Re: [cdi-dev] Producer#dispose(T instance) and similar

From: Pete Muir <pmuir(a)redhat.com&gt; To: Mark Struberg <struberg(a)yahoo.de&gt; Cc: Arne Limburg <arne.limburg(a)openknowledge.de>; cdi-dev <cdi-dev(a)lists.jboss.org&gt; Sent: Tuesday, December 11, 2012 4:11 PM Subject: Re: [cdi-dev] Producer#dispose(T instance) and similar Agreed, managed bean is a well defined term: " 3.1. Managed beans A managed bean is a bean that is implemented by a Java class." So I'm pretty sure producers aren't managed beans. On 11 Dec 2012, at 16:07, Mark Struberg wrote: > Actually I cannot read this restriction from the old wording. Please note that the terminus 'managed bean' is well defined and any producer method is a 'managed bean' as well as explicitly defined in the spec. This is not restricted to managed beans which are just classes imo. > > LieGrue, > strub > > > > ----- Original Message ----- >> From: Pete Muir <pmuir(a)redhat.com&gt; >> To: Mark Struberg <struberg(a)yahoo.de&gt; >> Cc: Arne Limburg <arne.limburg(a)openknowledge.de>; cdi-dev <cdi-dev(a)lists.jboss.org&gt; >> Sent: Monday, December 10, 2012 1:37 PM >> Subject: Re: [cdi-dev] Producer#dispose(T instance) and similar >> >> >> On 7 Dec 2012, at 22:06, Mark Struberg wrote: >> >>> Well, that restriction got only introduced with CDI-1.1. >> >> CDI 1.0 didn't require an impl to support this. To quote: >> >> "Interceptor bindings may be used to associate interceptors with any >> managed bean that is not itself an interceptor or decor- ator or with any EJB >> session or message-driven bean." >> >> "Decorators may be associated with any managed bean that is not itself an >> interceptor or decorator or with any EJB session bean." >> >> The restriction was just making it explicit, because people thought it should >> work. >> >>> >>> I've not noticed that, what was the reason? There is no technical >> necessity to do that imo! >> >> Maybe, but that isn't the way the spec is written in 1.0 :-) We can change >> it for sure, but it's a feature request. >> >>> >>> I can see that for >>> >>> >>> @Produces @Transactional User getUser() {..} >>> >>> >>> it is ambiguous whether the @Transactional interceptor should account for >> the method invocation or the produced bean. >>> But as Arne pointed out it is in CDI-1.0 very clear what should happen with >> >>> >>> @Produces @MyInterceptedStereotype User getUser() {} >>> >>> Should we reopen CDI-59? >>> >>> LieGrue, >>> strub >>> >>> >>> ----- Original Message ----- >>>> From: Pete Muir <pmuir(a)redhat.com&gt; >>>> To: Arne Limburg <arne.limburg(a)openknowledge.de&gt; >>>> Cc: Mark Struberg <struberg(a)yahoo.de>; cdi-dev >> <cdi-dev(a)lists.jboss.org&gt; >>>> Sent: Wednesday, December 5, 2012 4:55 PM >>>> Subject: Re: [cdi-dev] Producer#dispose(T instance) and similar >>>> >>>> Hey Arne, >>>> >>>> No, they can't :-) It's specifically called out in Chapter 8 >> and Chapter >>>> 9 that decorators and interceptors aren't applied to the result of >> producer >>>> methods. >>>> >>>> Pete >>>> >>>> On 5 Dec 2012, at 14:47, Arne Limburg wrote: >>>> >>>>> Hi Pete, >>>>> >>>>> >>>>> A little of topic and I don't want to disturb your discussion, >> but: >>>>> >>>>> Beans produced by producer methods CAN have interceptors as >> stereotypes >>>>> are supported on producer methods. >>>>> >>>>> Cheers, >>>>> Arne >>>>> >>>>> Am 04.12.12 17:46 schrieb "Pete Muir" unter >>>> <pmuir(a)redhat.com&gt;: >>>>> >>>>>> Hi Mark, I'll try to answer inline, but I'm missing a >> bit of >>>> background >>>>>> about what you are doing... >>>>>> >>>>>> On 4 Dec 2012, at 14:20, Mark Struberg wrote: >>>>>> >>>>>>> Another problem probably being an interceptor on the >> @Disposes >>>> method >>>>>>> itself. >>>>>>> Where does the Proucer#dispose(T instance) get the >> interceptor >>>> from? >>>>>>> >>>>>>> LieGrue, >>>>>>> strub >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> ----- Original Message ----- >>>>>>>> From: Mark Struberg <struberg(a)yahoo.de&gt; >>>>>>>> To: cdi-dev <cdi-dev(a)lists.jboss.org&gt; >>>>>>>> Cc: >>>>>>>> Sent: Tuesday, December 4, 2012 3:16 PM >>>>>>>> Subject: [cdi-dev] Producer#dispose(T instance) and >> similar >>>>>>>> >>>>>>>> Hi! >>>>>>>> >>>>>>>> I'm currently stumbling over implementing >>>>>>>> >>>>>>>> Producer#dispose(T instance) properly >>>>>>>> >>>>>>>> The Producer#produce(CreationalContext) >>>>>>>> >>>>>>>> has the CreationalContext parameter but the dispose >>>>>> >>>>>> Right, it would have been good to have included it here. >> I'm not >>>> sure why >>>>>> it wasn't, however I don't believe that it causes a >> problem >>>> with the