49 lines
1.3 KiB
TypeScript
49 lines
1.3 KiB
TypeScript
// Copyright: Ankitects Pty Ltd and contributors
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// License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
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import { mathIcon } from "./icons";
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const parser = new DOMParser();
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const errorPattern = /<title>(.*?)<\/title>/gsu;
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function getStyle(): HTMLStyleElement {
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const style = document.createElement("style") as HTMLStyleElement;
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const css = `svg { color: white; fill: white; font-size: 20px; }`;
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style.appendChild(document.createTextNode(css));
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return style;
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}
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function getEmptyIcon(): string {
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const style = getStyle();
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const icon = parser.parseFromString(mathIcon, "image/svg+xml");
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const svg = icon.children[0];
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svg.insertBefore(style, svg.children[0]);
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return svg.outerHTML;
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}
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export function convertMathjax(input: string): string {
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if (input.trim().length === 0) {
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return getEmptyIcon();
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}
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const output = globalThis.MathJax.tex2svg(input);
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const svg = output.children[0];
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if (svg.viewBox.baseVal.height === 16) {
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return getEmptyIcon();
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}
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if (!svg.innerHTML.includes("data-mjx-error")) {
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const style = getStyle();
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svg.insertBefore(style, svg.children[0]);
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return svg.outerHTML;
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} else {
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const match = errorPattern.exec(svg.innerHTML);
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throw match ? match[1] : "Unknown error";
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}
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}
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