[weld-dev] Re: Primitive type question regarding events

I think that it makes a lot of sense to follow the rules from type-safe resolution here, i.e. https://jakarta.ee/specifications/cdi/4.1/jakarta-cdi-spec-4.1#primitive_... . Martin On 17. 10. 24 9:39, Matej Novotny wrote: > Hello, > > this is a good candidate for spec issue. I've created one - > https://github.com/jakartaee/cdi/issues/829 > <https://github.com/jakartaee/cdi/issues/829> > My personal take is that Weld behavior is a way to go as otherwise you'd > have no use for observing primitive types. > Strictly speaking, it is ATM Weld value-add but I don't see why the spec > couldn't cover this or at least have some TCK for it (I found none). > > Matej > > On Thu, Oct 17, 2024 at 4:06 AM Laird Nelson <ljnelson(a)gmail.com > <mailto:ljnelson@gmail.com>> wrote: > > The CDI 4.0 spec says in section 2.8.1 > ( https://jakarta.ee/specifications/cdi/4.0/jakarta-cdi-spec-4.0#event_type... < https://jakarta.ee/specifications/cdi/4.0/jakarta-cdi-spec-4.0#event_type... >): > > "Any Java type may be an observed event type." > > That means I can do this: > > private void primitive(@Observes int i) { // any type, including > int, can be an observed event type > System.out.println("primitive: " + i); > } > > And this: > > private void wrapper(@Observes Integer i) { > System.out.println("wrapper: " + i); > } > > Then of course the only way to fire an event is by using the Event > object and specifying the type of even you want to fire as its sole > type argument: > > // for example > @Inject > private Event<Integer> e; > > (Type arguments of course cannot be primitive.) > > No mention in the specification's section on observer resolution > talks about primitive types and/or wrapper types and how they > interact. (Obviously there are unrelated sections regarding typesafe > resolution in the context of dependency injection that do talk about > this, but they do not seem to apply here without a biiiiiig stretch > (observed event parameters are not injection points; event types are > not bean types).) > > If I do e.fire(Integer.valueOf(42)), the primitive(int) observer > method above is called (in Weld 5.1.3.Final). So is the > wrapper(Integer) observer method. This certainly is convenient and > I'm kind of glad it works that way, but is it correct? Is it a Weld > value-add? Or should the spec have said something about > interoperability of primitives and wrapper types in observer resolution? > > Best, > Laird > _______________________________________________ > weld-dev mailing list -- weld-dev(a)lists.jboss.org > <mailto:weld-dev@lists.jboss.org> > To unsubscribe send an email to weld-dev-leave(a)lists.jboss.org > <mailto:weld-dev-leave@lists.jboss.org> > Privacy Statement: https://www.redhat.com/en/about/privacy-policy > <https://www.redhat.com/en/about/privacy-policy> > List Archives: > https://lists.jboss.org/archives/list/weld-dev@lists.jboss.org/message/ID... < https://lists.jboss.org/archives/list/weld-dev@lists.jboss.org/message/ID... > > > > _______________________________________________ > weld-dev mailing list -- weld-dev(a)lists.jboss.org > To unsubscribe send an email to weld-dev-leave(a)lists.jboss.org > Privacy Statement: https://www.redhat.com/en/about/privacy-policy > List Archives: https://lists.jboss.org/archives/list/weld-dev@lists.jboss.org/message/FZ... -- Martin Kouba Principal Software Engineer Red Hat, Czech Republic