rshinygetplumber

Is there a way to request a Shiny app via GET?

I'd like to execute a Shiny application via GET request, i.e. all scripts that are triggered when the Shiny app is initially called via a browser should be executed by the GET request. Is there a good way to handle this?

Could I solve this with httr package?

Example

library(httr)
GET("link_to_a_shiny_app")
Solution

  • This can be done via plumber (httr can be used on the client side).

    The following creates plumber API which runs a shiny app in a background R process and returns the according port of the shiny app once the port endpoint is accessed:

    library(plumber)
library(shiny)
library(httpuv)
library(callr)

#* @apiTitle Shiny runApp API
#* @apiDescription runs a shiny app and returns the port.

#* Echo back the input
#* @param port The shiny app port
#* @get /port
function() {
  ui <- fluidPage(
    h1("This is a test app")
  )
  server <- function(input, output, session) {}
  app <- shinyApp(ui, server)
  port <- httpuv::randomPort()
  r_bg(function(app, port){
    shiny::runApp(appDir = app,
           port = port,
           launch.browser = FALSE,
           host = "0.0.0.0")
    }, args = list(app = app, port = port), supervise = TRUE)

  port
}

# plumb(file='plumber.R')$run()
# http://127.0.0.1:6107/port

    Also see my answer here on how to handle http verbs directly with a shiny app.