[packagekit] portage backends filters

[Richard Hughes]

On Wed, Jun 24, 2009 at 10:04 PM, Mounir
Lamouri<mounir.lamouri at gmail.com> wrote:
> But, Richard, can I insist with collections ?
> I understand it's to filter collections when searching for something
> but why filtering collections ? I understand why someone want to get
> only free packages or only packages with or without a gui but why
> collections ?
> By the way, I think about supporting categories but I was not able to
> test it on fedora. I must try again.

Maybe you misunderstand what collections are. In fedora, we have a big
xml file, called comps. This comps file has a load of groups, each
containing a few packages. This allows you to install things like
"Text Internet" or "Arcade Games" without having metapackages pulling
them in a deps.

In add/remove software, if I do a SearchName for "games" I want to
return all the packages with "game" in the name, but I also want it to
match the virtual package. You can see that in the screenshot
http://www.packagekit.org/img/gpk-application-search.png where
sound-and-video is a virtual package, aka, collection.

Now, if a computer is doing the searching, and we are sure we want to
install an actual 100% genuine package (and not a virtual package),
then we can specify ~collections in the search filter.

Now, If we're designing a control center-type application, where we
_only_ want to show the 20 or so virtual packages, then we could do a
GetPackages with the filter set to collections.

Now, if your backend doesn't support virtual groups, then you have no
need of the GetCategories or the collections filter. I suspend that
might be the case with gentoo.

Richard.