Re: [dita] strategy for identifying DTD/schema artifacts

[ekimber <ekimber@reallysi.com>]

On 9/24/09 11:41 AM, "Grosso, Paul" <pgrosso@ptc.com> wrote:

> 
> 
>> -----Original Message-----
>> From: ekimber [mailto:ekimber@reallysi.com]
>> Sent: Thursday, 2009 September 24 11:17
>> To: Park Seth-R01164; dita
>> Subject: Re: [dita] strategy for identifying DTD/schema artifacts
> 
>  
>> XML allows public IDs to be either URIs or SGML-style public ID
> strings.
> 
> I wouldn't go so far as to imply that any URI can be
> used as a public identifier.  Public IDs have a
> restricted character set--see my earlier email.

Ah, didn't realize public IDs were more restricted than URIs.
 
> Also, using something like looked like a URL as a
> public id would lead to confusion.  A user would
> reasonably expect a URI entry in a catalog to be
> used to map such an entry, but that wouldn't work.

Yes, I can see that confusion--one reason I've long contended that public
ID's were bogus on their face (because they are redundant with unresolvable
URIs for SYSTEM IDs).

Of course, there is already confusion caused by Xerce's parser
implementation, which uses SYSTEM entries to resolve schemalocation URIs, so
there's no way users can win, except by always providing both system and URI
entries for all URIs. I submitted a bug for this a couple of years ago and
was told "broken as design, not going to fix it".

Anyway, the TC practice is to use public ID syntax for public IDs.

Cheers,

E.



----
Eliot Kimber | Senior Solutions Architect | Really Strategies, Inc.
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