Highlight current menu item in Jekyll for my cosmic radiation site

4 min. read

I decided to share my lab course from back in 2005, when I was teaching undergraduate students about the awesomity of cosmic radiation. As usual, I made a dedicated site for the project at http://cosmicrad.tk.

I had a lot of fun re-designing the lab guide and the old site so that it reminded of a spaceship, and this time I used HTML entities for the equations instead of MathJax. I turned it into a Jekyll site, so I could host it together with the code of the course. It is pretty similar to my other sites in terms of structure, and it includes a menu that highlights an item when it matches the current page.

Check out the portfolio post.

Highlight current menu item

I used a for loop to automatically populate the menu with the site's pages as I did in my Java snippets site. I also used permalinks and a short name for the items, whose value is specified in a Front Matter variable called short.

<ul>{% for p in site.pages %}{% if p.short %}
  <li><a {% if page.url == p.url %}class="selected"{% endif %} href="{{ p.url | prepend: site.baseurl }}">{{ p.short }}</a></li>{% endif %}{% endfor %}

To highlight the current item, I add a CSS class called "selected" if the current page matches the item. To check that, I compare the contents of the page.url liquid variable with the URL of the page of the current loop iteration, like this:

{% if page.url == p.url %}class="selected"{% endif %}

If the two URLs don't match, no class is added to the item.

Layouts folder

It has a default layout and an extra one to use with the 404 error page, where I change the header titles.

Includes folder

The structure is similar to my other pages, but I split the header file in two, to have different site titles for the error page and the rest of the pages.

Error page

For this site I tried the Google Custom Search (which is basically a script that you paste where you want the search form), since I still haven't got the time to fiddle with Jekyll search implementation. For what I've read in the manual, it doesn't look like there is a built-in searching capability. I might have to find the time to read this SO question more carefully.

The book

The PDF lab guide I made for this physics course looked a bit rusty after all these years. It was typeset with LaTeX, but it used all the LaTeX defaults. At that time I didn't care much about good looks XD. I decided to revamp it and that's how my first book-layout design ever made with LaTeX was born. If you are curious about it, I wrote about the process here. The site's code is in the GitHub repo.