downloadHandler(filename, content, contentType = NA, outputArgs = list())


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 file that 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". If NULL or NA, the content type will be guessed based on the filename extension, or application/octet-stream if the extension is unknown.
outputArgs A list of arguments to be passed through to the implicit call to downloadButton when downloadHandler is used in an interactive R Markdown document.


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.


## 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) }