Re: [xml-dev] So maybe ID isn't a problem after all.

[Gavin Thomas Nicol <gtn@rbii.com>]

On Tuesday 13 November 2001 08:52 am, John Cowan wrote:
> > (B) The other choice we can make is to say that ID-ness is important.
>
> I agree with this view, and on primarily data-centric grounds.  Without
> IDs, XML can only serialize trees.  With IDs, it can serialize
> arbitrary graphs in a fairly application-independent way, at least
> within a single document.  This is often an important facility.
>
> > The only solution that I've seen that works with choice (B)
> > is xml:idatt(s).
>
> I agree.

XML itself doesn't do anything with graphs, even with ID/IDREF pairs, beyond 
simple validation of constraints. As such I have to disagree with your 
assertion that "Without ID's, XML can only serialize trees" and put it down 
to FUD.

If I have a document:

  <doc>
      <p>Some text goes here.<anchor name="bar"/></p>
      <p>Some more text goes here.<link name="bar"/></p>
  </doc>

have I defined a graph or a tree? How do you know? How does the XML processor 
know? If I changed this to declare the "name" attributes as CDATA, does it 
change? How about if I define them as ID/IDREF?