Hi *, I didn't found in the CDI 1.0 spec a mention of the scope of CDI events. There is also no mention of scopes in the Observer Resolution section. Are CDI events scoped? Does observer resolution depend on the scope of the injected Event instance? Should we refine/clarify that in the CDI 1.1 spec? I didn't found an explicit mail in the archives either, thanks and sorry in case the issue is already resolved, adam _______________________________________________ cdi-dev mailing list cdi-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/cdi-dev

Hi Adam, Arne, The built-in Event bean is not stateless, it's @Dependent. The event payload - the event object - is really not managed and thus not scoped (and should not be IMHO). I also think the event object should be immutable since the order in which observer methods are called is not defined... Martin Dne 29.8.2012 12:06, Arne Limburg napsal(a): > Hi Adam, > > > Are you talking about the injected Event object or about the payload? > The Event object is stateless so the scope does not matter. > And the payload is not managed at all. > So, I'm afraid, I can't see your issue here? > Could you provide a use case for a scoped event? > > Cheers, > Arne > > Am 29.08.12 11:49 schrieb "Adam Bien" unter <abien(a)adam-bien.com&gt;: > >> Hi *, >> >> I didn't found in the CDI 1.0 spec a mention of the scope of CDI >>events. >> There is also no mention of scopes in the Observer Resolution section. >> >> Are CDI events scoped? >> >> Does observer resolution depend on the scope of the injected Event >> instance? >> >> Should we refine/clarify that in the CDI 1.1 spec? >> >> I didn't found an explicit mail in the archives either, >> >> thanks and sorry in case the issue is already resolved, >> >> adam >> _______________________________________________ >> cdi-dev mailing list >> cdi-dev(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/cdi-dev > > > _______________________________________________ > cdi-dev mailing list > cdi-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/cdi-dev > -- Martin Kouba JBoss Quality Assurance Engineer CDI TCK lead E-mail: mkouba(a)redhat.com Web: www.cz.redhat.com Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic _______________________________________________ cdi-dev mailing list cdi-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/cdi-dev

Hi Martin, If possible I would like to avoid immutable event objects, even though the order of observer methods is currently undefined. I have a couple of use cases where my event object will be modified by event observers. Two examples: - Execute secondary business logic after an entity was created/updated and add details to the entity. Here we might have ordering issues. However we did not encounter issues so far. We fire @Created or @Updated Entity events, where my payload is the entity itself. Example: Send welcome e-mail after a new customer was created. The primary business logic will create the customer and fire an @Created Customer event. A WelcomeMailObserver observes @Created Customer events, sends the e-mail and links it to the new customer. - Collect application wide information, e.g. statistics or health status information. My observers simply add local statistics or local health status details to the event object itself. Jens Am 29.08.12 12:14 schrieb "Martin Kouba" unter <mkouba(a)redhat.com&gt;: > Hi Adam, Arne, > > The built-in Event bean is not stateless, it's @Dependent. The event > payload - the event object - is really not managed and thus not scoped > (and should not be IMHO). I also think the event object should be > immutable since the order in which observer methods are called is not > defined... > > Martin > > > Dne 29.8.2012 12:06, Arne Limburg napsal(a): >> Hi Adam, >> >> >> Are you talking about the injected Event object or about the payload? >> The Event object is stateless so the scope does not matter. >> And the payload is not managed at all. >> So, I'm afraid, I can't see your issue here? >> Could you provide a use case for a scoped event? >> >> Cheers, >> Arne >> >> Am 29.08.12 11:49 schrieb "Adam Bien" unter <abien(a)adam-bien.com&gt;: >> >>> Hi *, >>> >>> I didn't found in the CDI 1.0 spec a mention of the scope of CDI >>> events. >>> There is also no mention of scopes in the Observer Resolution section. >>> >>> Are CDI events scoped? >>> >>> Does observer resolution depend on the scope of the injected Event >>> instance? >>> >>> Should we refine/clarify that in the CDI 1.1 spec? >>> >>> I didn't found an explicit mail in the archives either, >>> >>> thanks and sorry in case the issue is already resolved, >>> >>> adam >>> _______________________________________________ >>> cdi-dev mailing list >>> cdi-dev(a)lists.jboss.org >>> https://lists.jboss.org/mailman/listinfo/cdi-dev >> >> >> _______________________________________________ >> cdi-dev mailing list >> cdi-dev(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/cdi-dev >> >

