R: Create a Shiny app object

shinyApp {shiny} | R Documentation

## Create a Shiny app object

### 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`). You generally shouldn't need to use these functions to create/run applications; they are intended for interoperability purposes, such as embedding Shiny apps inside a knitr document.

### Usage

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

    shinyAppDir(appDir, options = list())

    shinyAppFile(appFile, options = list())

    as.shiny.appobj(x)

    ## S3 method for class 'shiny.appobj'
    as.shiny.appobj(x)

    ## S3 method for class 'list'
    as.shiny.appobj(x)

    ## S3 method for class 'character'
    as.shiny.appobj(x)

    is.shiny.appobj(x)

    ## S3 method for class 'shiny.appobj'
    print(x, ...)

    ## S3 method for class 'shiny.appobj'
    as.tags(x, ...)

### Arguments

`ui` | The UI definition of the app (for example, a call to `fluidPage()` with nested controls)
`server` | A server function
`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"`. This is equivalent to calling the `enableBookmarking()` function just before calling `shinyApp()`. With the default value (`NULL`), the app will respect the setting from any previous calls to `enableBookmarking()`. See `enableBookmarking` for more information.
`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
`x` | Object to convert to a Shiny app.
`...` | Additional parameters to be passed to print.

### 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()`.

### Value

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

### 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)
    }

[Package shiny version 1.2.0 Index]