[R-pkg-devel] develop package with lots of tcltk in it

[Seth Wenchel]

>
> "For users who don't know anything about R, this solution may work fine.
> But
> for users that do know R, it is unsatisfactory...program changes the
> working directory, fills it with hundreds of alien-looking functions and
> data, and crashes if working directory is changed or variables are modified
> by hand."


Is this something that can be solved with an environment inside of the
package?  I've done this in the past with good results.  Check out Dirk's
rpushbullet for an example:

https://github.com/eddelbuettel/rpushbullet/blob/master/R/init.R

the first line of code he sets one up
.pkgenv <- new.env(parent=emptyenv())

and then creates and access objects inside of that throughout the rest of
the package.

On Thu, May 12, 2016 at 1:25 PM, Dalthorp, Daniel <ddalthorp at usgs.gov>
wrote:

> Thanks, Dirk.
>
> Sorry for my lack of clarity. I do want to create a package and have
> created one and it works, but the structure is awkward. I'm hoping someone
> can help me straighten out the organization.
>
> In package/R folder, I have several files that define standalone functions
> that crunch data.
> In package/data folder, I have several source files that construct
> appropriate tktoplevel() windows with the desired widgets
> To start the application, user opens a main tktoplevel() window by entering
> a simple command from R.
> That main window has several buttons that source() files in package/data
> folder to build a new tktoplevel(), depending on user choice
>
> For users who don't know anything about R, this solution may work fine. But
> for users that do know R, it is unsatisfactory...program changes the
> working directory, fills it with hundreds of alien-looking functions and
> data, and crashes if working directory is changed or variables are modified
> by hand.
>
> I came up with that goofy solution to get around two issues:
> 1. I wasn't able to get away with defining tktoplevel windows with
> associated widgets and storing in .Rda's packaged in /data or as
> devtools::use_data(...internal = T), so I figured they needed to be defined
> and created as needed;
> 2. it is easy to define the tktoplevels via code in source() files, but I
> was having trouble with scoping and bookkeeping issues when trying to
> define them via functions instead. It would be convenient to have all the
> interesting data stored as globals and use the tkwidgets to edit and
> manipulate them without having to think specifically about how to pass the
> interesting data back and forth.
>
> E.g. is there an easy way to organize the following into a package that
> does not use 'source', treats tk.x and tk.y as globals, and does not take
> over the user's working directory with a bunch of variables like tt1,
> x.edit, tk.x, tk.y, etc.?
> tt1 <- tktoplevel()
> tk.x <- tclVar()
> x.edit <- tkentry(tt1, textvariable = tk.x, width = 5)
> x.lbl <- tklabel(tt1, text = "Enter x value: ")
> xcalc <- tkbutton(tt1, text = "Calculate", command = function()
> tkmessageBox(message = tclvalue(tk.x)))
> doMoreStuff <- tkbutton(tt1, text = "Do more...", command = function()
>  source('doStuff_form.R'))
> tkgrid(x.lbl, x.edit)
> tkgrid(xcalc,doMoreStuff)
>
> # in doStuff_form.R:
> tt2 <- tktoplevel()
> tk.y<-tclVar()
> y.edit<- tkentry(tt2, textvariable = tk.y, width = 5)
> anscalc <- tkbutton(tt2, text = "calculate answer", command = function()
>   tkmessageBox(message=as.numeric(tclvalue(tk.y)) *
> as.numeric(tclvalue(tk.x)))
> )
> tkgrid(y.edit, anscalc)
>
> -Dan
>
> On Thu, May 12, 2016 at 8:30 AM, Dirk Eddelbuettel <edd at debian.org> wrote:
>
> >
> > On 11 May 2016 at 12:56, Dalthorp, Daniel wrote:
> > | I have an R/tcltk application that is designed for use primarily by
> > people
> > | who don't know R and don't care to learn much about it. I'd like users
> to
> > | be able to use the software with a bare minimum interaction with R.
> > |
> > | Although the application has some 15000 lines of code in a couple dozen
> > .R
> > | files, in essence I don't think it's much more than an elaborate
> version
> > of
> > | the following:
> > |
> > | library(tcltk)
> > | tt <- tktoplevel() # a required container for tk objects (textboxes,
> > | radiobuttons, data tables, etc.)
> > | tk.x <- tclVar() # a tcl version of user variable x
> > | x.edit <- tkentry(tt, textvariable = tk.x, width = 5) # box for user to
> > | enter x value
> > | x.lbl <- tklabel(tt, text = "Enter x value: ") # a fixed label
> > | xcalc <- tkbutton(tt, text = "Calculate", command = function()
> > | tkmessageBox(message = tclvalue(tk.x))) # button that prints x to R
> > console
> > | tkgrid(x.lbl, x.edit, xcalc) # a function that puts the textbox, label,
> > and
> > | button onto the tk window
> > |
> > | The following doesn't work:
> > | # tt, x.edit, x.lbl, xcalc all seem to me like an R objects that will
> not
> > | be modified, so I tried
> > | devtools::use_data(tt, x.edit, x.lbl, xcalc, internal = F,
> overwrite=T) #
> > | (after defining them)
> > | # tk.x is a variable that I want to assign a value to at the beginning,
> > but
> > | user can later change the value:
> > | devtools::use_data(tt, x.edit, x.lbl, xcalc, internal = F, overwrite=T)
> > |
> > | The following does work, but it is not a good solution:
> > | (1) define working directory as package/data
> > | (2) create new tk windows via tkbutton commands = function()
> > | source(filename)
> > | This forces the user to use a pre-defined working directory. My
> > application
> > | fills that wd with several hundred functions and variables. If user
> > changes
> > | wd or changes values of variables that my app needs, the program
> crashes.
> > |
> > | Any help would be greatly appreciated!
> >
> > I haven't seen the obvious stated:  Have you looked into creating a
> > package?
> >
> > It can contain as much tcl/tk support code as you like,  etc pp.  And as
> > you
> > state you have '15000 lines of code in a couple dozen .R files' you are
> > well
> > passed the point where a package really is the best choice.
> >
> > Dirk
> >
> > --
> > http://dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org
> >
>
>
>
> --
> Dan Dalthorp, PhD
> USGS Forest and Rangeland Ecosystem Science Center
> Forest Sciences Lab, Rm 189
> 3200 SW Jefferson Way
> Corvallis, OR 97331
> ph: 541-750-0953
> ddalthorp at usgs.gov
>
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