I use MkDocs but wish the navigation were more compact like ReadTheDocs.

In this post I’ll recount the steps I followed to create the ReadTheDocs Dropdown theme.


Goal: Provide collapsable menu support in a MkDocs theme.

Results: mkdocs-rtd-dropdown

Preparing the Theme

Using their theming guide, I set up a theme repository with the ReadTheDocs theme from the mkdocs repo. At this point, the theme is just a copy of the existing ReadTheDocs theme.

Digging Deeper - Hacking MkDocs

The first step in adjusting a MkDocs theme is understanding what the MkDocs source does when it parses markdown.

To do this, I forked mkdocs and added debugging statements in a new dev branch

Development environment

Using virtualenv, I setup a env with my modified version of mkdocs. First I switch the official mkdocs package with my dev branch (currently commented out) in requirements.txt. Then I create and activate my environment with the following commands:

virtualenv .env
source .env/bin/activate
pip install -r requirements.txt
source .env/bin/activate

Now, when I run mkdocs serve the first output message i see is my development indicator:

(.env) mkdocs-rtd-dropdown $ mkdocs serve
INFO    -  Development Branch: cjsheets/mkdocs
INFO    -  Building documentation...

Now I can add debug statements anywhere in the mkdocs build process to inspect how my theme is being applied.

Alternatively, I can point requirements.txt to my local mkdocs repository and install using a local, development copy.

pip install -e /...path/mkdocs/