Adding handlers(globals = TRUE) for the global progression handler [#95]

NEWS

@@ -1,18 +1,20 @@
 Package: progressr
 ==================
 
-Version: 0.6.0-9000 [2020-11-16]
+Version: 0.6.0-9000 [2020-12-04]
 
 SIGNIFICANT CHANGES:
 
+ * The user can how use handlers(globals = TRUE) to enable progress reports
+   everywhere without having to use with_progress().  This works on in
+   R (>= 4.0.0) because it relies on global calling handlers.
+
  * A progressor must not be created in the global environment unless wrapped
    in with_progress() or without_progress() call.  Ideally, a progressor is
    created within a function or a local() environment.
 
 NEW FEATURES:
 
- * Add register_global_progression_handler().
-
  * progressor() gained argument 'on_exit = TRUE'.
 
  * Add the 'pbcol' handler, which renders the progress as a colored progress

R/handlers.R

@@ -16,9 +16,15 @@
 #' @param default The default progression calling handler to use if none
 #' are set.
 #'
+#' @param global If TRUE, then the global progression handler is enabled.
+#' If FALSE, it is disabled.  If NA, then TRUE is returned if it is enabled,
+#' otherwise FALSE.  Argument `global` must not used with other arguments.
+#'
 #' @return (invisibly) the previous list of progression handlers set.
 #' If no arguments are specified, then the current set of progression
 #' handlers is returned.
+#' If `global` is specified, then TRUE is returned if the global progression
+#' handlers is enabled, otherwise false.
 #'
 #' @details
 #' This function provides a convenient alternative for getting and setting
@@ -32,19 +38,37 @@
 #' @example incl/handlers.R
 #'
 #' @export
-handlers <- function(..., append = FALSE, on_missing = c("error", "warning", "ignore"), default = handler_txtprogressbar) {
+handlers <- function(..., append = FALSE, on_missing = c("error", "warning", "ignore"), default = handler_txtprogressbar, global = NULL) {
+  stop_if_not(
+    is.null(global) ||
+    ( is.logical(global) && length(global) == 1L )
+  )
   args <- list(...)
+  nargs <- length(args)
+
+  if (nargs == 0L) {
+    ## Get the current set of progression handlers?
+    if (is.null(global)) {
+      if (!is.list(default) && !is.null(default)) default <- list(default)
+      return(getOption("progressr.handlers", default))
+    }
+
+    ## Check, register, or reset global calling handlers?
+    if (is.na(global)) {
+      return(register_global_progression_handler(action = "query"))
+    }
+    action <- if (isTRUE(global)) "add" else "remove"
+    return(invisible(register_global_progression_handler(action = action)))
+  }
 
-  ## Get the current set of progression handlers?
-  if (length(args) == 0L) {
-    if (!is.list(default) && !is.null(default)) default <- list(default)
-    return(getOption("progressr.handlers", default))
+  if (!is.null(global)) {
+    stop("Argument 'global' must not be specified when also registering progress handlers")
   }
 
   on_missing <- match.arg(on_missing)
 
   ## Was a list specified?
-  if (length(args) == 1L && is.vector(args[[1]])) {
+  if (nargs == 1L && is.vector(args[[1]])) {
     args <- args[[1]]
   }
 

R/zzz.R

@@ -1,6 +1,20 @@
 .onLoad <- function(libname, pkgname) {
+  ## R CMD check
   if (in_r_cmd_check()) {
     options(progressr.demo.delay = 0.0)
   }
+
+  ## R CMD build
   register_vignette_engine_during_build_only(pkgname)
+
+  ## Register a global progression handler on load?
+  global <- Sys.getenv("R_PROGRESSR_GLOBAL_HANDLER", "FALSE")
+  global <- getOption("progressr.global.handler", as.logical(global))
+  if (isTRUE(global)) {
+    utils::str(globalCallingHandlers())
+    globalCallingHandlers(foo=function(c) utils::str(c))
+#    register_global_progression_handler()
+  }
 }
+
+

incl/handlers.R

@@ -2,5 +2,14 @@ handlers("txtprogressbar")
 if (requireNamespace("beepr", quietly = TRUE))
   handlers("beepr", append = TRUE)
 
-with_progress({ y <- slow_sum(10) })
+with_progress({ y <- slow_sum(1:5) })
 print(y)
+
+
+if (getRversion() >= "4.0.0") {
+  handlers(global = TRUE)
+  y <- slow_sum(1:4)
+  z <- slow_sum(6:9)
+  handlers(global = FALSE)
+}
+