Downloading a report - should the tempfile/dir be inside or outside the server function?

shiny
1

One can read in Chapter 9 Uploads and downloads | Mastering Shiny that:

RMarkdown works in the current working directory, which will fail in many deployment scenarios (e.g. on shinyapps.io). You can work around this by copying the report to a temporary directory when your app starts (i.e. outside of the server function):

However, the same section points to an example in Shiny - Generating downloadable reports where the temporary directory is used inside the server function.

So who's correct?

For example, would the following work on a server?

mod_download_server <- function(id, template_path, params = list()) {
  moduleServer(id, function(input, output, session) {
    output$report <- downloadHandler(
      filename = "report.html",
      content = function(file) {
        report_path <- withr::local_tempfile(
          lines = readr::read_file(template_path),
          fileext = ".Rmd"
        )
        callr::r(
          render_report,
          list(input = report_path, output = file, params = params)
        )
      }
    )
  })
}