No. It will be delivered to any matching observer method - belongs to an enabled bean, the event object is assignable to the observed event type and the observer method has all the event qualifiers (CDI 1.0). In CDI 1.1 qualifier matching rules will likely change: "The observer method has no event qualifiers or has a subset of the event qualifiers". (see 10.2. Observer resolution) Martin Dne 29.8.2012 12:32, Adam Bien napsal(a): > HI Martin, > > sure. But will the unmanaged payload be delivered only to observers belonging to the same scope as the sender? > > I didn't found any mention in the spec about that... > > thanks, > > adam > On 29.08.2012, at 12:14, Martin Kouba <mkouba(a)redhat.com&gt; wrote: > >> Hi Adam, Arne, >> >> The built-in Event bean is not stateless, it's @Dependent. The event payload - the event object - is really not managed and thus not scoped (and should not be IMHO). I also think the event object should be immutable since the order in which observer methods are called is not defined... >> >> Martin >> >> >> Dne 29.8.2012 12:06, Arne Limburg napsal(a): >>> Hi Adam, >>> >>> >>> Are you talking about the injected Event object or about the payload? >>> The Event object is stateless so the scope does not matter. >>> And the payload is not managed at all. >>> So, I'm afraid, I can't see your issue here? >>> Could you provide a use case for a scoped event? >>> >>> Cheers, >>> Arne >>> >>> Am 29.08.12 11:49 schrieb "Adam Bien" unter <abien(a)adam-bien.com&gt;: >>> >>>> Hi *, >>>> >>>> I didn't found in the CDI 1.0 spec a mention of the scope of CDI events. >>>> There is also no mention of scopes in the Observer Resolution section. >>>> >>>> Are CDI events scoped? >>>> >>>> Does observer resolution depend on the scope of the injected Event >>>> instance? >>>> >>>> Should we refine/clarify that in the CDI 1.1 spec? >>>> >>>> I didn't found an explicit mail in the archives either, >>>> >>>> thanks and sorry in case the issue is already resolved, >>>> >>>> adam >>>> _______________________________________________ >>>> cdi-dev mailing list >>>> cdi-dev(a)lists.jboss.org >>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>> >>> >>> _______________________________________________ >>> cdi-dev mailing list >>> cdi-dev(a)lists.jboss.org >>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>> >> >> -- >> Martin Kouba >> JBoss Quality Assurance Engineer >> CDI TCK lead >> E-mail: mkouba(a)redhat.com >> Web: www.cz.redhat.com >> Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic >> _______________________________________________ >> cdi-dev mailing list >> cdi-dev(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/cdi-dev > > workshops.adam-bien.com > blog.adam-bien.com > about.adam-bien.com > > Author of: > "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking Best Practices" > _______________________________________________ cdi-dev mailing list cdi-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/cdi-dev

No. It will be delivered to any matching observer method - belongs to an enabled bean, the event object is assignable to the observed event type and the observer method has all the event qualifiers (CDI 1.0). In CDI 1.1 qualifier matching rules will likely change: "The observer method has no event qualifiers or has a subset of the event qualifiers". (see 10.2. Observer resolution) Martin Dne 29.8.2012 12:32, Adam Bien napsal(a): > HI Martin, > > sure. But will the unmanaged payload be delivered only to observers belonging to the same scope as the sender? > > I didn't found any mention in the spec about that... > > thanks, > > adam > On 29.08.2012, at 12:14, Martin Kouba <mkouba(a)redhat.com&gt; wrote: > >> Hi Adam, Arne, >> >> The built-in Event bean is not stateless, it's @Dependent. The event payload - the event object - is really not managed and thus not scoped (and should not be IMHO). I also think the event object should be immutable since the order in which observer methods are called is not defined... >> >> Martin >> >> >> Dne 29.8.2012 12:06, Arne Limburg napsal(a): >>> Hi Adam, >>> >>> >>> Are you talking about the injected Event object or about the payload? >>> The Event object is stateless so the scope does not matter. >>> And the payload is not managed at all. >>> So, I'm afraid, I can't see your issue here? >>> Could you provide a use case for a scoped event? >>> >>> Cheers, >>> Arne >>> >>> Am 29.08.12 11:49 schrieb "Adam Bien" unter <abien(a)adam-bien.com&gt;: >>> >>>> Hi *, >>>> >>>> I didn't found in the CDI 1.0 spec a mention of the scope of CDI events. >>>> There is also no mention of scopes in the Observer Resolution section. >>>> >>>> Are CDI events scoped? >>>> >>>> Does observer resolution depend on the scope of the injected Event >>>> instance? >>>> >>>> Should we refine/clarify that in the CDI 1.1 spec? >>>> >>>> I didn't found an explicit mail in the archives either, >>>> >>>> thanks and sorry in case the issue is already resolved, >>>> >>>> adam >>>> _______________________________________________ >>>> cdi-dev mailing list >>>> cdi-dev(a)lists.jboss.org >>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>> >>> >>> _______________________________________________ >>> cdi-dev mailing list >>> cdi-dev(a)lists.jboss.org >>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>> >> >> -- >> Martin Kouba >> JBoss Quality Assurance Engineer >> CDI TCK lead >> E-mail: mkouba(a)redhat.com >> Web: www.cz.redhat.com >> Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic >> _______________________________________________ >> cdi-dev mailing list >> cdi-dev(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/cdi-dev > > workshops.adam-bien.com > blog.adam-bien.com > about.adam-bien.com > > Author of: > "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking Best Practices" > _______________________________________________ cdi-dev mailing list cdi-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/cdi-dev

