All and none.
The move to JCR means that your old database and JDBCProvider won't
work anymore. You will need to migrate to a new DB (and it's still a
bit early to say how exactly this is going to be done - JDBCProvider
is not a core component, so someone needs to figure out a way to do
the migration.)
However, this particular change that is mentioned below has no impact
whatsoever.
/Janne
On Dec 11, 2008, at 03:03 , Terry Steichen wrote:
Janne,
What will be the impact on those of us that use JDBC-based pages?
Terry
On Thu, 2008-12-11 at 00:55 +0200, Janne Jalkanen wrote:
Folks,
there is a minor problem with WikiPages and JCR.
In the old days, the recommended pattern was to create a WikiPage
with new WikiPage(WikiEngine,String). The problem is that with JCR,
this simply won't be possible, since the WikiPage ceases to be a
passive retainer of information, and will actually store a reference
to the JCR Node. This has a couple of impacts:
* WikiPages can no longer be cached (which wasn't a smart thing to do
previously either, though some internal components did so, mostly to
avoid hitting the repository. Which won't of course be a problem in
the future.)
* WikiPages cannot be directly constructed anymore - instead,
WikiPages will need to be fetched using WikiEngine.getPage() or
created with WikiEngine.createPage(). Otherwise, the JCR Node
reference would be null, and there would be a bunch of NPEs flying
around the code.
* WikiPages will not be thread-safe (though no guarantees were given
previously either - they just happened to be)
[In fact, that's exactly what it does right now, if you check my
latest commits to the jcr branch. We have used the new WikiPage() -
idiom pretty liberally everywhere, and that is currently causing some
pain.]
Now, this change would not be without its merits - it would allow
WikiPage to become an interface, and that is very nice (and almost
mandatory) if we consider the fact that we would like to have a
stable API. Also, any trick I can think of around this problem
either involves overloading WikiContext more, or creating a labyrinth
of if( getNode() == null ) setNode( m_engine.getContentManager
().getSession(m_engine.getWikiContextFactory().newViewContext
(null,null,this)).getRootNode().getNode(getName())) -calls in most of
the WikiPage methods. Which could be somewhat slow, and would also
create two WikiContexts for each request...
How do the fellow developers feel about this change? Does this pose
insurmountable problems for anyone, or change any plans?
/Janne
