Hi Carlisle,
> Carlisle Adams wrote: >
> Hi Polar, > >
----------
>
From:
Polar Humenn[SMTP:]
>
Sent:
Thursday, February 21, 2002 4:17 PM
>
To:
Carlisle Adams
>
Cc:
''
>
Subject:
Re: [xacml] RE: policy model, part 1 >
>
On Tue, 19 Feb 2002, Carlisle Adams wrote: > >
> A RuleStatement contains the following items. >
>
- a RuleCore, which is a triple ( subject , action , resource ), >
> although one or two of the components may be missing (meaning any ). >
>
I would still like to see place holders for that information, such as >
<AnySubject/>, <AnyAction/>, <AnyResource/>, so that it is explicit in
>
what it means. You can lock in the positions in the syntax as well, which
>
might lead to easier processing. > >
> This is fine, although the syntax is probably a little bit uglier (e.g., the <subjects> element now needs to be a choice of PredicateExpressionType and <AnySubject/>, rather than simply a PredicateExpressionType that may have zero predicates (minOccurs= 0 )). >
> But I can live with either. The nillable feature provided by XML Schema bears investigation. XML Schema allows elements to be made nillable So in the XACML schema we could say: <xs:element name= subjects type= xacml:PredicateExpressionType nillable=true /> Then the following XACML policy instance fragment would be considered valid <subjects xsi:nil = true ></subjects> (xsi is the XMLSchema-instance namespace)
So basically, the interpretation is that a nil subject is AnySubject. Would this interpretation work ? If so, then nillable needs to be investigated further to see if there are any reasons why we may not use it. But that is a work item when the focus shifts to XML syntax. >
> Carlisle.
--
Sekhar
