Concerning backwards compatibility in odf 1.2

[Lars Oppermann <Lars.Oppermann@Sun.COM>]

Dear TC,

We concluded in our last conference call, that many of the problems that 
we are seeing with the debate about lists and numbered paragraphs 
circles around the various notions about the guarantees that we are 
willing to make concerning the behavior of applications that were 
implemented with ODF 1.0/1.1 in mind when they are to open an ODF 1.2 
document.

There has also been the question of ODF 1.1 in ODF 1.2 applications, 
which I do not view as a problem at all. An ODF 1.2 Application can tell 
an ODF 1.1 document from an ODF 1.2 document by looking at the (now 
required) version-attribute in the office:document element. The 
application can then act accordingly. In cases, where implementors have 
come up with different interpretations of the ODF 1.1 spec, the 
application can chose to come up with its own interpretation or ask the 
user - that is not of concern to this group. (There also is a 
meta:generator element that implementors may use in this scenario.)

With regards to ODF 1.2 documents in ODF 1.1 applications, it is in my 
opinion useful to look at two cases:
(a) Documents including new elements/attributes not present in 1.1
(b) Documents constrained to the 1.1 vocabulary

In the case of (a), I do not want to guarantee that an old application 
will display the document like a 1.2-aware application. This is both 
unrealistic an infeasible. We should do our best to design new features 
in a way that allows old applications to "gracefully degrade", rather 
than completely breaking access to the document.

The case of (b) is largely unproblematic, except for situations, in 
which different ODF 1.1 applications implement certain aspects of the 
specification in a different way - whether this is due to ambiguities in 
the specifications of implementation errors is not relevant. We as a TC 
cannot change these old applications, and an interoperability 
disagreement among two 1.1 applications cannot be addressed by anything 
that we specify for ODF 1.2.

The lists and numbered-paragraph proposals that have been created by 
openoffice.org and koffice developers are very much in-line with the 
view presented above. They strike a balance between providing a good 
design for our new specification. ODF 1.2 applications will not have 
much burden when importing old documents and ODF 1.1 applications will 
be able to display documents in a gracefully-degrading manner. If none 
of the new constructs are used, the old applications will behave as 
always. If the new constructs are used, they will be ignored, yielding a 
presentation, that is degraded when comparing to the presentation 
offered by a newer 1.2-compliant application. This can from my point of 
view be accepted.

I would welcome if TC members would indicate whether their view 
regarding these matters is in line with what was presented above so that 
we may use the resulting guidelines to come to a conclusion regarding 
the ongoing debate about lists and numbered-paragraphs - hopefully being 
able to vote on a proposal in the next call.

Bests,
Lars
-- 
Lars Oppermann <lars.oppermann@sun.com>               Sun Microsystems
Software Engineer                                         Nagelsweg 55
Phone: +49 40 23646 959                         20097 Hamburg, Germany
Fax:   +49 40 23646 550                  http://www.sun.com/staroffice