downloadHandler
downloadHandler(filename, content, contentType = NA, outputArgs = list())Arguments
| filename | A string of the filename, including extension, that the user's web browser should default to when downloading the file; or a function that returns such a string. (Reactive values and functions may be used from this function.) | 
|---|---|
| content | A function that takes a single argument filethat is a
file path (string) of a nonexistent temp file, and writes the content to
that file path. (Reactive values and functions may be used from this
function.) | 
| contentType | A string of the download's
content type, for
example "text/csv"or"image/png". IfNULLorNA, the content type will be guessed based on the filename
extension, orapplication/octet-streamif the extension is unknown. | 
| outputArgs | A list of arguments to be passed through to the implicit
call to downloadButtonwhendownloadHandleris used
in an interactive R Markdown document. | 
Description
Allows content from the Shiny application to be made available to the user as
file downloads (for example, downloading the currently visible data as a CSV
file). Both filename and contents can be calculated dynamically at the time
the user initiates the download. Assign the return value to a slot on
output in your server function, and in the UI use
downloadButton or downloadLink to make the
download available.
Examples
## Only run examples in interactive R sessions
if (interactive()) {
ui <- fluidPage(
  downloadLink("downloadData", "Download")
)
server <- function(input, output) {
  # Our dataset
  data <- mtcars
  output$downloadData <- downloadHandler(
    filename = function() {
      paste("data-", Sys.Date(), ".csv", sep="")
    },
    content = function(file) {
      write.csv(data, file)
    }
  )
}
shinyApp(ui, server)
}