RE: [dita] Proposal: Update foreign topic to include processing info forgeneralization/specialization use case

[Michael Priestley <mpriestl@ca.ibm.com>]

The mechanism for adding foreign elements
to a DTD is through specialization of the foreign element. That way the
existence of new elements is signalled through the specialized element's
domain or type module (in the root type's class or domains att). If we
generalize and get rid of that domain, we also get rid of the signal that
those elements exist.

Michael Priestley
IBM DITA Architect and Classification Schema PDT Lead
mpriestl@ca.ibm.com
http://dita.xml.org/blog/25

"Grosso, Paul" <pgrosso@ptc.com>

10/17/2006 12:48 PM

To	<dita@lists.oasis-open.org>
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Subject	RE: [dita] Proposal: Update foreign topic to include processing info for generalization/specialization use case

> -----Original Message-----
> From: Eric Sirois [mailto:esirois@ca.ibm.com] 
> Sent: Tuesday, 2006 October 17 09:32
> To: dita@lists.oasis-open.org
> Subject: [dita] Proposal: Update foreign topic to include 
> processing info for generalization/specialization use case
> 
> The foreign content proposal (#35) for incorporating foreign 
> content in
> DITA did not have a use case that covered what would
> happen when an DITA document contain foreign content are 
> generalized the
> content is not longer valid, when using DTDs for
> validation, because the base DTD does not include the foreign 
> vocabularies.

When using DTDs, if it is desired for the generalized
content to be DTD-valid, then the foreign content elements
should be added to the DTD.

> I propose that we hide the foreign content via a processing 
> instruction in
> the generalized document. It gets us past the validator
> issue. The content could then be re-instated during the specialization
> process.  Hiding in a comment was discussed, but there
> is no guarantee that tools keep comments in the documents.  
> Also, it makes
> reinstating the foreign content during specialization
> much more difficult.

Putting what should be markup as characters in either a
comment or processing instruction (PI) is quite distasteful
to me.

Also, many tools toss PIs too--not ours unless such is
explicitly requested, but others do.

Note, your generalization process will need to get tricky
if the content you are trying to hide in a PI contains 
a "?>" string.

Finally, this all sounds too kludgy and implementation based 
to me for a specification.

> 
> In the case where <foreign> contains an <image>, <object>,
or 
> <desc>, they
> should not be hidden within the processing instruction.
> All content within <unknown> will be hidden in a processing
> instruction.

paul