Code syntax highlighting added to markdown fields.

Author: Martin Krulis

package.json

@@ -56,6 +56,7 @@
     "font-awesome-animation": "^0.2.1",
     "glob": "^7.1.2",
     "global": "^4.3.1",
+    "highlight.js": "^9.16.2",
     "immutable": "^3.8.1",
     "isomorphic-fetch": "^2.2.1",
     "js-yaml": "^3.13.1",

src/components/widgets/Markdown/Markdown.js

@@ -1,7 +1,20 @@
 import React from 'react';
 import PropTypes from 'prop-types';
 
-const md = require('markdown-it')().use(require('@iktakahiro/markdown-it-katex'));
+const hljs = require('highlight.js');
+const md = require('markdown-it')({
+  highlight: function(str, lang) {
+    if (lang && hljs.getLanguage(lang)) {
+      try {
+        return hljs.highlight(lang, str).value;
+      } catch (error) {
+        /* just ignore the error */
+      }
+    }
+
+    return ''; // use external default escaping
+  },
+}).use(require('@iktakahiro/markdown-it-katex'));
 
 const Markdown = ({ source }) => (
   <div

views/index.ejs

@@ -14,10 +14,8 @@
       integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u"
       crossorigin="anonymous"
     />
-    <link
-      rel="stylesheet"
-      href="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.9.0/katex.min.css"
-    />
+    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.9.0/katex.min.css" />
+    <link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/highlightjs/[email protected]/build/styles/default.min.css">    
     <link
       rel="stylesheet"
       href="https://cdn.jsdelivr.net/github-markdown-css/2.2.1/github-markdown.css"

yarn.lock

@@ -5075,6 +5075,11 @@ [email protected]:
   resolved "https://registry.yarnpkg.com/he/-/he-1.2.0.tgz#84ae65fa7eafb165fddb61566ae14baf05664f0f"
   integrity sha512-F/1DnUGPopORZi0ni+CvrCgHQ5FyEAHRLSApuYWMmrbSwoN2Mn/7k+Gl38gJnR7yyDZk6WLXwiGod1JOWNDKGw==
 
+highlight.js@^9.16.2:
+  version "9.16.2"
+  resolved "https://registry.yarnpkg.com/highlight.js/-/highlight.js-9.16.2.tgz#68368d039ffe1c6211bcc07e483daf95de3e403e"
+  integrity sha512-feMUrVLZvjy0oC7FVJQcSQRqbBq9kwqnYE4+Kj9ZjbHh3g+BisiPgF49NyQbVLNdrL/qqZr3Ca9yOKwgn2i/tw==
+
 history@^4.9.0:
   version "4.9.0"
   resolved "https://registry.yarnpkg.com/history/-/history-4.9.0.tgz#84587c2068039ead8af769e9d6a6860a14fa1bca"