Sigma theme for Jekyll

This theme is a subjective one focused on speed and SEO, taking care of a beautiful appearance.

• Golden proportion header.
• Modern and responsive design.
• Light/dark toggle button.
• Search using lunr.js.
• SEO friendly, fully optimized.
• Sticky menu + scroll up button.
• Sticky sidebar with sidenavs.
• Layouts with sidebar right/left/none.
• Set custom sidebar for every page.
• Code blocks syntax highlighting.
• LaTeX maths, Katex integrated.
• Loop posts in category pages.
• Top navigation links to next/prev posts.
• Bottom links to next/prev posts.
• Navigation links by category or by tag.
• Breadcrumbs with Schema.org.
• Schema.org for posts and categories.
• User interface multilanguage.
• Advertisements zones (content and sidebar).
• A lot of web services available.
  • Google Analytics
  • Open Graph
  • Twitter Cards
  • Sites verification

Check the Sigma theme unit test repository to test it.

Installation

Add this line to your Jekyll site's Gemfile:

gem "sigma-theme"

And add this line to your Jekyll site's _config.yml:

theme: sigma-theme
plugins:
  - jekyll-data
  - jekyll-feed
  - jekyll-sitemap
  - jekyll-minifier

And then execute:

$ bundle

Or install it yourself as:

$ gem install sigma-theme

Usage

Header config

Display the top bar, in _config.yml:

• topbar: true or false to show the top bar.

Top bar links, in _config.yml:

• twitter_username: Your Twitter username.
• facebook_username: Your Facebook username.
• linkedin_username: Your LinkedIn username.
• pinterest_username: Your Pinterest username.
• instagram_username: Your Instagram username.
• github_username: Your Github username.
• youtube_username: Your Youtube username.
• sitemap_link: true or false to show the link pointing to the sitemap.xml generated by the plugin jekyll-sitemap.
• search_url: The path of your search page. Then you will include search-lunr.html in that page.
• rss_feed: Paste here your custom feed link. If not, it will link to the default feed.xml file.
• color_toggle: Toggle between light and dark color schemes.

Logotype, in _config.yml:

logo:
  path: relative path
  width: an integer value
  height: an integer value

Sticky menu, in _config.yml:

• sticky_menu: true or false to make the menu sticky on scroll.

Scroll up button, in _config.yml:

• scrollup: true or false to display or hide the scroll up button.

Favicons, in _config.yml:

• favicon_ico: The relative path of your favicon.
• favicon_16: The relative path of a 16 pixels size icon.
• favicon_32: The relative path of a 32 pixels size icon.
• apple_touch: The relative path of your apple touch icon for Apple.
• webmanifest: The relative path of the webmanifest file for Android.
• browserconfig: The relative path of the browserconfig file for IE.
• mask_icon: The relative path of the SVG icon mask file for Safari.
• mask_color: An HEX color. The fill color needs to be defined.

This script generates the favicons.

Theme color, in _config.yml:

• theme_color: An HEX color. The fill color needs to be defined.

Breadcrumbs, in _config.yml:

• bc_sep: The breadcrumbs separator.

Insert custom CSS directly in the head:

• custom_css: The relative path of the .css file, that must be in _includes folder. It must be a CSS file, so you don't need to include the <style> tags.

Insert custom HTML directly in the head:

• custom_head: The relative path of the .html file, that must be in _includes folder. It must be an HTML file, so you will have to include the HTML tags.

Insert custom JS directly in the head:

• custom_js_top: The relative path of the .js file, that must be in _includes folder. It must be a JS file, so you don't need to include the <script> tags.

Insert custom JS directly in the foot:

• custom_js_foot: The relative path of the .js file, that must be in _includes folder. It must be a JS file, so you don't need to include the <script> tags.

Footer config

Bottom links, in _config.yml:

• Create the file footer-links.yml inside _data folder with the following structure:

docs:

- title:
  url:

Display the social media icons in the footer, in _config.yml:

• footer_icons: true or false to show the social media icons in the footer.

Copyright information, in _config.yml:

• first_year: Type here an integer, it should be the first year of your site. For example: 2012, it will output "2012-2019" (current year), automatically. If it's the same year as the current year, it will output simply "2019".
• copyright: Type here your copyright text. For example: «All rights reserved».

Sidebar config

First, in the post or page front matter:

sidebar: right / left / false

Sidebar structure:

1. Zone: sidebar top
2. Sidenav:

• Categories list in category pages
• Posts list in posts (same category)
• Pages list in pages

3. Custom layout for specific pages
4. Zone: sidebar bottom

Display a navigation menu in the sidebar (sidenav). Navigate between posts in the same category (layout = post), navigate between other categories in the category pages (layout = category) and navigate between pages in the pages itself (layout = page). Use it in the post or page front matter:

sidenav:
  categories: true
  posts: true
  pages: true

Use a custom layout in the sidebar for specific pages:

sidebar_custom: my-custom-menu-for-this-awesome-category.html

Advertisements zones: sidebar

You can display zones for advertisements in the top or the bottom of your sidebar.

Create html files into your _includes folder and use the filename as value in the post or page front matter:

zone:
  sidebar_top: ads-sidebar-top.html
  sidebar_bottom: ads-sidebar-bottom.html

Advertisements zones: content

You can also display zones for advertisements in the top or the bottom of your content.

Create html files into your _includes folder and use the filename as value in the post or page front matter:

zone:
  content_top: ads-above-h1.html
  content_bottom: ads-below-content.html

For the sidebar, first it must be displayed.

