R Shiny: Download existing file

A few years later, but I think there is a simpler way if you do not need dynamic file generation by placing the file in the www/ folder of the Shiny app:

|
|- app.R
|- www/
       - downloadme.csv

Then when your Shiny app is live the file is available at shiny-url.com/downloadme.csv - or when testing locally 127.0.0.1:1221/downloadme.csv

e.g. to use within your Shiny ui:

# in ui somewhere
...
  a(href="downloadme.csv", "Download CSV", download=NA, target="_blank")
...

After poking around with different file handling functions I discovered that file.copy can be used to download the file.

I change downloadHandler to:

output$downloadData <- downloadHandler(
  filename <- function() {
    paste("output", "zip", sep=".")
  },

  content <- function(file) {
    file.copy("out.zip", file)
  },
  contentType = "application/zip"
)