This is an interesting one :-) On 29 Aug 2012, at 12:10, Martin Kouba wrote: > This reminds me that the spec should clarify the case when the context of the bean declaring the observer is not active. Currently in RI (Weld) you get ContextNotActiveException. Which is logical although probably not the best from the user point of view. > > I will file an issue. Thanks for the tip! :-) > > M > > Dne 29.8.2012 12:43, Martin Kouba napsal(a): >> No. It will be delivered to any matching observer method - belongs to an enabled bean, the event object is assignable to the observed event type and the observer method has all the event qualifiers (CDI 1.0). In CDI 1.1 qualifier matching rules will likely change: "The observer method has no event qualifiers or has a subset of the event qualifiers". >> >> (see 10.2. Observer resolution) >> >> Martin >> >> Dne 29.8.2012 12:32, Adam Bien napsal(a): >>> HI Martin, >>> >>> sure. But will the unmanaged payload be delivered only to observers belonging to the same scope as the sender? >>> >>> I didn't found any mention in the spec about that... >>> >>> thanks, >>> >>> adam >>> On 29.08.2012, at 12:14, Martin Kouba <mkouba(a)redhat.com&gt; wrote: >>> >>>> Hi Adam, Arne, >>>> >>>> The built-in Event bean is not stateless, it's @Dependent. The event payload - the event object - is really not managed and thus not scoped (and should not be IMHO). I also think the event object should be immutable since the order in which observer methods are called is not defined... >>>> >>>> Martin >>>> >>>> >>>> Dne 29.8.2012 12:06, Arne Limburg napsal(a): >>>>> Hi Adam, >>>>> >>>>> >>>>> Are you talking about the injected Event object or about the payload? >>>>> The Event object is stateless so the scope does not matter. >>>>> And the payload is not managed at all. >>>>> So, I'm afraid, I can't see your issue here? >>>>> Could you provide a use case for a scoped event? >>>>> >>>>> Cheers, >>>>> Arne >>>>> >>>>> Am 29.08.12 11:49 schrieb "Adam Bien" unter <abien(a)adam-bien.com&gt;: >>>>> >>>>>> Hi *, >>>>>> >>>>>> I didn't found in the CDI 1.0 spec a mention of the scope of CDI events. >>>>>> There is also no mention of scopes in the Observer Resolution section. >>>>>> >>>>>> Are CDI events scoped? >>>>>> >>>>>> Does observer resolution depend on the scope of the injected Event >>>>>> instance? >>>>>> >>>>>> Should we refine/clarify that in the CDI 1.1 spec? >>>>>> >>>>>> I didn't found an explicit mail in the archives either, >>>>>> >>>>>> thanks and sorry in case the issue is already resolved, >>>>>> >>>>>> adam >>>>>> _______________________________________________ >>>>>> cdi-dev mailing list >>>>>> cdi-dev(a)lists.jboss.org >>>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>>> >>>>> >>>>> _______________________________________________ >>>>> cdi-dev mailing list >>>>> cdi-dev(a)lists.jboss.org >>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>>> >>>> >>>> -- >>>> Martin Kouba >>>> JBoss Quality Assurance Engineer >>>> CDI TCK lead >>>> E-mail: mkouba(a)redhat.com >>>> Web: www.cz.redhat.com >>>> Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic >>>> _______________________________________________ >>>> cdi-dev mailing list >>>> cdi-dev(a)lists.jboss.org >>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>> >>> workshops.adam-bien.com >>> blog.adam-bien.com >>> about.adam-bien.com >>> >>> Author of: >>> "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking Best Practices" >>> >> _______________________________________________ >> cdi-dev mailing list >> cdi-dev(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/cdi-dev >> > _______________________________________________ > cdi-dev mailing list > cdi-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/cdi-dev _______________________________________________ cdi-dev mailing list cdi-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/cdi-dev

> • scope @Dependent, <<

Resolution and scoping are orthogonal concepts in CDI. I'm not aware of a use case that is well addressed by considering scope as part of resolution. On 29 Aug 2012, at 11:43, Martin Kouba wrote: > No. It will be delivered to any matching observer method - belongs to an enabled bean, the event object is assignable to the observed event type and the observer method has all the event qualifiers (CDI 1.0). In CDI 1.1 qualifier matching rules will likely change: "The observer method has no event qualifiers or has a subset of the event qualifiers". > > (see 10.2. Observer resolution) > > Martin > > Dne 29.8.2012 12:32, Adam Bien napsal(a): >> HI Martin, >> >> sure. But will the unmanaged payload be delivered only to observers belonging to the same scope as the sender? >> >> I didn't found any mention in the spec about that... >> >> thanks, >> >> adam >> On 29.08.2012, at 12:14, Martin Kouba <mkouba(a)redhat.com&gt; wrote: >> >>> Hi Adam, Arne, >>> >>> The built-in Event bean is not stateless, it's @Dependent. The event payload - the event object - is really not managed and thus not scoped (and should not be IMHO). I also think the event object should be immutable since the order in which observer methods are called is not defined... >>> >>> Martin >>> >>> >>> Dne 29.8.2012 12:06, Arne Limburg napsal(a): >>>> Hi Adam, >>>> >>>> >>>> Are you talking about the injected Event object or about the payload? >>>> The Event object is stateless so the scope does not matter. >>>> And the payload is not managed at all. >>>> So, I'm afraid, I can't see your issue here? >>>> Could you provide a use case for a scoped event? >>>> >>>> Cheers, >>>> Arne >>>> >>>> Am 29.08.12 11:49 schrieb "Adam Bien" unter <abien(a)adam-bien.com&gt;: >>>> >>>>> Hi *, >>>>> >>>>> I didn't found in the CDI 1.0 spec a mention of the scope of CDI events. >>>>> There is also no mention of scopes in the Observer Resolution section. >>>>> >>>>> Are CDI events scoped? >>>>> >>>>> Does observer resolution depend on the scope of the injected Event >>>>> instance? >>>>> >>>>> Should we refine/clarify that in the CDI 1.1 spec? >>>>> >>>>> I didn't found an explicit mail in the archives either, >>>>> >>>>> thanks and sorry in case the issue is already resolved, >>>>> >>>>> adam >>>>> _______________________________________________ >>>>> cdi-dev mailing list >>>>> cdi-dev(a)lists.jboss.org >>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>> >>>> >>>> _______________________________________________ >>>> cdi-dev mailing list >>>> cdi-dev(a)lists.jboss.org >>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>> >>> >>> -- >>> Martin Kouba >>> JBoss Quality Assurance Engineer >>> CDI TCK lead >>> E-mail: mkouba(a)redhat.com >>> Web: www.cz.redhat.com >>> Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic >>> _______________________________________________ >>> cdi-dev mailing list >>> cdi-dev(a)lists.jboss.org >>> https://lists.jboss.org/mailman/listinfo/cdi-dev >> >> workshops.adam-bien.com >> blog.adam-bien.com >> about.adam-bien.com >> >> Author of: >> "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking Best Practices" >> > _______________________________________________ > cdi-dev mailing list > cdi-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/cdi-dev

Hi *, it would mean: If you are sending an event from a @RequestScoped bean all @SessionScoped observes (= all sessions) would receive that? Or more precisely ALL observes are intended to receive an event regardless of their scope?

