Creating a Hugo Theme From Scratch

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In this post I will show you how to build a minimalist theme for Hugo.

Pre-requisites

Hugo is written in Go, but you do not need to install it for now.

Getting started

  • Create a new Hugo site
    hugo new site example
  • Go into the newly created folder
    cd example
  • Create a new theme
    hugo new theme exampleTheme
  • This will have created a themes folder with a exampleTheme subfolder, the folder structure should look like this
    .
    ├── archetypes
    │   └── default.md
    ├── config.toml
    ├── content
    ├── data
    ├── layouts
    ├── resources
    │   └── _gen
    │       ├── assets
    │       └── images
    ├── static
    └── themes
        └── exampleTheme
            ├── LICENSE
            ├── archetypes
            │   └── default.md
            ├── layouts
            │   ├── 404.html
            │   ├── _default
            │   │   ├── baseof.html
            │   │   ├── list.html
            │   │   └── single.html
            │   ├── index.html
            │   └── partials
            │       ├── footer.html
            │       ├── head.html
            │       └── header.html
            ├── static
            │   ├── css
            │   └── js
            └── theme.toml
  • Check that everything is working fine by starting the server
    hugo server
  • Navigate to http://localhost:1313, and check there are no errors in the developer console (Chrome) or equivalent in your browser of choice
  • Check the config.toml file and make sure it looks like this
    baseURL = "http://example.org/"
    languageCode = "en-us"
    title = "My New Hugo Site"
  • I will be using this for the rest of the post, but feel free to customise it

Partials

Partials are small, context-aware components that can be used economically to keep your templating DRY.

  • Open example/themes/exampleTheme/layouts/partials/head.html in a text editor
  • This will be the place for metadata like the document title, character set, styles, scripts, and other meta information
  • Paste the following
    <head>
        <meta charset="utf-8">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <link rel="stylesheet" type="text/css" href="/css/bootstrap.min.css">
        <link rel="stylesheet" type="text/css" href="/css/style.css">
        {{ $title := print .Site.Title " | " .Title }}
        {{ if .IsHome }}{{ $title = .Site.Title }}{{ end }}
        <title>{{ $title }}</title>
    </head>
  • Here we are specifying the charset that our document will use, utf-8 in this case, the viewport information and couple of stylesheets
  • Let's go ahead and add the missing CSS files
  • Go to example/themes/exampleTheme/static/css and create a file called style.css, we will place our custom CSS here later on
  • Go to https://getbootstrap.com/ and download the latest version of Bootstrap (v4.4.1 at the time of writing)
  • Extract the ZIP file and copy bootstrap.min.css to example/themes/exampleTheme/static/css
  • Finally, for the title, we will render the site title as it appears in config.toml when we are at the homepage and we will concatenate the section name when we are in a section page e.g. My New Hugo Site | Posts
Script
  • In addition to Bootstrap, we are going to use Feather icons to display icons on our site
  • Go to https://github.com/feathericons/feather#client-side-javascript and download feather.min.js into example/themes/exampleTheme/static/js
  • Create a file example/themes/exampleTheme/layouts/partials/script.html and paste the following
    <script src="/js/feather.min.js"></script>
    <script>
      feather.replace()
    </script>
  • Let's add a nav to the header so that we can navigate between the different sections of our site
  • Open example/themes/exampleTheme/layouts/partials/header.html and paste the following
    <div id="nav-border" class="container">
        <nav id="nav" class="nav justify-content-center">
            {{ range .Site.Menus.main }}
            <a class="nav-link" href="{{ .URL }}">
            {{ if .Pre }}
            {{ $icon := printf "<i data-feather=\"%s\"></i> " .Pre | safeHTML }}
            {{ $icon }}
            {{ end }}
            {{ $text := print .Name | safeHTML }}
            {{ $text }}
            </a>
            {{ end }}
        </nav>
    </div>
  • Here we are creating a nav menu that will be centred at the top of each page
  • Each menu item will have a link and also an icon if we configure it as a pre property in config.toml, more on that later
  • For the footer let's just add a basic copyright disclaimer
    <p class="footer text-center">Copyright (c) {{ now.Format "2006"}} John Doe</p>
  • You can replace John Doe with your name
  • The current year will be displayed as well
  • If you are wondering why “2006”, you can find out more about it here
Metadata
  • Let's create one more partial to display metadata about each post e.g. date and tags
  • Create a new file example/themes/exampleTheme/layouts/partials/metadata.html
    {{ $dateTime := .PublishDate.Format "2006-01-02" }}
    {{ $dateFormat := .Site.Params.dateFormat | default "Jan 2, 2006" }}
    <i data-feather="calendar"></i>
    <time datetime="{{ $dateTime }}">{{ .PublishDate.Format $dateFormat }}</time>
    {{ with .Params.tags }}
    <i data-feather="tag"></i>
    {{ range . }}
    {{ $href := print (absURL "tags/") (urlize .) }}
    <a class="btn btn-sm btn-outline-dark tag-btn" href="{{ $href }}">{{ . }}</a>
    {{ end }}
    {{ end }}
  • We are using Feather icons to spice things up a little, but in fact we are just rendering the publication date and the tags
  • Tags will be passed in as parameters from the post itself in the front matter, more information here
    ---
    author: "John Doe"
    title: "My First Post"
    date: "2006-02-01"
    tags: ["foo", "bar"]
    ---

