Is there a way to run R code from JavaScript?

Question

If you're ok with having the R code run on a server, then you should take a look at OpenCPU. It provides a REST API and corresponding JavaScript library for sending R code to the server and getting the results back. In particular, it takes care of the security problems that can arise from running R as a server (R code can run arbitrary shell commands, among other things). There are public demo instances that you can use to try it out, and this page provides a simple tutorial.

How about R-node ?

I think another alterative would be to use node.js as a server (http://nodejs.org/) and call R from within as a child process, search the Node.js API docs for specifics.

Also look at this for confirmation: Is it possible to execute an external program from within node.js?

Note: node can run any JS script(s) you may have, they don't necessarily need to be node-specific.

This is by no means the best way, but I was able to do the following for my own Javascript+R project (silly.r is an R script that lives in the "r" directory). I basically ran the R code as a terminal command from my express server:

app.get('/sfunction', function (req, res) {
    exec('Rscript r/silly.r this is a test', function(error, stdout, stderr) {
        if (error) {
            console.log(error);
            res.send(error);
        }
        else if (stderr) {
            console.log(stderr);
            res.send(stderr);
        }
        else if (stdout) {
            console.log("RAN SUCCESSFULLY");
            res.sendfile("savedoutput/test.json");
        }
    });
});

The code is from lines 167-182 from here: https://github.com/ngopal/VisualEncodingEngine/blob/master/jsserver/app.js