with_progress() muffles a progression condition, if progressor is finished [#178]

Author: HenrikBengtsson

DESCRIPTION

@@ -1,5 +1,5 @@
 Package: progressr
-Version: 0.16.0-9005
+Version: 0.16.0-9006
 Title: An Inclusive, Unifying API for Progress Updates
 Description: A minimal, unifying API for scripts and packages to report progress updates from anywhere including when using parallel processing.  The package is designed such that the developer can to focus on what progress should be reported on without having to worry about how to present it.  The end user has full control of how, where, and when to render these progress updates, e.g. in the terminal using utils::txtProgressBar(), cli::cli_progress_bar(), in a graphical user interface using utils::winProgressBar(), tcltk::tkProgressBar() or shiny::withProgress(), via the speakers using beepr::beep(), or on a file system via the size of a file. Anyone can add additional, customized, progression handlers. The 'progressr' package uses R's condition framework for signaling progress updated. Because of this, progress can be reported from almost anywhere in R, e.g. from classical for and while loops, from map-reduce API:s like the lapply() family of functions, 'purrr', 'plyr', and 'foreach'. It will also work with parallel processing via the 'future' framework, e.g. future.apply::future_lapply(), furrr::future_map(), and 'foreach' with 'doFuture'. The package is compatible with Shiny applications.
 Authors@R: c(person("Henrik", "Bengtsson",

NEWS.md

@@ -1,7 +1,19 @@
 # Version (development version)
 
+## Significant Changes
+
+ * Now `with_progress()` muffles a `progression` condition, if the
+   progressor becomes complete ("reaches 100%"). This prevents it from
+   reaching, say, any global condition handlers and further attempts
+   to complete the already completed progressor.
+
 ## Bug Fixes
 
+ * Using `with_progress()` together with `handlers(global = TRUE)`
+   would produce a warning on "Received a progression 'update' request
+   (...) but is not listening to this progressor". Above update to
+   `with_progress()` avoids this warning.
+
  * Shiny apps running as background jobs in RStudio could fail with an
    error "object 'RStudio.Version' of mode 'function' was not found".
    This error occurred sporadically.

R/with_progress.R

@@ -44,6 +44,11 @@
 #' If the global progression handler is enabled, it is temporarily disabled
 #' while evaluating the `expr` expression.
 #'
+#' If a `progression` condition causes the progressor to be completed
+#' ("reaches 100%"), then `with_progress()` will muffle the `progression`
+#' condition preventing it from reaching, say, any global condition
+#' handlers.
+#'
 #' **IMPORTANT: This function is meant for end users only.  It should not
 #' be used by R packages, which only task is to _signal_ progress updates,
 #' not to decide if, when, and how progress should be reported.**
@@ -240,9 +245,16 @@ with_progress <- function(expr, handlers = progressr::handlers(), cleanup = TRUE
       }
 
       ## Let the registered 'progressr' calling handlers process
-      ## the 'progression' condition. If the progressor completed,
-      ## then 'finished' is TRUE (which we currently don't use)
+      ## the 'progression' condition. If this resulted in the
+      ## progressor being completed, then 'finished' is TRUE
       finished <- calling_handler(p)
+
+      ## If the progressor is completed, muffle the 'progression'
+      ## condition already here, to prevent it from reaching other
+      ## handlers such as global 'progression' handlers.
+      if (finished) {
+        invokeRestart("muffleProgression")
+      }
     },
 
     interrupt = handle_interrupt_or_error,