If so: in the spec an injection of @Dependent Event is mentioned: "10.3.2. The built-in Event The container must provide a built-in bean with: • Event<X> in its set of bean types, for every Java type X that does not contain a type variable, • every event qualifier type in its set of qualifier types, >> • scope @Dependent, << • no bean EL name, and • an implementation provided automatically by the container. ..."

It implies, that only observes belonging to the same scope would be notified. Otherwise this information is irrelevant,

thanks!, adam On 29.08.2012, at 13:54, Pete Muir <pmuir(a)redhat.com&gt; wrote: > Resolution and scoping are orthogonal concepts in CDI. I'm not aware of a use case that is well addressed by considering scope as part of resolution. > > On 29 Aug 2012, at 11:43, Martin Kouba wrote: > >> No. It will be delivered to any matching observer method - belongs to an enabled bean, the event object is assignable to the observed event type and the observer method has all the event qualifiers (CDI 1.0). In CDI 1.1 qualifier matching rules will likely change: "The observer method has no event qualifiers or has a subset of the event qualifiers". >> >> (see 10.2. Observer resolution) >> >> Martin >> >> Dne 29.8.2012 12:32, Adam Bien napsal(a): >>> HI Martin, >>> >>> sure. But will the unmanaged payload be delivered only to observers belonging to the same scope as the sender? >>> >>> I didn't found any mention in the spec about that... >>> >>> thanks, >>> >>> adam >>> On 29.08.2012, at 12:14, Martin Kouba <mkouba(a)redhat.com&gt; wrote: >>> >>>> Hi Adam, Arne, >>>> >>>> The built-in Event bean is not stateless, it's @Dependent. The event payload - the event object - is really not managed and thus not scoped (and should not be IMHO). I also think the event object should be immutable since the order in which observer methods are called is not defined... >>>> >>>> Martin >>>> >>>> >>>> Dne 29.8.2012 12:06, Arne Limburg napsal(a): >>>>> Hi Adam, >>>>> >>>>> >>>>> Are you talking about the injected Event object or about the payload? >>>>> The Event object is stateless so the scope does not matter. >>>>> And the payload is not managed at all. >>>>> So, I'm afraid, I can't see your issue here? >>>>> Could you provide a use case for a scoped event? >>>>> >>>>> Cheers, >>>>> Arne >>>>> >>>>> Am 29.08.12 11:49 schrieb "Adam Bien" unter <abien(a)adam-bien.com&gt;: >>>>> >>>>>> Hi *, >>>>>> >>>>>> I didn't found in the CDI 1.0 spec a mention of the scope of CDI events. >>>>>> There is also no mention of scopes in the Observer Resolution section. >>>>>> >>>>>> Are CDI events scoped? >>>>>> >>>>>> Does observer resolution depend on the scope of the injected Event >>>>>> instance? >>>>>> >>>>>> Should we refine/clarify that in the CDI 1.1 spec? >>>>>> >>>>>> I didn't found an explicit mail in the archives either, >>>>>> >>>>>> thanks and sorry in case the issue is already resolved, >>>>>> >>>>>> adam >>>>>> _______________________________________________ >>>>>> cdi-dev mailing list >>>>>> cdi-dev(a)lists.jboss.org >>>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>>> >>>>> >>>>> _______________________________________________ >>>>> cdi-dev mailing list >>>>> cdi-dev(a)lists.jboss.org >>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>>> >>>> >>>> -- >>>> Martin Kouba >>>> JBoss Quality Assurance Engineer >>>> CDI TCK lead >>>> E-mail: mkouba(a)redhat.com >>>> Web: www.cz.redhat.com >>>> Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic >>>> _______________________________________________ >>>> cdi-dev mailing list >>>> cdi-dev(a)lists.jboss.org >>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>> >>> workshops.adam-bien.com >>> blog.adam-bien.com >>> about.adam-bien.com >>> >>> Author of: >>> "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking Best Practices" >>> >> _______________________________________________ >> cdi-dev mailing list >> cdi-dev(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/cdi-dev > workshops.adam-bien.com blog.adam-bien.com about.adam-bien.com Author of: "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking Best Practices"

Hi Adam, comments inline... Dne 29.8.2012 14:43, Adam Bien napsal(a): > Hi *, > > it would mean: > > If you are sending an event from a @RequestScoped bean all @SessionScoped observes (= all sessions) would receive that? Or more precisely ALL observes are intended to receive an event regardless of their scope? Yes.

> > If so: in the spec an injection of @Dependent Event is mentioned: > > "10.3.2. The built-in Event > The container must provide a built-in bean with: > > • Event<X> in its set of bean types, for every Java type X that does not contain a type variable, > > • every event qualifier type in its set of qualifier types, > >>> • scope @Dependent, << > > • no bean EL name, and > > • an implementation provided automatically by the container. > > ..." This is the built-in bean used to fire events (an alternative to BeanManager#fireEvent()). > > It implies, that only observes belonging to the same scope would be notified. Otherwise this information is irrelevant, No, I don't think so. It only says that if you use built-in bean Event to fire events, it will depend on the bean where you inject it.

