Thanks a lot for a thorough reply. I should hav been more specific about what I meant by "not working". Yes you are absolutely correct, the class got added but the code chunk got parsed as Mathjax.
The reason why I'd like to avoid
.className is that I am extending xaringan using, among other things some xaringanExtra features, and I want the "framwork" to be as easy to use as possible. I would like it to be used by teachers at my uni so ease of use is highly desirable.
What I need is for all code in a div of that class to be processed with
echo= being globally set to
FALSE. Also, less typing is better...
So the idea was to have a chunk opt, e.g.
panel=TRUE that would take care both of
echo= and the wrapper
<div>class. I then have some JS that uses xaringanExtra-style tabs and displays the plot in the chunk and the corresponding code in two tabs (see https://and.netlify.app/lectures/01/slides/#5)
And sure, it can be done with
echo=TRUE but that's not elegant