Enabling Custom Jekyll Plugins with TravisCI

Sun, 12 Aug 2018 02:14:14 -0700

I just learned about TravisCI (actually, about continuous integration (CI) in general) after attending Neurohackademy 2018. We learned about CI from the perspective of ensuring that your code builds properly when you update files in your packages, incorporate new methods, refactor your code, etc. Pretty neat.

Fast forward a couple days, and I’m trying to incorporate custom Jekyll plugins into my blog – I quickly realized GitHub doesn’t allow this for security reasons, but I couldn’t find a convenient work-around. Some posts suggested using a separate repo branch to build the site, and then push the static HTML files up to a remote repo to do the actual hosting, but for some reason I couldn’t get that approach to work.

Finally, I saw some mentions of using TravisCI and CircleCI to build and push the site using continuous integration. I ended up using the approach suggested by Josh Frankel.

Josh’s site gives a really clear explanation of the necessary steps, given some very minmal prequisite knowledge about using Git. His instructions actually worked almost perfectly for me, so I won’t repeat them again here (just follow the link above, if you’re interested) – however, there were a few issues that arose on my end:

For some reason, I had an about.html file and index.html file in the main repo directory – my built blog wouldn’t register any updates I made to about.md or index.md while these files were around, so I deleted the HTML files. This might have been an obvious bug to someone with more web programming experience, but I’m a novice at that. If you’re seeing any wonky behavior, check to make sure you don’t have any unnecessary files hanging around.
Ruby version: I had to change the version of Ruby I was using to ruby-2.4.1.
Plugins: Make sure any Jekyll plugins you want to use are already installed.
Emails: You can turn off email reporting from TravisCI by adding notifications: email: false to your .travis.yml file.

But now, you can incorporate custom, user-built Jekyll plugins and let TravisCI do the heavy lifting! I specifically wanted the ability to reference papers using BibTex-style citation links with Jekyll, like you can with LaTex or Endnote – this capability isn’t currently supported by GitHub. Happy blogging!

Rendering LaTex In Markdown Using Jekyll

Sat, 11 Aug 2018 02:14:14 -0700

In putting together this blog, I wanted to be able to talk about various mathematical topics that I found interesting, which inevitably lead to using LaTex in my posts.

I’m currently using Atom as my editor (having converted from Sublime), and needed to install a bunch of packages first. First and foremost, I wanted to be able to render my markdown posts before hosting them on the blog, and consequentially needed a way to render LaTex. For this, I installed a few Atom packages:

To preview your post in Atom, you just type ctrl+shift+M, which will display both in-line and block math sections.

However, if you build your site locally with the command bundle exec jekyll serve or push it to a remote repo, the LaTex no longer renders properly. After Googling around a bit, I determined that this was due to the way markdown converters in Jekyll, like kramdown and redcarpet, do the conversion using MathJax – specifically, in-line math segments are not properly rendered. I wanted a way to both preview the LaTex in Atom, and properly render it usng Jekyll. I found two links that solved the problem for me:

In short, the following steps solved the problem of LaTex not rendering for me. I’m using the minima theme, so I first found the theme directory with bundle show minima. In this directory, I copied the ./layouts/post.html to a local directory in my project folder called ./_layouts/post.html.

Within this file, I pasted the following two sections of HTML code:

<script type="text/x-mathjax-config">
 MathJax.Hub.Config({
 tex2jax: {
 skipTags: ['script', 'noscript', 'style', 'textarea', 'pre'],
 inlineMath: [['$','$']]
 }
 });
 </script>
<script src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML" type="text/javascript"></script>

And voila – building the posts now correctly renders LaTex!

Jekyll |

Enabling Custom Jekyll Plugins with TravisCI

Rendering LaTex In Markdown Using Jekyll