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/* eslint no-console:0 */
import katex from "katex";
import splitAtDelimiters from "./splitAtDelimiters";
/* Note: optionsCopy is mutated by this method. If it is ever exposed in the
* API, we should copy it before mutating.
*/
const renderMathInText = function(text, optionsCopy) {
const data = splitAtDelimiters(text, optionsCopy.delimiters);
if (data.length === 1 && data[0].type === 'text') {
// There is no formula in the text.
// Let's return null which means there is no need to replace
// the current text node with a new one.
return null;
}
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(elem, optionsCopy) {
for (let i = 0; i < elem.childNodes.length; i++) {
const childNode = elem.childNodes[i];
if (childNode.nodeType === 3) {
// Text node
// Concatenate all sibling text nodes.
// Webkit browsers split very large text nodes into smaller ones,
// so the delimiters may be split across different nodes.
let textContentConcat = childNode.textContent;
let sibling = childNode.nextSibling;
let nSiblings = 0;
while (sibling && (sibling.nodeType === Node.TEXT_NODE)) {
textContentConcat += sibling.textContent;
sibling = sibling.nextSibling;
nSiblings++;
}
const frag = renderMathInText(textContentConcat, optionsCopy);
if (frag) {
// Remove extra text nodes
for (let j = 0; j < nSiblings; j++) {
childNode.nextSibling.remove();
}
i += frag.childNodes.length - 1;
elem.replaceChild(frag, childNode);
} else {
// If the concatenated text does not contain math
// the siblings will not either
i += nSiblings;
}
} 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(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 after $$
// Render AMS environments even if outside $$…$$ delimiters.
{left: "\\begin{equation}", right: "\\end{equation}", display: true},
{left: "\\begin{align}", right: "\\end{align}", display: true},
{left: "\\begin{alignat}", right: "\\end{alignat}", display: true},
{left: "\\begin{gather}", right: "\\end{gather}", display: true},
{left: "\\begin{CD}", right: "\\end{CD}", display: true},
{left: "\\[", right: "\\]", display: true},
];
optionsCopy.ignoredTags = optionsCopy.ignoredTags || [
"script", "noscript", "style", "textarea", "pre", "code", "option",
];
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;
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