> > > thanks!, > > adam > > On 29.08.2012, at 13:54, Pete Muir <pmuir(a)redhat.com&gt; wrote: > >> Resolution and scoping are orthogonal concepts in CDI. I'm not aware of a use case that is well addressed by considering scope as part of resolution. >> >> On 29 Aug 2012, at 11:43, Martin Kouba wrote: >> >>> No. It will be delivered to any matching observer method - belongs to an enabled bean, the event object is assignable to the observed event type and the observer method has all the event qualifiers (CDI 1.0). In CDI 1.1 qualifier matching rules will likely change: "The observer method has no event qualifiers or has a subset of the event qualifiers". >>> >>> (see 10.2. Observer resolution) >>> >>> Martin >>> >>> Dne 29.8.2012 12:32, Adam Bien napsal(a): >>>> HI Martin, >>>> >>>> sure. But will the unmanaged payload be delivered only to observers belonging to the same scope as the sender? >>>> >>>> I didn't found any mention in the spec about that... >>>> >>>> thanks, >>>> >>>> adam >>>> On 29.08.2012, at 12:14, Martin Kouba <mkouba(a)redhat.com&gt; wrote: >>>> >>>>> Hi Adam, Arne, >>>>> >>>>> The built-in Event bean is not stateless, it's @Dependent. The event payload - the event object - is really not managed and thus not scoped (and should not be IMHO). I also think the event object should be immutable since the order in which observer methods are called is not defined... >>>>> >>>>> Martin >>>>> >>>>> >>>>> Dne 29.8.2012 12:06, Arne Limburg napsal(a): >>>>>> Hi Adam, >>>>>> >>>>>> >>>>>> Are you talking about the injected Event object or about the payload? >>>>>> The Event object is stateless so the scope does not matter. >>>>>> And the payload is not managed at all. >>>>>> So, I'm afraid, I can't see your issue here? >>>>>> Could you provide a use case for a scoped event? >>>>>> >>>>>> Cheers, >>>>>> Arne >>>>>> >>>>>> Am 29.08.12 11:49 schrieb "Adam Bien" unter <abien(a)adam-bien.com&gt;: >>>>>> >>>>>>> Hi *, >>>>>>> >>>>>>> I didn't found in the CDI 1.0 spec a mention of the scope of CDI events. >>>>>>> There is also no mention of scopes in the Observer Resolution section. >>>>>>> >>>>>>> Are CDI events scoped? >>>>>>> >>>>>>> Does observer resolution depend on the scope of the injected Event >>>>>>> instance? >>>>>>> >>>>>>> Should we refine/clarify that in the CDI 1.1 spec? >>>>>>> >>>>>>> I didn't found an explicit mail in the archives either, >>>>>>> >>>>>>> thanks and sorry in case the issue is already resolved, >>>>>>> >>>>>>> adam >>>>>>> _______________________________________________ >>>>>>> cdi-dev mailing list >>>>>>> cdi-dev(a)lists.jboss.org >>>>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> cdi-dev mailing list >>>>>> cdi-dev(a)lists.jboss.org >>>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>>>> >>>>> >>>>> -- >>>>> Martin Kouba >>>>> JBoss Quality Assurance Engineer >>>>> CDI TCK lead >>>>> E-mail: mkouba(a)redhat.com >>>>> Web: www.cz.redhat.com >>>>> Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic >>>>> _______________________________________________ >>>>> cdi-dev mailing list >>>>> cdi-dev(a)lists.jboss.org >>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>> >>>> workshops.adam-bien.com >>>> blog.adam-bien.com >>>> about.adam-bien.com >>>> >>>> Author of: >>>> "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking Best Practices" >>>> >>> _______________________________________________ >>> cdi-dev mailing list >>> cdi-dev(a)lists.jboss.org >>> https://lists.jboss.org/mailman/listinfo/cdi-dev >> > > workshops.adam-bien.com > blog.adam-bien.com > about.adam-bien.com > > Author of: > "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking Best Practices" > > > > > >

