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

[Gábor Csárdi]

Maybe you'll also find the 'rappdirs' package useful.

Gabor

On Sun, Dec 13, 2015 at 8:34 AM, Peter Meissner
<retep.meissner at gmail.com> wrote:
> 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
>>
>>
>>
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>>
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>> https://stat.ethz.ch/mailman/listinfo/r-package-devel
>>
>
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>
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