Create a Shiny app object — shinyApp

v1.7.4|Source: R/shinyapp.R

Description

These functions create Shiny app objects from either an explicit UI/server pair (shinyApp), or by passing the path of a directory that contains a Shiny app (shinyAppDir).

shinyApp(
  ui,
  server,
  onStart = NULL,
  options = list(),
  uiPattern = "/",
  enableBookmarking = NULL
)

shinyAppDir(appDir, options = list())

shinyAppFile(appFile, options = list())

Arguments

ui

The UI definition of the app (for example, a call to fluidPage() with nested controls).

If bookmarking is enabled (see enableBookmarking), this must be a single argument function that returns the UI definition.

server

A function with three parameters: input, output, and session. The function is called once for each session ensuring that each app is independent.

onStart

A function that will be called before the app is actually run. This is only needed for shinyAppObj, since in the shinyAppDir case, a global.R file can be used for this purpose.

options

Named options that should be passed to the runApp call (these can be any of the following: "port", "launch.browser", "host", "quiet", "display.mode" and "test.mode"). You can also specify width and height parameters which provide a hint to the embedding environment about the ideal height/width for the app.

uiPattern

A regular expression that will be applied to each GET request to determine whether the ui should be used to handle the request. Note that the entire request path must match the regular expression in order for the match to be considered successful.

enableBookmarking

Can be one of "url", "server", or "disable". The default value, NULL, will respect the setting from any previous calls to enableBookmarking(). See enableBookmarking() for more information on bookmarking your app.

appDir

Path to directory that contains a Shiny app (i.e. a server.R file and either ui.R or www/index.html)

appFile

Path to a .R file containing a Shiny application

Value

An object that represents the app. Printing the object or passing it to runApp() will run the app.

Details

Normally when this function is used at the R console, the Shiny app object is automatically passed to the print() function, which runs the app. If this is called in the middle of a function, the value will not be passed to print() and the app will not be run. To make the app run, pass the app object to print() or runApp().

Examples

## Only run this example in interactive R sessions
if (interactive()) {
  options(device.ask.default = FALSE)

  shinyApp(
    ui = fluidPage(
      numericInput("n", "n", 1),
      plotOutput("plot")
    ),
    server = function(input, output) {
      output$plot <- renderPlot( plot(head(cars, input$n)) )
    }
  )

  shinyAppDir(system.file("examples/01_hello", package="shiny"))


  # The object can be passed to runApp()
  app <- shinyApp(
    ui = fluidPage(
      numericInput("n", "n", 1),
      plotOutput("plot")
    ),
    server = function(input, output) {
      output$plot <- renderPlot( plot(head(cars, input$n)) )
    }
  )

  runApp(app)
}