R devel - Sep 2006 - Package dependencies and imports

Dear list members,

I'm encountering the following problem with package dependencies and
imports: 

The Rcmdr package doesn't declare a formal dependency (via depends or
suggests in the package DESCRIPTION) on the rgl package because the latter
apparently causes problems on some systems. This allows the Rcmdr package to
build and check on systems without rgl present; if rgl isn't present, then
menu items using it are disabled (in the development version of the Rcmdr
package, not installed in the first place). 

If rgl is present, however, the Rcmdr package uses some unexported functions
in it. I've done this via rgl::: to avoid importing from the rgl namespace:
Because rgl isn't declared as a dependency, I can't import its
namespace. In
the current R 2.4.0 alpha and R 2.5.0 devel, however, using rgl::: generates
a warning when the package is checked.

Is there a way around this short of literally copying the unexported
functions in rgl that Rcmdr uses?

Thanks,
 John

--------------------------------
John Fox
Department of Sociology
McMaster University
Hamilton, Ontario
Canada L8S 4M4
905-525-9140x23604
http://socserv.mcmaster.ca/jfox

>>>>> "JohnF" == John Fox <jfox at mcmaster.ca>
>>>>>     on Thu, 21 Sep 2006 11:22:17 -0400 writes:
    JohnF> Dear list members,

    JohnF> I'm encountering the following problem with package
dependencies and
    JohnF> imports: 

    JohnF> The Rcmdr package doesn't declare a formal dependency
    JohnF> (via depends or suggests in the package DESCRIPTION)
    JohnF> on the rgl package because the latter apparently
    JohnF> causes problems on some systems. This allows the
    JohnF> Rcmdr package to build and check on systems without
    JohnF> rgl present; if rgl isn't present, then menu items
    JohnF> using it are disabled (in the development version of
    JohnF> the Rcmdr package, not installed in the first place).

    JohnF> If rgl is present, however, the Rcmdr package uses
    JohnF> some unexported functions in it. I've done this via
    JohnF> rgl::: to avoid importing from the rgl namespace:
    JohnF> Because rgl isn't declared as a dependency, I can't
    JohnF> import its namespace. In the current R 2.4.0 alpha
    JohnF> and R 2.5.0 devel, however, using rgl::: generates a
    JohnF> warning when the package is checked.

    JohnF> Is there a way around this short of literally copying the
unexported
    JohnF> functions in rgl that Rcmdr uses?

I think you should use the new DESCRIPTION field and say
  'Enhances: rgl'

but I haven't checked if this prevents the warning,  though I
think it should..

Regards,
Martin