RE: [higgins-dev] ContextFactory.getContexts() clarification

["Paul Trevithick" <paul@xxxxxxxxxxxxxxxxx>]

Greg wrote:
> 
> 
> This doesn't seem compatible with the notion of searching for a
> ContextProvider that services a particular Context. (In other words,
> look for a Context, find the appropriate ContextProvider, then open the
> Context...)

You're right. I may have gone too far. I'm struggling for a practical middle
ground. Maybe we could make the ability to list all "openable" Contexts an
_optional_ capability. Would that work? 

Another example of a middle ground is only requiring that the provider
implement a predicate that returns whether or not a given Context URI is
openable (for a given requester). This would support your use case #3 here:
http://spwiki.editme.com/IDASUseCases without requiring exhaustive
enumeration.

> 
> Also, do you mean "open for this particular requester" or just open in
> general? Since opening requires AuthN, what good is it to know whether
> some Context happens to be open for some other consumer? This requester
> still might not be able to open it.

Good point. We could say that 'getContexts(String filter)' "returns the set
of Context References (URIs) that have been opened by the current requester
and are managed by this provider". 

And perhaps if it has the limited function that I've been talking about it
should be renamed 'getOpenContexts()'. That way we can discuss separately
whether we wish to have a 'getContext()' that returns the list of all
potentially openable (by _this_ requester) contexts.

> 
> On the other hand, I don't think that a ContextProvider must freely
> advertise all of its Context URIs. (I keep thinking about
> dynamically-created (probably non-persistent) Contexts for specific
> views of data, which might be sensitive. I know that's not what we've
> been talking about lately, but it's my understanding that that's part of
> the model.)
> 
> ...Greg
>