- From: David Powell <djpowell@djpowell.net>
- Date: Thu, 3 Feb 2005 22:02:05 +0000
- To: Danny Ayers <danny.ayers@gmail.com>
- CC: www-rdf-interest@w3.org
> PS. Looking good, although rather verbose. > It rather suggests having an alternate, less explicit version. Yes there are a number of shortcuts that are possible. I decided to make it as clear and mechanical as possible (it uses xsl:for-each a lot) to make it easier to port. I think, for example, that a Java based version that went straight from SAX to Jena would be a lot more efficient and concise. It would also do away with that painful XSLT-based URIRef parser :) > I'm not really sure of the purpose of feedInstance either. entryInstance is more useful than feedInstance, but it is essentially there to decouple the changable feed metadata from the fixed feed URI - see below... > Why not collapse e.g. (random chunk): a) > <atomrdf:Feed rdf:about="http://example.org/feed"> > <atomrdf:feedInstance> > <atomrdf:FeedInstance> > down to... > <atomrdf:Feed rdf:about="http://example.org/feed"> I introduced FeedInstance and EntryInstance because feeds and entries are expected to change. If you detach each instance from the concept identified by the id, then you can merge two feed documents without any unintended smushing. With the RSS1.0 model if you attempt to merge two documents you either get a bit of a mess (multiple titles etc), or you have to do some application level interpretation to select which instance of which entry should be included in the output. With separate "instance" resources, (which you would probably want to tag with atomrdf:receivedDate or something), you don't have to remove statements from the model, you are instead modelling a bunch of statements, some of which are historic, and some of which are current. If you aren't interested in the historic data, then you can just drop it from the view. This seems to fit better with the monotonic RDF model. Note that there there is no collection construct that links feeds and entries, but EntryInstances do have two links back to the feed (via atomrdf:containingFeed and atomrdf:originFeed). So you can use those links to get a big list of all entries ever in the feed. I prefer this than using collection constructs, because both rdf:List and rdf:Seq are essentially closed which doesn't seem right since feeds are more like continuous streams. b) > <atomrdf:link> > <atomrdf:Link> > down to > <atomrdf:link rdf:parseType="Resource"> Yeah, could do. It loses the typed node though. I know that the type is implied by the RDFS, but I tend not to rely on RDFS inference. -- Dave
Received on Friday, 4 February 2005 08:03:28 UTC