port pkg-plist when files change every build?

[Ian Downes]

I'm porting an application (RStudio server) which generates files with
unique names every time you build it. The files are web resources
(javascript, images etc) and I don't have any control over their naming.

What's the recommended way to deal with this? My current thought is to
install to a staging dir in WRKSRC and then dynamically build the plist
from there during pre-install before cp'ing to the actual install dir. I
don't think it's a problem that a package has a particular set of names.

thanks,
Ian