RE: I-D draft-weijing-netconf-interface-01.txt

["Chen, Weijing" <Weijing_Chen@labs.sbc.com>]

> >Explicit vs. implicit
> >Option is explicitly stated by XML schema.
> >Operating.XSD
> >Vs. option is implicitly inferred from URL.
> > <capabilities>
> >       <capability>http://ietf.org/xmlconf/1.0/base</capability>
> >       <capability>http://ietf.org/xmlconf/1.0/base#lock</capability>
> >       <capability>http:/example.net/router/2.3/core#cool-
> feature</capability>
> > </capabilities>
>
> So I'm still confused about why this is a good thing.  I'd _much_
> rather write code that looks like:
> 
> 
>    if (device.hasCapability(CAP.COOL_FEATURE)) {
>        req = buildFooRequest();
>        device.sendRequest(req);
>    }
> 
> than code that looks like:
> 
>     req = buildFooRequest();
>     if (device.getXSD.isValid(req)) {
>         device.sendRequest(req);
>     }
>
No, I wouldn't write code like the above.  I would do the something like:

allXSD = loadXSD(all the XSDs I will support);
req = allXSD.buildFooRequest(XML document input by user);
if (req.valid)
{
    device.sendRequest(req);
}

Without XSD, how do I know whether I can build the valid request from the
input XML document or not?



--

Weijing Chen


> -----Original Message-----
> From: Phil Shafer [mailto:phil@juniper.net]
> Sent: Sunday, September 07, 2003 5:05 PM
> To: Chen, Weijing
> Cc: netconf@ops.ietf.org
> Subject: Re: I-D draft-weijing-netconf-interface-01.txt
> 
> "Chen, Weijing" writes:
> >Explicit vs. implicit
> >Option is explicitly stated by XML schema.
> >Operating.XSD
> >Vs. option is implicitly inferred from URL.
> > <capabilities>
> >       <capability>http://ietf.org/xmlconf/1.0/base</capability>
> >       <capability>http://ietf.org/xmlconf/1.0/base#lock</capability>
> >       <capability>http:/example.net/router/2.3/core#cool-
> feature</capability>
> > </capabilities>
> 
> So I'm still confused about why this is a good thing.  I'd _much_
> rather write code that looks like:
> 
> 
>    if (device.hasCapability(CAP.COOL_FEATURE)) {
>        req = buildFooRequest();
>        device.sendRequest(req);
>    }
> 
> than code that looks like:
> 
>     req = buildFooRequest();
>     if (device.getXSD.isValid(req)) {
>         device.sendRequest(req);
>     }
> 
> That is, I'd rather know that the device supports the particular
> feature I'm attempting to use directly, instead of assuming that
> if the request isn't schema-valid for the particular device, it
> must be because the device does not support the feature.
> 
> The code that is trying to invoke an operation has to know that
> operation specifically. It cannot learn it via XSD. Even if the
> application can fetch the device schema and the schema has explicit
> details about the devices locking capabilities, the application
> cannot suddenly spawn code that knows how to invoke those capabilities.
> There has to be some semantic understanding on the application
> developers part that understands locking and wants to invoke it.
> Short of that, how will the application ever know what those bits
> of xsd do?
> 
> Thanks,
>  Phil

--
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/>