Unhardcode timeout in callRemote(), callFun(), showDialog(). Fixes rs…

…tudio#291.

Revised function signatures:
showDialog(title, message, url = "", timeout = 10)
callFun(fname, ...)
callRemote(call, frame, timeout = 10)

Original function signatures:
showDialog(title, message, url = "")
callFun(fname, ...)
callRemote(call, frame)

To avoid adding arguments to callFun(), I make an object of list(...) and check whether it has a `timeout` element, then callRemote() with two or three arguments as needed.

R/code.R

@@ -81,7 +81,8 @@ getVersion <- function() {
 #' 
 #' 
 #' @param fname name of the RStudio function to call.
-#' @param ... Other arguments passed on to the function
+#' @param ... Other arguments passed on to the function.
+#'   In particular, a `timeout` argument (in seconds) can be specified, by keyword only, for a remote call if running as a job (see `?isJob`).
 #' @examples
 #' 
 #' if (rstudioapi::isAvailable()) {
@@ -90,9 +91,18 @@ getVersion <- function() {
 #' 
 #' @export callFun
 callFun <- function(fname, ...) {
+  args <- list(...)
 
-  if (isJob())
-    return(callRemote(sys.call(), parent.frame()))
+  if (isJob()) {
+    if (is.null(args$timeout)) {
+      return(callRemote(sys.call(), 
+                        parent.frame()))
+    } else {
+      return(callRemote(sys.call(), 
+                        parent.frame(),
+                        timeout = args$timeout))
+    }
+  }
 
   verifyAvailable()
 
@@ -103,7 +113,6 @@ callFun <- function(fname, ...) {
 
   # drop arguments that aren't accepted by RStudio
   # (ensure backwards-compatibility with older versions of RStudio)
-  args <- list(...)
   if (!"..." %in% names(formals(f)))
     if (length(args) > length(formals(f)))
       length(args) <- length(formals(f))

R/dialogs.R

@@ -10,10 +10,11 @@
 #' dialog area. Contents can contain the following HTML tags: "p", "em",
 #' "strong", "b" and "i".
 #' @param url An optional url to display under the \code{message}.
+#' @param timeout Timeout (in seconds) passed to `callFun()` if running as a job (see `?isJob`).
 #' @note The \code{showDialog} function was added in version 1.1.67 of RStudio.
 #' @export showDialog
-showDialog <- function(title, message, url = "") {
-  callFun("showDialog", title, message, url)
+showDialog <- function(title, message, url = "", timeout = 10) {
+  callFun("showDialog", title, message, url, timeout = timeout)
 }
 
 

R/remote.R

@@ -34,7 +34,19 @@ isWorkbenchJob <- function() {
   identical(Sys.getenv("RSTUDIO_WORKBENCH_JOB"), "1")
 }
 
-callRemote <- function(call, frame) {
+#' Make remote call.
+#' 
+#' This function facilitates making a remote call in an RStudio job by serializing
+#' the call and its arguments, sending them to the remote environment, and waiting
+#' for the response.
+#'
+#' @param call An unevaluated function call captured by `sys.call()`, representing
+#'   the original function invocation to be executed remotely.
+#' @param frame The environment in which to evaluate the arguments of the `call`.
+#'   This is typically the parent frame captured by `parent.frame()` in the calling function.
+#' @param timeout Timeout (in seconds) if running as a job (see `?isJob`).
+#' @return The response from the remote execution of the function call.
+callRemote <- function(call, frame, timeout = 10) {
 
   # check for active request / response
   requestFile  <- Sys.getenv("RSTUDIOAPI_IPC_REQUESTS_FILE", unset = NA)
@@ -80,7 +92,7 @@ callRemote <- function(call, frame) {
 
     # check for lack of response
     diff <- difftime(Sys.time(), now, units = "secs")
-    if (diff > 10)
+    if (diff > timeout)
       stop("RStudio did not respond to rstudioapi IPC request")
 
     # wait a bit