Grouper Developers Forum

["GW Brown, Information Systems and Computing" <>]

--On 26 May 2005 08:58 -0500 Tom Barton 
<>
 wrote:

> GW Brown, Information Systems and Computing wrote:
> > > > 2)Similarly, a GrouperList.firstInChain method would allow me to
> > > > indicate  in the UI which immediate membership of the current group
> > > > caused an  effective membership.
> > >
> > >
> > > _GrouperList.via()_ provides the first group in the via chain.
> >
> > Confusion over direction! I was working from the 'working' group to the
> > immediate membership ultimately responsible for the effective membership
> > i.e. if groupA has groupB as a member has groupC as a member has subject
> > Z as a member I was interested in groupB->groupC
>
> Algorithmically, it is more efficient to start with a subject and
> determine all of its effective memberships than to start with a group and
> recursively determine its effective members. The API manages effective
> membership using the former approach. To best leverage what's already
> there, perhaps what is needed is a method that takes the set of all
> "upward" membership chains starting from a subject and prunes that set to
> retain only those chains that terminate on a specified group. That
> depicts the set of "reasons" why the subject has the effective membership
> (or priv).
I see what you are getting at. Currently I think that the listVals method 
returns a Subject multiple times - one for each effective membership and 
once for an immediate membership. As the membership list returned is not 
sorted the same subject will generally not be grouped
> Should such a method be in the UI or API?
I think that the listEffVals and listVals methods ought to return a Set - 
each subject only once. Rather than trying to provide links here to the 
effective group memberships separately, the subject would be a link which, 
when clicked, would resolve to either:
1) a summary page listing all ways in which the subject is a member of the 
group and probably some links to effect changes - but this could be quite 
difficult to explain to end users
2) the priv/membership screen as we do now - if a subject is a member once 
via an immediate membership

I think it ought to be straightforward to write a query against 
Grouper_List to return GrouperList objects for each occurrence of a subject 
as a member of a group - so this should be in the API. For each effective 
membership I would show the information on chain.png
> > > > e.g. can you revoke a privilege for an individual when it was granted
> > > > to a group?
> > >
> > >
> > > You should not be able to.  If you can it is a bug.  You need to remove
> > > the individual from the group that they are an immediate member of to
> > > revoke the privilege.
> >
> > I wasn't suggesting that this happened - just that anyone using the UI
> > would in effect try to do this. I think we need to make it clear, in the
> > UI, how a subject came to have a privilege/membership - atleast as a
> > prerequisite to modifying privileges/memberships. It is impossible to
> > know what to expect otherwise.
>
> See above.
>
> Tom



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GW Brown, Information Systems and Computing