On Wed, 2018-10-10 at 19:23 -0700, Andy Bierman wrote:
>
>
> On Wed, Oct 10, 2018 at 6:59 PM, Reshad Rahman (rrahman) <rrah...@cisco.com>
> wrote:
> > On 2018-10-10, 9:59 AM, "netmod on behalf of Martin Bjorklund" <
> > netmod-boun...@ietf.org on behalf of m...@tail-f.com> wrote:
> >
> > Ladislav Lhotka <lho...@nic.cz> wrote:
> > > Martin Bjorklund <m...@tail-f.com> writes:
> > >
> > > > Hi,
> > > >
> > > > While reviewing restconf-notif, I saw this example:
> > > >
> > > > {
> > > > "ietf-subscribed-notifications:input": {
> > > > "stream": "NETCONF",
> > > > "stream-xpath-filter": "/ds:foo/",
> > > > "dscp": "10"
> > > > }
> > > > }
> > > >
> > > > Note the "stream-xpath-filter". It has a prefix in the XPath
> > string.
> > > > How are prefixes declared when JSON is used?
> > > >
> > > > The leaf "stream-xpath-filter" says:
> > > >
> > > > o The set of namespace declarations are those in
> > scope on
> > > > the 'stream-xpath-filter' leaf element.
> > > >
> > > > (I think I provided that text...)
> > > >
> > > > This assumes that the encoding is XML, or at leas that the encoding
> > > > can somehow transfer namespace declarations.
> > >
> > > It can't. There are two options:
> > >
> > > 1. have different representations of this value in XML and JSON,
> > > analogically to instance indentifiers (sec. 6.11 in RFC 7951).
> > >
> > > 2. use a module name rather than a prefix in XML, too.
> > >
> > > I would suggest #2.
> > <RR> But that means making non-backwards compatible change to the XML
> > representation?
>
> Not really. It means NETMOD WG would be creating its own special variant of
> XPath.
The thing is that XPath is "XML Path Language", so using it outside XML is
problematic.
Lada
>
> > Hmm, so you mean change the leaf "stream-xpath-filter" to say:
> >
> > o The set of namespace declarations has one member for each
> > YANG module supported by the server. This member maps
> > from the YANG module name to the YANG module namespace.
> >
> > This means that in the XPath expression, the module name
> > serves as the prefix.
> >
> > .... and then also give an example of this.
> >
> > This is probably what we need to do in all places where yang:xpath1.0
> > is used, going forward. Maybe even define a new type
> > yang:xpath1.0-2 (name?) with the set of namespace declarations
> > built-in.
>
>
> We should avoid making off-the-shelf implementations of standards like XPath
> unusable.
> At the very least this should be only available if the server supports it
> (with a capability URI)
>
>
> > <RR> So we need an update to RFC7951?
> >
> > Regards,
> > Reshad.
> >
>
>
> Andy
>
> > /martin
> >
> >
> >
> >
> >
> > >
> > > Lada
> > >
> > > >
> > > > How is this supposed to work with JSON?
> > > >
> > > >
> > > > /martin
> > > >
> > > > _______________________________________________
> > > > netmod mailing list
> > > > netmod@ietf.org
> > > > https://www.ietf.org/mailman/listinfo/netmod
> > >
> > > --
> > > Ladislav Lhotka
> > > Head, CZ.NIC Labs
> > > PGP Key ID: 0xB8F92B08A9F76C67
> > >
> >
> > _______________________________________________
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> > https://www.ietf.org/mailman/listinfo/netmod
> >
> >
> > _______________________________________________
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>
>
--
Ladislav Lhotka
Head, CZ.NIC Labs
PGP Key ID: 0xB8F92B08A9F76C67
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