[jboss-dev-forums] [Design the new POJO MicroContainer] - Re: JBKERNEL-12 - Scoped Deployments

"marius.bogoevici" wrote : | So, the beginning question is, what are the current thoughts regarding the Scoped Deployments feature, and if there is a list of outstanding TODOs? | There are currently no exact thoughts on the scoped deployment. Hence this discussion is very welcome. The current scoped *kernels* are initial prototype of what can be done, at least a simple hierarchy based lookup and registry is there. But of course it is missing a lot of proper API, to be really useful. Although I wouldn't limit the scoping to plain parent-child lookup, I always had in mind a more peer model, a plane graph - hence GraphController. "marius.bogoevici" wrote : | However, there is no generic "deploy in XYZ scope" | Not yet, but there should be one, once we properly discuss this. "marius.bogoevici" wrote : | operation or "get the Controller corresponding to the XYZ scope", | Currently scoping is more an impl detail, once we have proper API this should be part of GraphController. "marius.bogoevici" wrote : | or "get Bean from XYZ scope". | You actually have this with @Search (which is deprecated; was initial impl) and something a member of the community contributed - moving this search notion into inject; see its search attribute. "marius.bogoevici" wrote : | As well, every deployment gets some scope associated with it, but I can't see this being used in any practical fashion. | Not yet, but I think this is the right way to go, and we'll simply re-use this. "marius.bogoevici" wrote : | Also, while injection works properly with scoping (i.e. beans will be injected into other beans only if found in the appropriate scope), consuming scoped beans is somehow inconsistent, in that getBean("someBean") called on a Kernel will return the first encountered bean with a given name, defined in the global Kernel controller, or any of its children. If there are multiple beans with the same name defined in the Kernel, in different scopes, an arbitrary bean (first encountered) is chosen and returned. | That was one of the reasons I pushed @Search in, to have a consistent / deterministic behavior. But this is actually a common problem with any hierarchy/graph lookup; see classloading. ;-) "marius.bogoevici" wrote : | - all MC-registered beans created by a deployment are created in the Scope of the Deployment | They should only be put into deployment's scope if this is explicitly defined. Otherwise it should go into top level / main / global (depending on the structure) scope. Or we will break or had to hack too many things. To sum things up, I think your understanding of the current code is OK. I see we also agree on the need for proper API, on Deployers and Kernel side. My guess is we should just play a bit with this, prototype around existing working stuff, and see what would be the best way to extend this into some useful feature set. e.g. add new scoping info metadata into current pojo, mbean metadata * proper elements in KernelDeployment/BeanMetaData or ServiceDeployment/ServiceMetaData * external new descriptors that setup proper scoping * re-check PolicyMetaData First impression is that this would't take much work, adding a few new deployers, and modifying BeanMetaDataDeployer to consider this new info on top of GraphController. I guess hidding the actual scoping impl under more generic (peer) model would be more work. And it's really a question if we should do that, as mostly such lookups are expected to be hierarchical. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4244543#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...