Am Mi, den 14.04.2004 schrieb Mats Nor�n um 10:08:
> Hi,
> I've been following the discussions on both the repository API and the
> Slide Source and I have a few questions to consider.
> The Source IF is an abstraction layer but not a particularly good one in
> this context.
> I agree that the Slide Source should be dropped but I don�t agree that
> another source is the complete solution.
> A source in this context is (in my POV) a data object and you need ways
> to manipulate data objects in the scope of a transaction, this is not
> possible with a Source as it stands to day.
> I�ve been a part of a project that built a CMS on top of Cocoon (flow),
> Slide and the *unstable* Slide Source.
> The biggest problem with the Source abstraction is the manipulation of
> properties and content and the lack of transactions spanning over
> several source actions when doing these manipulations.
> Sources were designed for reading information and not for manipulating them.
> Naturally one could build something on top of a Source abstraction that
> encapsulated Source operations within a transaction but what�s the point
> in that when you could have a repository IF working directly with Slide
> which supports transactions?
> I guess what I'm trying to say is that a WebDAV Source + a Repository
> IF that doesn�t overlap is what I would have liked if I were to build
> yet another CMS on top of Cocoon and WebDAV. :)
Thank you for your input. And yes transactions are a problem, especially
for webdav. I don't know the status of the transactions handling within
the webdav client. But I think the transaction handling must be
orthogonal to the interface, and not supported by it.
UserTransaction tx = (UserTransaction)
new InitialContext().lookup("java:comp/UserTransaction");
tx.begin();
try {
...//doing some soure or repository stuff
tx.commit();
} catch (Exception e) {
tx.rollback();
}
Through my memories reading the book "Concurrency (State models & java
programs)" the transactions can be implemented by using ThreadLocals.
So I think there is no need make the transactions explicit. Handling
transactions over the webdav protocol is a different capter, but I
thought that I read that Slide support it.
Stephan.
