Re: [dita] ITEM: Cross-references to Topicheads and ImplicitTitle-only Topics

[Eliot Kimber <ekimber@reallysi.com>]

On 3/31/09 11:09 AM, "Grosso, Paul" <pgrosso@ptc.com> wrote:

> I'm not able to follow all this.  It's sure sounding complicated.
> 
> We're not talking about adding anything to DITA 1.2 here, are we?

Not from a markup standpoint. We're simply clarifying behavior already
arguably implicit in existing features.

In particular, I'm proposing that if a topichead has an effective  chunk
value of "to-content" that processors are obligated to behave as though a
title-only topic exists whose title is the navtitle of the topichead. In
addition, if that topichead happens to have a crossref to it, that the
effective target of the crossref is the implicit title-only topic.

If a topichead does not have an effective value of "to-content" for chunk
then processors *must not* imply title-only topics (that is, the implication
of title-only topics for topicheads must be entirely under author control in
order to avoid surprising differences in behavior from different processors
for the same map).

We're also saying that normal copy-to= semantics apply, such that the
implicit topic, if it results in a unique storage object in the rendition
(e.g., an HTML file), will be named according to the existing rules for
copy-to.

For example, given this topichead in a map:

<topichead
  key="about-this-book"
  chunk="to-content select-topic"
  copy-to="about-this-book"
>
  <navtitle>About This Book</navtitle>
</topichead>

The HTML rendition will result in a generated topic "about-this-book.html".

Likewise, given this xref in a topic used from the map containing this
topichead:

<xref keyref="about-this-book"/>

The effective target of the xref in the HTML rendition will be the
about-this-book.html HTML file.

Likewise, in a PDF rendering, there would be a body division with the title
"About This Book" and the xref would point to it in the PDF rendering.

I'm also suggesting that an xref to a topicref *has always* represented an
indirect reference from the xref to the ultimate target of the topicref. The
DITA 1.1 spec was not explicit on this matter, but given the existence of
keyref= in DITA 1.2 and our explicit statement that keyrefs to topicrefs are
indirect references to the ultimate target of the topicref, then, by the
principle that form of address doesn't change the semantic of a link, then
href= pointers to topicrefs are also indirections to the topics pointed to
by those topicrefs (because *any* type of pointer to a topicref must be an
indirection if any specific type of pointer is an indirection).


Cheers,

Eliot
 

----
Eliot Kimber | Senior Solutions Architect | Really Strategies, Inc.
email:  ekimber@reallysi.com <mailto:ekimber@reallysi.com>
office: 610.631.6770 | cell: 512.554.9368
2570 Boulevard of the Generals | Suite 213 | Audubon, PA 19403
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