Re: Foreign attributes in <*-properties> elements

[David Faure <faure@kde.org>]

On Thursday 12 February 2009, Michael Brauer - Sun Germany - ham02 - Hamburg wrote:
> My suggestion was that we add the following text to chapter 16:
> 
> > The <*-properties> elements may, in addition to the elements and
> > attributes defined by the OpenDocument schema, contain elements and
> > attributes not defined by the schema. These *shall not* be associated
> > with a namespace defined by this specification. The semantics of these
> > elements and attributes are implementation defined. They *shall not*
> > influence how the document is displayed, but *may* be evaluated when the
> > document is modified, for instance, when the properties of an object are
> > modified or new objects are inserted. 
> 
> While it has been suggested to remove the last sentence, I still think 
> we should keep it, or something similar, because otherwise we would 
> allow adding formatting properties that may have any kind of influence 
> on the display of a document. 

I have since realized that forbidding any influence on the display is wrong,
there are many features which might "appear in a way", I see no reason to
forbid them. Like Florian said: there is no definition of the way an ODF document
should be layouted and rendered even now in the standard, so it doesn't
make sense to "prevent changes in the display", when the display itself is
undefined in the first place...

I guess what you meant to say was that it's better to standardize attributes
that have their place in the standard, and I think we all agree on that.
My examples of koffice-1.1 extensions to ODF were agreed as "not harmful"
because they had no influence on the display, only on editing, but this is
just one special case, surely there are tons of "not harmful" extensions
possible that would still influence the display, as long as it's just extra
features -- indicators, etc.
Imagine an attribute related to a specific implementation of spellchecking...
it will influence the display of the document (red underline), but yet it
won't harm interoperability.

> This would be in so far and issue, as  
> there is no strict conformance anymore, which explicitly forbids these 
> attributes.

I don't understand this sentence.

> So, this still would be my proposal. However, if I read the mails from 
> Thomas Zander, it is not clear to me whether this extension mechanism 
> alone would be sufficient for KOffice, or whether there are other 
> extensions that are outside formatting properties. 

Ah, let me clear up this confusion. I was listing the extensions I created for
KOffice-1.1.x, while Thomas is talking about the extensions necessary for
KOffice-2.0. I'm the expert on ODF in 1.1, he's the expert about 2.0.
If our statements seem contradictory, it's only because we are not 
knowledgeable about the same version of KOffice :-)

So, for KOffice-1.1.x, *-properties extensions is enough, while Thomas
showed examples of other extensions needed for KOffice-2.0.

> I would further like  
> to point out that there still is a conformance mode that allows foreign 
> elements and attributes anywhere, which as been renamed to "extended 
> conformance", and that the case we are discussing here is just a special 
> case of that conformance mode.

Right. The question is what difference does it make in practice, whether a document
is conformant to the strict conformance or to the extended conformance.
I just don't want KOffice documents to be treated as second-class citizens....
but I admit that I don't know what difference it really makes.
I fear the day where e.g. OOo refuses to fix a bug coming from a koffice-created
document just because it is not "strictly" conformant for unrelated reasons
(i.e. the bug would be totally unrelated to any koffice extensions, but the first
thing people will see is "OK, the problem probably comes from the document
since it's not strictly conformant")... You see what I mean by 2nd-class citizens :)

> Taking it all together, it seems to me that you are in a much better 
> position than me to decide whether this extension would be useful for 
> KOffice, and also how the precise wording could be to meet the scope of 
> KOffice's extensions. Provided this is okay for you, I therefore would 
> like to ask you care about this proposal if you think that's reasonable. 
> It of cause is fine for me if you would just adopt my suggestion.

I'm not sure what you mean by "care about the proposal", I think we all care
about what happens with it. My proposal would simply be like yours but
without the last sentence, i.e.:

 The <*-properties> elements may, in addition to the elements and
 attributes defined by the OpenDocument schema, contain elements and
 attributes not defined by the schema. These *shall not* be associated
 with a namespace defined by this specification. The semantics of these
 elements and attributes are implementation defined. 

-- 
David Faure, faure@kde.org, sponsored by Qt Software @ Nokia to work on KDE,
Konqueror (http://www.konqueror.org), and KOffice (http://www.koffice.org).