[hibernate-dev] HHH-9440 - full instantiation of composites

[Steve Ebersole]

My concern with entities is not so much the full instantiation case... its
where I know this goes next - namely requests to allow a mix where some
attributes are ctor-injected while others are injected normally.  Allowing
ctor injection of any persistent state is going to open that window.

Also, given the folks that want the "domain driven" approach of allowing
injection of services into an entity (which I am much more inclined to
consider) during instantiation, how would these 2 mesh?


On Tue, Dec 19, 2017 at 3:52 AM Sanne Grinovero <sanne at hibernate.org> wrote:

> Haven't thought it through and I'm possibly not aware of all
> consequences but I'd be curious to hear more about why you'd be
> completely in disagreement with having such a feture for any model,
> inlcuding entities.
>
> We have since recently "refential caching" which requires entities to
> be fully immutable, and also a feature request to have a global option
> to run the whole SessionFactory in "read only mode".
>
> For both cases I'd prefer to see the entities to be mapped as really
> immutable rather than having to stick to trusting the users about not
> making changes to them.
> We could even consider enabling such features as referential caching
> automatically when we detect the entity to be (really) immutable, that
> would be a great usability improvement as such performance
> improvements could be applied without the users having to know about
> such aspects.
>
> Not least it would simply HHH-9440 as people wouldn't need to
> understand where this can be done or not: another usability win.
>
> Thanks,
> Sanne
>
>
> On 18 December 2017 at 21:12, Steve Ebersole <steve at hibernate.org> wrote:
> > OK then...
> >
> > HHH-9440 is requesting to allow full instantiation of a composite (i.e.
> > treat its state as final).  E.g.:
> >
> > @Embeddable
> > class Name {
> >     private final String first;
> >     private final String last;
> >
> >     public Name(String first, String last) {
> >         ...
> >     }
> > }
> >
> > I wanted to see what everyone thought of this.  Personally I am fine with
> > this, provided:
> >
> >    1. We limit this to composites.  The original request wanted entities
> as
> >    well, which I completely disagree with
> >    2. Limit this such that none of the composite's state can be lazy if
> >    using this feature.  It *can* have lazy associations because that
> still
> >    injects a reference for that attribute
> >
> > Thoughts?
> >
> > On Mon, Dec 18, 2017 at 3:06 PM Steve Ebersole <steve at hibernate.org>
> wrote:
> >
> >> HHH-9440 is re
> >>
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>