Mathlifier

A wrapper for KaTeX renderToString for inline and displayed math

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Why Mathlifier?

Using KaTeX with dynamic/reactive mathematical content, or with server side rendering, typically mean calling katex.renderToString() many times.

Mathlifier repackages these function calls as math() and display(), along with 3 opinions:

Opinion 1: throwOnError: false

While KaTeX sets throwOnError to true by default, we have opted to set it to false

We think that this facilitates quicker debugging (especially useful when hot module reloading (HMR) is active).

Opinion 2: No line break in inline math

By default, we wrap all inputs with braces to prevent automatic line-breaking.

Disable this with an option

Opinion 3: Displayed math with overflow-x: auto

By default, we place displayed math inside a container styled with overflow-x: auto. We believe this modification makes the output more mobile-friendly.

Disable this with an option

Installing Mathlifier

npm i mathlifier

Using Mathlifier

// import functions
import { math, display } from 'mathlifier';
// example of using these functions
const inlineMath = math('ax^2+bx+c=0');
const displayedMath = display('x=\\frac{-b\\pm\\sqrt{b^2-4ac}}{2a}');

Subsequently, attach the HTML string(s) generated to the DOM.

KaTeX Stylesheet

Just like in KaTeX, we will need to add a stylesheet. Refer to the KaTeX Documentation for more details, or add the following into the head element.

<link
	rel="stylesheet"
	href="https://cdn.jsdelivr.net/npm/katex@0.16.4/dist/katex.min.css"
	integrity="sha384-vKruj+a13U8yHIkAyGgK1J3ArTLzrFGBbBc0tDp4ad/EyewESeXE/Iv67Aj8gKZ0"
	crossorigin="anonymous"
/>

Custom Mathlifier options

We can disable the default behavior (opinions 2 and 3 above) of Mathlifier vs regular KaTeX

// example of Mathlifier options
const allowBreak = math('e^{i\\pi} = -1', { wrap: true });
const noContainer = display('\\sum_{r=1}^n = \\frac{n(n+1)}{2}', { overflowAuto: false });

KaTeX options

All KaTeX options are passed along.

// example of KaTeX options
const leftEqn = display('\\begin{equation} A = \\pi r^2 \\end{equation}', {
	leqno: true,
	fleqn: true,
});

Other features

We also have quick wrappers for four of the commonly used display environments: align, align*, gather, gather*.

// display environments
import { align, alignStar, gather, gatherStar } from 'mathlifier';
const gatherEnv = alignStar(`
  x+3y &= 3 \\\\
  2x-y &= -2
`);
// equivalent to
// display(`\\begin{align*}
//   x+3y &= 3 \\\\
//   2x-y &= -2
// \\end{align*}
// `);

Typesetting Utils

We have also added linebreak (to add the html <br> tag) and the function bold(x) (to wrap x in the <strong></strong> environment).

This is to facilitate using the same javascript code to generate both HTML (via KaTeX) and LaTeX by swapping out this library for an upcoming package (Mathlifier2?).

Credits

KaTeX

License

MIT