Default layouts

  • Now we have all the basic ingredients to work on the layouts
  • These are placed under example/themes/exampleTheme/layouts/_default and, at least, consist of
    • baseof
    • list
    • single
Baseof

This will be the base template for all pages, and should reference the different partials we edited above.

  • Open example/themes/exampleTheme/layouts/_default/baseof.html, it should look like this
    <!DOCTYPE html>
    <html>
        {{- partial "head.html" . -}}
        <body>
            {{- partial "header.html" . -}}
            <div id="content">
            {{- block "main" . }}{{- end }}
            </div>
            {{- partial "footer.html" . -}}
        </body>
    </html>
  • Let's also include the script.html partial with our Feather icons
    <!DOCTYPE html>
    <html>
        {{- partial "head.html" . -}}
        <body>
            {{- partial "header.html" . -}}
            <div id="content">
            {{- block "main" . }}{{- end }}
            </div>
            {{- partial "footer.html" . -}}
            {{- partial "script.html" . -}}
        </body>
    </html>
  • It's good practice to place our scripts at the end of the HTML code so that it doesn't block rendering the page
List

This layout will be used to display the list of posts on our site.

  • Open example/themes/exampleTheme/layouts/_default/list.html
  • We will define the main section of the baseof layout like this
    {{ define "main" }}
    <h1>{{ .Title }}</h1>
    {{ range .Pages.ByPublishDate.Reverse }}
    <p>
        <h3><a class="title" href="{{ .RelPermalink }}">{{ .Title }}</a></h3>
        {{ partial "metadata.html" . }}
        <a class="summary" href="{{ .RelPermalink }}">
            <p>{{ .Summary }}</p>
        </a>
    </p>
    {{ end }}
    {{ end }}
  • We are displaying the metadata i.e. publication date and tags, and the summary of the post
  • We are also sorting posts by publication date in reverse order, most recent first
Single

This layout will be used to display a single post.

  • Open example/themes/exampleTheme/layouts/_default/single.html
  • Similarly to what we did above, let's define the main section
    {{ define "main" }}
    <h1>{{ .Title }}</h1>
    {{ partial "metadata.html" . }}
    <br><br>
    {{ .Content }}
    {{ end }}
  • Like before, we will display the metadata, but in this case, we will display the full content instead of the summary

Homepage

This will be the landing page at the root of our site.

  • Open example/themes/exampleTheme/layouts/index.html in a text editor
  • With Bootstrap in place, we can now use the Jumbotron component to render a hero section
  • Paste the following
    {{ define "main" }}
    <div id="home-jumbotron" class="jumbotron text-center">
      <h1 class="title">{{ .Site.Title }}</h1>
    </div>
    {{ end }}

404

This is used to customise an error message for when a link is broken. However, Hugo comes with a default one, so let's delete it for now.

