113 lines
3.4 KiB
JavaScript
113 lines
3.4 KiB
JavaScript
/* eslint no-console:0 */
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/* global katex */
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const splitAtDelimiters = require("./splitAtDelimiters");
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const splitWithDelimiters = function(text, delimiters) {
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let data = [{type: "text", data: text}];
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for (let i = 0; i < delimiters.length; i++) {
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const delimiter = delimiters[i];
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data = splitAtDelimiters(
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data, delimiter.left, delimiter.right,
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delimiter.display || false);
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}
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return data;
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};
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const renderMathInText = function(text, delimiters) {
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const data = splitWithDelimiters(text, delimiters);
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const fragment = document.createDocumentFragment();
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for (let i = 0; i < data.length; i++) {
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if (data[i].type === "text") {
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fragment.appendChild(document.createTextNode(data[i].data));
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} else {
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const span = document.createElement("span");
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const math = data[i].data;
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try {
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katex.render(math, span, {
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displayMode: data[i].display,
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});
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} catch (e) {
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if (!(e instanceof katex.ParseError)) {
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throw e;
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}
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console.error(
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"KaTeX auto-render: Failed to parse `" + data[i].data +
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"` with ",
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e
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);
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fragment.appendChild(document.createTextNode(data[i].rawData));
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continue;
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}
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fragment.appendChild(span);
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}
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}
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return fragment;
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};
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const renderElem = function(elem, delimiters, ignoredTags) {
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for (let i = 0; i < elem.childNodes.length; i++) {
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const childNode = elem.childNodes[i];
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if (childNode.nodeType === 3) {
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// Text node
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const frag = renderMathInText(childNode.textContent, delimiters);
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i += frag.childNodes.length - 1;
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elem.replaceChild(frag, childNode);
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} else if (childNode.nodeType === 1) {
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// Element node
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const shouldRender = ignoredTags.indexOf(
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childNode.nodeName.toLowerCase()) === -1;
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if (shouldRender) {
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renderElem(childNode, delimiters, ignoredTags);
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}
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}
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// Otherwise, it's something else, and ignore it.
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}
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};
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const defaultOptions = {
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delimiters: [
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{left: "$$", right: "$$", display: true},
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{left: "\\[", right: "\\]", display: true},
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{left: "\\(", right: "\\)", display: false},
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// LaTeX uses this, but it ruins the display of normal `$` in text:
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// {left: "$", right: "$", display: false},
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],
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ignoredTags: [
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"script", "noscript", "style", "textarea", "pre", "code",
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],
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};
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const extend = function(obj) {
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// Adapted from underscore.js' `_.extend`. See LICENSE.txt for license.
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let source;
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let prop;
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const length = arguments.length;
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for (let i = 1; i < length; i++) {
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source = arguments[i];
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for (prop in source) {
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if (Object.prototype.hasOwnProperty.call(source, prop)) {
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obj[prop] = source[prop];
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}
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}
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}
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return obj;
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};
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const renderMathInElement = function(elem, options) {
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if (!elem) {
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throw new Error("No element provided to render");
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}
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options = extend({}, defaultOptions, options);
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renderElem(elem, options.delimiters, options.ignoredTags);
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};
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module.exports = renderMathInElement;
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