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ColinFay
Launch and interact with a NodeJS session from R
DISCLAIMER: THIS IS A WORK IN PROGRESS, DO NOT USE UNLESS FOR TESTING / TOYING WITH THE PACKAGE.
bubble
The goal of {bubble} is to launch and interact with a NodeJS session,
from R.
Installation
You can install the dev version of {bubble} with:
remotes::install_github("colinfay/bubble")
Example
Note that you’ll need to have NodeJS installed on your machine
Using bubble to launch and communicate with a NodeJS session
Launch a new NodeJS session with NodeSession$new().
This function uses the path to your NodeJS binary. On MacOS, it can be
found with Sys.which("node"), on Debian Sys.which("nodejs") (if
installed through apt-get install nodejs).
NodeSession$new() tries to guess where NodeJS is by looking at both
these Sys. If they are both empty, you’ll get an error, and need to
provide the path manually. The function to find Node is exported and
called find_node(). It will either return the path to your local
installation of Node or an error
library(bubble)
find_node()
#> node
#> "/usr/local/bin/node"
The NodeSession$new() function returns an object that can be used to
interact with the launched Node session.
n <- NodeSession$new()
n$eval("var x = 12")
#> undefined
n$eval("var y = 17")
#> undefined
n$eval("x + ")
n$eval("y")
#> 29
# Return the x and y values
x <- n$get(x, y)
class(x)
#> [1] "integer"
sum(x)
#> [1] 29
n$state()
#> [1] "running"
n$kill()
#> [1] TRUE
n$state()
#> [1] "terminated"
Using {bubble} to launch an express app
n <- NodeSession$new()
n$eval("const express = require('express');")
#> undefined
n$eval("app = express()", print = FALSE)
n$eval("app.get('/', function (req, res) {", print = FALSE)
n$eval(" res.send('Hello R!')")
n$eval("})", print = FALSE)
n$eval("app.listen(3002)", print = FALSE)
x <- httr::GET("http://127.0.0.1:3002")
httr::content(x)
#> {html_document}
#> <html>
#> [1] <body><p>Hello R!</p></body>
n$kill()
#> [1] TRUE
httr::GET("http://127.0.0.1:3002")
#> Error in curl::curl_fetch_memory(url, handle = handle): Failed to connect to 127.0.0.1 port 3002: Connection refused
Using {bubble} to launch a NodeJS terminal
node_repl()
This REPL has been inspired by the one from
{reticulate}: https://rstudio.github.io/reticulate/
Using {bubble} to launch a NodeJS script
n <- NodeSession$new(
bin = "/usr/local/bin/node",
params = "inst/launch.js"
)
x <- httr::GET("http://127.0.0.1:3000")
httr::content(x)
#> {html_document}
#> <html>
#> [1] <body><p>Hello R!</p></body>
n$terminate()
#> [1] TRUE
Knitr
{bubble} comes with a knitr engine that can be set with
bubble::set_node_engine() at the top of your markdown.
Then, each chunck {node} will be evaluated in a Node session.
You’ll find an example in inst/rmdexample.Rmd
CoC
Please note that the ‘bubble’ project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.
ColinFay