[R-pkg-devel] Removing packages files

[Duncan Murdoch]

On 2025-01-03 10:04 a.m., Lluís Revilla wrote:
> Thanks Henrik for confirming there is nothing similar currently.
> 
> Duncan: Letting the user choose when to remove the folder/data at will is easy.
> I was trying to ensure that the system is clean after removing the package.
> Thanks.

No, I was suggesting that you require the user to explicitly ask for the 
data.  You don't want CRAN to install the data during testing and then 
have it left behind at the end.

Duncan Murdoch

> 
> On Thu, 2 Jan 2025 at 22:42, Henrik Bengtsson
> <henrik.bengtsson using gmail.com> wrote:
>>
>> As a first step, this sounds like something for the 'tools' package,
>> e.g. tools::cleanup_R_user_dir() that wipes package subfolders of
>> packages no longer installed, or the specified package, iff given.
>> With that in place, one could argue for adding a 'cleanup' argument to
>> remove.packages() that use the former.
>>
>> Agree, it would be neat if a package could clean up after itself when
>> uninstalled.
>>
>> /Henrik
>>
>> On Thu, Jan 2, 2025 at 1:37 PM Lluís Revilla <lluis.revilla using gmail.com> wrote:
>>>
>>> Dear Duncan,
>>>
>>> Thank you for your answer. I checked again and made a mock package
>>> that removes a file with .onDetach.
>>> The file was not removed upon uninstalling the package.
>>>
>>> Lluís
>>>
>>> On Thu, 2 Jan 2025 at 17:23, Duncan Murdoch <murdoch.duncan using gmail.com> wrote:
>>>>
>>>> On 2025-01-02 9:55 a.m., Lluís Revilla wrote:
>>>>> Hi list,
>>>>>
>>>>> I am developing a package that will download some data, and I'd like
>>>>> to store it locally to not recalculate it often.
>>>>> The CRAN policy requires tools::R_user_dir to be used and "the
>>>>> contents are actively managed (including removing outdated material)"
>>>>> or using TMPDIR but "such usage should be cleaned up".
>>>>>
>>>>> When loading a package there is .onLoad or .onAttach to fill or check
>>>>> those files and other settings required for a package. Is there
>>>>> something for when a package is removed?
>>>>>
>>>>> I found some related functions like .Last or reg.fnalizer and setHook
>>>>> or packageEvent but they are about closing a session or don't have a
>>>>> specific event for when uninstalling packages via (remove.packages). I
>>>>> appreciate any feedback, thanks in advance.
>>>>>
>>>>
>>>> Yes, those are described in section "1.5.3 Load hooks" of writing R
>>>> extensions:
>>>>
>>>> "Packages can use a .onDetach or .Last.lib function (provided the latter
>>>> is exported from the namespace) when detach is called on the package. It
>>>> is called with a single argument, the full path to the installed
>>>> package. There is also a hook .onUnload which is called when the
>>>> namespace is unloaded (via a call to unloadNamespace, perhaps called by
>>>> detach(unload = TRUE)) with argument the full path to the installed
>>>> package’s directory. Functions .onUnload and .onDetach should be defined
>>>> in the namespace and not exported, but .Last.lib does need to be exported."
>>>>
>>>> Duncan Murdoch
>>>>
>>>
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