knitr + jekyll + so simple theme or Why I started this...

Why a blog? Why about R?

The hole R blog idea is something that have been around of my mind since several years. But I had always a very good excuse to pospone it and to procastinate with another project.

I love R and the rich ecosystem which seems to be growing around it (hadleyverse, shiny, htmlwidgets…) even in those frustating moments when struggling with the code to achieve some data analysis or visualization with no fortune. And after a while, it seems to me the perfect timing to start writing about beardy data and other R adventures.

Data with beards? What the…?

After ten years trying to get some juice from different data sources, I have never found a perfect data set like the ones in the documentation or the examples. Sometimes data has beards, and mustaches, and in one ocassion, I met some data with sideburns.

So, I’m gonna try to use no so perfect data whenever I can in this blog, but no promises, though, iris is so damn pretty ;)

Why knitr, jekyll and so simple theme?

If I’m gonna write about R, I want to be able to write in Rmd files. This will allow to show the code and/or the results with no worries. Plus, I’m confident writing in markdown.
First option seemed to be R markdown websites, with its pros and cons, a subjective ones by the way.

• Pros

  1. It uses rmarkdown v2, which is nice because it allows you all the interactive stuff like htmlwidgets.

  2. You can use the RStudio IDE to build the pages, the same way when building a package or a shiny app.

• Cons

  1. Early development, only available from the preview version of RStudio. But it won’t surprise me if all the cons listed below are fixed sooner than later.

  2. No blog friendly. You can generate the html files, but all the blog structure and the goodies (rss feeds, tags, categories…) are missing.

  3. Involve too much tinkering to get something similar to a blog page to my pleasure. The idea of only write the Rmd files and after that some black magic creates the pages seemed very attractive for me.

Second option is jekyll:

• Pros

  1. It leverages the post-processing after writing the markdown document and creates all the necessary blog infrastructure.

  2. Lot of themes and templates, easy to find one that matches my taste.

  3. Integrates well with web servers and GitHub Pages

• Cons

  1. Generate static content, so forgot about fancy interactive apps with htmlwidgets. There is a workaround for this by Brendan Rocks.

  2. Works with md files, not Rmd. Umm, seems like I can not have it all.

  3. No integration with RStudio IDE, so I have to run system command to build the pages.

But, after a google search, I found this which led me to this repository. Here, Yihui Xie, software engineer at RStudio, explains how to use the servr package to be able to use Rmd documents in the jekyll workflow.

Finally I found the perfect combination. It allowed writing in R markdown and working in the RStudio IDE as a project combined with a git repository for control version, so I can feel like home. Also, using jekyll opened a world full of possibilities about themes and templates. After some searching, I found so simple theme, which is in fact an easy theme to use and configure.
As to htmlwidgets and shiny integration, if they can not be in the blog at least a small shiny-server can do the trick.

How to

Instructions on how to set up something similar are better detailed in the links above, but a summary is given:

1. Fork, clone and rename the so simple theme repository.

2. Install jekyll (In archlinux, first install ruby and after that use gem to install jekyll and bundler: gem install jekyll bundler).

3. Execute bundle install in the blog root folder. This way all theme dependencies are installed.

4. Replace all the template info with blog and author info. Replace example posts with your posts. Replace icons and logos with your icons and logos…
   tl_dr: replace all you need from the theme templates.

5. Configure _config.yml, _sass/_variable.scss and _sass/_syntax.scss files if needed. I did it to get the solarized style.

6. Create a build.R script as in the knitr-jekyll repository, and install servr package. Now servr::jekyll() is available.

After executing servr::jekyll() a _site folder is created in the root of the project. This folder contains all the structure and the pages of the blog and can be pushed to a web server in production mode.

And that is all

After the install and configuration now I only have to write an R markdown post and execute servr::jekyll(). After checking everything is ok I can push the _site folder to the server and the new post is online.
If you want to pick a look to the code used to generate this site, you can find it here.