Add custom RSS/Atom feed for blog

docs/_blog/feed_template.xml

@@ -0,0 +1,127 @@
+---
+layout: none
+permalink: feed/blog.xml
+title: "Research Object Crate (RO-Crate) | Blog"
+---
+<?xml version="1.0" encoding="utf-8"?>
+<!--This is an Atom feed adapted from https://github.com/jekyll/jekyll-feed/blob/master/lib/jekyll-feed/feed.xml under the MIT license.
+Changes from that source:
+* simplified how the title is set
+* removed if/else statements that could adapt the feed according to tags and categories (we don't need this)
+* added a check that hides posts dated in the future (the jekyll-feed gem doesn't do this for non-default collections)
+-->
+{% if page.xsl %}
+  <?xml-stylesheet type="text/xml" href="{{ '/feed.xslt.xml' | absolute_url }}"?>
+{% endif %}
+<feed xmlns="http://www.w3.org/2005/Atom" {% if site.lang %}xml:lang="{{ site.lang }}"{% endif %}>
+  <generator uri="https://jekyllrb.com/" version="{{ jekyll.version }}">Jekyll</generator>
+  <link href="{{ page.url | absolute_url }}" rel="self" type="application/atom+xml" />
+  <link href="{{ '/' | absolute_url }}" rel="alternate" type="text/html" {% if site.lang %}hreflang="{{ site.lang }}" {% endif %}/>
+  <updated>{{ site.time | date_to_xmlschema }}</updated>
+  <id>{{ page.url | absolute_url | xml_escape }}</id>
+
+  {% if page.title %}
+    <title type="html">{{ page.title | xml_escape }}</title>
+  {% endif %}
+
+  {% if site.description %}
+    <subtitle>{{ site.description | xml_escape }}</subtitle>
+  {% endif %}
+
+  {% if site.feed.icon %}
+    {% assign feed_icon = site.feed.icon %}
+    {% unless feed_icon contains "://" %}
+      {% assign feed_icon = feed_icon | absolute_url %}
+    {% endunless %}
+    <icon>{{ feed_icon | xml_escape }}</icon>
+  {% endif %}
+
+  {% if site.feed.logo %}
+    {% assign feed_logo = site.feed.logo %}
+    {% unless feed_logo contains "://" %}
+      {% assign feed_logo = feed_logo | absolute_url %}
+    {% endunless %}
+    <logo>{{ feed_logo | xml_escape }}</logo>
+  {% endif %}
+
+  {% if site.author %}
+    <author>
+        <name>{{ site.author.name | default: site.author | xml_escape }}</name>
+      {% if site.author.email %}
+        <email>{{ site.author.email | xml_escape }}</email>
+      {% endif %}
+      {% if site.author.uri %}
+        <uri>{{ site.author.uri | xml_escape }}</uri>
+      {% endif %}
+    </author>
+  {% endif %}
+
+  {% assign posts = site.blog | where_exp: "post", "post.layout == 'post'" %}
+  {% assign posts = posts | sort: "date" | reverse %}
+  {% assign posts_limit = site.feed.posts_limit | default: 10 %}
+  {% assign current_date = "now" | date: '%s' | integer %}
+  {% for post in posts limit: posts_limit %}
+    {% unless site.future %}
+      {% assign post_date = post.date | date: '%s' | integer %}
+      {% if post_date > current_date %}
+        {% continue %}
+      {% endif %}
+    {% endunless %}
+
+    <entry{% if post.lang %}{{" "}}xml:lang="{{ post.lang }}"{% endif %}>
+      {% assign post_title = post.title | smartify | strip_html | normalize_whitespace | xml_escape %}
+
+      <title type="html">{{ post_title }}</title>
+      <link href="{{ post.url | absolute_url }}" rel="alternate" type="text/html" title="{{ post_title }}" />
+      <published>{{ post.date | date_to_xmlschema }}</published>
+      <updated>{{ post.last_modified_at | default: post.date | date_to_xmlschema }}</updated>
+      <id>{{ post.id | absolute_url | xml_escape }}</id>
+      {% assign excerpt_only = post.feed.excerpt_only | default: site.feed.excerpt_only %}
+      {% unless excerpt_only %}
+        <content type="html" xml:base="{{ post.url | absolute_url | xml_escape }}"><![CDATA[{{ post.content | strip }}]]></content>
+      {% endunless %}
+
+      {% assign post_author = post.author | default: post.authors[0] | default: site.author %}
+      {% assign post_author = site.data.authors[post_author] | default: post_author %}
+      {% assign post_author_email = post_author.email | default: nil %}
+      {% assign post_author_uri = post_author.uri | default: nil %}
+      {% assign post_author_name = post_author.name | default: post_author %}
+
+      <author>
+          <name>{{ post_author_name | default: "" | xml_escape }}</name>
+        {% if post_author_email %}
+          <email>{{ post_author_email | xml_escape }}</email>
+        {% endif %}
+        {% if post_author_uri %}
+          <uri>{{ post_author_uri | xml_escape }}</uri>
+        {% endif %}
+      </author>
+
+      {% if post.category %}
+        <category term="{{ post.category | xml_escape }}" />
+      {% elsif post.categories %}
+        {% for category in post.categories %}
+          <category term="{{ category | xml_escape }}" />
+        {% endfor %}
+      {% endif %}
+
+      {% for tag in post.tags %}
+        <category term="{{ tag | xml_escape }}" />
+      {% endfor %}
+
+      {% assign post_summary = post.description | default: post.excerpt %}
+      {% if post_summary and post_summary != empty %}
+        <summary type="html"><![CDATA[{{ post_summary | strip_html | normalize_whitespace }}]]></summary>
+      {% endif %}
+
+      {% assign post_image = post.image.path | default: post.image %}
+      {% if post_image %}
+        {% unless post_image contains "://" %}
+          {% assign post_image = post_image | absolute_url %}
+        {% endunless %}
+        <media:thumbnail xmlns:media="http://search.yahoo.com/mrss/" url="{{ post_image | xml_escape }}" />
+        <media:content medium="image" url="{{ post_image | xml_escape }}" xmlns:media="http://search.yahoo.com/mrss/" />
+      {% endif %}
+    </entry>
+  {% endfor %}
+</feed>

docs/_config.yml

@@ -107,6 +107,11 @@ collections:
     permalink: /blog/:path
     output: true
 
+feed: # RSS/Atom feed settings, used in _blog/feed_template.xml
+  logo: assets/img/ro-crate.svg
+  icon: assets/img/favicon.ico
+  posts_limit: 100
+
 theme_variables:
   topnav:
     theme: light
@@ -115,10 +120,6 @@ theme_variables:
     twitter: false
   theme_color: 39989F
 
-feed: # RSS/Atom feed settings
-  collections:
-    - blog
-
 plugins:
   - elixir-toolkit-theme-plugins
   - jekyll-redirect-from