param mathjax is useless in function build_reference

[BruceZhaoR]

pkgdown/R/build-reference.R

Lines 205 to 210 in b279865

	data_reference_topic <- function(topic,
	pkg,
	examples = TRUE,
	run_dont_run = FALSE,
	mathjax = TRUE
	) {

pkgdown:::data_reference_topic seems mathjax useless?

pkgdown/inst/templates/head.html

Lines 57 to 58 in b279865

	<!-- mathjax -->
	<script src='https://mathjax.rstudio.com/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML'></script>

The mathjax in head.html template didn't have any condition and apply to all sites.

BTW: https://mathjax.rstudio.com/... is unstable in China, sometimes can't be loaded. Why not use cdnjs ? #314

[jayhesselberth]

We can use cdnjs to provide mathjax.

The param is a separate issue, it doesn't get propagated the way it should. I think it should be passed in these as_data calls:

pkgdown/R/build-reference.R

Line 232 in b279865

out$description <- as_data(tags$tag_description[[1]])

pkgdown/R/build-reference.R

Line 255 in b279865

purrr::map(as_data) %>%

[jayhesselberth]

#833 will change the CDN for Mathjax.

I'm not sure why the mathjax param exists; it may be a vestigial parameter, I'll have to do some more digging.

The mathjax param in rmarkdown::html_document controls whether the Mathjax JS library is bundled with the document or not, but pkgdown loads it regardless. Alternatively it might have been used to control pandoc args.

[jayhesselberth]

@hadley Can you track down why this param exists? AFAICT it leads nowhere. Maybe we just remove it; including mathjax by default doesn't seem to be that much overhead.

[hadley]

I think it's vestigial and I'll remove it