How to categorize your posts in Jekyll

Amit Merchant · August 27, 2020 ·

When I first started blogging using Jekyll, I was using a popular Jekyll theme called jekyll-now. The theme is quite minimalistic in nature, bare-bone and lacking some key features. But in those earlier days, I was okay with its simplicity.

Then, over time, my number of articles grew and I was writing about an array of different topics and at this point, I’ve felt that something is missing. The content became unmanageable and unsearchable and so, I needed a way to get around with it. And that’s where the idea of implementing categories/tags arrived. I’ll walk you through how I implemented it on this blog.

Adding categories in posts

The first and foremost thing I needed to do is to just add a categories variable in the frontmatter of each post. Here’s how you can add categories into the frontmatter.

So, if your post falls under the JavaScript, you can set it like so.

categories: JavaScript

And for adding multiple categories:

categories: [PHP, Laravel]

By adding this into the frontmatter, about 50% of the task is done.

Now, by using this categories variable, we can do many different things. Such as creating category pages, make post searchable, and several other things.

Creating a category page

Using the category frontmatter variable, we can make a categories page called categories.md in the _pages directory where you can categorize and list each post by its category like so.

---
layout: page
permalink: /categories/
title: Categories
---

<div id="archives">
  {% for category in site.categories %}
    <div class="archive-group">
      {% capture category_name %}{{ category | first }}{% endcapture %}
      <div id="#{{ category_name | slugize }}"></div>
      <h3 class="category-head">{{ category_name }}</h3>
      <a name="{{ category_name | slugize }}"></a>
      {% for post in site.categories[category_name] %}
      <article class="archive-item">
        <h4>
            <a href="{{ site.baseurl }}{{ post.url }}">{{post.title}}</a>
        </h4>
      </article>
      {% endfor %}
    </div>
  {% endfor %}
</div>

Notice, we’re using site.categories which will get us all the categories the posts are using and then we can loop over them. And in the loop, we can get the post based on the current category in the loop using the following loop.

{% for post in site.categories[category_name] %}

This page looks like the following: https://www.amitmerchant.com/categories

Individual a category page

You can also create an individual category page for selected categories. For instance, you can see a category page for “PHP”: https://www.amitmerchant.com/posts/php

You can make such a category page called php.md in the _pages directory using the following code.

---
layout: page
permalink: /posts/php/
title: Posts about "PHP"
---

<div class="posts">
  {% for post in site.categories['PHP'] %}
    <article class="post">
      <h1>
          <a href="{{ site.baseurl }}{{ post.url }}">{{ post.title }}</a>
      </h1>
      <div>
        <p class="post_date">{{ post.date | date: "%B %e, %Y" }}</p>
      </div>
      <div class="entry">
        {{ post.excerpt }}
      </div>
      <a href="{{ site.baseurl }}{{ post.url }}" class="read-more">
          Read More
      </a>
    </article>
  {% endfor %}
</div>

This page will enlist all the posts which have categories set to PHP.

You can also utilize categories in your search. For instance, I’m using a library called Simple-Jekyll-Search to power my blog’s search.

What this library does is use a small dataset file called search.json which contains all the posts in the form of a JSON to perform the searches on the client-side. You can place the following code in search.json in the root of your Jekyll blog.

---
---
[
  {% for post in site.posts %}
    {

      "title"    : "{{ post.title | escape }}",
      "url"      : "{{ site.baseurl }}{{ post.url }}",
      "category" : "{{ post.categories | join: ', '}}",
      "date"     : "{{ post.date | date: "%B %e, %Y" }}"
    } {% unless forloop.last %},{% endunless %}
  {% endfor %}
]

As you can see here, we’ve used a JSON key called category which will hold the category of the post. And this way, we can utilize categories while search posts as well.

Hi there! I'm Amit. I write articles about all things web development. If you like what I write and want me to continue doing the same, I would like you buy me some coffees. I'd highly appreciate that. Cheers!