FYI: the katex gem

[glebm]

Hi! I needed server-side KaTeX in Ruby a while ago and maintain this gem: https://github.com/glebm/katex-ruby (predates sskatex by about 10 months).

It has some differences: the assets are bundled with the gem (allowing for a simpler API), and Rails is supported out of the box.

I also use my gem with kramdown (for Thredded): https://github.com/thredded/thredded-markdown_katex/blob/master/lib/thredded/markdown_katex/kramdown/katex_converter.rb

[ccorn]

Interesting! Some remarks:

• Bundling KaTeX removes the need to expose Javascript location setters, which enables secure handling of untrusted configuration input.
• On the other hand, that takes control of the KaTeX version away from users. Upgrading katex.js can introduce incompatible changes like the handling of \color which can change the output in a significant way. Users need a way to control that.
• Bundling KaTeX requires commitment to watch KaTeX releases.
• The use of Javascript wrappers in SsKaTeX should be sufficiently general that changing those wrappers could allow interfacing with MathJax instead of KaTeX. I have not tried that yet, and I like KaTeX's ease of use, but getting MathJax to work with SsKaTeX would be cool.
• So basically SsKaTeX is a toolset that leaves control to its users, while katex-ruby is the batteries-included ready-to-use approach.
• I like your explicit catching of KaTeX ParseError if throwOnError is off. Seems like a good idea to me, and I might patch the tex_to_html.js wrapper accordingly.

[glebm]

I agree with all the remarks but this one:

On the other hand, that takes control of the KaTeX version away from users. Upgrading katex.js can introduce incompatible changes like the handling of \color which can change the output in a significant way. Users need a way to control that.

The user can control this by choosing the appropriate gem version, assuming all KaTeX releases have a corresponding gem release.

[ccorn]

Perhaps a best of both worlds approach would be to bundle KaTeX while also allowing the user to specify a different JS file at initialization. I'll look into adding this to the katex gem.

Note that adding such an option necessitates security considerations and hardening efforts. Which is why I recommend against installation of the SsKaTeX gem for kramdown as long as the configuration can be changed by untrusted users. Your bundling of KaTeX has the advantage that no JS injection points need to be exposed. You might want to keep it that way.

[glebm]

You're right. Also for a motivated user it is easy to fork the gem and run rake update[v1.2.3] if they need a different version.