My understanding is of your questions is below:
Matthias Kohl wrote:
> Dear R devels,
>
> let's say I have three packages "pkg1", "pkg2" and "pkg3" which all
> contain new S4 classes and methods. Where "pkg3" depends on "pkg2" and
> "pkg2" depends on "pkg1". Moreover, all three packages have namespaces.
>
> 1) I use ".onLoad <- function(lib, pkg) require(methods)". Do I also
> have to import the namespace of "methods" package?
No.
>
> 2) If I use import("pkg1") in the namespace of "pkg2", does this also
> (correctly) import the S4 classes and methods of "pkg1"? Or do I
> explicitly have to use importClassesFrom resp. importMethodsFrom?
Importing an entire package namespace will import all of the exported
classes/methods from "pkg1".
>
> 3) If I import the Namespace of "pkg2" in "pkg3", where the namespace of
> "pkg2" has import("pkg1") (or maybe importClassesFrom,
> importMethodsFrom) and I also want to use S4 classes and methods of
> "pkg1" in "pkg3". Is it sufficient to have import("pkg2") in the
> Namespace of "pkg3" or do I need import("pkg1") and import("pkg2")?
I believe you need to import each separately since the S4
classes/methods from "pkg1" will not be available to you simple because
you imported "pgk2" (i.e. I don't think the chain rule applies here).
>
> Many thanks for your help and advice
> Matthias
>
--
Roger D. Peng | http://www.biostat.jhsph.edu/~rpeng/
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
