Re: DOCBOOK-APPS: How to select <imageobject> alternativein<mediaobject>?

[Jirka Kosek <jirka at kosek dot cz>]

Bob Stayton wrote:

> > 1. image selection based on role attribute should be controlled by
> > on/off parameter
> 
> It seems that this should be a feature of the profiling
> step, not the processing step.  As you say, if someone has
> role attributes on their imageobjects and are doing
> profiling without taking "html;fo" into account, then by
> the time the regular stylesheet gets the content, they
> won't have the elements for this option to act on.  If they
> are taking it into account, then they would always want the
> option on during the formatting step anyway.  So it would
> seem that it is the profiling step that needs such an
> option, to enable the profiling step to make exceptions for
> imageobject role attributes during the profiling step so
> they survive to the formatting step.

But I think that exatly for this reason there should be option how to
switch off new behaviour. Imagine that someone is using role="html" and
role="fo" on normal paragrahs with profiling to distinguish between
print and HTML version. If I will add html and fo targets as defaults to
profile.role, these users wouldn't be happy because profiling will be
broken for them. 
 
> I'm thinking that people might have other conflicts for the
> use of the role attribute in their documents. For example,
> <emphasis role="bold">, or <emphasis role="mystyle"> with
> the 'emphasis.propagates.style' attribute set to 1 so the
> HTML stylesheet does <span class="mystyle"> in the HTML.
> Essentially if you use role for profiling, you cannot use
> role for other purposes without always including those
> values in your "profile.role" selection.
> 
> Perhaps the non-profiling role values should be in a
> separate "profile.role.accept" parameter that is a
> permanent fixture of the stylesheet or customization.  One
> would perform a particular profiling by setting their
> profile.role on the command line, and that would be merged
> by the stylesheet with the values in profile.role.accept.
> That way, the profiling gets taken care of and the other
> role attributes survive to be acted upon by the formatting
> stylesheet.  The default value of profile.role.accept could
> be "html;fo", and it is customizable.

I think that profiling on role is not good idea as a whole so I think
that we shouldn't make profiling code more complex by introducing some
"magic" like profile.role.accept. I think that people should just have
option to switch off selection of images based on role if they want to
do so. After that they can still control image inclusion based on role
by profiling.

I'm quite tired now so I might be missing some important point of view,
sorry. :-(

				Jirka 

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  Jirka Kosek  	                     
  e-mail: jirka@kosek.cz
  http://www.kosek.cz