Web services

Google Analytics, in _config.yml:

• google_analytics: Type here your Analytics ID. Format: UA-nnnnnnnn-n

Open Graph, in _config.yml:

• fb_admins: Your Facebook admin ID.
• fb_app_id: Your Facebook app ID.
• og_locale: The language locale. For example: en_US, es_CA, es_ES, etc.

In the post or page front matter:

• image: Add the relative path of the post/page image.

Twitter Cards, in _config.yml:

• twc_user: Your Twitter username to use in the Twitter cards.

Sites verification, in _config.yml:

• google_sv: Your Google site verification.
• bing_sv: Your Bing site verification.

SEO:

• For the title tag, it will use the post/page title.
• For the canonical link, it will use the post/page link.

Meta tags, in post or page front matter:

• robots: Must be a robots setup: index,follow, noindex,follow…
• metadesc: A description of the page. Less than 160 characters is recommended.
• kewyords: A list of keywords. Google does not use them, though.

There is no prevision of using pagination in this theme at the moment, so rel="prev" and rel="next" are not included in category pages. This theme lists all posts of a category in one category page.

To-Do: Make the pagination customizable.

Insert backlink to the copied text when someone decides to copy text:

• linking: true or false.

Maths

Katex library, in post or page front matter:

• latex: true or false to use Katex.

Misc

Tools for the content, in post or page front matter:

• read_time: true or false to show the read time of a page/post.
• breadcrumbs: true or false to show the breadcrumbs.
• postmeta: true or false to show the 'post meta' under the h1.
• nav_by: "cat" or "tag" to navigate between posts by category or by tag.
• navbar: true or false to show top links to next/prev posts and index.
• posts_np: true or false to show bottom links to next/prev posts.
• share: true or false to show the share buttons.
• sidebar: right or left to show the sidebar.
• sticky_side: true or false to make the sidebar sticky on scroll.
• rouge: true to load the rouge CSS.
• order: customize the posts order in the loops.
• cookies: the html filename.
• version: any value, version number or date for CSS/JS files.
• suffix: true or false to add a suffix to the post/page: " | MySite" with the title site.
• ldjson: true or false to add JSON-LD structured data snippet into posts or pages.
• og_type: introduce Open Graph metadata about of the type of your content: article, video, music, book, profile or website.

Setting up default settings for all posts and pages, automatically

You can configure default settings for all posts or pages. If then you configure an option in the post/page front matter, this will be the option used, overriding the default setting. Example with random values:

defaults:
  - scope:
      path: ""
      type: "posts"
    values:
      read_time: true
      breadcrumbs: true
      nav_by: cat
      navbar: ture
      posts_np: ture
      share: true
      latex: true
      sidebar: right
      sticky_side: true
      sidenav:
        posts: true
      zone:
        content_top: content-top.html
        content_bottom: content-bottom.html
        sidebar_top: ads-sidebar-top.html
        sidebar_bottom: ads-sidebar-bottom.html
  - scope:
      path: ""
      type: "pages"
    values:
      read_time: false
      breadcrumbs: true
      share: false
      sidebar: false
      sidenav:
        pages: true
        categories: true
      robots: noindex,nofollow

Category pages

Create a markdown page in your root site, with this minimal front matter:

---
layout: category
title: An awesome category and more things!
cat: Awesome category
h1: The Awesome Category
permalink: /awesome-category/
---

The cat must be the same of the category in posts: it will be used to show the total posts of a category.

About the total posts (counter):

• By default, it will count posts by category.
• To count posts by tag, use: counter: tag
• Don't show the total posts: counter: false

Include this line in the content to list all the posts of a category:

{% include loop-excerpt-cat.html cat="Awesome category" %}

Include this line in the content to list all the posts of a tag:

{% include loop-excerpt-tag.html tag="Beautiful tag" %}

Use excerpt: in the front matter of posts to display posts description in the category page.

You can use many categories as subcategories (i.e., /category/another/onemore/), and the breadcrumbs will show the links with the right path leveled → / (1), /category/ (2), /category/another/ (3) and /category/another/onemore/ (4). That means you must create category pages with this permalinks to avoid a 404 error.

If you wanted, you could create automatic permalinks with this: /:categories/:title/, however, if a category contains spaces it will not be correctly slugified, you should set permalinks manually in the front-matter or use /:slugified_categories/:title/, feature added in Jekyll version 4.1.

For posts, it doesn't matter if the permalink contains the categories or not, because after all, levels are present in the breadcrumbs using the Schema.org. So, for posts you still can use /:title/, without the categories.

I applied this philosophy since I'm not in favor of having multiple categories for a single post. Every post should have only one category, so having several categories becomes a leveled path of subcategories; that makes more sense to me.

Layouts

Define them in the front matter:

• home: Use it in your index.md, it's empty (only content included).
• page: Use it for your regular pages.
• post: Use if for your posts.
• category: Use it to create pages for categories.

Tips

• nav_by: cat and navbar: true or posts_np: true will link to the next/prev posts within the same category. It will use the last category assigned, because it's the subcategory. For example: categories: [vehicles, cars] will only navigate between cars. Therefore, it's a good idea to have the same level of categories in a project.
• nav_by: tag and navbar: true or posts_np: true will link to the next/prev posts within the same tag. Use only one keyword to agroup posts for next/prev navigation.

General front matter for posts

---
layout: post
title: A nice title for this post
h1: The heading of the post
author: An expert
last_modified_at: 2020-10-20
permalink: /the-post/
order: 55
category: "Awesome category"
metadesc: This is for the meta description
excerpt: >-
  This is the excerpt text of the post
image: images/whatever.jpg
sidebar_custom: original-sidebar.html
nav_by: tag
navbar: true
posts_np: true
tag: Art
---

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/gerardbm/sigma-theme. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The theme is available as open source under the terms of the MIT License.