Thanks, Berry. Interesting! Both this suggestion and my previous effort seem a
little baroque – fighting against the system.
However after thinking about this some more, I found this:
delayedAssign('landmarks', testdataalias::landmarks.2017)
which feels a bit safer (although does not try to automatically find the most
recent object as per your suggestion).
Thanks again,
Greg.
> On 9 Oct 2017, at 13:36, Berry Boessenkool <berryboessenk...@hotmail.com>
> wrote:
>
>
> Another approach, maybe overkill / not thought through:
>
> latestLandmark <- function()
> {
> files <- dir(file.path(system.file(package="yourpackage"), "data"),
> pattern="landmark", full.names=TRUE)
> env <- environment()
> dataset <- load(tail(files, 1), envir=env)
> return(invisible(get(dataset, envir=env)))
> }
>
> landmark <- latestLandmark()
>
>
> Regards,
> Berry
>
>
> From: R-package-devel <r-package-devel-boun...@r-project.org
> <mailto:r-package-devel-boun...@r-project.org>> on behalf of Gregory Jefferis
> <jeffe...@gmail.com <mailto:jeffe...@gmail.com>>
> Sent: Sunday, October 8, 2017 14:45
> To: Michael Dewey
> Cc: r-package-devel@r-project.org <mailto:r-package-devel@r-project.org>
> Subject: Re: [R-pkg-devel] referring to a package data object by two names
>
> Dear Michael,
>
> Many thanks for writing.
>
> > Do any of the suggestions in section 1.5.3 of Writing R Extensions "Load
> > hooks" work?
>
> I thought I had tried all the various permutations in .onLoad but at your
> prompting I tried some more and this seems to work:
>
> .onLoad <- function (libname, pkgname) {
> # set up default landmarks object
> assign('landmarks',
> envir = parent.env(environment()),
> testdataalias::landmarks.2017)
>
> }
>
> It doesn't seem to tickle R CMD check, but I'm not yet convinced that it is
> 100% safe. Any comments either way are welcome!
>
> Best wishes,
>
> Greg.
>
> ______________________________________________
> R-package-devel@r-project.org <mailto:R-package-devel@r-project.org> mailing
> list
> https://stat.ethz.ch/mailman/listinfo/r-package-devel
> <https://stat.ethz.ch/mailman/listinfo/r-package-devel>
--
Gregory Jefferis, PhD
Division of Neurobiology
MRC Laboratory of Molecular Biology
Francis Crick Avenue
Cambridge Biomedical Campus
Cambridge, CB2 OQH, UK
http://www2.mrc-lmb.cam.ac.uk/group-leaders/h-to-m/g-jefferis
http://jefferislab.org
http://www.zoo.cam.ac.uk/departments/connectomics
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