[RDDL] Cache / Security Model

[Jeff Rafter <jeffrafter@earthlink.net>]

I have seen this group actually take on some of the more challenging,
controversy laden, arguments lately with success, so I thought I would start
us on another.  Should RDDL have a layer that implements a caching mechanism
which contains: expiration dates, automatic lookup, namespace aliases,
public/private key signing, options for turning off namespace resolution?

My thinking is that this would address some of the biggest question marks
left regarding RDDL.  Such as:

1) Should the namespace be resolved blindly?-- I think yes, but if your
parser implemented an RDDLCache with an RDDLSecurityLayer you could turn it
off if you disagree.

2) Will usages of common namespaces (such as the XHTML or XML Schema
namespaces) overload the Internet?-- Probably and having a caching system
built into the resolution model would alleviate some of that.  Namespace
aliases could also help in this area-- they could point to a local cache or
another trusted server where the appropriate documents are stored.

I think that the signing mechanism would be a great addition and might help
to satisfy some of the trust issues that have been brought up. I am thinking
in VERY simple terms right now, however-- not some overarching Internet
changing system that takes months to agree upon.  Only the basics with the
mindset of developer extension.

One possible extension would be an RDDLMap that would create an XML tree of
all included (nested) resources referred to by the RDDL-- it may even point
out circular references to namespaces-- just a thought.

Thanks,
Jeff Rafter
Defined Systems