...
Resources:
http://www.loc.gov/standards/premis/ontology-announcement.html
https://wiki.duraspace.org/display/FF/Fedora+Repository+Home
https://wiki.duraspace.org/display/FF/Properties+CRUD
https://wiki.duraspace.org/display/FF/RESTful+HTTP+API
https://github.com/futures/fcrepo4/blob/master/fcrepo-audit/src/main/java/org/fcrepo/audit/LogbackAuditor.java
https://github.com/futures/fcrepo4/blob/master/fcrepo-jms/src/main/java/org/fcrepo/jms/observer/JMSTopicPublisher.java
http://id.loc.gov/vocabulary/preservation/eventType.html
A New Eventing System
The current eventing system accumulates the javax.jcr.observation.Event events in a Iterator, applies a pluggable filter to the objects in the iterator, and publishes them using the google eventbus as FedoraEvents that can then be retrieved by any method implementing the Subscribe annotation. The jcr events are as follows:
NODE_ADDED
NODE_MOVED
NODE_REMOVED
PERSIST
PROPERTY_ADDED
PROPERTY_CHANGED
PROPERTY_REMOVED
These event types are artifacts of the jcr implemention underneath fedora, and don't reflect the event types in fedora that would ideally be best to expose. To provide for the types of events we'd like to publish and preserve, once solution would be to systematically inventory the fedora services (found in fcrepo-kernel) and create and publish FedoraEvents with event types that represent these service methods. A non-exhaustive list includes:
NodeServiceImpl.findOrCreateObject
NodeServiceImpl.getObject
NodeServiceImpl.deleteObject
NodeServiceImpl.copyObject
NodeServiceImpl.moveObject
DatastreamServiceImpl.createDatastream
DatastreamServiceImpl.getDatastream
DatastreamServiceImpl.getFixity
DatastreamServiceImpl.<note -there is no removeDatastream>
LockServiceImpl.acquireLock
LockServiceImpl.getLock
LockServiceImpl.releaseLock
ObjectServiceImpl.createObject
ObjectServiceImpl.getObject
TransactionServiceImpl.beginTransaction
TransactionServiceImpl.commit
TransactionServiceImpl.rollback
VersionServiceImpl.createVersion
VersionServiceImpl.revertToVersion
VersionServiceImpl.removeVersion
FedoraResourceImpl.updatePropertiesDataset
FedoraResourceImpl.getPropertiesDataset
FedoraResourceImpl<getTriples,getHierarchyTriples,getVersionTriples,replaceProperties?>
LowLevelStorageService<transformLowLevelCacheEntriesgetLowLevelCacheEntriesFromStore?>
The PREMIS service would then subscribe to events with event types representing these methods, to create an PREMIS record reflecting these event types. The methods which generate these events also have application in the task of implementing a XACML authorization system as policies can be built with finer grained action targets that what is currently possible with modeshape actions. <to be described here>