Hello Ben 1. A ResourceAttribueFinderModule sounds like the way to go here -- how do you envisage the policies looking to make use of this? Also it might be worth looking at some of the FeSL code -- not sure if you are intending this as part of FeSL or the existing Fedora XACML functionality (or both), but I believe there is a configurable Resource Index attribute finder module in FeSL which could possibly be used (I have to go away and dig a bit to be sure). In any case something generic and re-usable would be useful, eg a generic XML datastream + Xpath specification of a resource property that could be picked up by a ResourceAttributeFinderModule; and a generic RDF-based similar ResourceAttribueFinderModule.
An alternative thought - rather than having an embargo date as an object property, it could be part of the policy specification, with application of that policy to a set of objects that have the same embargo date. Depends on the detail of your use case I guess, but there's a question to explore as to whether it is a property of the resource itself or it belongs as part of a policy specification for the object. And the granularity to which you wish to go in specifying resouce policies vs generic policies. 2. I think a content hash is a useful object identifier to be published in general. Although it's not guaranteed globally unique (but there again nor is a UUID in the extreme), I think it is sufficiently unique (sorry, oxymoronic I know) to be worth exposing as an identifier, rather than an attribute, of a resource. On that basis would it make sense to expose it as dc:identifier? You'd get both inclusion in basic search and the resource index for nothing. It might be worth exploring if there are any URI schemes for md5, sha-1, sha-2 etc. I have seen urn:md5:xxxx used in practice but I don't believe that's actually a registered urn namespace(http://www.iana.org/assignments/urn-namespaces/urn-namespaces.xml) . And it would appear as a literal rather than a URI in the resource index. There is an issue here of compound vs atomistic content models if you want to publish the hash as an identifier for more than one datastream in an object using dc:identifier (though RELS-INT does provide a vehicle for this if you wanted to go down the resource index route). A thought - if a content hash was felt to be a sufficiently useful identifier, maybe inclusion in the core SQL database and RI of checksums should be a core feature? Regards Steve > -----Original Message----- > From: Benjamin Armintor [mailto:armin...@gmail.com] > Sent: 28 October 2010 16:38 > To: fedora-commons-users@lists.sourceforge.net > Subject: [fcrepo-user] Some library use-case solicitations > > > Hello, > > I'm sketching out some potential Fedora customizations, but would > like to canvas the user community for solutions to a couple of > library-oriented needs first. > > 1. Embargo dates and XACML: We'd like to be able to indicate a date > property on an object before which actions are denied to > non-administrative users. My proposal would involve a > ResourceAttributeFinderModule that provides an object property that > can be compared to the existing current date functions in XACML. Are > there any other solutions out there? > > 2. Searching objects or datastreams by content hash: This could be > spun off into an external search (like gsearch), but has anyone > experimented with Fedora search customizations to push md5 hash values > into the object search database? I'd rather avoid using the > triplestore both to minimize the size of the graph and to avoid > reproducing the hash value twice in an object. > > regards, > Ben Armintor > > -------------------------------------------------------------- > ---------------- > Nokia and AT&T present the 2010 Calling All Innovators-North > America contest > Create new apps & games for the Nokia N8 for consumers in > U.S. and Canada > $10 million total in prizes - $4M cash, 500 devices, nearly > $6M in marketing > Develop with Nokia Qt SDK, Web Runtime, or Java and Publish > to Ovi Store > http://p.sf.net/sfu/nokia-dev2dev > _______________________________________________ > Fedora-commons-users mailing list > Fedora-commons-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/fedora-commons-users > ------------------------------------------------------------------------------ Nokia and AT&T present the 2010 Calling All Innovators-North America contest Create new apps & games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev _______________________________________________ Fedora-commons-users mailing list Fedora-commons-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/fedora-commons-users
