rehype-katex

rehype plugin to transform <span class=math-inline> and <div class=math-display> with KaTeX.

Install

npm:

npm install rehype-katex

Use

Say we have the following file, example.html:

<p>
  Lift(<span class="math math-inline">L</span>) can be determined by Lift Coefficient
  (<span class="math math-inline">C_L</span>) like the following equation.
</p>

<div class="math math-display">
  L = \frac{1}{2} \rho v^2 S C_L
</div>

And our script, example.js, looks as follows:

const vfile = require('to-vfile')
const unified = require('unified')
const parse = require('rehype-parse')
const katex = require('rehype-katex')
const stringify = require('rehype-stringify')

unified()
  .use(parse, {fragment: true})
  .use(katex)
  .use(stringify)
  .process(vfile.readSync('example.html'), function(err, file) {
    if (err) throw err
    console.log(String(file))
  })

Now, running node example yields:

<p>
  Lift(<span class="math math-inline"><span class="katex"><span class="katex-mathml"><math><semantics><mrow><mi>L</mi></mrow><annotation encoding="application/x-tex">L</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.68333em;vertical-align:0em;"></span><span class="mord mathdefault">L</span></span></span></span></span>) can be determined by Lift Coefficient
  (<span class="math math-inline"><span class="katex"><span class="katex-mathml"><math><semantics><mrow><msub><mi>C</mi><mi>L</mi></msub></mrow><annotation encoding="application/x-tex">C_L</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.83333em;vertical-align:-0.15em;"></span><span class="mord"><span class="mord mathdefault" style="margin-right:0.07153em;">C</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.32833099999999993em;"><span style="top:-2.5500000000000003em;margin-left:-0.07153em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathdefault mtight">L</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span></span>) like the following equation.
</p>

<div class="math math-display"><span class="katex-display"><span class="katex"><span class="katex-mathml"><math><semantics><mrow><mi>L</mi><mo>=</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><mi>ρ</mi><msup><mi>v</mi><mn>2</mn></msup><mi>S</mi><msub><mi>C</mi><mi>L</mi></msub></mrow><annotation encoding="application/x-tex">
  L = \frac{1}{2} \rho v^2 S C_L
</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.68333em;vertical-align:0em;"></span><span class="mord mathdefault">L</span><span class="mspace" style="margin-right:0.2777777777777778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2777777777777778em;"></span></span><span class="base"><span class="strut" style="height:2.00744em;vertical-align:-0.686em;"></span><span class="mord"><span class="mopen nulldelimiter"></span><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:1.32144em;"><span style="top:-2.314em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">2</span></span></span><span style="top:-3.23em;"><span class="pstrut" style="height:3em;"></span><span class="frac-line" style="border-bottom-width:0.04em;"></span></span><span style="top:-3.677em;"><span class="pstrut" style="height:3em;"></span><span class="mord"><span class="mord">1</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.686em;"><span></span></span></span></span></span><span class="mclose nulldelimiter"></span></span><span class="mord mathdefault">ρ</span><span class="mord"><span class="mord mathdefault" style="margin-right:0.03588em;">v</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641079999999999em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span></span></span></span></span><span class="mord mathdefault" style="margin-right:0.05764em;">S</span><span class="mord"><span class="mord mathdefault" style="margin-right:0.07153em;">C</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.32833099999999993em;"><span style="top:-2.5500000000000003em;margin-left:-0.07153em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathdefault mtight">L</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span></span></span></span></span></div>

API

rehype().use(katex[, options])

Transform <span class="math-inline"> and <div class="math-display"> with KaTeX.

options

options.throwOnError

Throw if a KaTeX parse error occurs (boolean, default: false). See KaTeX options.

options.<*>

All other options, except for displayMode, are passed to KaTeX.

Security

Use of rehype-katex renders user content with KaTeX, so any vulnerability in KaTeX can open you to a cross-site scripting (XSS) attack.

Always be wary of user input and use rehype-sanitize.

Contribute

See contributing.md in remarkjs/.github for ways to get started. See support.md for ways to get help.

This project has a Code of Conduct. By interacting with this repository, organisation, or community you agree to abide by its terms.

License

MIT © Junyoung Choi