Re: JSON Profile Issues (was Re: [xacml] Thursday Meeting)

[Steven Legg <steven.legg@viewds.com>]

Hi David,

On 11/05/2013 9:20 AM, David Brossard wrote:
> Regarding the following
>
>     The examples show instances where what is described as an array in the
>     text is shown instead as a single value (noting that an object is a JSON
>     value). I think it would be useful to make a statement somewhere early in
>     the profile that an array with a single JSON value MAY, or MUST if that is
>     your intent, be encoded directly as that value rather than as an array
>     of one value (although the profile would be easier to implement if an
>     array is always an array, even if it has only one value).
>
>     Section 5.2.5: I found the wording "It is simply an array of ..." misleading,
>     suggesting something like this:
>
>        Obligations:[{
>         Id:"urn:oasis:names:tc:xacml:__3.0:ipc:obligation:encrypt"
>        },
>        {
>         Id:"urn:oasis:names:tc:xacml:__3.0:ipc:obligation:marking",
>         AttributeAssignment:{
>          AttributeId:"urn:oasis:names:__tc:xacml:3.0:example:__attribute:text",
>          DataType:"http://www.w3.org/__2001/XMLSchema#string <http://www.w3.org/2001/XMLSchema#string>"
>         }
>        }]
>
>     rather than this:
>
>        Obligations:{
>         ObligationsOrAdvice:[{
>          Id:"urn:oasis:names:tc:xacml:__3.0:ipc:obligation:encrypt"
>         },
>         {
>          Id:"urn:oasis:names:tc:xacml:__3.0:ipc:obligation:marking",
>          AttributeAssignment:{
>           AttributeId:"urn:oasis:names:__tc:xacml:3.0:example:__attribute:text",
>           DataType:"http://www.w3.org/__2001/XMLSchema#string <http://www.w3.org/2001/XMLSchema#string>"
>          }
>         }]
>        }
>
>     Assuming the latter is correct, then it would be better to say "It simply
>     contains an array of ...".
>
> I don't actually see the point in a double-nesting.

There is no reason for it in this case, apart from consistency with
the XML Schema.

> So I would rather have "Obligations": [{"Id":"",.......],{}]
> rather than "Obligations": {"ObligationOrAdvice" :  [{"Id":"",.......],{}] }

I'm okay with such a change. You could equally well use the names "Obligation"
and "Advice" instead of "Obligations" and "AssociatedAdvice". It just depends
on which element layer in the XML Schema we believe we are stripping out.

> It also applies to Advice as you pointed out and to Response / Result.
>
> Am I missing a JSON subtlety here?

None that I'm aware of.

Regards,
Steven