Re: [office] Embedded Metadata in <office:document>

[Svante Schubert <Svante.Schubert@Sun.COM>]

Hi Dennis,

You are mentioning problems of the ODF flat format being an adequate 
syntax, which the metadata proposal does not intent to fix.
Although I agree that the metadata proposal make those problems more 
obvious.
I would rather suggest to drop the ODF flat format from the ODF 
specification, instead of adding further unnecessary complexity.

Please fine my detailed answer in the text.

Happy holidays,
Svante

Dennis E. Hamilton wrote:
> I want to look at this single topic: understanding how the metadata
> extension can work as part of an <office:document> root element on an XML
> document.  
>
> 1. I am not asking about whether other kinds of material are easily embedded
> in an <office:document> single XML document.  My question is specifically
> about the RDF metadata.  That is, is there a natural element for carrying
> such elements, with no special encoding since there is a perfectly fine
> XML-embedding of RDF, last time I checked.
>   
There is no natural element for carrying XML files.
Remember only images and OLE objects that are referenced/used from the 
content.xml and styles.xml are currently preserved by a BASE64 encoding 
(enlarging the data to 33%).
There is no element for XML file preserving nor a way to map files that 
are not referenced.
Therefore since ODF 1.0 any other user data part of the package is lost 
in the flat format, there is no generic mechanism of mapping.

Than there exist an algorithm how to map the file specific identifier 
(xml:id) from all package files to a single XML document to ensure a 
stable roundtrip among ODF applications.

Finally there is no mime type nor suffix although having a different 
file format (XML instead of ZIP).

 From my view the single <office:document> syntax is boiler plate to 
ODF. It is a burden for implementations by duplicating the format from a 
zip to a single file, without a benefit adding complexities, as you show 
not sufficient solved.
> 2. Also, whether <office:document> is an uninteresting format compared to
> the Zip package, it is specified as a legitimate OpenDocument Format
> document representation.  In addition, <office:document> elements may appear
> within <draw:object> and some other elements as some sort of embedding.  It
> is also legitimate to include an <office:document> XML document by reference
> from a <draw:object> and other elements.  I suppose that embeddings could be
> accomplished by entity reference as well, provided that there was a way to
> define entity references (and I've never seen anything that bans DOCTYPE
> declarations on standalone <office:document> XML documents and on package
> items such as content.xml).  [If I've missed that, please let me know where
> it is in the specification.]
>
> I am interested in whether or not RDF XML metadata should be specified to
> have a place as elements, perhaps immediately in the <office:document>
> content and preceding any other content, or just anywhere?
>   
I would suggest to drop the flat format for the follow up of ODF 1.2 (as 
there are no further proposals for ODF 1.2).
Or does anybody still see a sense in the existence of the file format, 
justifying the effort of the ODF applications?

>  - Dennis
>
> SIDE NOTE: I don't want to discuss the general xml:id topic here, but I note
> that there are some special cases that apply to <office:document> elements.
> First, my understanding is that when an <office:document> appears as a
> content element under an element such as <draw:object>, the rules for xml:id
> apply to that element as just another element within the overall XML
> document (e.g., a content.xml root-element XML document or a single-file or
> package-item <office:document>).  I assume that is not the case when an
> <office:document> XML document is linked into another document via
> <draw:object> or other linkage.  I also presume that the components of a
> global master document and the global master document itself are each
> independent with respect to xml:id rules.  I am baffled about what the rule
> should be for inclusions by entity-reference, if entity-reference is
> possible at all. [I must re-read the xml:id 1.0 specification one more time
> on that question.]
>
> -----Original Message-----
> From: Svante.Schubert@Sun.COM [mailto:Svante.Schubert@Sun.COM] 
> Sent: Monday, December 15, 2008 04:19
> To: dennis.hamilton@acm.org
> Cc: 'OASIS Office'; 'Michael Stahl'
> Subject: Re: [office] Single ODF 1.2 metadata proposal
>
> Hello Dennis,
>
> thank you very much for your valuable feed-back.
> Please find my answers below:
>
> Dennis E. Hamilton wrote:
> [ ... ]
>   
>> 3. Is there a way to have this proposal work with a single-file XML
>>     
> document
>   
>> having <office:document> root element?  Does the embedded-within-the
>> document case handle that.  That isn't clear to me.  It appears that the
>>     
> in
>   
>> Content Metadata is constrained to appear on particular elements and not
>>     
> sit
>   
>> over the entire document the way a separate metadata RDF file would appear
>> to be. 
>>   
>>     
> Of course it is possible to move every single files of a package into a 
> flat file, embedding all RDF/XML files into a single XML file.
> AFAIK there is no generic way specified to move every file of a package 
> into a single stream.
> For instance dependent on the mime type every user data (e.g. RDF/XML) 
> could be plain or BASE64 encoded embedded into a flat XML file.
> Personally I do not like the flat XML file. The only usage of flat XML 
> files I am aware of - the XSLT handling in OOo - I am about to adopt to 
> work on the ODF package instead of the flat XML file. (Neglecting 
> performance/memory annoying BASE64 encoding for images)
> [ ... ]
>
>
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