feat: add math equation support in Tinymce (#233)

apps/backend/package.json

@@ -30,6 +30,7 @@
     "express": "^4.17.1",
     "express-rate-limit": "^6.9.0",
     "form-data": "^4.0.0",
+    "katex": "^0.16.10",
     "marked": "^7.0.3",
     "multer": "^1.4.3",
     "nodemon": "^3.0.1",

apps/backend/server.js

@@ -9,6 +9,7 @@ const uploadVideo = require('./src/routes/uploadVideo');
 const downloadCertificate = require('./src/routes/downloadCertificate');
 const downloadLesson = require('./src/routes/downloadLesson');
 const downloadCourse = require('./src/routes/downloadCourse');
+const katex = require('./src/routes/katex');
 
 // Express server
 const app = express();
@@ -32,6 +33,7 @@ app.use('/downloadCertificate', downloadCertificate);
 app.use('/downloadLesson', downloadLesson);
 app.use('/downloadCourse', downloadCourse);
 app.use('/uploadVideo', uploadVideo);
+app.use('/katex', katex);
 
 app.get('/', (req, res) => {
   res.send('Welcome to ClassroomIO');

apps/backend/src/routes/katex.js

@@ -0,0 +1,24 @@
+const express = require('express');
+// https://ben.page/node-latex-to-html
+const katex = require('katex');
+
+const router = express.Router();
+
+// localhost:3002/katex
+router.get('/', async (req, res) => {
+  const original = req._parsedUrl.search;
+
+  const latexString = original.replace('?', '').replaceAll('+', '+').replaceAll('&space;', '');
+  console.log({ latexString });
+
+  const html = katex.renderToString(latexString, {
+    throwOnError: false,
+    output: 'mathml'
+  });
+
+  console.log({ html });
+
+  res.send(html);
+});
+
+module.exports = router;