Re: notification-08 comments

[Martin Bjorklund <mbj@tail-f.com>]

Andy Bierman <ietf@andybierman.com> wrote:
> Martin Bjorklund wrote:
> > Andy Bierman <ietf@andybierman.com> wrote:
> >> 3.6, para 1:
> > 
> > [...]
> > 
> >>     If a filter element
> >>     is specified to look for data of a particular value, and the data
> >>     item is not present within a particular event notification for its
> >>     value to be checked against, the notification will be filtered out.
> >>
> >> This is not precise enough.
> >> For starters, subtree and Xpath filters return a subset of
> >> conceptual 'input node set', not a boolean expression.
> >> The output node set is returned in the <get> or <get-config> response.
> >>
> >> What does it mean to convert this mechanism to a boolean filter?
> >>
> >> Does it mean that any output at all from the filter means
> >> it 'passes', and an empty output node set means the filter 'failed'?
> > 
> > This is already defined for XPath, we should not change that.  Note
> > that an XPath expression does not have to return a 'node set', it can
> > also return a boolean, number or a string.  The XPath spec defines how
> > to interpret any of these as a boolean.
> > 
> 
> Doesn't the draft need to say the Xpath expression needs to
> be the boolean form? Or does it need to specify how the other
> forms are converted to boolean? Or is this already handled in Xpath
> and the draft can just say "convert to boolean"?

The latter IMO.  (This is sort of underspecified in the base spec as
well - it just says that the filter is an XPath expression, but it is
not defined how the node-set is represented in the XML rpc-reply, and
nothing is said about boolean/number/string expressions.)


/martin

--
to unsubscribe send a message to netconf-request@ops.ietf.org with
the word 'unsubscribe' in a single line as the message text body.
archive: <http://ops.ietf.org/lists/netconf/>