blog/static/katex/contrib/auto-render.mjs

223 lines
5.9 KiB
JavaScript
Raw Permalink Normal View History

2022-02-07 22:32:10 +00:00
import katex from '../katex.mjs';
/* eslint no-constant-condition:0 */
var findEndOfMath = function findEndOfMath(delimiter, text, startIndex) {
// Adapted from
// https://github.com/Khan/perseus/blob/master/src/perseus-markdown.jsx
var index = startIndex;
var braceLevel = 0;
var delimLength = delimiter.length;
while (index < text.length) {
var 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;
};
var escapeRegex = function escapeRegex(string) {
return string.replace(/[-/\\^$*+?.()|[\]{}]/g, "\\$&");
};
var amsRegex = /^\\begin{/;
var splitAtDelimiters = function splitAtDelimiters(text, delimiters) {
var index;
var data = [];
var regexLeft = new RegExp("(" + delimiters.map(x => escapeRegex(x.left)).join("|") + ")");
while (true) {
index = text.search(regexLeft);
if (index === -1) {
break;
}
if (index > 0) {
data.push({
type: "text",
data: text.slice(0, index)
});
text = text.slice(index); // now text starts with delimiter
} // ... so this always succeeds:
var i = delimiters.findIndex(delim => text.startsWith(delim.left));
index = findEndOfMath(delimiters[i].right, text, delimiters[i].left.length);
if (index === -1) {
break;
}
var rawData = text.slice(0, index + delimiters[i].right.length);
var math = amsRegex.test(rawData) ? rawData : text.slice(delimiters[i].left.length, index);
data.push({
type: "math",
data: math,
rawData,
display: delimiters[i].display
});
text = text.slice(index + delimiters[i].right.length);
}
if (text !== "") {
data.push({
type: "text",
data: text
});
}
return data;
};
/* eslint no-console:0 */
/* Note: optionsCopy is mutated by this method. If it is ever exposed in the
* API, we should copy it before mutating.
*/
var renderMathInText = function renderMathInText(text, optionsCopy) {
var 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;
}
var fragment = document.createDocumentFragment();
for (var i = 0; i < data.length; i++) {
if (data[i].type === "text") {
fragment.appendChild(document.createTextNode(data[i].data));
} else {
var span = document.createElement("span");
var 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;
};
var renderElem = function renderElem(elem, optionsCopy) {
for (var i = 0; i < elem.childNodes.length; i++) {
var childNode = elem.childNodes[i];
if (childNode.nodeType === 3) {
// Text node
var frag = renderMathInText(childNode.textContent, optionsCopy);
if (frag) {
i += frag.childNodes.length - 1;
elem.replaceChild(frag, childNode);
}
} else if (childNode.nodeType === 1) {
(function () {
// Element node
var className = ' ' + childNode.className + ' ';
var 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.
}
};
var renderMathInElement = function renderMathInElement(elem, options) {
if (!elem) {
throw new Error("No element provided to render");
}
var optionsCopy = {}; // Object.assign(optionsCopy, option)
for (var 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 { renderMathInElement as default };