LaTeX Maths — proper equations in any post

Members write LaTeX. Your community renders it. An integral looks like an integral, a matrix looks like a matrix, and a fraction stops being (a+b)/(c+d) typed in despair.

Invision Community offers LaTeX support on its Cloud plans. On a self-hosted Classic licence it is not available at any price. This is that feature, for the licence you already own.

What it does

• Renders maths anywhere content is shown. Forums, Pages, Blog, Clubs, comments — one pass covers them all, because it works on the rendered page rather than hooking each application in turn.
• Display and inline. $$ … $$ gives a centred equation on its own line; \( … \) sets maths inside a sentence, so a variable can sit in the middle of a paragraph without breaking the line.
• An editor button. Members who do not know the syntax press it, get the delimiters, and type between them.
• Nothing to sign up for. No API key, no service, no per-equation cost. The renderer ships inside the application and runs in the reader's browser.

It renders when the page is shown, not when the post is saved

This is the decision the whole application turns on, and it is worth understanding before you buy.

Your posts keep the notation exactly as it was typed. Nothing is rewritten in your database, so a member editing a two-year-old post edits what they wrote rather than a wall of generated markup — and if you ever switch the application off, or remove it, every post simply shows its notation again. There is no migration, and nothing to unpick.

The things that usually go wrong, and do not here

• Money stays money. Treating a single $ … $ as maths is off by default, because "it cost $5 and then $10 more" is a sentence, not an equation. Turn it on if yours is a maths or science community where that trade makes sense; \( … \) does the same job with no ambiguity.
• Code stays code. Anything inside a code block is left alone, so a member explaining LaTeX is not silently rendered by the thing they are explaining.
• A typo does not take the page down. Malformed notation shows in red, in place. Every other equation on the page still renders.
• A pasted thesis cannot hang a browser. There is a ceiling on how many equations one post will typeset. Past it, the notation is left as text rather than rendered.

Requirements

• Invision Community 5.0 or newer, self-hosted
• Nothing else. No account, no key, no external service, and no outbound connection — the maths renderer is bundled and served from your own site, so it works on a closed network and under a strict content security policy

Built to be safe

Rendering is done by KaTeX, the typesetting library used by Khan Academy, and it runs with the LaTeX commands that can reach outside a post — \href and friends — switched off, so a member's equation cannot become a link out of your community.

It is upgrade-safe: it adds no database tables, hooks no templates, and never edits a core file.

Version 1.0.0 · Invision Community 5 · self-hosted