Oh, yes Pete is right. I misread Adam's question. Sorry for confusion. Pete: Maybe this should be clarified somehow somewhere so that is't a little bit more clear... Something like: "For normal scoped beans the event is delivered to observer methods of the current instances of the contextual type." Martin Dne 29.8.2012 15:25, Pete Muir napsal(a): > > On 29 Aug 2012, at 13:52, Martin Kouba wrote: > >> Hi Adam, >> >> comments inline... >> >> Dne 29.8.2012 14:43, Adam Bien napsal(a): >>> Hi *, >>> >>> it would mean: >>> >>> If you are sending an event from a @RequestScoped bean all @SessionScoped observes (= all sessions) would receive that? Or more precisely ALL observes are intended to receive an event regardless of their scope? >> >> Yes. > > Actually, no. Working through the spec: > > 10.5 says > > "When an event is fired by the application, the container must: > > • determine the observer methods for that event according to the rules of observer resolution defined by Section 10.2, “Observer resolution”, then, > > • for each observer method, either invoke the observer method immediately, or register the observer method for later in- vocationduringthetransactioncompletionphase,usingaJTASynchronization. > > The container calls observer methods as defined in Section 5.5.6, “Invocation of observer methods”." > > and 5.5.6 says > > " • Obtain a contextual instance of the bean which declares the observer method according to Section 6.5.2, “Contextual instance of a bean”. If this observer method is a conditional observer method, obtain the contextual in- stance that already exists, only if the scope of the bean that declares the observer method is currently active, without creating a new contextual instance. > > • Invoke the observer method on the resulting instance, if any, as a business method invocation, as defined in Sec- tion 7.2, “Container invocations and interception”." > > and 6.5.2 says > > "From time to time, the container must obtain a contextual instance of a bean. The container must: > > • obtain the active context object for the bean scope, then > > • obtain an instance of the bean by calling Context.get(), passing the Bean instance representing the bean and an in- stance of CreationalContext." > > Finally, we need to look at 6.3, which defines how normal scopes work. Specifically, we can see that "The get() operation of the context object for an active normal scope returns the current instance of the given contextual type."and that "The context associated with the current thread is called the current context for the scope. The mapped instance of a contex- tual type associated with a current context is called the current instance of the contextual type." > > If we put that together, we can see that observer methods, on any bean of any scope are called *only* for the session associated with the current request. > > Events *do not* provide a way to widen a context. It's definitely not recommended to bridge sessions this way. Instead, you should inject an application scoped bean, or observe an event on application scoped bean. > >> >>> >>> If so: in the spec an injection of @Dependent Event is mentioned: >>> >>> "10.3.2. The built-in Event >>> The container must provide a built-in bean with: >>> >>> • Event<X> in its set of bean types, for every Java type X that does not contain a type variable, >>> >>> • every event qualifier type in its set of qualifier types, >>> >>>>> • scope @Dependent, << >>> >>> • no bean EL name, and >>> >>> • an implementation provided automatically by the container. >>> >>> ..." >> >> This is the built-in bean used to fire events (an alternative to BeanManager#fireEvent()). >> >>> >>> It implies, that only observes belonging to the same scope would be notified. Otherwise this information is irrelevant, >> >> No, I don't think so. It only says that if you use built-in bean Event to fire events, it will depend on the bean where you inject it. > > No it doesn't. It's just describing how the built in Event bean works, not how observers are notified (which I outlined above for your bedtime reading :-) > >> >>> >>> >>> thanks!, >>> >>> adam >>> >>> On 29.08.2012, at 13:54, Pete Muir <pmuir(a)redhat.com&gt; wrote: >>> >>>> Resolution and scoping are orthogonal concepts in CDI. I'm not aware of a use case that is well addressed by considering scope as part of resolution. >>>> >>>> On 29 Aug 2012, at 11:43, Martin Kouba wrote: >>>> >>>>> No. It will be delivered to any matching observer method - belongs to an enabled bean, the event object is assignable to the observed event type and the observer method has all the event qualifiers (CDI 1.0). In CDI 1.1 qualifier matching rules will likely change: "The observer method has no event qualifiers or has a subset of the event qualifiers". >>>>> >>>>> (see 10.2. Observer resolution) >>>>> >>>>> Martin >>>>> >>>>> Dne 29.8.2012 12:32, Adam Bien napsal(a): >>>>>> HI Martin, >>>>>> >>>>>> sure. But will the unmanaged payload be delivered only to observers belonging to the same scope as the sender? >>>>>> >>>>>> I didn't found any mention in the spec about that... >>>>>> >>>>>> thanks, >>>>>> >>>>>> adam >>>>>> On 29.08.2012, at 12:14, Martin Kouba <mkouba(a)redhat.com&gt; wrote: >>>>>> >>>>>>> Hi Adam, Arne, >>>>>>> >>>>>>> The built-in Event bean is not stateless, it's @Dependent. The event payload - the event object - is really not managed and thus not scoped (and should not be IMHO). I also think the event object should be immutable since the order in which observer methods are called is not defined... >>>>>>> >>>>>>> Martin >>>>>>> >>>>>>> >>>>>>> Dne 29.8.2012 12:06, Arne Limburg napsal(a): >>>>>>>> Hi Adam, >>>>>>>> >>>>>>>> >>>>>>>> Are you talking about the injected Event object or about the payload? >>>>>>>> The Event object is stateless so the scope does not matter. >>>>>>>> And the payload is not managed at all. >>>>>>>> So, I'm afraid, I can't see your issue here? >>>>>>>> Could you provide a use case for a scoped event? >>>>>>>> >>>>>>>> Cheers, >>>>>>>> Arne >>>>>>>> >>>>>>>> Am 29.08.12 11:49 schrieb "Adam Bien" unter <abien(a)adam-bien.com&gt;: >>>>>>>> >>>>>>>>> Hi *, >>>>>>>>> >>>>>>>>> I didn't found in the CDI 1.0 spec a mention of the scope of CDI events. >>>>>>>>> There is also no mention of scopes in the Observer Resolution section. >>>>>>>>> >>>>>>>>> Are CDI events scoped? >>>>>>>>> >>>>>>>>> Does observer resolution depend on the scope of the injected Event >>>>>>>>> instance? >>>>>>>>> >>>>>>>>> Should we refine/clarify that in the CDI 1.1 spec? >>>>>>>>> >>>>>>>>> I didn't found an explicit mail in the archives either, >>>>>>>>> >>>>>>>>> thanks and sorry in case the issue is already resolved, >>>>>>>>> >>>>>>>>> adam >>>>>>>>> _______________________________________________ >>>>>>>>> cdi-dev mailing list >>>>>>>>> cdi-dev(a)lists.jboss.org >>>>>>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>>>>>> >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> cdi-dev mailing list >>>>>>>> cdi-dev(a)lists.jboss.org >>>>>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>>>>>> >>>>>>> >>>>>>> -- >>>>>>> Martin Kouba >>>>>>> JBoss Quality Assurance Engineer >>>>>>> CDI TCK lead >>>>>>> E-mail: mkouba(a)redhat.com >>>>>>> Web: www.cz.redhat.com >>>>>>> Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic >>>>>>> _______________________________________________ >>>>>>> cdi-dev mailing list >>>>>>> cdi-dev(a)lists.jboss.org >>>>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>>>> >>>>>> workshops.adam-bien.com >>>>>> blog.adam-bien.com >>>>>> about.adam-bien.com >>>>>> >>>>>> Author of: >>>>>> "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking Best Practices" >>>>>> >>>>> _______________________________________________ >>>>> cdi-dev mailing list >>>>> cdi-dev(a)lists.jboss.org >>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>> >>> >>> workshops.adam-bien.com >>> blog.adam-bien.com >>> about.adam-bien.com >>> >>> Author of: >>> "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking Best Practices" >>> >>> >>> >>> >>> >>>

