Re: [hibernate-dev] hiberate-commons-annotations and locating annotations

https://github.com/hibernate/hibernate-orm/pull/591 On Thu 05 Sep 2013 10:06:14 PM CDT, Shaozhuang Liu wrote: > I can give it a try > ------------------------- > Best Regards, > > Strong Liu <stliu at hibernate.org> > http://about.me/stliu/bio > > On 2013Sep 6, at 8:15 AM, Steve Ebersole <steve(a)hibernate.org&gt; wrote: > >> I have something mostly working and not causing regressions. Its quite fugly, but I blame that on binders and hcann :) >> >> I'd really like to do a pull request for this one and have y'all take a look. But at the same time I'd also really like to do the 4.3 Beta4 release tomorrow. Anyone familiar with those bits of code willing to look this over in the next 12 hours if I go through the steps of creating the PR? >> >> >> On 09/05/2013 12:10 PM, Steve Ebersole wrote: >>> On Thu 05 Sep 2013 11:52:22 AM CDT, Shaozhuang Liu wrote: >>>>> Also, I am not sure that iterating properties yet again is a great idea. >>>>> >>>>> One alternative I had considered was to hook this in with >>>>> PropertyBinder, where it calls SimpleValueBinder. That needs to happen >>>>> anyway; the plan was to delegate the call to determine the Convert to >>>>> use PropertyHolder and to pass that Convert into SimpleValueBinder. >>>>> That code would need to pass in the XProperty anyway. So currently >>>>> PropertyBinder does: >>>>> >>>>> simpleValueBinder.setType( property, returnedClass, containerClassName ); >>>>> >>>>> My plan was to instead have it do: >>>>> >>>>> simpleValueBinder.setType( property, returnedClass, containerClassName, >>>>> holder.resolveAttributeConverter( property ) ); >>>>> >>>>> I *think* that when resolveAttributeConverter() would be called, we'd >>>>> have enough info to fully resolve the converter to use properly. >>>>> >>>>> There are similar concerns in ComponentPropertyHolder, but maybe a >>>>> discussion of the above will shed light on those concerns too. >>>> >>>> doesn't this work? >>> >>> What exactly? >>> >>> >>>> at this time, the PropertyHolder is resolved, so it knows the convert it holds, >>>> then the convert defined on the attribute get applied first, then the one in PropertyHolder >>> >>> I am not sure what you mean by "resolved" here. At no time that is useful in this process does PropertyHolder have full access to all the properties the thing holds. >>> >>> If by "the convert it holds" you mean the converts specifically defined on the @Entity or @Embedded (and therefore @Embeddable), then yes. >>> >>> But "then the convert defined on the attribute get applied first" is actually wrong for composite paths. For composites, you actually want the one higher up to have higher precedence. In the Person.homeAddress.city example, a convert defined on Address#city should actually have the *lowest* precedence. >>> >>> I think what we'll have to end up doing is to not normalize the composite paths to one place unfortunately. Then we'd have to pass the XProperty for which we are trying to resolve the converter to use into the PropertyHolder method. For composite paths this will just have to mean walking multiple levels (one per path-part). The down side to this is that at no time do we have an overview of the overall converts for a property path (aside from walking the composite path to actually resolve the converter to use). >>> >>> >>>> >>>> any problem with this approach ? >>>> >>>>> >>>>> >>>>> >>>>> On Wed 04 Sep 2013 02:44:40 PM CDT, Steve Ebersole wrote: >>>>>> >>>>>> I am still a bit confused on how to apply the normalization to make >>>>>> sure it happens in the proper order. >>>>>> >>>>>> Let's look at: >>>>>> >>>>>> @Entity >>>>>> class Person { >>>>>> ... >>>>>> @Embedded >>>>>> @Convert( attributeName="city", converter=Converter2.class ) >>>>>> public Address homeAddress; >>>>>> } >>>>>> >>>>>> @Embeddable >>>>>> class Address { >>>>>> ... >>>>>> @Convert( converter=Converter1.class ) >>>>>> public String city; >>>>>> } >>>>>> >>>>>> >>>>>> So here, the Converter2 class ought to be the one applied to >>>>>> "homeAddress.city" path. >>>>>> >>>>>> Now granted there are a few different ways to skin this cat, but the >>>>>> plan I had was to normalize these all on the root of the path. So >>>>>> here, both of these conversions would get stored on >>>>>> ClassPropertyHolder<Person> under the "homeAddress.city" path. When I >>>>>> go to build the SimpleValue for Person.homeAddress.city, I'd ask the >>>>>> CompositePropertyHolder for Person.homeAddress to resolve the explicit >>>>>> (non-autoApply) conversion for its city attribute (the simple value). >>>>>> The trouble I have though is applying the conversions in the proper >>>>>> order. For example, here, I'd want to apply the conversions defined >>>>>> directly on the Embeddable first (the Embeddable conversions should >>>>>> always act as the baseline), then the conversions at its Embedded >>>>>> point (via XML or annotations). >>>>>> >>>>>> One idea was to hook into org.hibernate.cfg.PropertyHolder#addProperty >>>>>> in terms of normalizing the paths. I am just not sure of the timing >>>>>> between these PropertyHolder#addProperty (and how populated the passed >>>>>> Property objects are at that point) and the calls to >>>>>> SimpleValueBinder/PropertyBinder. >>>>>> >>>>>> Interestingly, I still am not sure we have enough here to report an >>>>>> error in cases like: >>>>>> >>>>>> @Entity >>>>>> @Convert( attributeName="homeAddress.city", converter=Converter3.class ) >>>>>> class Person { >>>>>> ... >>>>>> @Embedded >>>>>> @Convert( attributeName="city", converter=Converter2.class ) >>>>>> public Address homeAddress; >>>>>> } >>>>>> >>>>>> Unless we somehow kept "proximity info" or "location info" about the >>>>>> conversion in PropertyHolder. >>>>>> >>>>>> >>>>>> On Wed 04 Sep 2013 01:27:21 AM CDT, Emmanuel Bernard wrote: >>>>>>> >>>>>>> >>>>>>> On Tue 2013-09-03 17:22, Steve Ebersole wrote: >>>>>>>> >>>>>>>> >>>>>>>> 2.a) It seems like there are times when >>>>>>>> org.hibernate.cfg.AbstractPropertyHolder#parent would be useful for >>>>>>>> what I need to do. But there appears to be times when this is null. >>>>>>>> For entity mappings (ClassPropertyHolder) thats fine. But for the >>>>>>>> others, that would be problematic. Going back to the >>>>>>>> Person#homeAddress example, I'd really need the >>>>>>>> ComponentPropertyHolder for Person#homeAddress to register the >>>>>>>> converts with ClassPropertyHolder<Person> under the "homeAddress" >>>>>>>> base key ("homeAddress.city" for example). Is there a time here >>>>>>>> where AbstractPropertyHolder#parent would be null for >>>>>>>> ComponentPropertyHolder/CollectionPropertyHolder? >>>>>>> >>>>>>> >>>>>>> >>>>>>> I looked around the code base and the only case I could find is for >>>>>>> ClassPropertyHolder whose parent is indeed null. >>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> 2.b) Is this AbstractPropertyHolder#parent the best way you see to >>>>>>>> handle path-based converts? Or do you see a better option? >>>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> Yes I still think it's the best aproach and frankly I don't quite see >>>>>>> alternatives. >>>>> _______________________________________________ >>>>> hibernate-dev mailing list >>>>> hibernate-dev(a)lists.jboss.org >>>>> https://lists.jboss.org/mailman/listinfo/hibernate-dev >>>> >> >