Add LaTeX/MathML support

[bogdan-kulynych]

It would be great if Mastodon client could render mathematical equations in the toots. This can be very easily accomplished for web clients by including the MathJax script (62 Kb).

[RaitoBezarius]

After "working" on this issue a bit.
Some pointers are:

• ideally, we should load MathJax dynamically if user options allow it.
• then, we should hook in Redux actions creator when a new post is added to analyze if there is some kind of LaTeX in it, and then run http://docs.mathjax.org/en/latest/advanced/typeset.html on it.

I wonder if we could have a MathJax function which would turn a string of LaTeX to a bunch of DOM nodes.

Last concern: what about theming? How to integrate MathJax theme into Mastodon properly?

[RaitoBezarius]

After fighting with MathJax, I tried KaTeX and got this nice result with exactly two line changes:

→ http://screencloud.net/v/BAG8q

Basically, all that remains is:

• Load KaTeX dynamically using options.

• Hook in status_content.jsx a soft renderer which will output the same content if KaTeX throw or is unavailable else will return DOM nodes as strings (just filter out the <p> and unwanted data, check for ( ), etc…)

• Handle styling issues (when the mathematics overflows, wrapping them, etc…)

• PROFIT!!! 🎉

Also, it would be nice to handle new commands or aliases, how that would be persisted through an instance?
IMHO, ideally, I see two steps:

• Persist aliases on the local instance (we could easily imagine different aliases for different themed instances: statisticians, analysts, etc…)
• Protocol extension: Announce aliases to other instances to ensure compatibility. "Hey, this message is using these aliases, use them and not the ones on your instance!"

@bogdan-kulynych What do you think?

[bogdan-kulynych]

@RaitoBezarius
Looks great!
There's a gem for KaTeX. It can then be included as a sprockets conditional require in application_public.js. Probably user_params can be used directly in the require.

Aliases seems to be quite an advanced functionality. Why not start with basic maths support for this issue?

[Gargron]

I enjoy the fact that there is an instance which implements this (mathstodon), however including the Latex browser rendering runtime for everybody, even though barely anybody will use it except for very specialized cases, makes me believe we will not accept this into upstream.