On 2/20/07, Allen Gilliland <[EMAIL PROTECTED]> wrote:
Dave wrote:
> Here's some status of the work in the roller_4.0 branch:
> a) Datamapper / JPA backend has been promoted
> - It's been moved from sandbox and into main source directories
>
> b) Datamapper / JPA passing all but one test and UI is working
> - And I'll be working to keep it in-sync with the Hibernate implementation
> - Open issue: JPA wants weblogcategory.websiteid to be nullable
> - Open issue: some parameterized queries should be cleaned up
In general, my feeling about the new Datamapper/JPA backend is that it's
more confusing and difficult to understand and work on than the current
Hibernate backend. Parameterized queries are definitely one part of the
problem.
After a couple of off-list discussions with Allen and Elias, I've
decided to develop a straight-to-JPA back-end implementation. I hope
to have code in place by early next week and passing all tests by late
next week.
Both Allen and Elias feel that the datamapper is an unnecessary layer.
It's purpose is to allow multiple persistence implementations but 1)
consensus seems to be that we will only-ever need one persistence
layer implementation and 2) JPA itself is a persistence layer
abstraction that allows multiple implementations.
I did not oppose the datamapper because I think it's fairly thin layer
that gives us additional flexibility, but I can't really argue against
those points above.
Fortunately, Craig and Mitesh have done all of the hard work. That's
why I believe I can do this work so quickly -- plus, I've rewritten
Roller's back-end a couple of times before.
I will leave the existing datamapper/JPA implementation in place and
I'll continue to maintain it for the time being -- it's still a
contender.
Hopefully, in the very near future we can compare code quality and
performance characteristics of JPA vs. Datamapper/JPA vs. iBatis
implementations.
- Dave
