Re: [Ecrit] Profiles (was: Consensus Call) - namespaces

[Andrew Newton <andy at hxr.us>]

Perhaps we do need to restart the discussion.  I was never arguing  
for anything as strong as XML validity.  That was one of your  
arguments.  However, if you take a schema that has the following  
definition (pasted from 4119):

    <xs:sequence>
      <xs:any namespace="##other" processContents="lax" minOccurs="0"
         maxOccurs="unbounded"/>
    </xs:sequence>

Now take a look at the following from draft-ietf-geopriv-pdif-lo- 
profile:

         <gp:geopriv>
           <gp:location-info>
             <gml:Point srsName="urn:ogc:def:crs:EPSG::4326"
                <gml:pos>-43.5723 153.21760</gml:pos>
             </gml:Point>
             <cl:civicAddress>
               <cl:FLR>2</cl:FLR>
             </cl:civicAddress>
           </gp:location-info>
           <gp:usage-rules/>
         </gp:geopriv>

What is there to say that <cl:civicAddress> can legally follow  
<gml:Point>?  Nothing.  From an XML processors perspective, it could  
be GML followed by some other stuff that can be ignored (look at  
processContents="lax").  What's the cue to the application that it  
shouldn't ignore <cl:civicAddress>?  How does it know that is  
important information, if even it may not have the schema in its  
catalog?

-andy

On Apr 26, 2007, at 11:26 PM, Henning Schulzrinne wrote:

> Maybe we need to restart this discussion, as I'm lost. I still  
> haven't heard a single technical argument as to what additional  
> information a profile name, outside the XML, contains that would  
> not be visible in the namespace and tag declarations. I was taught  
> that XML documents could stand alone, without additional meta  
> information, once you have pointers to the namespaces. Do you have  
> a citation that indicates that this is wrong?
>
> I'm looking at Walmsley, "Definitive XML Schema" and it says:
>
> "Instances can be related to schemas in a variety of ways ...
>
> * ...
> * dereferencing the namespace. The namespace can be dereferenced to  
> retrieve a schema document or resource directory."
>
> In this case, this is a URN and all relevant schema will be known  
> to the receiver and we have a one-to-one relationship between  
> namespace and schema, so there's no ambiguity. (Walmsley points out  
> various reasons why an HTTP-like namespace identifier may not be a  
> good idea, but none of them seem to apply here.)
>
> Also, as I mentioned before, XMPP seems to follow roughly the same  
> model as 4119. E.g., the core spec defines a schema and namespace  
> urn:ietf:params:xml:ns:xmpp-sasl and urn:ietf:params:xml:ns:xmpp- 
> tls. There is no profile indication, as far as I can tell, even for  
> the various extensions (say, namespace jabber:x:data).
>
> Can you please provide a reference or other authority that supports  
> or explains your view?
>
> Henning
>
> On Apr 26, 2007, at 11:03 PM, Andrew Newton wrote:
>
> > On Apr 26, 2007, at 10:53 PM, Henning Schulzrinne wrote:
> >
> > > I've asked a few times, but why would LoST care that the  
> > > civicAddr is derived from DHCP as opposed to, say, entered  
> > > manually? Obviously, the current profile doesn't convey that  
> > > information, either.
> >
> > I don't think it should care.  The point wasn't that it came from  
> > DHCP, the point was that it was a 3825-like compound location.   
> > Sorry if that was confusing.
> >
> > -andy


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