Where does the data come from ?

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

This isn't a request to update the minutes but rather a followup to Martin's
question.

On 12/06/2015 8:39 AM, Bill Parducci wrote:
> Minutes of XACML TC Meeting 28 May 2015
>     Martin:
>      I reviewed this and was wondering where does the data come from?

An unstated assumption of the Entities Profile is that the data model for
an application comes first. By "data model" I mean a description of the
types of entities that are available and the attributes that they hold.
It could be simple prose as in the opening paragraphs of Section 7.2 of
the profile or it could be as formal as an entity-relationship diagram.
It could be internal documentation for a custom development or written
up in a standardized profile.

For a custom development, the data model needs to be devised with an
understanding of what data are available. A standardization profile can
only be supported if the required data are going to be available.

Once the data model is established, the PEPs, context handler and/or PIPs
can be configured (ideally) or engineered to provide the necessary entities
and attributes from the available data sources.

Finally, the policy writers write their policies in conformance with the
established data model.

There is no expectation that policy writers can use whatever data model
comes to mind and that somehow the context handler and PIPs will know
where to get the necessary data from.

Regards,
Steven