runcode: Construct to let you run arbitrary R code live in a Shiny app

In shinyjs: Easily Improve the User Experience of Your Shiny Apps in Seconds

Description

Sometimes when developing a Shiny app, it's useful to be able to run some R code on-demand. This construct provides your app with a text input where you can enter any R code and run it immediately.

This can be useful for testing and while developing an app locally, but it should not be included in an app that is accessible to other people, as letting others run arbitrary R code can open you up to security attacks.

To use this construct, you must add a call to runcodeUI() in the UI of your app, and a call to runcodeServer() in the server function. You also need to initialize shinyjs with a call to useShinyjs() in the UI.

Usage

runcodeUI(
  code = "",
  type = c("text", "textarea", "ace"),
  width = NULL,
  height = NULL,
  includeShinyjs = NULL,
  id = NULL
)

runcodeServer()

Arguments

code	The initial R code to show in the text input when the app loads
type	One of "text" (default), "textarea", or "ace". When using a text input, the R code will be limited to be typed within a single line, and is the recommended option. Textarea should be used if you want to write long multi-line R code. Note that you can run multiple expressions even in a single line by appending each R expression with a semicolon. Use of the "ace" option requires the shinyAce package.
width	The width of the editable code input (ignored when type="ace")
height	The height of the editable code input (ignored when type="text")
includeShinyjs	Deprecated. You should always make sure to initialize shinyjs using useShinyjs.
id	When used inside a shiny module, the module's id needs to be provided to runcodeUI. This argument should remain NULL when not used inside a module.

Note

You can only have one runcode construct in your shiny app. Calling this function multiple times within the same app will result in unpredictable behaviour.

See Also

useShinyjs

Examples

if (interactive()) {
  library(shiny)

  shinyApp(
    ui = fluidPage(
      useShinyjs(),  # Set up shinyjs
      runcodeUI(code = "shinyjs::alert('Hello!')")
    ),
    server = function(input, output) {
      runcodeServer()
    }
  )
}

Example output

Attaching package: 'shinyjs'

The following objects are masked from 'package:methods':

    removeClass, show

shinyjs documentation built on Dec. 23, 2021, 5:06 p.m.