On Mon, Oct 05, 2015 at 01:32:46PM +0200, Ladislav Lhotka wrote:
>
> > On 05 Oct 2015, at 11:57, Juergen Schoenwaelder
> > <j.schoenwael...@jacobs-university.de> wrote:
> >
> > On Mon, Oct 05, 2015 at 11:48:10AM +0200, Ladislav Lhotka wrote:
> >
> >> I am certainly concerned. The current definition of "anydata" ("an
> >> unknown set of nodes that can be modelled with YANG") is IMO
> >> insufficient because, for one, it doesn't even eliminate mixed content
> >> in XML, which can be modelled with YANG's "anyxml" statement.
> >
> > Good point. I think we should clarify that anyxml is excluded.
>
> Then YANG extensions probably need to be excluded, too.
>
> >
> >> In my view, the idea behind "anydata" was that it would be possible to
> >> build a regular data (sub)tree from schema-less data. However, this
> >> seems to be difficult, at least on a server supporting both XML and
> >> JSON, and so benefits of "anydata" over "anyxml" are really
> >> questionable.
> >
> > I do not think anydata was driven by the idea to build a regular data
> > (sub)tree from schema-less data.
> >
> > I think anydata works fine with both JSON and XML as long as the
> > encoder has the data model, which seems to be a reasonable assumption
>
> If it is so, then what we really need is a standard mechanism that allows
> for signalling the data model at run time. Without that, as Randy pointed
> out, there is no way to make sure that the server and client use the same
> data model for a particular “anydata” node, and then the difference between
> “anydata” and “anyxml” is no more interesting. All external means (or
> descriptions) that may potentially provide “late binding” of the data model
> are applicable to “anyxml” as well.
>
XML uses namespace URIs to identify the data model, JSON uses module
names to identify the data model. The only discussion point here is
the level of uniqueness (and of course why we use two different data
model identifiers - but it seems nobody except me or perhaps Randy
cares).
And no, anyxml was defined to be 'any XML' and anydata has been
defined to be 'any data modeled in YANG' (without anyxml). This really
has been settled, please read the archives if you are still unsure
what the difference is.
/js
--
Juergen Schoenwaelder Jacobs University Bremen gGmbH
Phone: +49 421 200 3587 Campus Ring 1 | 28759 Bremen | Germany
Fax: +49 421 200 3103 <http://www.jacobs-university.de/>
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