Re: DOCBOOK-APPS: RE: XML catalog resolution problems

[Daniel Veillard <veillard at redhat dot com>]

On Wed, Oct 30, 2002 at 11:25:02AM -0600, Paul Grosso wrote:
> >  I haven't received any justification yet from the commitee about the
> >reason to distinguish those exept "they are different", no sorry ...
> 
> Well, when Microsoft said "I see no reason not to support empty end 
> tags (i.e., </>) in XML", people rose in protest.  One justification
> is that this is the standard, and you are refusing to follow it.

  Thanks for the association, greatly appreciated :-(((
There was technical reason exposed for refusing </> once being that
redudancy allowed to catch errors. There was support for
having clearly marked ending tags outside of the XML Working Group,
I have yet to see one user which is not confused by the SYSTEM/URI
distinction. I mean real user, the categories of persons I tend
to get them to adop XML, and use Catalogs, not a 20 years veteran
specialized in the field.

> But I will try again to give you a more technical explanation.
> 
> The use of systemId in the XML Catalog is expressly to model 
> production [75], ExternalID, of the XML spec.  I think it is 
> good architecture to model what the catalog does on what the 
> XML spec is doing.

  The XML spec in 4.2.2 explicitely state that in production 75 
the System ID is an URI-Reference and link to RFC 2396.
  The XInclude spec does the same for the href attribute.
  There is no XML Base, so both references uses the same base
and anybody with some common sense would expect the two references
to get to the same resource.

> XML has no concept of a URI.  It only has a concept of ExternalID
> with a SystemLiteral.

  It does expose the System ID as being an URI reference, sorry
reread 4.2.2, it does reference RFC 2396 and Co. 

> Furthermore, XML's SystemLiteral cannot have a fragment ID:

  Which is precisely a rule it adds at the semantic level on that
string associating it as an URI precisely !

> So the datatype of the systemId entry is different from the datatype
> of the uri entry.  Another reason it makes good architectural

  No both are a URI References. XML may impose some restriction
on the final URI generated. XInclude also expose sonme restrictions,
but those are two object of the same kind with the same properties
and with the same base they ought to point to the same resource !

Daniel

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