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auto-render.mjs (6081B)

---

 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 default renderMathInElement;