README.md

directoryInput

A widget for interactive selection of directories for R Shiny Applications

Application

Provides an input for users to select directories via an interactive, and os native dialog, rather than having to type in paths in a textInput().

NOTE: This is intended to only be used with locally run shiny applications. It will not work on server deployed applications because it uses OS shell calls to present a directory choosing dialog. There is currently no way (that I'm aware) of securely presenting a client side directory selection dialog from a hosted web application.

Install the package

First install the shiny R-package from CRAN as it is required:

install.packages('shiny')

Then install this package from github:

devtools::install_github('wleepang/shiny-directory-input')

Special Requirements

• Windows:
  • PowerShell 3 or higher

Run the demo

Simply run the code to see the widget in action:

library(shinyDirectoryInput)
shinyDirectoryInput::runDirinputExample()

Use the widget

In global.R in your own app (create it if it doesn't already exist) add the line:

library('shinyDirectoryInput')

In ui.R:

• Add the widget

directoryInput('directory', label = 'select a directory')

• Add the widget with a default value

directoryInput('directory', label = 'select a directory', value = '~')

In server.R:

• Important: Pass session into the server, it is used to communicate with the client-side widget

shinyServer(function(input, output, session) {
  # ...
}

• Invoke the dialog

path = readDirectoryInput(session, 'directory')

• Update the widget value

path = 'path/to/directory'
updateDirectoryInput(session, 'directory', value = path)

• Example: Observe when a user clicks the ... button to select a new directory

observeEvent(
  ignoreNULL = TRUE,
  eventExpr = {
    input$directory
  },
  handlerExpr = {
    if (input$directory > 0) {
      # condition prevents handler execution on initial app launch
      
      # launch the directory selection dialog with initial path read from the widget
      path = choose.dir(default = readDirectoryInput(session, 'directory'))
      
      # update the widget value
      updateDirectoryInput(session, 'directory', value = path)
    }
  }
)