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

Installation

# install.packages("remotes")
remotes::install_github("devOpifex/communicate")

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:

• Character
• Numeric
• Integer
• Date
• Dataframe
• Posixct
• Posixlt
• Character
• List
• Function

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:

• com - communicate.
• hasCom - check if communication channel registered.
• getCom - get communication channel and its arguments.
• getComs - get all communication channels registered.

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))