Hi Craig,
Here are the two best reasons that I can think of to allow the
combination you propose to eliminate.
One: since we are seeking harmony with JPA in the long term, we should
consider that JPA allows XML metadata to override object model annotations.
Two: the easiest rule to learn doesn't have exceptions. XML metadata
overrides annotations.
Cheers,
David
Craig L Russell wrote:
Hi,
I'm looking at how annotations can be overridden by the xml metadata
files. It seems that the .jdo metadata that's not .orm metadata is an
exact duplicate of the annotation metadata. Is there ever a case where
you would want to override the annotation with jdo metadata? Seems that
it's really only the orm metadata in the annotations that you want to
override.
We did carefully consider that the orm metadata is just mapping, and
doesn't include information that would affect the object model. In this
case, it seems that you would want to support these combinations:
no annotations + .jdo (with jdo and orm metadata)
no annotations + .jdo (with jdo and orm metadata) + .orm (overrides all
orm in the jdo)
annotations alone (includes jdo and orm metadata)
annotations + .orm (overrides all orm in the annotations)
So I'm proposing that we disallow annotations + jdo metadata file. In
other words, if you make the decision to provide annotations, you can't
override the jdo metadata. The annotations are closer to the Java file
which is what the jdo metadata is for.
Craig
Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:[EMAIL PROTECTED]
P.S. A good JDO? O, Gasp!
