cli_process_start: Indicate the start and termination of some computation in the...
In RonMobile/cli: Helpers for Developing Command Line Interfaces

Description Usage Arguments Details Value See Also Examples

Typically you call cli_process_start() to start the process, and then cli_process_done() when it is done. If an error happens before cli_process_done() is called, then cli automatically shows the message for unsuccessful termination.

cli_process_start(
  msg,
  msg_done = paste(msg, "... done"),
  msg_failed = paste(msg, "... failed"),
  on_exit = c("auto", "failed", "done"),
  msg_class = "alert-info",
  done_class = "alert-success",
  failed_class = "alert-danger",
  .auto_close = TRUE,
  .envir = parent.frame()
)

cli_process_done(
  id = NULL,
  msg_done = NULL,
  .envir = parent.frame(),
  done_class = "alert-success"
)

cli_process_failed(
  id = NULL,
  msg = NULL,
  msg_failed = NULL,
  .envir = parent.frame(),
  failed_class = "alert-danger"
)

`msg`	The message to show to indicate the start of the process or computation. It will be collapsed into a single string, and the first line is kept and cut to `console_width()`.
`msg_done`	The message to use for successful termination.
`msg_failed`	The message to use for unsuccessful termination.
`on_exit`	Whether this process should fail or terminate successfully when the calling function (or the environment in `.envir`) exits.
`msg_class`	The style class to add to the message. Use an empty string to suppress styling.
`done_class`	The style class to add to the successful termination message. Use an empty string to suppress styling.a
`failed_class`	The style class to add to the unsuccessful termination message. Use an empty string to suppress styling.a
`.auto_close`	Whether to clear the status bar when the calling function finishes (or ‘.envir’ is removed from the stack, if specified).
`.envir`	Environment to evaluate the glue expressions in. It is also used to auto-clear the status bar if `.auto_close` is `TRUE`.
`id`	Id of the status bar container to clear. If `id` is not the id of the current status bar (because it was overwritten by another status bar container), then the status bar is not cleared. If `NULL` (the default) then the status bar is always cleared.

If you handle the errors of the process or computation, then you can do the opposite: call cli_process_start() with on_exit = "done", and in the error handler call cli_process_failed(). cli will automatically call cli_process_done() on successful termination, when the calling function finishes.

See examples below.

Id of the status bar container.

Other status bar: cli_status_clear(), cli_status_update(), cli_status()

## Failure by default
fun <- function() {
  cli_process_start("Calculating")
  if (interactive()) Sys.sleep(1)
  if (runif(1) < 0.5) stop("Failed")
  cli_process_done()
}
tryCatch(fun(), error = function(err) err)

## Success by default
fun2 <- function() {
  cli_process_start("Calculating", on_exit = "done")
  tryCatch({
    if (interactive()) Sys.sleep(1)
    if (runif(1) < 0.5) stop("Failed")
  }, error = function(err) cli_process_failed())
}
fun2()