mixin node types and node identifier (uuid)

["kazim_ssuet@yahoo.com" <ka...@yahoo.com>]

Hi,
My understanding is that Node Identifier (UUID) is associated with nodes
that are of mixin type and if you try to get identifier of a non-mixin type
u get null.
But when I look at ${schemaObjectPrefix}BUNDLE table it has NODE_ID column
and it appears that all nodes have an id assigned...Confused.
Can somebody shed some light on this?

Thanks,
KS.
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Re: mixin node types and node identifier (uuid)

[Alexander Klimetschek <ak...@day.com>]

On Wed, Oct 27, 2010 at 21:13, kazim_ssuet@yahoo.com
<ka...@yahoo.com> wrote:
> My understanding is that Node Identifier (UUID) is associated with nodes
> that are of mixin type and if you try to get identifier of a non-mixin type
> u get null.
> But when I look at ${schemaObjectPrefix}BUNDLE table it has NODE_ID column
> and it appears that all nodes have an id assigned...Confused.
> Can somebody shed some light on this?

The JCR 1.0 API defines that a node only has a "public" UUID
(node.getUUID()) when it has the mix:referenceable mixin assigned (or
part of its primary node type).

Internally, Jackrabbit always gives nodes a UUID which is also used in
the persistence layer (which is a key-value store, key being UUID and
value being a so-called node bundle with a node and all its
properties). Hence you see the NODE_ID column in the sql-based
persistence managers. This UUID is also exposed via getUUID(), but
only if mix:referenceable is assigned.

Note that JCR 2.0 deprecates getUUID() and replaces it by
getIdentifier() which is not so strict, i.e. it also returns something
for non-referenceable nodes, but also defines no structure of the
string (could be anything that the implementation wants). In
Jackrabbit 2.x, this always returns the UUID.

Regards,
Alex

-- 
Alexander Klimetschek
alexander.klimetschek@day.com