Determination of subjects/objects (was: ISSUE-42)

I follow here Niklas' advice[1] on starting a new thread. It is indeed a
central issue and it is better tracked that way. Reminder: there was an
algorithmic description on what happens in Ben's mail[2] and an older
one from me[3] as well as my proposal for anonymous nodes[4].

Let me also reproduce here, for easier reference, Ben's algorithm[2]. I
believe it is cleaner than mine[3] because it does not give a different
behaviour to @resource (apart from a priority issue). Niklas has already
started to match it against various use cases and we should probably
follow that. So here it is:

Consider the concept of an HTML element's "corresponding RDF identity".

- the "corresponding RDF identity" is determined as follows:
  - @resource takes precedence
  - if no @resource, @href is next
  - if no @href, then @id.
  - if no @id, then @about.
  - if all else fails, a bnode.

- the element's corresponding RDF identity is the subject of an rdf:type
triple when instanceof appears.

- the element's corresponding RDF identity is also the object of any
@rel, or the subject of any @rev.

- the subject of a @rel, or the object of a @rev, is determined using
the normal @about rules.

- the subject of an element's *content* is the element's corresponding
RDF identity when @rel, @rev, @href, @resource, or @instanceof appears.
Otherwise, it's @about resolution.


I will react on some of the issues here in a separate mail, to have a
clean thread.

I hope this helps

Ivan



[1]
http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2007Jul/0159.html
[2]
http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2007Jul/0158.html
[3]
http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2007Jul/0153.html
[4]
http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2007Jul/0144.html
-- 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
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