CDI >>>>>> 1.0 spec, but just limits us going forward. >>>>>> >>>>>>>> and others do not have it. >>>>>> >>>>>> Yes. >>>>>> >>>>>>>> >>>>>>>> Problem here is that a Producer could probably get >> exchanged >>>> via a >>>>>>>> portable >>>>>>>> extension via ProcessProducer#setProducer(Producer) >>>>>> >>>>>> Yes, this is definitely supported >>>>>> >>>>>>>> so it could be from a >>>>>>>> foreign source which must not know anything about >> container >>>>>>>> implementation >>>>>>>> details. >>>>>> >>>>>> Yes. >>>>>> >>>>>> I think the critical part of the spec to understand this is >> 11.2. >>>> I'm >>>>>> quoting here from the CDI 1.1 spec, into which we have add the >>>>>> clarification that "The instance returned by produce() may >> be a >>>> proxy.". >>>>>> The part about building interceptors and decorators is there in >> CDI >>>> 1.0. >>>>>> >>>>>>> For a Producer that represents a class: >>>>>>> >>>>>>>       € produce() calls the constructor annotated @Inject if >> it >>>> exists, or >>>>>>> the constructor with no parameters otherwise, as defined in >>>>>>> [instantiation], and returns the resulting instance. If the >> class >>>> has >>>>>>> interceptors,produce() is responsible for building the >> interceptors >>>> and >>>>>>> decorators of the instance. The instance returned by >> produce() may >>>> be a >>>>>>> proxy. >>>>>>> >>>>>>>       € dispose() does nothing. >>>>>> >>>>>> and >>>>>> >>>>>>> For a Producer that represents a producer method or field: >>>>>>> >>>>>>>       € produce() calls the producer method on, or accesses >> the >>>> producer >>>>>>> field of, a contextual instance of the bean that declares >> the >>>> producer >>>>>>> method, as defined in [methods]. >>>>>>> >>>>>>>       € dispose() calls the disposer method, if any, on a >> contextual >>>>>>> instance of the bean that declares the disposer method, as >> defined >>>> in >>>>>>> [methods], or performs any additional required cleanup, if >> any, to >>>>>>> destroy state associated with a resource. >>>>>> >>>>>> Now, let me start to break down your sentence :-) >>>>>> >>>>>>>> >>>>>>>> What now about having an interceptor on @PreDestroy? >>>>>> >>>>>> For a start, it's worth remembering interceptors can only >> be >>>> associated >>>>>> with beans defined by a class. If the bean is a producer, then >> you >>>> can't >>>>>> intercept the instance produced (only the invocation of the >> producer). >>>>>> >>>>>>>> This is what you get if >>>>>>>> your interceptor has a@PreDestroy method himself as per >> the >>>>>>>> interceptors and EJB >>>>>>>> specs. That would mean that the instance passed to >> dispose() >>>> whould be >>>>>>>> the >>>>>>>> proxy? That purely sounds wrong to me. >>>>>> >>>>>> Based on my comment from above, I think it's clear that >> dispose() >>>> should >>>>>> never try to invoke predestroy methods. That is the job of >>>>>> InjectionTarget.preDestroy(). I would expect a proxy to be >> passed to >>>>>> preDestroy(). >>>>>> >>>>>>> >>>>>>> >>>>>>>> >>>>>>>> Another issue being InjectionTarget#postConstruct() >> only having >>>> the >>>>>>>> instance T >>>>>>>> as well. Now what about @PostConstruct interceptors as >> defined >>>> in the >>>>>>>> interceptors spec? >>>>>> >>>>>> Again, I would expect a proxy to be passed to postConstruct(). >> Anyway, >>>>>> I'm not sure why you need access to the creational context >> in the >>>>>> postConstruct()? Here you should just invoke the postConstruct >>>> callback, >>>>>> which should create any new dependent objects. >>>>>> >>>>>>>> Currently we have a dirty hack in OWB to pass over the >>>>>>>> CreationalContext which >>>>>>>> contains the dependent scoped interceptors for our own >>>> Producers and >>>>>>>> InjectionTargets. But I have no clue yet how that >> should get >>>>>>>> implemented if one >>>>>>>> plugs in a portable Producer via an Extension ^^ >>>>>>>> >>>>>>>> Who is responsible of performing the interception? The >>>> Producer? Or >>>>>>>> must the >>>>>>>> instance being handed into already be a Proxy? >>>>>> >>>>>> The instance returned from produce() should have interceptors >> and >>>>>> decorators applied. >>>>>> >>>>>> Please let me know if above makes sense, it took me a while to >> work out >>>>>> whether what was defined was sane. After quite a lot of >> thinking + >>>>>> talking to Jozef and Stuart I came to the conclusion it was, >> but  if >>>> you >>>>>> can poke holes then please do! >>>>>> _______________________________________________ >>>>>> cdi-dev mailing list >>>>>> cdi-dev(a)lists.jboss.org >>>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>>> >>>> >>