How Mozilla Rhino can use nodejs "fs" module?

Question

Let's say I have my.js file that has dependency on nodejs fs module. Like:

var fs = require('fs');

The question: How can I load Core NodeJS module like "FS" in My Mozilla Rhino Java Code to be able to run my.js that depends on it ?

Monophagous

Answer 1

I don't think you can do this. fs module just a wrapper for native bindings built into node.js itself. There are some thoughts flying in the sky of node.js community about being able to use different JS engines inside node.js but I don't think we will see this in the near future.

Zhao

some related links I'm looking at: github.com/nodyn/jvm-npm nodyn.io – Monophagous

Looks promising but, again, you can't load native node.js modules, you can only require them if they were implemented in jvm-npm/nodyn.io. They are not modules in regular way. BTW, there is ticket for that: github.com/nodyn/nodyn/issues/26 – Zhao

Answer 2

You can also write your own fs.js, only implementing the functions you need. Here is a start:

exports.readFile = function(file, enc, callback) {
  try {
    text = readFile(file, enc);
    callback(null, text);
  }
  catch (e) {
    callback(e, null);
  }
}

I've used this together with jvm-npm.

Sergei

How would that work when fs.js requires Node's built-in native functions for file access? – Humidistat

The fs module is Node's native file access. That's not available on Rhino, so you have to write your own. – Sergei

fs.js is not written in native code. – Humidistat