Saving selected values in gcheckboxgroup in R? - r

Question

The following R script is a simple GUI using gWidgets.
I was wondering why this code does not save the selected values by user in gcheckboxgroup.
#### Clear the Global Environment:
rm(list=ls())
library(rattle)
library(RGtk2)
library(gWidgets)
library(tcltk)
library(lubridate)
w <- gwindow("checkbox example")
gp <- ggroup(container=w)
codes = c(
"1000 F",
"0100 Q",
"0010 M",
"0001 s")
cbg <- gcheckboxgroup(codes, cont=w)
selected_codes <- paste(svalue(cbg))
ff <- function(h,...)
selected_codes <- svalue(cbg)
obj_run <- gbutton("Run", container=w, handler = ff)

Answer 1

Thanks for jverzani's comment.
However, that was not the solution.
Actually, by clicking the Run button in GUI, we have the selected_code is the R memory. But it can not be saved as it is inside the function/handler. So, we need to save (write) it in a file (.txt for example) using this code:
rm(list=ls())
library(rattle)
library(RGtk2)
library(gWidgets)
library(tcltk)
library(lubridate)
w <- gwindow("checkbox example")
gp <- ggroup(container=w)
codes = c(
"1000 F",
"0100 Q",
"0010 M",
"0001 s")
cbg <- gcheckboxgroup(codes, cont=w)
obj_run <- gbutton("Run", container=w, handler = function (h ,...){
selected_codes <- paste0(svalue(cbg))
write(selected_codes, file = "selected_codes.txt",
ncolumns = if(is.character(selected_codes)) 1 else 1,
append = FALSE, sep = " ")
})

Answer 2

Try this, it is less hassle:
library(gWidgets2)
w <- gwindow("checkbox example")
gp <- ggroup(container=w)
codes = c(
"1000 F",
"0100 Q",
"0010 M",
"0001 s")
g <- ggroup(cont=w, horizontal=FALSE)
cbg <- gcheckboxgroup(codes, cont=g)
selected_codes <- paste(svalue(cbg))
ff <- function(h,...) {
selected_codes <<- svalue(cbg)
}
obj_run <- gbutton("Run", container=g, handler = ff)
(You may have had issues due to the containers.)