wdown: katex/contrib/auto-render.mjs comparison

comparison katex/contrib/auto-render.mjs @ 8:4a25b534c81c javascript-experiment

Add v8 engine and include katex

author	Jonatan Werpers <jonatan@werpers.com>
date	Wed, 17 Jun 2020 21:43:52 +0200
parents
children

comparison

equal deleted inserted replaced

-:a5aa39557726
+:4a25b534c81c
+import katex from '../katex.mjs';
+/* eslint no-constant-condition:0 */
+const findEndOfMath = function findEndOfMath(delimiter, text, startIndex) {
+// Adapted from
+// https://github.com/Khan/perseus/blob/master/src/perseus-markdown.jsx
+let index = startIndex;
+let braceLevel = 0;
+const delimLength = delimiter.length;
+while (index < text.length) {
+const character = text[index];
+if (braceLevel <= 0 && text.slice(index, index + delimLength) === delimiter) {
+return index;
+} else if (character === "\\") {
+index++;
+} else if (character === "{") {
+braceLevel++;
+} else if (character === "}") {
+braceLevel--;
+}
+index++;
+}
+return -1;
+};
+const splitAtDelimiters = function splitAtDelimiters(startData, leftDelim, rightDelim, display) {
+const finalData = [];
+for (let i = 0; i < startData.length; i++) {
+if (startData[i].type === "text") {
+const text = startData[i].data;
+let lookingForLeft = true;
+let currIndex = 0;
+let nextIndex;
+nextIndex = text.indexOf(leftDelim);
+if (nextIndex !== -1) {
+currIndex = nextIndex;
+finalData.push({
+type: "text",
+data: text.slice(0, currIndex)
+});
+lookingForLeft = false;
+}
+while (true) {
+if (lookingForLeft) {
+nextIndex = text.indexOf(leftDelim, currIndex);
+if (nextIndex === -1) {
+break;
+}
+finalData.push({
+type: "text",
+data: text.slice(currIndex, nextIndex)
+});
+currIndex = nextIndex;
+} else {
+nextIndex = findEndOfMath(rightDelim, text, currIndex + leftDelim.length);
+if (nextIndex === -1) {
+break;
+}
+finalData.push({
+type: "math",
+data: text.slice(currIndex + leftDelim.length, nextIndex),
+rawData: text.slice(currIndex, nextIndex + rightDelim.length),
+display: display
+});
+currIndex = nextIndex + rightDelim.length;
+}
+lookingForLeft = !lookingForLeft;
+}
+finalData.push({
+type: "text",
+data: text.slice(currIndex)
+});
+} else {
+finalData.push(startData[i]);
+}
+}
+return finalData;
+};
+/* eslint no-console:0 */
+const splitWithDelimiters = function splitWithDelimiters(text, delimiters) {
+let data = [{
+type: "text",
+data: text
+}];
+for (let i = 0; i < delimiters.length; i++) {
+const delimiter = delimiters[i];
+data = splitAtDelimiters(data, delimiter.left, delimiter.right, delimiter.display || false);
+}
+return data;
+};
+/* Note: optionsCopy is mutated by this method. If it is ever exposed in the
+* API, we should copy it before mutating.
+*/
+const renderMathInText = function renderMathInText(text, optionsCopy) {
+const data = splitWithDelimiters(text, optionsCopy.delimiters);
+const fragment = document.createDocumentFragment();
+for (let i = 0; i < data.length; i++) {
+if (data[i].type === "text") {
+fragment.appendChild(document.createTextNode(data[i].data));
+} else {
+const span = document.createElement("span");
+let math = data[i].data; // Override any display mode defined in the settings with that
+// defined by the text itself
+optionsCopy.displayMode = data[i].display;
+try {
+if (optionsCopy.preProcess) {
+math = optionsCopy.preProcess(math);
+}
+katex.render(math, span, optionsCopy);
+} catch (e) {
+if (!(e instanceof katex.ParseError)) {
+throw e;
+}
+optionsCopy.errorCallback("KaTeX auto-render: Failed to parse `" + data[i].data + "` with ", e);
+fragment.appendChild(document.createTextNode(data[i].rawData));
+continue;
+}
+fragment.appendChild(span);
+}
+}
+return fragment;
+};
+const renderElem = function renderElem(elem, optionsCopy) {
+for (let i = 0; i < elem.childNodes.length; i++) {
+const childNode = elem.childNodes[i];
+if (childNode.nodeType === 3) {
+// Text node
+const frag = renderMathInText(childNode.textContent, optionsCopy);
+i += frag.childNodes.length - 1;
+elem.replaceChild(frag, childNode);
+} else if (childNode.nodeType === 1) {
+// Element node
+const className = ' ' + childNode.className + ' ';
+const shouldRender = optionsCopy.ignoredTags.indexOf(childNode.nodeName.toLowerCase()) === -1 && optionsCopy.ignoredClasses.every(x => className.indexOf(' ' + x + ' ') === -1);
+if (shouldRender) {
+renderElem(childNode, optionsCopy);
+}
+} // Otherwise, it's something else, and ignore it.
+}
+};
+const renderMathInElement = function renderMathInElement(elem, options) {
+if (!elem) {
+throw new Error("No element provided to render");
+}
+const optionsCopy = {}; // Object.assign(optionsCopy, option)
+for (const option in options) {
+if (options.hasOwnProperty(option)) {
+optionsCopy[option] = options[option];
+}
+} // default options
+optionsCopy.delimiters = optionsCopy.delimiters || [{
+left: "$$",
+right: "$$",
+display: true
+}, {
+left: "\\(",
+right: "\\)",
+display: false
+}, // LaTeX uses $…$, but it ruins the display of normal `$` in text:
+// {left: "$", right: "$", display: false},
+//  \[…\] must come last in this array. Otherwise, renderMathInElement
+//  will search for \[ before it searches for $$ or  \(
+// That makes it susceptible to finding a \\[0.3em] row delimiter and
+// treating it as if it were the start of a KaTeX math zone.
+{
+left: "\\[",
+right: "\\]",
+display: true
+}];
+optionsCopy.ignoredTags = optionsCopy.ignoredTags || ["script", "noscript", "style", "textarea", "pre", "code"];
+optionsCopy.ignoredClasses = optionsCopy.ignoredClasses || [];
+optionsCopy.errorCallback = optionsCopy.errorCallback || console.error; // Enable sharing of global macros defined via `\gdef` between different
+// math elements within a single call to `renderMathInElement`.
+optionsCopy.macros = optionsCopy.macros || {};
+renderElem(elem, optionsCopy);
+};
+export default renderMathInElement;