Feel free to play with the contents of the file if you want to customise your error messages.

Configuration

We have created the template, now we need to tell Hugo to use it for our site.

  • Open example/config.toml and add a line to select the theme like this
    theme = "exampleTheme"
  • We'll also need a menu to navigate to the different sections, let's add it
    [menu]
      [[menu.main]]
        name = "Home"
        pre = "home"
        url = "/"
        weight = 1
      [[menu.main]]
        name = "Posts"
        pre = "pen-tool"
        url = "/posts/"
        weight = 2
      [[menu.main]]
        name = "Tags"
        pre = "tag"
        url = "/tags/"
        weight = 3
  • Here we are defining a menu, and referencing it with the name main to match our header (.Site.Menus.main)
  • In Hugo there is another way to create a menu quickly, and that is by adding this line to your config.toml file instead, more information here
    sectionPagesMenu = "main"
  • However we want to be able to customise our nav menu and add icons, therefore we'll go with the manual approach

Write your first post

The real value of a website is its content. Let's create a post before we have a look at the final result.

  • Open a terminal and use the following command from the root of your site to create a post
    hugo new posts/my-first-post.md
  • Open the newly created example/content/posts/my-first-post.md
  • Add some tags to the front matter
    tags: ["foo", "bar"]
  • Add some content under the front matter
  • Hugo automatically takes the first 70 words of your content as its summary and stores it into the .Summary variable
  • Instead, you can manually define where the summary ends with a <!--more--> divider
  • Alternatively, you can add a summary to the front matter if you don't want your summary to be the beginning of your post
  • The final result should look similar to this
    ---
    title: "My First Post"
    date: 2020-01-26T23:11:13Z
    draft: true
    tags: ["foo", "bar"]
    ---
    Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor 
    incididunt ut labore et dolore magna aliqua. Pellentesque eu tincidunt tortor 
    aliquam nulla facilisi cras fermentum odio. A erat nam at lectus urna duis. 
    Sed velit dignissim sodales ut eu sem. Lectus urna duis convallis convallis 
    tellus. Diam sit amet nisl suscipit adipiscing bibendum est. Sed felis eget 
    velit aliquet sagittis id consectetur. Vulputate dignissim suspendisse in est 
    ante in nibh mauris cursus. Morbi quis commodo odio aenean. Mollis nunc sed id 
    semper risus in hendrerit gravida rutrum.
    
    <!--more-->
    
    Ac ut consequat semper viverra nam. Hac habitasse platea dictumst vestibulum 
    rhoncus. Amet porttitor eget dolor morbi non. Justo eget magna fermentum 
    iaculis eu non. Id eu nisl nunc mi ipsum faucibus vitae aliquet nec. Aliquam 
    id diam maecenas ultricies. Non sodales neque sodales ut etiam. Amet massa 
    vitae tortor condimentum lacinia quis. Erat imperdiet sed euismod nisi porta. 
    Nisl suscipit adipiscing bibendum est ultricies integer quis auctor. Viverra 
    suspendisse potenti nullam ac. Tincidunt id aliquet risus feugiat in. Varius 
    quam quisque id diam vel. Egestas erat imperdiet sed euismod nisi. Scelerisque 
    felis imperdiet proin fermentum leo vel orci porta non. Ut faucibus pulvinar 
    elementum integer. Fermentum odio eu feugiat pretium nibh ipsum consequat nisl.

Trying it out

  • Open a terminal and run the following from the root folder of your site
    hugo server -D
  • The -D option means to include content marked as draft
  • Alternatively, edit the front matter of your post and change this line draft: true to draft: false
  • Navigate to http://localhost:1313
  • You should see something like this image

Final thoughts

In this post I've showed how to create a simple template and apply it to a new Hugo site. From here, you can customise the look and feel with the style.css file and modify the template to add more features.

In future posts I will show how to add share buttons and analytics to our site.

If you want to jump ahead and see the final template that I use for my site, you can find it in GitHub here.

Thanks for reading!