Re: Possible error in 7.22.7. indicate-destination

At 14:15 2004-05-21 +0200, wrote:

>while implementing the basic-link formatting object for PDF output, I 
>looked for a way to indicate to the PDF renderer when to make links 
>visible and when not.
>The property 7.22.7 "indicate-destination" almost seems to do this.
>The spec reads: "The areas that belong to the link target when traversed 
>should, in a system-dependent manner, be indicated."
>Did you perhaps intend "The areas that belong to link *source*....."? If 
>yes, the property makes perfects sense to me. If not, would you consider 
>adding a new property for XSL 1.1? Also, in case this is meant as it is 
>written, what is the use case for highlighting a link destination instead 
>of a link source?

This wording in the spec is not in error.

The source is the contents of the fo:basic-link, and your stylesheet
can apply any property you want to that content--for example, underlining
it is common.

The indicate-destination allows the target of a basic-link to be, say,
highlighted in some fashion.  The use case is as clear as highlighting
the source, I guess.  Some people like to know what elements in their
document are potential link targets.  (The fact that support for
indicate-destination is so rare indicates to me that the use case is
not a common one, but the use case isn't hard to understand.)

Presumably, indicating the target is only feasible currently for 
internal-destination links.  In theory, one could have a renderer 
that can load a web of inter-linked documents and recognize in one 
document the target of a link in another document, but I am not 
aware of any such XSL-FO aware tool at this time.  Also, this only
makes sense if your external links use URIs with a fragment 
identifier--such as XPointer, but nothing has yet been officially 
stardardized as the fragment identifier for the XML media type.

I'm not entirely sure what you mean by "indicate to the PDF renderer 
when to make links visible and when not" (I am not a PDF expert), but
visibility is an XSL FO property.  If you want to make such visibility
dynamic, consider using the fo:multi-switch FO.

If there is something else you need to tell the PDF renderer, you might
need to invent and use your own property.

As far as something for XSL 1.1, the XSL FO subgroup is trying its best 
to keep 1.1 to a manageable size so that we can get something out this year 
(and we're having a hard time as it is), but you are welcome to make a more
specific suggestion.  (Perhaps your description of "indicate to the PDF 
renderer when to make links visible and when not" is clear enough to
others on the XSL FO SG who know PDF better, but in case it isn't any
clearer to them than it is to me, you might want to elaborate.)  I can't
promise anything about 1.1, but you can certainly make your case.


(not speaking officially for the XSL FO SG at this time)

Received on Friday, 21 May 2004 10:39:34 UTC