MathJax is So Easy to Install
(How Easy? So Easy)
Wow, I had no idea. It takes like 2 minutes to add MathJax to your site, if you use their CDN.
It’s pretty much what you’d think up if you had to spit out a stupidsimple install:
 you add the CDN include at the bottom of your
<body>
<script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
<script id="MathJaxscript" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/texmmlchtml.js"></script>

you write
\[math_{jax} * stuff = anywhere\]$$math_{jax} * stuff = anywhere$$
and it renders as:
Inline MathJax
If you try to write it inline (like $$x+2$$ so
) it shows up like \(x+2\) so, which really isn’t bad, and is probably what I’d do with pen & paper anyway. Markdown syntax highlighting does get confused by a single asterisk, though, so there might be a better way.
If I write inline in a <span>$$x+3$$</span>
I get \(x+3\), so no luck there.
Dumb mistakes
I just now realize $$ .. $$
is intended to signify BLOCK MODE and $ .. $
may be intended to signify INLINE MODE.^{1}
The docs are much more useful:
The default math delimiters are
$$...$$
and\[...\]
for displayed mathematics, and\(...\)
for inline mathematics. Note in particular that the$...$
inline delimiters are not used by default. That is because dollar signs appear too often in nonmathematical settings, which could cause some text to be treated as mathematics unexpectedly.
I guess that makes sense why I couldn’t get $..$
working, either.
Let’s try: like \[block = mode\] so
like [block = mode] so.
Let’s try: like \\[block = mode\\] so
like \[block = mode\] so.
Let’s try: like \(block = mode\) so
like (block = mode) so.
Let’s try: like \\(block = mode\\) so
like \(block = mode\) so.
Finally! I have found the inline mode: \\(x + 2\\)
will give me \(x + 2\) like I desired.
Downsides
Right now, there’s a weird TypeError: cannot convert null to object
from texmmlchtml.js:1:32937
which I am not going to look into. It kind of ruins the fastascrap responses I’m used to, but I could maybe probably:

work to get back to wrapping the MathJax sources into my blog output, so they’re hosted on this domain

work to only put the source includes on pages that have actual math on them, if possible

work to put that into a JavaScript snippet, and calculate the sha256/base64 for an updated ContentSecurityPolicy
Or I could just bet on the cache and use the CDN. Maybe my new take will be: browsers should come with MathJax and pulling it in from a CDN in the meantime is just the polyfill we need in this world.
Alternate includes
Maybe I need to find a different, or more slimmeddown include.
MathJax says I need this:
https://polyfill.io/v3/polyfill.min.js?features=es6
Do I? Is that the best ?features=
option?
It says I need:
https://cdn.jsdelivr.net/npm/mathjax@3/es5/texmmlchtml.js
Is that the only thing I can include? I don’t know. I know there’s a bit of lag sometimes, just livereloading between saves.
The plot thickens
The plot added corn starch.
No, really, the MathJax Getting Started says:
Note: the configuration file texmmlchtml.js is a great way to test both TeX and MathML input options at once. You can find leaner combined configuration packages in our documentation.
AKA Jackpot, Baby.
Reading on, MathML is some weird (not bad! just XML/SGML whatever) input format I most certainly won’t be typing any time soon ^{2}. So I could maybe subtract that out of my include.
To review, there are 8 configs to choose from:
texchtml < likely a better default for me
texchtmlfull < tempting..
texsvg
texsvgfull
texmmlchtml < default..
texmmlsvg
mmlchtml
mmlsvg
I could probably drop down to the texchtml
or down/up to texchtmlfull
. I’ll go down, knowing I can go to full if I want. Great!
I’m tempted to remove the polyfill include, but I don’t mind at the moment, unless it annoys me later. Right now, the texchtml.js
resource is 766.84 KB, 167.39 KB transferred. I could drop that single file out in my ./static/
directory, and include it in every single post (but not in lists).
I could even just leave the default off (so there is no impact at all to pages that don’t use it, like true bypass), and make blog posts that use math include a <script ..></>
tag themselves. I actually did that by accident, trying to demo how to include the CDN <script>
tags.
If you just write a <script>
tag in your Markdown, it’ll get included in the output^{3}.
MathJax: highly recommended!