R WebSocket REPL demo

A minimal demo of an R REPL session running a background WebSocket server.

Instructions

Start an R session in the directory demo:

cd demo
R

The .Rprofile file in demo starts a WebSocket server. You can still use it as a normal R session by typing in the prompt. Set the variable x:

x <- 1

In a NEW window, in the base directory (not in demo), start R and run the following code to connect to the running WebSocket server:

ws <- websocket::WebSocket$new("ws://127.0.0.1:8080/")
ws$onMessage(function(event) { cat("Client received message:", event$data, "\n") })

Wait for a moment before running the next line:

ws$send("hello world")

You should see the output:

Client received message: HELLO WORLD x: 1

The result uses both the input from the client ('hello world') and a value from the first R session (x).

You can still use the R session in the first window as normal.