Fedora 4 it
seems to me has gone too far in obscuring the distinction between the
representation of a digital object (and indeed an entire repository)
and the persistence of its attributes.
While everyone agrees RDF is
useful and important on many levels, it's far less clear to me at
least that it is an appropriate general purpose persistence mechanism
to manage content at scale.
> email to fedora-community+unsubscribe@googlegroups.com.
--
David Chandek-Stark
dchand...@gmail.com
--
You received this message because you are subscribed to the Google Groups "Fedora Community" group.
To unsubscribe from this group and stop receiving emails from it, send an email to fedora-community+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
--
You received this message because you are subscribed to the Google Groups "Fedora Community" group.
To unsubscribe from this group and stop receiving emails from it, send an email to fedora-community+unsubscribe@googlegroups.com.
> email to fedora-community+unsubscribe@googlegroups.com.
--
David Chandek-Stark
dchand...@gmail.com
--
You received this message because you are subscribed to the Google Groups "Fedora Community" group.
To unsubscribe from this group and stop receiving emails from it, send an email to fedora-community+unsubscribe@googlegroups.com.
>> > email to fedora-community+unsubscribe@googlegroups.com.
>> > For more options, visit https://groups.google.com/d/optout.
>>
>>
>>
>> --
>> David Chandek-Stark
>> dchand...@gmail.com
>>
>> --
>> You received this message because you are subscribed to the Google Groups
>> "Fedora Community" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to fedora-community+unsubscribe@googlegroups.com.
>> For more options, visit https://groups.google.com/d/optout.
>
>
> --
> You received this message because you are subscribed to the Google Groups
> "Fedora Community" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to fedora-community+unsubscribe@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
--
David Chandek-Stark
dchand...@gmail.com
--
You received this message because you are subscribed to the Google Groups "Fedora Community" group.
To unsubscribe from this group and stop receiving emails from it, send an email to fedora-community+unsubscribe@googlegroups.com.
To unsubscribe from this group and stop receiving emails from it, send an email to fedora-community+unsubscribe@googlegroups.com.
I'm referring more to the RDF way of representing information
than to the (mis)use of URLs in this context. That is probably a
totally different thread. Basically, having a fully normalized
information model (e.g. only Triples) does not free us from
referring to a concise data model and shared understanding
whenever representations of resources are exchanged (which REST is
all about).
I noticed a couple of things about attempts to store and exchange data in RDF serializations:
That's why I saw some people abandoning RDF (and graph databases) and turning to document stores instead. Bigger aggregates are simpler to manage and closer to the data that is currently produced in many contexts (and their use cases!). Fedora 4 is all about LDP, but it supports binaries as well and does not enforce the RDF data representation - which is a reasonable thing to do.
-Ralf
To unsubscribe from this group and stop receiving emails from it, send an email to fedora-communi...@googlegroups.com.
To unsubscribe from this group and stop receiving emails from it, send an email to fedora-community+unsubscribe@googlegroups.com.
>>> > email to fedora-community+unsubscribe@googlegroups.com.
>>> > For more options, visit https://groups.google.com/d/optout.
>>>
>>>
>>>
>>> --
>>> David Chandek-Stark
>>> dchand...@gmail.com
>>>
>>> --
>>> You received this message because you are subscribed to the Google Groups
>>> "Fedora Community" group.
>>> To unsubscribe from this group and stop receiving emails from it, send an
>>> email to fedora-community+unsubscribe@googlegroups.com.
>>> For more options, visit https://groups.google.com/d/optout.
>>
>>
>
> --
> You received this message because you are subscribed to the Google Groups
> "Fedora Community" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to fedora-community+unsubscribe@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
--
David Chandek-Stark
dchand...@gmail.com
--
You received this message because you are subscribed to the Google Groups "Fedora Community" group.
To unsubscribe from this group and stop receiving emails from it, send an email to fedora-community+unsubscribe@googlegroups.com.
One can look to OAI-ORE for an opinionated perspective on using the architecture of the web to describe {concepts, RWO, whatever}.
The key idea there is that somebody publishes a _document_ on the web which contains an authoritative description of a _thing_. In the care of ORE, that _thing_ is an aggregation of resources as a conceptual entity, and the _document_ is called a resource map. But you can imagine the pattern applied to RWOs.
Anyway, ORE stipulates that:
You can use that pattern today in Fedora 4 if you want to. The big issue is that the onus is on _you_ to model things in that way. The other, more esoteric issue is that there is only one way to have URIs of the _thing_ have the desired characteristic of being resolvable yet distinct from the authoritative document -- hash URIs. Relaxing the single-subject restriction will allow more flexibility for the URIs of the _things_.
