js-foreign-lib/mathjax.js

   1 var mathjax = require('mathjax-node'),
   2     chunks = [],
   3     size = null;
   4
   5 mathjax.config({ MathJax: { loader: {load: ['ui/safe']},
   6                             extensions: ["Safe.js"] } });
   7
   8 process.stdin.on('data', (chunk) => {
   9         if(size === null) {
  10                 size = chunk.readUInt32LE();
  11                 onDataChunk(chunk.subarray(4));
  12         } else {
  13                 onDataChunk(chunk);
  14         }
  15 });
  16
  17 function onDataChunk(chunk) {
  18         if(chunk.length > size) {
  19                 var excessChunk = chunk.subarray(size);
  20                 process.stdin.unshift(excessChunk);
  21                 chunk = chunk.subarray(0, size);
  22         }
  23
  24         chunks.push(chunk);
  25
  26         if(chunk.length == size) {
  27                 onMessage(Buffer.concat(chunks).toString());
  28                 size = null;
  29                 chunks = [];
  30         }
  31         else {
  32                 size -= remainingChunk.length;
  33         }
  34 }
  35
  36 function onMessage(input) {
  37         mathjax.typeset(
  38                 { math: input,
  39                   format: "inline-TeX",
  40                   html: true,
  41                   css: true
  42                 },
  43                 (data) => {
  44                         var sizeBuf = Buffer.alloc(4);
  45                         if(data.errors) {
  46                                 sizeBuf.writeUInt32LE(0);
  47                                 process.stdout.write(sizeBuf);
  48                         }
  49                         else {
  50                                 var dataBuf = Buffer.from("<style>"+data.css+"</style>"+data.html);
  51                                 sizeBuf.writeUInt32LE(dataBuf.length);
  52                                 process.stdout.write(sizeBuf);
  53                                 process.stdout.write(dataBuf);
  54                         }
  55                 }
  56         );
  57 }