Hi Pete, but: scopes are not even mentioned in 10.2: " • 10.2. Observer resolution The process of matching an event to its observer methods is called observer resolution. The container considers event type and qualifiers when resolving observers. Observer resolution usually occurs at runtime. An event is delivered to an observer method if: • The observer method belongs to an enabled bean. • The event object is assignable to the observed event type, taking type parameters into consideration. • The observer method has all the event qualifiers. An observer method has an event qualifier if it has an observed event qualifier with (a) the same type and (b) the same annotation member value for each member which is not annotated @javax.enterprise.util.Nonbinding. • Either the event is not a container lifecycle event, as defined in Section 11.5, “Container lifecycle events”, or the ob- server method belongs to an extension. If the runtime type of the event object contains a type variable, the container must throw an IllegalArgumentException. For a custom implementation of the ObserverMethod interface defined in Section 11.1.3, “The ObserverMethod interface”, the container must call getObservedType() and getObservedQualifiers() to determine the observed event type and qualifiers. " I think we should clarify this section and at least mention the observer scoping. We should at least provide references to the sections mentioned in your previous email. Description in 5.5.6 is perfect, but extremely hard to find... adam On 29.08.2012, at 15:25, Pete Muir <pmuir(a)redhat.com&gt; wrote: > > On 29 Aug 2012, at 13:52, Martin Kouba wrote: > >> Hi Adam, >> >> comments inline... >> >> Dne 29.8.2012 14:43, Adam Bien napsal(a): >>> Hi *, >>> >>> it would mean: >>> >>> If you are sending an event from a @RequestScoped bean all @SessionScoped observes (= all sessions) would receive that? Or more precisely ALL observes are intended to receive an event regardless of their scope? >> >> Yes. > > Actually, no. Working through the spec: > > 10.5 says > > "When an event is fired by the application, the container must: > > • determine the observer methods for that event according to the rules of observer resolution defined by Section 10.2, “Observer resolution”, then, > > • for each observer method, either invoke the observer method immediately, or register the observer method for later in- vocationduringthetransactioncompletionphase,usingaJTASynchronization. > > The container calls observer methods as defined in Section 5.5.6, “Invocation of observer methods”." > > and 5.5.6 says > > " • Obtain a contextual instance of the bean which declares the observer method according to Section 6.5.2, “Contextual instance of a bean”. If this observer method is a conditional observer method, obtain the contextual in- stance that already exists, only if the scope of the bean that declares the observer method is currently active, without creating a new contextual instance. > > • Invoke the observer method on the resulting instance, if any, as a business method invocation, as defined in Sec- tion 7.2, “Container invocations and interception”." > > and 6.5.2 says > > "From time to time, the container must obtain a contextual instance of a bean. The container must: > > • obtain the active context object for the bean scope, then > > • obtain an instance of the bean by calling Context.get(), passing the Bean instance representing the bean and an in- stance of CreationalContext." > > Finally, we need to look at 6.3, which defines how normal scopes work. Specifically, we can see that "The get() operation of the context object for an active normal scope returns the current instance of the given contextual type."and that "The context associated with the current thread is called the current context for the scope. The mapped instance of a contex- tual type associated with a current context is called the current instance of the contextual type." > > If we put that together, we can see that observer methods, on any bean of any scope are called *only* for the session associated with the current request. > > Events *do not* provide a way to widen a context. It's definitely not recommended to bridge sessions this way. Instead, you should inject an application scoped bean, or observe an event on application scoped bean. > >> >>> >>> If so: in the spec an injection of @Dependent Event is mentioned: >>> >>> "10.3.2. The built-in Event >>> The container must provide a built-in bean with: >>> >>> • Event<X> in its set of bean types, for every Java type X that does not contain a type variable, >>> >>> • every event qualifier type in its set of qualifier types, >>> >>>>> • scope @Dependent, << >>> >>> • no bean EL name, and >>> >>> • an implementation provided automatically by the container. >>> >>> ..." >> >> This is the built-in bean used to fire events (an alternative to BeanManager#fireEvent()). >> >>> >>> It implies, that only observes belonging to the same scope would be notified. Otherwise this information is irrelevant, >> >> No, I don't think so. It only says that if you use built-in bean Event to fire events, it will depend on the bean where you inject it. > > No it doesn't. It's just describing how the built in Event bean works, not how observers are notified (which I outlined above for your bedtime reading :-) > >> >>> >>> >>> thanks!, >>> >>> adam >>> >>> On 29.08.2012, at 13:54, Pete Muir <pmuir(a)redhat.com&gt; wrote: >>> >>>> Resolution and scoping are orthogonal concepts in CDI. I'm not aware of a use case that is well addressed by considering scope as part of resolution. >>>> >>>> On 29 Aug 2012, at 11:43, Martin Kouba wrote: >>>> >>>>> No. It will be delivered to any matching observer method - belongs to an enabled bean, the event object is assignable to the observed event type and the observer method has all the event qualifiers (CDI 1.0). In CDI 1.1 qualifier matching rules will likely change: "The observer method has no event qualifiers or has a subset of the event qualifiers". >>>>> >>>>> (see 10.2. Observer resolution) >>>>> >>>>> Martin >>>>> >>>>> Dne 29.8.2012 12:32, Adam Bien napsal(a): >>>>>> HI Martin, >>>>>> >>>>>> sure. But will the unmanaged payload be delivered only to observers belonging to the same scope as the sender? >>>>>> >>>>>> I didn't found any mention in the spec about that... >>>>>> >>>>>> thanks, >>>>>> >>>>>> adam >>>>>> On 29.08.2012, at 12:14, Martin Kouba <mkouba(a)redhat.com&gt; wrote: >>>>>> >>>>>>> Hi Adam, Arne, >>>>>>> >>>>>>> The built-in Event bean is not stateless, it's @Dependent. The event payload - the event object - is really not managed and thus not scoped (and should not be IMHO). I also think the event object should be immutable since the order in which observer methods are called is not defined... >>>>>>> >>>>>>> Martin >>>>>>> >>>>>>> >>>>>>> Dne 29.8.2012 12:06, Arne Limburg napsal(a): >>>>>>>> Hi Adam, >>>>>>>> >>>>>>>> >>>>>>>> Are you talking about the injected Event object or about the payload? >>>>>>>> The Event object is stateless so the scope does not matter. >>>>>>>> And the payload is not managed at all. >>>>>>>> So, I'm afraid, I can't see your issue here? >>>>>>>> Could you provide a use case for a scoped event? >>>>>>>> >>>>>>>> Cheers, >>>>>>>> Arne >>>>>>>> >>>>>>>> Am 29.08.12 11:49 schrieb "Adam Bien" unter <abien(a)adam-bien.com&gt;: >>>>>>>> >>>>>>>>> Hi *, >>>>>>>>> >>>>>>>>> I didn't found in the CDI 1.0 spec a mention of the scope of CDI events. >>>>>>>>> There is also no mention of scopes in the Observer Resolution section. >>>>>>>>> >>>>>>>>> Are CDI events scoped? >>>>>>>>> >>>>>>>>> Does observer resolution depend on the scope of the injected Event >>>>>>>>> instance? >>>>>>>>> >>>>>>>>> Should we refine/clarify that in the CDI 1.1 spec? >>>>>>>>> >>>>>>>>> I didn't found an explicit mail in the archives either, >>>>>>>>> >>>>>>>>> thanks and sorry in case the issue is already resolved, >>>>>>>>> >>>>>>>>> adam >>>>>>>>> _______________________________________________ >>>>>>>>> cdi-dev mailing list >>>>>>>>> cdi-dev(a)lists.jboss.org >>>>>>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>>>>>> >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> cdi-dev mailing list >>>>>>>> cdi-dev(a)lists.jboss.org >>>>>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>>>>>> >>>>>>> >>>>>>> -- >>>>>>> Martin Kouba >>>>>>> JBoss Quality Assurance Engineer >>>>>>> CDI TCK lead >>>>>>> E-mail: mkouba(a)redhat.com >>>>>>> Web: www.cz.redhat.com >>>>>>> Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic >>>>>>> _______________________________________________ >>>>>>> cdi-dev mailing list >>>>>>> cdi-dev(a)lists.jboss.org >>>>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>>>> >>>>>> workshops.adam-bien.com >>>>>> blog.adam-bien.com >>>>>> about.adam-bien.com >>>>>> >>>>>> Author of: >>>>>> "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking Best Practices" >>>>>> >>>>> _______________________________________________ >>>>> cdi-dev mailing list >>>>> cdi-dev(a)lists.jboss.org >>>>> https://lists.jboss.org/mailman/listinfo/cdi-dev >>>> >>> >>> workshops.adam-bien.com >>> blog.adam-bien.com >>> about.adam-bien.com >>> >>> Author of: >>> "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking Best Practices" >>> >>> >>> >>> >>> >>> > workshops.adam-bien.com blog.adam-bien.com about.adam-bien.com Author of: "Real World Java EE Night Hacks", "Real World Java EE Patterns--Rethinking Best Practices"

