Okay, let me see if I understand you correctly. 1. You can repeat information stored in a datastream to the RELS-INT stream, to make it accesiable from the Resource index. 2. Given the name of the "hasDatastream" relation (which I do not recall, but know exist) you can query about objects with certain RELS-INT properties.
There is no way to validate whether or not the properties defined in RELS-INT is valid for the datastreams the specify? Or, in other ways, how are RELS-INT linked with the specified datastream? I do not know if you are familiar with the enhanced content models (ecm.sourceforge.net) but we use OWL ontologies (in the content models) to specify the contents of the RELS-EXT datastream. I will have to think the implications through, but the very same system could easily be used to specify rules for required and allowed RELS-INT properties. A RELS-INT property, what can it point to? Can I use it to specify a relation from one datastream to another? And if this other datastream is in another object? Is this allowed? Regards On Fri, 2009-07-03 at 10:57 +0200, Steve Bayliss wrote: > No design documents at the moment other than what's written below and what's > written in the Tracker item - but feel free to ask if you have specific > questions. Once it's in the trunk, I will write some documentation on how > to use it. > > Essentially you can do everything that you can do with RELS-EXT, but with a > datastream URI as the subject of relationships, rather than a digital object > URI (but with some validation restrictions). > > Maybe an example would help: > > RELS-INT: > > <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"; > xmlns:exif="http://ns.adobe.com/exif/1.0/";> > <rdf:Description rdf:about="info:fedora/demo:SmileyPens/MEDIUM_SIZE"> > <exif:PixelXDimension>320</exif:PixelXDimension> > <exif:PixelYDimension>240</exif:PixelYDimension> > </rdf:Description> > <rdf:Description rdf:about="info:fedora/demo:SmileyPens/FULL_SIZE"> > <exif:PixelXDimension>800</exif:PixelXDimension> > <exif:PixelYDimension>600</exif:PixelYDimension> > </rdf:Description> > </rdf:RDF> > > You could then issue the following (with a Mulgara resource index) to find > all datastreams with particular image size properties: > > select $s $p $o > from <#ri> > where > $s <http://ns.adobe.com/exif/1.0/PixelXDimension> '320' > and > $s <http://ns.adobe.com/exif/1.0/PixelYDimension> '240' > > (You could modify this to give the digital object URI as well as the > datastream URI). > > Regards > Steve > > > > -----Original Message----- > From: Asger Blekinge-Rasmussen [mailto:[email protected]] > Sent: 03 July 2009 08:59 > To: Steve Bayliss > Cc: [email protected] > Subject: Re: [Fedora-commons-developers] FCREPO-441 ready for code review > and merge > > > Hi > > I was very much looking forward to this. Do you have any design documents > written so far? > > Depending on some details, this might have great implications for Enhanced > Content Models > > Regards > > On Thu, 2009-07-02 at 14:03 +0200, Steve Bayliss wrote: > > I've created a branch for FCREPO-441, and implemented the necessary > > changes (created from the trunk this morning). > > > > This is now ready for review. > > > > Implementation notes: > > > > * RDF in RELS-INT is now parsed and triples are propagated to resource > > index > > * The subjects of RELS-INT relationships must be syntactically-valid > > datastreams for the object in which RELS-INT resides (but the > > datastream does not have to exist) > > * Multiple subjects are allowed in a single RELS-INT datastream (ie > > multiple <rdf:Description ref:about="..." ... />), to allow assertions > > to be made about several datastreams > > * Validation is otherwise as per RELS-EXT, except Dublin Core > > assertions are allowed, and some specific fedora-model assertions > > which are allowed for RELS-EXT are not allowed for RELS-INT > > * local server demos - image collection demo - contains some examples > > of RELS-INT, in SmileyPens and SmileyGreetingCard (these are also used > > in system tests) > > * No changes made to the API (this will require some discussion and > > agreement on what should be implemented) > > * No changes made to the java client application (though of course > > RELS-INT can be edited as per any other XML datastream) > > > > Any volunteers to review this change? > > > > If there's any interest I could also create a patch against 3.2.1. > > > > Many Thanks > > Steve > > ------------------------------------------------------------------------------ _______________________________________________ Fedora-commons-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/fedora-commons-developers
