From 48fb82b84581c7f6b499e5827b01330241bfaa70 Mon Sep 17 00:00:00 2001
From: ajrgodfrey <a.j.godfrey@massey.ac.nz>
Date: Mon, 4 Sep 2023 08:27:34 +1200
Subject: [PATCH] addin GrabLast()

---
 NEWS.md           |  2 +-
 R/Callback.R      | 19 +++++++++++++++++--
 man/SessionLog.Rd | 10 +++++++---
 3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index 79ec5ff0..21ed86c4 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,7 +1,7 @@
 # BrailleR 1.1.0
 - added GetPython() to mirror GetPython3(); ditto for GetWxPython()
 - R Project Sprint 2023 work with Deepayan led to improvement in the ability to extract content of graphics devices; added him as author
-- R Project Sprint 2023 work with Gabe led to a working solution to extract recent console output; added him as author
+- R Project Sprint 2023 work with Gabe led to a working solution to extract recent console output; added him as author. See SessionLog() and GrabLast()
 
 
 # BrailleR 1.0.2
diff --git a/R/Callback.R b/R/Callback.R
index 56a7bc29..8997aa06 100644
--- a/R/Callback.R
+++ b/R/Callback.R
@@ -1,8 +1,23 @@
 # with much help from Gabe Becker
 BrailleR <- NULL
 
-SessionLog <- function(file = "") {
-    df <- .get_session_log()
+
+GrabLast <- function(file = "", n=1) {
+.SessionLogWorker(file = file, n=n) 
+return(invisible(NULL))
+}
+
+SessionLog <- function(file = "", n=NULL) {
+.SessionLogWorker(file = file, n=NULL) 
+return(invisible(NULL))
+}
+
+.SessionLogWorker <- function(file = "", n=NULL) {
+    df <- .get_session_log() 
+if(!is.null(n)){
+NRows = nrow(df)
+df = df[(NRows+1-n): NRows, ]
+}
     mapply(function(expr, pr) cat(c(paste(">", paste(expr, collapse = "\n")), pr, ""), sep = "\n", file = file),
            expr = df$expr,
            pr = df$pr_output)
diff --git a/man/SessionLog.Rd b/man/SessionLog.Rd
index eaf5279f..ba2c6fb0 100644
--- a/man/SessionLog.Rd
+++ b/man/SessionLog.Rd
@@ -1,16 +1,20 @@
 \name{SessionLog}
 \alias{SessionLog}
+\alias{GrabLast}
 \title{Retrieve a copy of the console input/output}
 \description{
-Retrieve the output from the last top level call. This function is designed to cater for situaitons wher ehte output scrolls off the screen and is no longer accessible to a screen reader user.}
+Retrieve the output from the last n top level calls, or the hole current session. These functions are designed to cater for situations where the output scrolls off the screen and is no longer accessible to a screen reader user.}
 \usage{
-SessionLog(file = "")
+Grablast(file = "", n=1)
+
+SessionLog(file = "", n=MULL)
 }
 \arguments{
   \item{file}{a filename; if left unspecified, the output is printed in the console}
+\item{n}{the number of calls to retrieve}
 }
 \details{
-A stack of top level calls and the resulting output is stored, courtesy of a setting established on package load. This function retrieves elements from that stack.}
+A stack of top level calls and the resulting output is stored, courtesy of a setting established on package load. These functions retrieve elements from that stack.}
 \value{NULL, invisibly; not the output wich is either printed to the console or the file specified}
 \author{Gabe Becker and some very minor edits from A. Jonathan R. Godfrey}