Add 'void' progression handler [#72]

Author: HenrikBengtsson

NAMESPACE

@@ -14,6 +14,7 @@ export(handler_progress)
 export(handler_shiny)
 export(handler_tkprogressbar)
 export(handler_txtprogressbar)
+export(handler_void)
 export(handler_winprogressbar)
 export(handlers)
 export(make_progression_handler)

NEWS

@@ -3,6 +3,10 @@ Package: progressr
 
 Version: 0.4.0-9000 [2020-04-06]
 
+NEW FEATURES:
+
+ * Add 'void' progression handler.
+
 BUG FIXES:
 
  * Only the last of multiple progression handlers registered was used.

R/handler_void.R

@@ -0,0 +1,28 @@
+#' Progression Handler: No Progress Report
+#'
+#' @inheritParams make_progression_handler
+#'
+#' @param \ldots Additional arguments passed to [make_progression_handler()].
+#'
+#' @examples
+#' \donttest{\dontrun{
+#' handlers(handler_void())
+#' with_progress(y <- slow_sum(1:100))
+#' print(y)
+#' }}
+#'
+#' @details
+#' This progression handler give not output - it is invisible and silent.
+#'
+#' @export
+handler_void <- function(intrusiveness = 0, ...) {
+  reporter <- local({
+    list(
+      initiate = function(config, state, progression, ...) NULL,
+      update = function(config, state, progression, ...) NULL,
+      finish = function(config, state, progression, ...) NULL
+    )
+  })
+  
+  make_progression_handler("void", reporter, intrusiveness = intrusiveness, ...)
+}