Thanks Lincoln, it's much clearer to me what you mean now. I would express this as "the ability to resolve the *bean* using EL, and then invoke a method on the bean using reflection (e.g. annotations, method name pattern matching)".
On 12 Apr 2010, at 20:18, Lincoln Baxter, III wrote:
> I'm sure I'm not being clear ;)
>
> Let me ask a question.
>
> Assuming the following constraint:
> • No given dependencies to any one given bean-container, just knowledge that a bean container exists, and that it is registered with the ELContext
> How would you write a bean-container-portable extension (spring, guice, cdi, faces, other...,) using annotations, to invoke methods on Beans via EL?
>
> @Named("service") //CDI
> public class BusinessService {
>
> @InvokeBefore(RENDER_RESPONSE)
> public String doSomething()
> {
> return "success";
> }
> }
>
> In this scenario, @InvokeBefore should be the equivalent of using EL: #{service.doSomething()}
>
> --Lincoln
>
>
> On Mon, Apr 12, 2010 at 7:44 AM, Pete Muir <pmuir_at_redhat.com> wrote:
>
> On 11 Apr 2010, at 20:40, Lincoln Baxter, III wrote:
>
> > Exactly the scenario I mentioned above ;) Someone creates a framework (like prettyfaces) and wants to provide annotation support, but doesn't want to depend on CDI, Spring, Juice, or other implementations. However, there *is* a dependency on EL, which ends up being an abstraction over these containers.
> >
> > Because EL already knows the names of the beans, and the classes of the beans (I think?) it can probably generate a list of names for each Bean Class. This would allow products to invoke EL via annotations
>
> I'm sure I'm being obtuse, but I don't understand what this means, let alone how you would use it....
>
> > without knowing which Bean-container is in use -- there may even be multiple bean-containers.
> >
> > It would be possible to write extensions for each bean-container, but resolving against the EL would be much more portable, since it is already the home for bean names in Java EE / Java web-tier.
> >
> > --Lincoln
> >
> > On Fri, Apr 9, 2010 at 6:43 AM, Pete Muir <pmuir_at_redhat.com> wrote:
> > What scenarios do you see this being useful in?
> >
> > On 1 Apr 2010, at 00:06, Lincoln Baxter, III wrote:
> >
> > > I'm seeing benefit for a TypeMapper or NameMapper off of the ELContext object.
> > >
> > > When working with Bean Containers, each container has a different API for looking up beans and getting information about them. For instance, if I wanted to know what names were associated with a bean of type "com.ocpsoft.MyBean," there's currently no way of doing that through EL. I can go out to the bean containers themselves in order to get that information, but EL hides it.
> > >
> > > The use case:
> > > I've annotated a class, and a method on that class, and want to use that annotation to invoke an operation on that bean:
> > >
> > > @ExtensionDefined
> > > @javax.enterprise.context.Named("something")
> > > public class MyBean {
> > >
> > > @ExecuteThis
> > > public void action() {}
> > >
> > > }
> > >
> > > The custom annotations' scanner has access to the Class Type, but without providing direct support for Spring, CDI, Seam, Guice, JSF, etc -- has no idea what that class is named in the EL.
> > >
> > > The ELContext has hooks into whatever bean-container backs it (if there even is one -- it could be completely custom) and can provide names for a given type.
> > >
> > > So:
> > >
> > > @Inject ELContext context; //assume this works for example purposes...
> > > TypeMapper mapper = context.getTypeMapper();
> > > Set<String> names = mapper.getNames(Class<?> clazz); // lists all names for which the provided type is registered.
> > >
> > > This is a very rough concept, but what do you think? I think the value is there, but specifics need to be worked out.
> > >
> > > --
> > > Lincoln Baxter, III
> > > http://ocpsoft.com
> > > http://scrumshark.com
> > > "Keep it Simple"
> >
> >
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> >
> >
> >
> >
> > --
> > Lincoln Baxter, III
> > http://ocpsoft.com
> > http://scrumshark.com
> > "Keep it Simple"
>
>
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>
>
>
> --
> Lincoln Baxter, III
> http://ocpsoft.com
> http://scrumshark.com
> "Keep it Simple"