Re: [office] Proposal for lists/numbered paragraphs

[Daniel Vogelheim <Daniel.Vogelheim@sun.com>]

Hello Paul,

Paul Grosso wrote:
 >> [... proposal for lists + number element ...]

> Coming from a structured markup world and not a WP one, I don't really
> understand this stuff.  I can't really imagine what the use case is (I'm
> sure there are many in WP land, I just have a hard time imagining most
> things in WP land).
> 
> Is the number that is put in front of a numbered paragraph given as part
> of the style, or is it supposed to be computed automatically by counting
> something?  And if the latter, what is counted?

In internal word-processor implementations (apparently, OOo Writer, 
WordPerfect, KOffice, Word share this trait), the style assigns the 
paragraph into a certain numbering domain. So all paragraphs in the same 
numbering domain receive a hierarchical numbering based on their 
numbering level.

The user interfaces often try to make this look more list-like, so one 
could argue that this is somewhat of a legacy. I'm tempted to take this 
position for Writer, but I'd probably get in trouble with my 
collegues... ;-)


> Since I don't really have my head wrapped around this stuff, I can't really
> tell how this might work in an XSL world, but I'm nervous that this could
> cause problems for XSL.

I see your point. The problem, as I see it, is that the word-processing 
world has one kind of concept, and HTML, XSL, and basically any other 
XML format, have a different kind of concept. We want to do good XML, we 
need to represent word-processing documents, and hence we have a 
problem: How do we join these two? Both issues are listed in the charter 
as requirements, the former as  4) and 6), the latter as 1).

The OOo team has given an answer, one which has been accepted as the 
base specification: Use HTML-style lists, plus an extra 
'continue-numbering' attribute. For all I can tell, this covers both 
requirements (being reasonable XML-wise, and being able to represent all 
documents), and hence it is a good answer. However, nothing is perfect, 
and this does place a burden on implementers for file format converters.

Instead, one could choose a representation that is close(r) to the 
word-processing side of things. This would make it easier for those 
people, but would make it harder for the structured markup people. And 
this is, in my view, the core of the discussion: There is inherent 
complexity in trying to bridge two worlds, and the committee gets to 
decide where to push that complexity, and how to slice it up.

The one suggestion is to do structured lists + continue-numbering.
+ structure where there is structure
- pseudo-structure in some other places where list numbering is used
   without proper list.
+ easy for XML conversion
- the structure may be hard to generate during conversions, and the
   pseudo-structure is ugly
Essentially, the conversions is where we push the complexity to.

The next suggestion (Michael) uses that as base, but adds an 'escape' 
[i.e. declaring an individual paragraph to be listed at some level] to 
take away some of the burden from the filter people:
+ (optional) structure where there is structure
- easy generation using the escape
- redundant representation: there may be badly-behaved documents that
   don't generate any lists even where suitable
- corollary from above: For complete processing one really needs to
   fully support both.
Here, we distribute the complexity more equally, and various parties get 
to choose how much effort they want to put into it. Problem may be that 
the process may just not work very well if everyone chooses the easy way 
out.

The third suggestion would be to do things word-processor style 
completely, i.e. by having lists as a side-effect of formatting.
+ easy to generate from existing wp formats
- structure may be hard to generate during XML processing
- one may need alternative list structures for other parts of the
   format, i.e. for presentation modules.
Here, we push the complexity over to the XML/structured markup side. You 
want lists? You make them!
To some degree, this solution would fail the previously mentioned 
requirements 4)+6), while doing quite well on the 1) side. I'm not sure 
how good of a solution this is, given that the previous ones seem to 
cover all bases properly.

There has been an argument that goind the first route may be trying to 
be overly clean on this fairly arbitrary issue, while taking the easier 
way with other items (e.g. headers vs DocBook style sections). I'm not 
sure if I can follow this, but it was one of the given arguments and 
thus should be mentioned.


Paul, you said you sense trouble for XSL. Well, I think the necessary 
conversions are expressable as XSLT, if ugly. Given my taxonomy above, 
the third (and possibly second) solution places the complexity squarly 
in your lap, so you're quite right about sensing trouble. As I said 
before, I think it's doable, but I also think the other solutions are a 
better way to go.


As a general guideline, I would say that 'clean' XML solutions are to be 
preferred _if_ they can represent existing documents. This seems to be 
the case with solutions 1 (and 2) above.
If we _cannot_ find a 'clean' XML way to represent existing documents, 
we have a problem and will need to do funny stuff. Example: tabs. I 
don't think lists qualify here, because a workable, XML-like solution 
exists.



Hope this helps!

Daniel