R/tableau_extension.R

In plumbertableau: Turn 'Plumber' APIs into 'Tableau' Extensions

#' Modify a Plumber router to function as a Tableau Analytics Extension
#'
#' Most of the time, you won't call this function directly. Instead, you'll
#' place it at the end of a Plumber router, under a `#* @plumber` annotation,
#' with no trailing parentheses or arguments. This tells Plumber to use the
#' function to modify the router object.
#'
#' @usage tableau_extension
#' @usage tableau_extension(pr)
#'
#' @param pr A plumber router
#'
#' @return A modified plumber router that functions as a Tableau Analytics
#'   Extension
#'
#' @examples
#' \dontrun{
#' library(plumber)
#' library(plumbertableau)
#'
#' #* Capitalize incoming text
#' #* @post /capitalize
#' function(req, res) {
#'   dat <- req$body$data
#'   toupper(dat)
#' }
#'
#' #* @plumber
#' tableau_extension
#' }
#'
#' @export
tableau_extension <- function(pr) {
  # Print info message to the console
  message(info_message())

  warnings <- getOption("plumbertableau.warnings", default = FALSE)
  if (warnings) {
    lapply(pr$routes, function(route) {
      check_route(route)
    })
  }

  # Infer Tableau handler information
  lapply(pr$endpoints, function(routes) {
    # Modify route in place
    lapply(routes, function(route) {
      route$.__enclos_env__$private$func <- infer_tableau_handler(route)
    })
  })

  pr %>%
    plumber::pr_get("/", create_user_guide(pr), serializer = plumber::serializer_html()) %>%
    plumber::pr_get("/setup", create_setup_instructions(pr), serializer = plumber::serializer_html()) %>%
    plumber::pr_static("/__plumbertableau_assets__",
                       system.file("www", package = "plumbertableau", mustWork = TRUE)) %>%
    plumber::pr_filter("rsc_filter", rsc_filter) %>%
    plumber::pr_filter("reroute", reroute) %>%
    plumber::pr_hooks(list(
      preroute = preroute_hook,
      postroute = postroute_hook
    )) %>%
    plumber::pr_set_api_spec(tableau_openapi(pr)) %>%
    plumber::pr_set_error(error_handler) %>%
    plumber::pr_set_parsers("json") %>%
    plumber::pr_set_serializer(plumber::serializer_unboxed_json())
}