websocket

This is an R WebSocket client library backed by the websocketpp C++ library.

Usage examples

You may need to step through the $send() commands because there will be a small amount of time before the response is received. The onMessage() callback is invoked asynchronously (using the later package) when a response arrives.

library(websocket)

ws <- WebsocketClient$new("ws://echo.websocket.org/",
  onOpen = function() {
    cat("Connection opened\n")
  },
  onMessage = function(msg) {
    cat("Client got msg: ", msg, "\n")
  },
  onClose = function() {
    cat("Client disconnected\n")
  }
)

ws$send("hello")

ws$send( charToRaw("hello") )

ws$close()

websocket supports ws:// and wss:// URLs.

Development setup

Currently we do local development by running a simple httpuv-backed WebSocket server written in R that lives at tmp/websocketServer.R.

To run it, you need to install the Github version of httpuv.

Running testing WebSocket server on macOS

Note: If you want httpuv to build faster, you can create a file at ~/.Renviron with the following content: MAKEFLAGS=-j4

To install the development version of httpuv, run:

remotes::install_github("rstudio/httpuv")`

Then to run the WebSocket server, run this in a terminal:

R -e 'source("tmp/websocketServer.R"); httpuv::service(Inf)'

Finally, to test the WebSocket client, run this in R.

library(websocket)

ws <- WebsocketClient$new("ws://127.0.0.1:8080/",
  headers = list(Cookie = "Xyz"),
  onOpen = function() {
    cat("Connection opened.\n")
  },
  onMessage = function(msg) {
    cat("Client received message: ", msg, "\n")
  },
  onClose = function() {
    cat("Connection closed.\n")
  },
  accessLogChannels = "all" # enable all websocketpp logging
)

ws$send("hello")

ws$send( charToRaw("hello") )

ws$close()