For example (in pseudo turtle) the contents of http://my.fedora/resource/painting123:
<> a fedora:resource ;
fedora:serverManagedTripleIDontCareAbout “whatever” ;
dc:creator “Fedo Raadmin” ;
dct:created 2015 ;
myns:describes <#RWO> .
<#RWO> a myns:RealWorldObject, myns:Painting ;
dc:creator “Leonardo” ;
dct:created 1503 ;
myns:image <http://my.fedora.org/images/1234.jpg> .
Notice how both of the subjects we see in the RDF would resolve to the same authoritative document in a browser or client
http://my.fedora/resource/painting123
http://my.fedora/resource/painting123#RWO
Anyway, you can think of LDP as providing an API to a _document_ repository, where these documents are _web resources_ (some of which may contain RDF). The document (web resource) is the unit of management in the fedora spec, which builds upon LDP; authorization is at the document level, notifications are at the document level, etc.
Not interested in putting your resources on the web, or linking to your resources, or traversing hyperlinks within your resources? Then LDP (and the fedora spec) might not be interesting do you.
Fedora 3 was not really a technology of the web. Unlike fedora 4, it really _did_ have a specific object model, though (fedora object as as a collection of datastreams + properties + behaviours). There was a mapping of fedora 3 resources onto RDF (which included the contents of the RELS-EXT datastream, among others). To be honest, it also suffers from the same RWO subtleties, at least if we look at that RDF. <http://my.fedora/resource/painting123> is no more of a painting than <info:fedora/painting:123> is. You sure have to do a lot more work to figure out what <info:fedora/painting:123> is, though.
-Aaron
--
I think part of the problem is that Fedora and LDP (the spec) neither constrain nor inform one’s worldview of repository resources; they’re just documents on the web. Fedora4 the software _does_ constrain resources in a particular way (single-subject restriction), but the explanation is unsatisfying. It seems to suggest that the object model essentially JCR. To me, that feels flexible, constraining, and anemic at the same time.
https://wiki.duraspace.org/display/FEDORA4x/The+Fedora+4+object+model
Another problem revealed in this thread is that some don’t seem to have use cases for repository resources as web resources at all. In that world, resolvable URLs for resources don’t make sense, and HTTP and LDP are merely “the API and protocol of the day.” Fedora 3 was firmly of this tradition, whereas Fedora 4 (and the fedora spec) are firmly in the “of the web” camp. There is a bit of tension there that I don’t think has fully resolved.
In any case, eliminating the single-subject restriction would further tilt the balance toward Fedora being “of the web” and the implementation being more like a “document store”, where the notion of object modelling is purely a client/domain-level concern. Depending on one’s perspective that may be a good or bad thing; so it is good that we’re having this debate.
-Aaron
I think part of the problem is that Fedora and LDP (the spec) neither constrain nor inform one’s worldview of repository resources; they’re just documents on the web. Fedora4 the software _does_ constrain resources in a particular way (single-subject restriction), but the explanation is unsatisfying. It seems to suggest that the object model essentially JCR. To me, that feels flexible, constraining, and anemic at the same time.
https://wiki.duraspace.org/display/FEDORA4x/The+Fedora+4+object+model
Another problem revealed in this thread is that some don’t seem to have use cases for repository resources as web resources at all. In that world, resolvable URLs for resources don’t make sense, and HTTP and LDP are merely “the API and protocol of the day.” Fedora 3 was firmly of this tradition, whereas Fedora 4 (and the fedora spec) are firmly in the “of the web” camp. There is a bit of tension there that I don’t think has fully resolved.
In any case, eliminating the single-subject restriction would further tilt the balance toward Fedora being “of the web” and the implementation being more like a “document store”, where the notion of object modelling is purely a client/domain-level concern. Depending on one’s perspective that may be a good or bad thing; so it is good that we’re having this debate.
-Ralf
> To unsubscribe from this group and stop receiving emails from it, send an email to fedora-community+unsubscribe@googlegroups.com<mailto:fedora-community+unsubscribe@googlegroups.com>.
> For more options, visit https://groups.google.com/d/optout.
>
--
You received this message because you are subscribed to the Google Groups "Fedora Community" group.
To unsubscribe from this group and stop receiving emails from it, send an email to fedora-community+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
--
You received this message because you are subscribed to the Google Groups "Fedora Community" group.
To unsubscribe from this group and stop receiving emails from it, send an email to fedora-community+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
--
You received this message because you are subscribed to the Google Groups "Fedora Community" group.
To unsubscribe from this group and stop receiving emails from it, send an email to fedora-community+unsubscribe@googlegroups.com.