Throughout the Fedora Future 4 build-out, we've maintained a Sufia-based Hydra head that consumes the Fedora APIs. At the June 2013 Hydra partners' meeting, we were able to cut over from the "legacy" Fedora 3-like APIs to the new, RDF based APIs.
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- use Rubydora exclusively for interacting with Fedora
- remove assumptions about the behavior of Fedora 3 (default DC datastreams, RELS-EXT, etc) and features not-yet-present in Fedora 4 (e.g. external datastreams)
- stop using FOXML to store fixture objects, and instead build them up programmatically.
Hydra is taking advantage of some of the new Fedora 4 features, including:
- Using RDF responses that contain full profile information for the object and datastreams to minimize HTTP round-trips
- Allowing (and exposing) arbitrary properties on objects, and pushing that through the stack, in order to let Hydra heads "tag" objects with arbitrary, non-datastream information
Running a Hydra head over fcrepo4
Our Sufia-based hydra head is maintained at https://github.com/futuresfcrepo4-labs/fcrepo4-demo-hydra-app. It uses a forked version of Rubydora:
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