Am 29.08.12 13:10 schrieb "Martin Kouba" unter <mkouba(a)redhat.com&gt;: > This reminds me that the spec should clarify the case when the context of > the bean declaring the observer is not active. Currently in RI (Weld) you > get ContextNotActiveException. Which is logical although probably not the > best from the user point of view. > > I will file an issue. Thanks for the tip! :-) Maybe it should be handled in https://issues.jboss.org/browse/CDI-75 too. Why? Initially I thought it would be a good idea to ignore an observer method if a scope is not active and notifyObserver is IF_EXISTS. But now I believe this is partially wrong. Too me there is a difference between A) the observer bean scope is active without an active bean in scope and B) the observer bean scope is not active IF_EXISTS refers to A) only, I believe. Because if IF_EXISTS applies to A) and B) I am unable to support ALWAYS for active scopes while being ignored if a scope is not active. Why would someone need that? Very often we initialize our application during startup. During startup request and application scope are active [1]. Usually a session scoped observer should be ignored during startup. But at runtime - with an active session scope - I need ALWAYS semantics for those observers. So I would vote for: - ALWAYS observer methods will throw an ContextNotActiveException(?) if scope is not active. - IF_EXISTS observer methods will throw an ContextNotActiveException(?) if scope is not active. - IF_EXISTS observer methods will be ignored if scope is active but no active bean is in scope. - (The newly created) IF_ACTIVE observer method (naming TBD) will be ignored if scope is inactive. If scope is active it will be treated as ALWAYS. - There might be a need for IF_ACTIVE_AND_EXISTS;). This might break backwards compatibility though. Jens [1] We do that manually but would love to see @Startup/@PostConstruct support with active application and request scopes. _______________________________________________ cdi-dev mailing list cdi-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/cdi-dev