Server-side LaTeX rendering

[MinimizationOrg]

Hello,

Thank you for your great work! The set of features provided by Quarto is very impressive!

We are converting a math heavy website from Jekyll to Quarto, and are surprised to learn that Quarto doesn't support server-side math rendering.

Would it be possible to consider adding this feature?

Both MathJax and KaTeX support server-side rendering for many years now, so hopefully this will not be too complicated to achieve. Another idea could be perhaps using pandoc to parse LaTeX directly.

Thank you in advance for your reply!

[mcanouil]

If MathJax/KaTeX can do that, then it should work within Quarto as long as you configure MathJax/KaTeX to use such feature.

Also note that the Math equation feature is from Pandoc as described in https://quarto.org/docs/output-formats/html-basics.html#latex-equations and from Pandoc documentation https://pandoc.org/MANUAL.html#math-rendering-in-html.

[cderv]

Server side math rendering is indeed not support by Quarto as Pandoc does not support it out of the box.
This would be an interesting feature for Quarto indeed.

I know of a solution in R that offers KaTeX server side rendering, which a post processor function for HTML document produced by Pandoc
https://docs.ropensci.org/katex/reference/pandoc.html

I'll convert to a feature request to follow discussion and future work on this.

[mcanouil]

I remembered a blog post on the matter which was edited to mention KaTeX and just found it, see https://masalmon.eu/2021/06/15/serverside-mathjax/.

[cderv]

Yes - remember than one about the experimentation by Maelle.

[MinimizationOrg]

Thanks @cderv and @mcanouil! Looking forward to the official implementation.

There are some existing Pandoc filters that could do the job. For example, for MathJax the following seem to work well:

• https://github.com/shreevatsa/pandoc-mathjax-filter
• https://github.com/pandoc/lua-filters/tree/master/math2svg

By the way, is there a way to globally disable math rendering in Quarto altogether? We are opting for a server-side rendering solution and it seems to have some incompatibility with the existing one.

[MinimizationOrg]

Update: In my new test, the superscript also happens for a^2+b^2=c^2 without math delimiters, so indeed this has nothing to do with math parsing.

[cderv]

The equation inside \begin{equation}\end{equation} has disappeared.

Yes your LaTeX part will be seen as raw latex, and this is not supposed to be in a HTML output. You can force Pandoc to include that in your output by using a raw LaTeX block I believe. or wrapping the content in some HTML tag you need.

Note that the superscript conversion did not happen outside the math delimiters (2^x and x^2 remain the same)

This is because by deactivating math parsing, you are telling pandoc that this is usual markdown syntax, and ^2+b^ will be seen a the Markdown superscript syntax (https://quarto.org/docs/authoring/markdown-basics.html#text-formatting), unless you espace this to avoid superscript processing.

What you want is almost a custom reader and / or writer that would parse the document differently than usual markdown and output differently than default Pandoc. I really think you should look into custom lua filter (through Quarto extension) so that you let Pandoc parse Math, but you catch them in Lua to write yourself the output you want.

Hope this clarifies what is happening in your tests.

[MinimizationOrg]

@cderv Thanks for the explanation, that totally makes sense! I have some ideas for the Lua filter that I'm going to try, will keep you updated! By the way, is it possible to apply a filter globally (i.e. to all documents)?

[cderv]

By the way, is it possible to apply a filter globally (i.e. to all documents)?

Yes you need to set configuration in _quarto.yml

Have a look at Extension also https://quarto.org/docs/extensions/ - you can store and share filter very easily this way.

[MinimizationOrg]

@cderv Great, thanks! I will share my filter for server-side MathJax rendering (which is just an upgrade of https://github.com/pandoc/lua-filters/tree/master/math2svg to MathJax v3).

[mcanouil]

Closing in favour of #5229