feat(auto-render): add option to ignore escaped special characters ou…

…tside of LaTeX math mode (KaTeX#437)
lnasrc · Jun 26, 2023 · de8d0e1 · de8d0e1
1 parent ad03d1e
commit de8d0e1
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Showing 4 changed files with 233 additions and 43 deletions.
diff --git a/contrib/auto-render/auto-render.js b/contrib/auto-render/auto-render.js
@@ -7,18 +7,30 @@ import splitAtDelimiters from "./splitAtDelimiters";
  * API, we should copy it before mutating.
  */
 const renderMathInText = function(text, optionsCopy) {
-    const data = splitAtDelimiters(text, optionsCopy.delimiters);
+    const data = splitAtDelimiters(text, optionsCopy.delimiters,
+        optionsCopy.supportEscapedSpecialCharsInText);
     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;
+        if (!optionsCopy.supportEscapedSpecialCharsInText) {
+            return null;
+        }
     }
 
     const fragment = document.createDocumentFragment();
 
     for (let i = 0; i < data.length; i++) {
         if (data[i].type === "text") {
+            if (optionsCopy.supportEscapedSpecialCharsInText) {
+                data[i].data = data[i].data.replace(/\\\$/g, '$');
+                data[i].data = data[i].data.replace(/\\%/g, '%');
+                data[i].data = data[i].data.replace(/\\_/g, '_');
+                data[i].data = data[i].data.replace(/\\&/g, '&');
+                data[i].data = data[i].data.replace(/\\#/g, '#');
+                data[i].data = data[i].data.replace(/\\{/g, '{');
+                data[i].data = data[i].data.replace(/\\}/g, '}');
+            }
             fragment.appendChild(document.createTextNode(data[i].data));
         } else {
             const span = document.createElement("span");
@@ -136,6 +148,9 @@ const renderMathInElement = function(elem, options) {
     // math elements within a single call to `renderMathInElement`.
     optionsCopy.macros = optionsCopy.macros || {};
 
+    optionsCopy.supportEscapedSpecialCharsInText =
+        optionsCopy.supportEscapedSpecialCharsInText || false;
+
     renderElem(elem, optionsCopy);
 };
 

diff --git a/contrib/auto-render/splitAtDelimiters.js b/contrib/auto-render/splitAtDelimiters.js
@@ -27,19 +27,38 @@ const findEndOfMath = function(delimiter, text, startIndex) {
     return -1;
 };
 
-const escapeRegex = function(string) {
-    return string.replace(/[-/\\^$*+?.()|[\]{}]/g, "\\$&");
+const escapeRegex = function(string, supportEscapedSpecialCharsInText) {
+    if (supportEscapedSpecialCharsInText) {
+        if (string === "$") {
+            /* negative lookbehind to find any dollar not preceded by a
+             backslash */
+            return "(?<!\\\\)\\$";
+        } else if (string === "(") {
+            /* negative lookbehind to find any parenthesis not preceded by a
+             backslash */
+            return "(?<!\\\\)\\(";
+        } else if (string === "\\(") {
+            return "\\\\\\(";
+        } else if (string === "\\$") {
+            return "\\\\\\$";
+        } else {
+            return string.replace(/[-/\\^$*+?.)|[\]{}]/g, "\\$&");
+        }
+    } else {
+        return string.replace(/[-/\\^$*+?.()|[\]{}]/g, "\\$&");
+    }
 };
 
 const amsRegex = /^\\begin{/;
 
-const splitAtDelimiters = function(text, delimiters) {
+const splitAtDelimiters = function(text, delimiters,
+    supportEscapedSpecialCharsInText) {
     let index;
     const data = [];
 
-    const regexLeft = new RegExp(
-        "(" + delimiters.map((x) => escapeRegex(x.left)).join("|") + ")"
-    );
+    const regexLeft = new RegExp("(" + delimiters.map((x) =>
+        escapeRegex(x.left, supportEscapedSpecialCharsInText),
+    ).join("|") + ")");
 
     while (true) {
         index = text.search(regexLeft);