[R-pkg-devel] saving user preferences per workspace

Hey,

as far as I understand it, it is not ok to do any writing to the filesystem
(except tempfiles) behind the back of the user - never ever (except on
installation).

But what you can do is implement explicit functions to explicitly save and
load options.

Furthermore, you can tell the user, that the load function will always look
for:

1. brailer_options_file.opt in the current working directory
2. for an brailer_options_file entry in the .Renviron file to determine if
there might be a file to load options from (e.g. brailer_options_file
entry=~/brailer_options_file.opt)
3. else the function does not laod any options

Depending on what is appropriate for your package you might than run the
options load function on package startup via putting an .onLoad function
into your R/zzz.R file.

I am not sure if that's the most elegant or efficient way to implement such
a thing but it served me well for the wikipediatrend package where I needed
a way for caching downloads and I am convinced that it is CRAN policies
compliant.

If there are better ideas or room for discussion I am eager to here it.


Best, Peter

2015-12-12 21:52 GMT+01:00 Godfrey, Jonathan <A.J.Godfrey at massey.ac.nz>:

Hello,

I wish to offer users of my BrailleR package the ability to save their
preferences, which may change by the workspace.

I've toyed with the ideas:

1.        saving a file in the corresponding folder;  or,

2.       creating an object containing all the settings in the workspace


In either scenario, the settings get picked up next time the user loads
the package in the right workspace. Both have worked.

My problem is that I think my functions to create or modify the file or
object breach CRAN policies. I am certainly getting a NOTE for using
assign(..., pos=1)

I had thought to try using the parent environment instead of explicitly
using 'pos=1' but sometimes my functions are operating at the grandchild
level with respect to pos=1 and therefore fail.

I think my previous solution of writing a file in the current folder was
only getting past the CRAN checks because I was doing it with a condition
of running R in interactive mode. if(interactive()){...}
But I think it is a breach of the policies to write a file to the user's
hard drive, and sneaking around with a solution that CRAN checks can't cope
with (yet) really doesn't work for me.

Any ideas, especially pointers to other packages that do manage this task
would help me greatly.

Thanks for any help/advice,
Jonathan



        [[alternative HTML version deleted]]

        [[alternative HTML version deleted]]