Early file format design

[Jos van den Oever]

On 08/30/2012 08:44 PM, Inge Wallin wrote:
> On Thursday, August 30, 2012 16:20:01 Jos van den Oever wrote:
>> On 08/29/2012 11:10 PM, Inge Wallin wrote:
>>> This mail is about designing a new file format. It will be relevant to
>>> Calligra Author and possibly also for Calligra Words if Boemann wants it.
>>>
>>> Everybody who is not interested in file formats can skip this thread.
>>
>> I'm going to throw a potential solution out there and see if it sticks.
>>
>> The solution: use ODT with RDF for anything that is missing from ODT.
>> I'll describe the details as they come up.
>
> Ok, so I have read this mail several times and I realise that I don't
> understand the implications of choosing this alternative.

I'm mainly pointing out that there is a supported way of storing 
arbitrary information in ODF and that Calligra supports this. You can 
link the information to parts of your document. You can think of an RDF 
file as a database. But it's very simple at it's core. You make 
statements in triples. For example you could say "calligra is a software 
project", "calligra has a release 2.5.1".

>
> I have several times heard the RDF parts of Calligra described as
> "complicated" and "immature" (paraphrased) so I didn't thinkof it as an
> alternative.

RDF can be complicated for two reasons: it's very hard to be precise. 
Where do you stop adding details? This is a matter of taste and really 
is a problem that comes up in all data modelling. It's just that in RDF 
it's so easy to add more, that you can lose yourself in adding really a lot.

That is why it is useful to define a schema. This lists types and 
relationships that can be used. When writing a UI, it helps to have a 
schema to program for.

> So where should I read up on how RDF, ontologies and the other Nepomuk stoff
> works?

Here are some interesting links:
http://www.w3.org/2000/10/swap/Primer
http://www.co-ode.org/resources/tutorials/intro/slides/OWLFoundationsSlides.pdf

Cheers,
Jos