Re: adding xlink:type attribute

Hi Benno,

I will go through our catalogs and add the xlink:type attribute. I'll 
also add it to our catalog generation tools.

In the InvCatalog 0.6 spec xlink:type had a default value of "simple". 
Looks like that got dropped in 1.0. Does adding this as a default seem 
like a good idea? Or would requiring it but no default value be preferable?

The Xlink spec has a non-normative DTD but no W3C Schema. How do others 
deal with including Xlink in their schemas? We just included a small 
XLink subset into our schema. Other ideas?

Thanks,

Ethan

Benno Blumenthal wrote:

> Hi John,
>
> OK, so my adding xlink:type="simple" does not break anything.  Good.
>
> But
>
> >       3.2 Markup Conformance
> >
> > An XML element conforms to XLink if:
> >
> >   1.
> >
> >       it has a |type| attribute from the XLink namespace whose value
> >       is one of "simple", "extended", "locator", "arc", "resource",
> >       "title", or "none", and
> >
> >   2.
> >
> >       it adheres to the conformance constraints imposed by the chosen
> >       XLink element type, as prescribed in this specification.
>
> So I am asking, politely I hope, to make xlink:type required, so that 
> we conform to the xlink spec.
> For starters, could all the thredds files that you generate have that 
> attribute?
>
> Benno
>
>
>
> John Caron wrote:
>
> >  we do already allow the "show" and "type" attribute on an Xlink, see:
> >
> > http://www.unidata.ucar.edu/projects/THREDDS/tech/catalog/InvCatalogSpec.html#XLink 
> >
> >
> > >       XLink Attribute Group
> > >
> > >  <xsd:attributeGroup name="XLink">
> > >    <xsd:attribute ref="xlink:href" />
> > >    <xsd:attribute ref="xlink:title" />
> > >    <xsd:attribute ref="xlink:show"/>
> > >    <xsd:attribute ref="xlink:type" />
> > >  </xsd:attributeGroup>
> > >
> > > These are attributes from the XLink specification 
> > > <http://www.w3.org/TR/xlink/> that are used to point to another web 
> > > resource. The /xlink:href/ attribute is used for the URL of the 
> > > resource itself. The /xlink:title/ attribute is what should be 
> > > displayed to the user. These are the only two attributes currently 
> > > used in the THREDDS software.You can also add the /xlink:type /or/ 
> > > xlink:show /attributes/. /

--
Ethan R. Davis                                Telephone: (303) 497-8155
Software Engineer                             Fax:       (303) 497-8690
UCAR Unidata Program Center                   E-mail:    address@hidden
P.O. Box 3000
Boulder, CO  80307-3000                       http://www.unidata.ucar.edu/
---------------------------------------------------------------------------