Added related posts section (#1168)

Gemfile

@@ -1,16 +1,17 @@
 source 'https://rubygems.org'
 group :jekyll_plugins do
+    gem 'classifier-reborn'
     gem 'jekyll'
     gem 'jekyll-archives'
     gem 'jekyll-diagrams'
     gem 'jekyll-email-protect'
     gem 'jekyll-feed'
     gem 'jekyll-imagemagick'
+    gem 'jekyll-link-attributes'
     gem 'jekyll-minifier'
     gem 'jekyll-paginate-v2'
     gem 'jekyll-scholar'
     gem 'jekyll-sitemap'
-    gem 'jekyll-link-attributes'
     gem 'jekyll-twitter-plugin'
     gem 'jemoji'
     gem 'mini_racer'
@@ -18,6 +19,6 @@ group :jekyll_plugins do
     gem 'webrick'
 end
 group :other_plugins do
-    gem 'httparty'
     gem 'feedjira'
+    gem 'httparty'
 end

README.md

@@ -159,6 +159,7 @@ Images2Symbols (CogSci: <a href="https://images2symbols.github.io/" target="_bla
       - [Theming](#theming)
       - [Social media previews](#social-media-previews)
       - [Atom (RSS-like) Feed](#atom-rss-like-feed)
+      - [Related posts](#related-posts)
   * [Contributing](#contributing)
     + [Core Contributors](#core-contributors)
   * [License](#license)
@@ -221,7 +222,7 @@ Assuming you have [Ruby](https://www.ruby-lang.org/en/downloads/) and [Bundler](
 $ git clone git@github.com:<your-username>/<your-repo-name>.git
 $ cd <your-repo-name>
 $ bundle install
-$ bundle exec jekyll serve
+$ bundle exec jekyll serve --lsi
 ```
 
 Now, feel free to customize the theme however you like (don't forget to change the name!).
@@ -269,7 +270,7 @@ uses the `master` branch for the source code and deploys the webpage to `gh-page
 
 If you decide to not use GitHub Pages and host your page elsewhere, simply run:
 ```bash
-$ bundle exec jekyll build
+$ bundle exec jekyll build --lsi
 ```
 which will (re-)generate the static webpage in the `_site/` folder.
 Then simply copy the contents of the `_site/` foder to your hosting server.
@@ -289,7 +290,7 @@ Firstly, from the deployment repo dir, checkout the git branch hosting your publ
 
 Then from the website sources dir (commonly your al-folio fork's clone):
 ```bash
-$ bundle exec jekyll build --destination $HOME/repo/publishing-source
+$ bundle exec jekyll build --lsi --destination $HOME/repo/publishing-source
 ```
 
 This will instruct jekyll to deploy the website under `$HOME/repo/publishing-source`.
@@ -535,6 +536,12 @@ It generates an Atom (RSS-like) feed of your posts, useful for Atom and RSS read
 The feed is reachable simply by typing after your homepage `/feed.xml`.
 E.g. assuming your website mountpoint is the main folder, you can type `yourusername.github.io/feed.xml`
 
+#### Related posts
+By default,  there will be a related posts section on the bottom of the blog posts.
+These are generated by selecting the `max_related` most recent posts that share at least `min_common_tags` tags with the current post.
+If you do not want to display related posts on a specific post, simply add `related_posts: false` to the front matter of the post.
+If you want to disable it for all posts, simply set `enabled` to false in the `related_blog_posts` section in `_config.yml`.
+
 ## Contributing
 
 Contributions to al-folio are very welcome!

_config.yml

@@ -124,6 +124,10 @@ permalink: /blog/:year/:title/
 pagination:
   enabled: true
 
+related_blog_posts:
+  enabled: true
+  max_related: 5
+
 # Giscus comments (RECOMMENDED)
 # Follow instructions on https://giscus.app/ to setup for your repo to fill out
 # the information below.

_includes/related_posts.html

@@ -0,0 +1,19 @@
+{% assign have_related_posts = false %}
+
+{% for post in site.related_posts | limit: site.related_blog_posts.max_related %}
+  {% unless have_related_posts %}
+    {% assign have_related_posts = true %}
+    <br>
+    <hr>
+    <br>
+    <ul class="list-disc pl-8"></ul>
+
+    <!-- Adds related posts to the end of an article -->
+    <h2 class="text-3xl font-semibold mb-4 mt-12">Enjoy Reading This Article?</h2>
+    <p class="mb-2">Here are some more articles you might like to read next:</p>
+  {% endunless %}
+
+  <li class="my-2">
+    <a class="text-pink-700 underline font-semibold hover:text-pink-800" href="{{ site.baseurl }}{{ post.url }}">{{ post.title }}</a>
+  </li>
+{% endfor %}

_layouts/post.html

@@ -43,6 +43,12 @@ layout: default
     {{ content }}
   </article>
 
+  {%- if site.related_blog_posts.enabled -%}
+    {%- if page.related_posts == null or page.related_posts -%}
+      {% include related_posts.html %}
+    {%- endif %}
+  {%- endif %}
+
   {%- if site.disqus_shortname and page.disqus_comments -%}
     {% include disqus.html %}
   {%- endif %}

_posts/2015-10-20-disqus-comments.md

@@ -5,5 +5,6 @@ date: 2015-10-20 11:59:00-0400
 description: an example of a blog post with disqus comments
 categories: sample-posts external-services
 disqus_comments: true
+related_posts: false
 ---
 This post shows how to add DISQUS comments.

_posts/2015-10-20-math.md

@@ -5,6 +5,7 @@ date: 2015-10-20 11:12:00-0400
 description: an example of a blog post with some math
 tags: formatting math
 categories: sample-posts
+related_posts: false
 ---
 This theme supports rendering beautiful math in inline and display modes using [MathJax 3](https://www.mathjax.org/) engine. You just need to surround your math expression with `$$`, like `$$ E = mc^2 $$`. If you leave it inside a paragraph, it will produce an inline expression, just like $$ E = mc^2 $$.
 

_posts/2022-02-01-redirect.md

@@ -5,3 +5,5 @@ date: 2022-02-01 17:39:00
 description: you can also redirect to assets like pdf
 redirect: /assets/pdf/example_pdf.pdf
 ---
+
+Redirecting to another page.

_posts/2022-12-10-giscus-comments.md

@@ -5,5 +5,6 @@ date: 2022-12-10 11:59:00-0400
 description: an example of a blog post with giscus comments
 categories: sample-posts external-services
 giscus_comments: true
+related_posts: false
 ---
 This post shows how to add GISCUS comments.

bin/cibuild

@@ -1 +1 @@
-bundle exec jekyll build
+bundle exec jekyll build --lsi

bin/deploy

@@ -93,7 +93,7 @@ git checkout -b $DEPLOY_BRANCH
 export JEKYLL_ENV=production
 
 # Build site
-bundle exec jekyll build
+bundle exec jekyll build --lsi
 
 # Delete and move files
 find . -maxdepth 1 ! -name '_site' ! -name '.git' ! -name 'CNAME' ! -name '.gitignore' -exec rm -rf {} \;