Use these functions to create a download button or link; when clicked, it
will initiate a browser download. The filename and contents are specified by
the corresponding downloadHandler() defined in the server
function.
downloadButton(
  outputId,
  label = "Download",
  class = NULL,
  ...,
  icon = shiny::icon("download")
)
downloadLink(outputId, label = "Download", class = NULL, ...)The name of the output slot that the downloadHandler
is assigned to.
The label that should appear on the button.
Additional CSS classes to apply to the tag, if any.
Other arguments to pass to the container tag function.
An icon() to appear on the button. Default is icon("download").
if (FALSE) { # \dontrun{
ui <- fluidPage(
  p("Choose a dataset to download."),
  selectInput("dataset", "Dataset", choices = c("mtcars", "airquality")),
  downloadButton("downloadData", "Download")
)
server <- function(input, output) {
  # The requested dataset
  data <- reactive({
    get(input$dataset)
  })
  output$downloadData <- downloadHandler(
    filename = function() {
      # Use the selected dataset as the suggested file name
      paste0(input$dataset, ".csv")
    },
    content = function(file) {
      # Write the dataset to the `file` that will be downloaded
      write.csv(data(), file)
    }
  )
}
shinyApp(ui, server)
} # }