Re: [hibernate-dev] Envers compile issue
Hello Steve,
In general Envers does not support formula columns. Probably we should save
formula value to audit table. This can be tricky and I have to think it
over. Copying formula column to audit entity would not produce expected
result in all cases (e.g. time functions used in formula expression).
Currently we support @DiscriminatorFormula annotation without saving its
value to audit table, since entities do not change their type.
@Adam: Thoughts? What do you think about copying formula column to audit
entity directly? Simplest solution AFAIK.
All usages of org.hibernate.mapping.Value#**getColumnIterator(), except the
one in
org.hibernate.envers.configuration.internal.metadata.BasicMetadataGenerator,
map relation properties. IMO it is safe assumption that we are dealing with
columns there.
@Steve: if you agree, feel free to throw an exception if encountered
formula column in BasicMetadataGenerator asking to register new feature.
Best regards,
Lukasz
2013/4/11 Steve Ebersole <steve(a)hibernate.org>
One option just came to mind. Looking at the code, I have to assume
envers really just does not support formulas. Otherwise, all these compile
errors would eventually have resulted in runtime (CCE) exceptions.
If that is really the case, I could add detection of that and throw a more
meaningful exception. If that sounds like a reasonable option, just let me
know and I'll make that change.
Alternatively I could just log a message and keep going, but i don't think
that's a good choice.
On Thu 11 Apr 2013 04:07:27 PM CDT, Steve Ebersole wrote:
> I just made a change to help catch runtime problems that kept cropping
> up. The change was to org.hibernate.mapping.Value#**getColumnIterator.
> The problem is that code in many modules (hem, envers) that actually
> deals with mapping code were making a bad assumption here. The
> returned iterator actually returns a Iterable<Selectable>, not
> Iterable<Column>. Selectable is the contract shared between Column and
> Formula. So when code non-defensively tries to treat that thing as a
> Iterable<Column> we often have issues.
>
> Yes, the method is very poorly named. Actually it predates formula as
> a feature. But be that as it may, the code casting those elements to
> Column are just wrong.
>
> For envers, I am not actually sure how to handle Formula elements. I
> need some help there. The issues are all isolated to
> org.hibernate.envers.**configuration.internal.**metadata Could someone
> more familiar with envers (and especially its entity definition stuff)
> take a look?
>
> Thanks!
>