Marcel Reutegger schrieb:
Hi Julian,
Julian Reschke wrote:
How about using an intermediate structure like jackrabbit does and
expose the version histories that way?
I have to confess that I'm not sure how it currently does that
(pointer?).
jackrabbit uses the 6 highest digits of the uuid of the versionable node
to construct an intermediate structure to the version history of that
node. the label of the version history node is the full uuid of the
versionable node.
Understood. For the record: in a previous project where we exposed
version histories in the namespace we choose a similar approach.
The trouble is that in the system I currently have I can't enumerate
version histories *at all* (well, except by looking at every single
node in the system and asking it for it's version history).
can you at least search for version history uuids with a certain
pattern? That would allow you to group your version histories in a sub
node structure under jcr:versionStorage. But I guess when you say you
can't enumerate them at all, that means it *is* impossible...
Right. I don't have an API for that.
I think that's indeed a specification issue. Can a client always rely
on a node's ability to enumerate all children?
well, according to the spec it can...
I'd rephrase that slightly as "the spec ignores the issue" :-). JCR
clients already have to deal with child nodes not showing up in the
parent collection, for instance due to permission problems.
I think requiring this makes many use cases extremely hard, if not
impossible, to implement.
what use cases do you have in mind?
Well, this one for instance.
Another one would be where the system exposes all referenceable nodes
with a second path, consisting of a collection ("/jcr:flat/") plus the
UUID. That's an approach I've seen in use to provide users with an
alternate, stable, identifier. The common pattern here is that the nodes
exposed at a certain part of the namespace are just projections from
somewhere else, and not something that is persisted under that name.
Back in September, I claimed that implementing simple versioning was
trivial, maybe I now have to take that back ;-)
Best regards, Julian
