Small framework to communicate between Shiny client and server via HTTP requests. Run communicate::example() for a short demo.

Site

Installation

# install.packages("remotes")
# remotes::install_github("devOpifex/communicate")
install.packages("communicate", repos = c('https://devopifex.r-universe.dev', 'https://cloud.r-project.org'))

How it works

Create a shiny application and "commincation channels." Add callback functions with com.

library(shiny)
library(communicate)

add <- \(x){
  x + 2
}

ui <- fluidPage(
  h1("Hello")
)

server <- \(input, output, session){
  com("add", add)
}

shinyApp(ui, server)

Then use the JavaScript library to communicate.

library(shiny)
library(communicate)

add <- \(x){
  x + 2
}

script <- "
  $('#btn').on('click', () => {
    communicate.com('add', {x: 1})
      .then(res => alert(`equals: ${res}`));
  })
"

ui <- fluidPage(
  # import dependencies
  useCommunicate(),
  h1("Hello"),
  tags$a("Communicate", id = "btn"),
  tags$script(HTML(script))
)

server <- \(input, output, session){
  com("add", add)
}

shinyApp(ui, server)

Types

Though optional it is recommended to specify the types of the arguments of your callback function. This enables type conversion and type check when communicating from the client.

Existing types:

library(shiny)
library(communicate)

add <- \(x){
  x + 2
}

script <- "
  $('#btn').on('click', () => {
    communicate.com('add', {x: 1})
      .then(res => alert(`equals: ${res}`));
  })
"

ui <- fluidPage(
  # import dependencies
  useCommunicate(),
  h1("Hello"),
  tags$a("Communicate", id = "btn"),
  tags$script(HTML(script))
)

server <- \(input, output, session){
  com("add", add)(x = Integer)
}

shinyApp(ui, server)

Defaults

You can also specifiy callback functions' argument defaults as done below.

library(shiny)
library(communicate)

add <- \(x, y){
  x + y
}

script <- "
  $('#btn').on('click', () => {
    communicate.com('add', {x: 1})
      .then(res => alert(`equals: ${res}`));
  })
"

ui <- fluidPage(
  # import dependencies
  useCommunicate(),
  h1("Hello"),
  tags$a("Communicate", id = "btn"),
  tags$script(HTML(script))
)

server <- \(input, output, session){
  com("add", add)(x = Integer, y = Numeric)(y = 1.1)
}

shinyApp(ui, server)

JavaScript

Accessible from communicate, functions:

Dependency

You import the dependency with useCommunicate(). Alternatively you can install the npm package, e.g.: if you use packer.

npm install @devopifex/communicate

Or with packer:

packer::npm_install("@devopifex/communicate")

Usage

communicate.hasCom("add")

communicate.getCom("add")

communicate.com("add", {x: 1, y: 2})
  .then(data => console.log(data))
  .catch(error => console.error(error))