Re: [office] ODF 1.2 Single-Level Conformance and Law of UnintendedConsequences

[robert_weir@us.ibm.com]

David Faure <faure@kde.org> wrote on 01/19/2009 02:10:28 PM:

> 
> On Monday 19 January 2009, robert_weir@us.ibm.com wrote:
> > Since current implementations do not (to my 
> > knowledge) introduce foreign attributes and elements into documents, 
they 
> > would not be impacted by this change.
> 
> By foreign, do you mean attributes and elements not defined by ODF?
> Then I beg to differ, there are plenty of these, see below.
> 

We talking about ODF 1.0 and ODF 1.1, section 1.5 Document Conformance, "
Documents that conform to the OpenDocument specification may contain 
elements and attributes not specified within the OpenDocument schema." 
We're considering restricting this. 

> > Arbitrary extensions are outside of any basis for interoperability, so 
I'd 
> > argue they should be outside of conformance.
> 
> Obviously.
> 
> > The point is that the ODF 1.2 metadata was designed to remove the need 
for 
> > foreign elements and attributes. That original extensibility feature 
was 
> > not intended for extending the processing model of ODF, though in 
theory 
> > it could be (mis)used for that purpose.  But in practice, the 
mechanism 
> > has not been used at all.
> 
> I am very surprised by this; either I'm misunderstanding what this is 
about,
> or the use of extensions isn't known enough by this TC.
> 
> Let me point out some examples:
> 
> * KWord can save a table style that points to a frame+paragraph 
> style, it does that by using the
> koffice:frame-style-name and koffice:paragraph-style-name properties
> in the style. This doesn't
> create a huge interop problem since existing documents are rendered 
> fine by other implementations,
> those properties are only used when creating new tables.
> 
> * KWord can define the behavior of a frame when a new page is 
> created (for DTP-like usage
> where you might want a similar frame to be created on the next page 
> at the exact same position;
> another one use case is a company logo in a page corner for instance).
> This is done with koffice:frame-behavior-on-new-page in the frame 
> style; and here again it
> only affects further editing, not rendering of a given document.
> 
> * OpenOffice has similar things, using the xmlns:ooo="http://
> openoffice.org/2004/office" namespace for instance.
> or xmlns:ooow="http://openoffice.org/2004/writer"; or xmlns:oooc="
> http://openoffice.org/2004/calc";.
> 

OK.  I was not aware of these.  Thanks for pointing this out.

> Is this what "foreign elements and attributes" was about?
> 

Yes, I believe so.  Would it be too much trouble to eliminate these in 
KOffice as part of supporting ODF 1.2?  For example, can they be expressed 
using another ODF mechanism? 

Although in your particular case, these may be benign and not effect 
rendering, you can see how in general this mechanism can easily be abused. 
 It is hard enough for an implementation to ensure interoperability with 
what ODF does actually define, without having to also worry about what 
another implementation might add to an ODF document which is undefined.

-Rob