    <description>{{ post.content | xml_escape }}</description>
  </item>
{% endfor %}

After we add the YAML front-matter, so Liquid will process our file, the end result looks like this:

---
layout: nil
---

<?xml version="1.0" encoding="utf-8"?>
<rss version="2.0">
  <channel>
    <title>Mikael Konutgan</title>
    <link>{{ site.url }}</link>
    <description>Thoughts on programming and technology</description>
    {% for post in site.posts limit:20 %}
      <item>
        <title>{{ post.title }}</title>
        <link>{{ site.url }}{{ post.url }}</link>
        <guid isPermaLink="true">{{ site.url }}{{ post.url }}</guid>
        <pubDate>{{ post.date | date_to_rfc822 }}</pubDate>
        <description>{{ post.content | xml_escape }}</description>
      </item>
    {% endfor %}
  </channel>
</rss>

See the RSS 2.0 specification for all of the details and optional elements and validate your feed when you’re done. Using the method above should produce a valid feed without warnings.