Monday 23 October 2023

Markdown (and Mermaid) on Blogger in 2023

Building on the fine work of [cs905s](href="") on GitHub, I wanted to Markdown-enable my own blog and thought the process could be brought up-to-date - seven years have passed after all, and _that_ work was in turn based on something from [2011](! Blogger has, slowly but surely, changed since those instructions were written, so at the very least, here's an updated guide on how to do it. ### Extra Goals I had a couple of extra requirements over the previous solution, however. - I want to write **my whole post** in [GitHub-flavoured Markdown](; I use it all day (for PR descriptions, in Slack, writing documentation) and I'm pretty sick of the verbosity of `BOO` compared to `**BOO**`! - I also _never want to have to type `<` ever again_ so I want the script to perform that replacement for me. - I have fallen in love with [Mermaid]( for Markdown-inspired/embedded diagrams and want them to _Just Work_ in my blog in the same way GitHub does it, with a ` ```mermaid ... ``` ` code fence For a fairly-techy blog, just those changes, plus being able to use backticks and other speedups, _just like it's GitHub/Slack_ is really valuable to me. Here's an example embedded Mermaid flowchart, just because I can now: ```mermaid flowchart TD A[Have Blogger-hosted Blog] -->|Configure Markdown| B(Write blog post) B --> C{Has markdown-enabled label ?} C -->|Yes| D[Render Markdown to HTML post body] D --> E[Hide original Markdown area] C -->|No| F[Leave post body untouched] F --> G{Has pre with class markdown ?} G -->|Yes| H[Render pre to HTML] E --> I{Has pre with class mermaid ?} H --> I I --> |Yes| J[Render with Mermaid.js] I --> |No| K[Done] ``` So once you've added a `markdown-enabled` **Label** on your post, the entire **blog post body** will be considered the Markdown source. I decided to "opt-in" like this as I've got a couple-of-hundred non-Markdown-annotated blog posts that I didn't really fancy going back and opting-out of. Well, actually I did try to automate this but lost data in the process, so aborted that little yak-shaving side-mission. The script will also remove that particular label from the DOM so nobody will see that "load-bearing label" 😉. The source is [here on GitHub](, and I'll endeavour to keep it working well on the Blogger platform over time. Check the README for the step-by-step instructions if you want to Markdown-enable your own blog!