Re: [netmod] evaluation of "when" under NMDA

On Mon, Dec 4, 2017 at 9:22 AM, Juergen Schoenwaelder <
j.schoenwaelder@jacobs-university.de> wrote:

> On Mon, Dec 04, 2017 at 06:05:58PM +0100, Ladislav Lhotka wrote:
> > On Mon, 2017-12-04 at 17:34 +0100, Martin Bjorklund wrote:
> > > Ladislav Lhotka <lhotka@nic.cz> wrote:
> > > > Hi,
> > > >
> > > > if we have
> > > >
> > > > augment "/target/node" {
> > > >   when "...";
> > > >   ...
> > > > }
> > > >
> > > > is the "when" expression supposed to be evaluated separately in each
> > >
> > > datastore,
> > > > and the augment applied only in those datastores where the result is
> true?
> > >
> > > Yes.
> >
> > But then it cannot be guaranteed that the schema for <operational> is a
> superset
> > of the schema of configuration datastores - the when expression can
> evaluate to
> > false in <operational> but true in <intended>.
> >
>
> For me, its still the same schema - a when expression does not change
> my notion of 'schema'.
>

Agreed, but it changes the validation results against the schema.
As Martin pointed out, we already have this separate validation issue in
<candidate>.
This is not a problem though because only <running> is required to pass
validation tests.

I think NMDA works out fine because the YANG validation of config=true nodes
is done in <intended>, not in <operational>.  Only the config=false nodes
would be validated in <operational>, done by the client, not the server.
(Server implementations do not validate their own output).

> /js
>

Andy

>
> --
> 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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