gitlab-org--gitlab-foss/app/assets/javascripts/render_math.js
2018-01-30 14:54:23 -06:00

63 lines
1.5 KiB
JavaScript

/* global katex */
// Renders math using KaTeX in any element with the
// `js-render-math` class
//
// ### Example Markup
//
// <code class="js-render-math"></div>
//
import { __ } from './locale';
import axios from './lib/utils/axios_utils';
import flash from './flash';
// Only load once
let katexLoaded = false;
// Loop over all math elements and render math
function renderWithKaTeX(elements) {
elements.each(function katexElementsLoop() {
const mathNode = $('<span></span>');
const $this = $(this);
const display = $this.attr('data-math-style') === 'display';
try {
katex.render($this.text(), mathNode.get(0), { displayMode: display, throwOnError: false });
mathNode.insertAfter($this);
$this.remove();
} catch (err) {
throw err;
}
});
}
export default function renderMath($els) {
if (!$els.length) return;
if (katexLoaded) {
renderWithKaTeX($els);
} else {
axios.get(gon.katex_css_url)
.then(() => {
const css = $('<link>', {
rel: 'stylesheet',
type: 'text/css',
href: gon.katex_css_url,
});
css.appendTo('head');
})
.then(() => axios.get(gon.katex_js_url, {
responseType: 'text',
}))
.then(({ data }) => {
// Add katex js to our document
$.globalEval(data);
})
.then(() => {
katexLoaded = true;
renderWithKaTeX($els); // Run KaTeX
})
.catch(() => flash(__('An error occurred while rendering KaTeX')));
}
}