Media types: version parameter?

[<remon.sinnema@emc.com>]

All,


> -----Original Message-----
> From: xacml@lists.oasis-open.org [mailto:xacml@lists.oasis-open.org] On
> Behalf Of Bill Parducci
> Sent: Thursday, February 23, 2012 8:29 PM
> To: XACML TC
> Subject: [xacml] Minutes for XACML TC Meeting 23 Fenruary 2012
> 
 
>  Media types
>   Ray got doc started, Robin from Oasis offered to help. Need to get
>   types defined to move forward. Ray asked if there were XACML version
>   dependencies on the types. Hal noted this was not necessary for XML
>   but noted that we need to mechanism for JSON is separate, Ray's
>   initial types should cover these cases.

Even though an XACML policy/request/response includes a namespace that indicates the version used, there may be value in a separate version identification mechanism.

A good example is content negotiation [1]. One client can request a version 2.0 response from the PDP, whereas a different client can request a version 3.0 response. The same PDP could answer both clients in their preferred manner. This makes it a lot easier to evolve a PDP, since not all clients need to be upgraded right away.

Thanks,
Ray

[1] http://en.wikipedia.org/wiki/Content_negotiation