Re: [opendocument-users] RE: Foreign elements and attributes

[Dave Pawson <dave.pawson@gmail.com>]

2009/3/4 Dennis E. Hamilton <dennis.hamilton@acm.org>:

> The following remarks are all speculative, because we don't know whether
> anyone will stub their toe on these or not.

A little Dennis, just a little :-)


> ANALYSIS
> ========
>
> 1. We still have a problem with foreign attribute values on existing
> attributes.  When such an attribute has no default value (the defined
> fall-back) and the attribute is required, the document would be
> unacceptable.  I don't think your proposal addresses this case anyhow, but I
> do notice that language being introduced for it has this hole.  I also note
> that those places, such as table:formula, where all of the values are
> foreign in ODF 1.1 [and presumably still permitted in ODF 1.2 (extended)
> documents], the fallback from only one something to only nothing is pretty
> stark.

As a generality, I'm not in favour of backwards compatibility.
I'd suggest 1.1 'extensions' be treated as any other 'extension'


>
> 2. One problem with the use of attributes only is that there can only be one
> occurrence of an attribute of the same name per element.  There is no
> provision for multiplicity, repetition, etc.

Same local-name, different namespace?
Are they 'different'?

>
> 3. One way to deal with situations like (2) is to use the ODF counterparts
> of <div> and <span> or (hack, cough) the ODF bookmark provisions that allow
> hierarchy to be transcended in the manner exploited by the RDF Metadata
> feature.

Scenario. You are an implementor. You come across a valid ODF element
with foo:bar="The quick brown fox" as an attribute.

Would it make sense to treat this as content? I don't think so.
I'd suggest as a 'maximum', the presentation layer is asked to inform
the reader that such foreign content exist.
More practically, as a document, report that it contains an extension
and leave it at that.



>
> 4. I said this is all speculative, because we don't know whose situation
> would be thwarted by the constriction.


The only applications that can reasonably process extensions are those
that comprehend the element/attribute/namespace combinations,
probably because that application generates them.

That makes sense, in a local, non conformant usage which I see
as doing no harm when used in that way.
  That's how good features can be trialled for adoption by
the standard.


regards




-- 
Dave Pawson
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