RE: [office-collab] Using RDF for Change Tracking serialization?

["Dennis E. Hamilton" <dennis.hamilton@acm.org>]

On May 14, I noticed some material on RDF/XML and RDFa related to a completely different discussion than the one here.  However, it reminded me of the key accomplishment of the World Wide Web and Tim Berners-Lee: It is not necessary to maintain consistency of links nor for the targets of links to be aware of those links whatsoever.  (There are others, such as Ted Nelson, who claim this is a gigantic failure of the web.)

I take that principle to mean that an ODF document should definitely be concerned about referential integrity within its ODF-specified structure (e.g., references to style names, references to bookmarks and bibliography entries in the content, references to other sheets from a spreadsheet formula, references from fields to sources of their content in metadata, etc.).  I see no reason that the ODF document have any obligation with regard to the referential integrity of references into the document structure from separate RDF/XML or even embedded RDFa, since there is no way to mechanically determine what the dependency is, at a semantic level, and ODF 1.2 specifies no specific semantics for specialized use that an ODF consumer would be expected to interpret.

I agree that xml:id attributes and there values should be preserved when the element having them is preserved in the document structure.  (If the element is swept up in a deletion, it seems to me that so is the xml:id, and it is not available for reuse until the deletion is accepted and no longer tracked.)  [This creates a problem that has to be resolved if moves are treated as a combination of a deletion and an insertion.]

I'm not sure that *any* implementation of ODF as a native format preserves xml:id, and we should check for that.  I would definitely be surprised that xml:id is preserved by import into a non-ODF document processor where the manipulated document is then exported back to ODF format.  (I don't expect that RDF/XML and embedded RDFa will survive such a journey either.)

 - Dennis

SIDE NOTES

Here is the material that had me remember Sir Tim's achievement and the principle that has worked so well for the web:

> http://dev.iptc.org/rNews
> 
> http://www.iptc.org/site/Home/
> 
> http://www.beet.tv/2011/05/the-semantic-web-is-coming-to-newsrooms-this-summer-hearsts-cto-michael-dunn.html
> 
> Via Tim Berners-Lee via Shelly Powers
>

I also notice that the IPTC folk are clear that RDFa is for HTML and web pages and RDF/XML is for XML documents, a distinction that is not maintained in ODF 1.2 for our own idiosyncratic reasons.  

It is useful that xml:id should be preserved when the element is preserved.  We must also keep in mind that no element can have more than one attribute with value of type ID (an odd but very specific limitation of XML), so we have to be careful about how xml:id is chosen for internal ODF document structure reasons and how it might be injected/borrowed as a fragment ID that is referenced by a URI somewhere, whether some RDF/XML elsewhere in a package or somewhere else.  Unfortunately, the limited cases where xml:id is permitted for arbitrary purposes and cases where xml:id is part of a specific ODF document structure provision have been comingled in a way that is difficult to untangle.  (The law of unintended consequences has stepped in.)

-----Original Message-----
From: Dennis E. Hamilton [mailto:dennis.hamilton@acm.org] 
Sent: Thursday, May 12, 2011 10:33
To: 'Robin LaFontaine'; office-collab@lists.oasis-open.org
Subject: RE: [office-collab] Using RDF for Change Tracking serialization?

SHORT ANSWER

It is unacceptable to use the existing RDF provisions of ODF to incorporate the data structures involved in change tracking.

[ ... ]

-----Original Message-----
From: Robin LaFontaine [mailto:robin.lafontaine@deltaxml.com] 
Sent: Thursday, May 12, 2011 02:40
To: office-collab@lists.oasis-open.org
Subject: Re: [office-collab] Using RDF for Change Tracking serialization?

[ ... ]

Regarding your first aside about xml:id attributes - this is a big problem and the only practical solution I have seen is the simple one that requires applications to keep the IDs where possible (cut and paste does as you say require new IDs to be generated). Applications don't want to do that but the problem of matching up changed IDs is very complex and computationally expensive, so IMHO it is best to require that they are preserved. After all the rest of the XML needs to be retained, so why not the ID values? Perhaps the RDF itself could be used to preserve them??

Robin

[ ... ] 


---------------------------------------------------------------------
To unsubscribe from this mail list, you must leave the OASIS TC that
generates this mail.  Follow this link to all your TCs in OASIS at:
https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php