[cdi-dev] Hierarchy of ManageableContext and Context
mkouba at redhat.com
Tue Jul 19 03:26:25 EDT 2016
I don't see a problem if we introduce a ManageableContext interface
(with activate/deactivate) and a custom context implements it. In other
words, I don't think it has to be used only for built-in contexts.
Also the context definition is clear (6.2. The Context interface) and
again, if these are two different things then we should not call it a
context at all .
Dne 18.7.2016 v 13:19 John D. Ament napsal(a):
> I'm starting a discussion thread outside of the PR to avoid folks on the
> EG not receiving github notifications. I want to drive to get the
> opinions of the broader EG and use this as feedback on whether or not we
> change the hierarchy.
> I've been against having ManageableContext (MC) extend
> Context/AlterableContext (AC). There's a few reasons. First,
> semantically I can register a context, but I shouldn't be able to
> register a MC. That means from an inheritance standpoint MC does not
> pass the is-a check on AC. MC may be a composition style, or nothing at
> all since it may not be associated to any specific thread in the
> future. While we can put in spec verbiage and exceptions to cover the
> cases where someone does implement MC and try to register it,
> realistically if it's there as a compilation time option, I shouldn't
> get an error if it passes.
> I can agree that the bulk of the methods on MC should match AC. That's
> where I introduced a new base class for the two and had MC extend that.
> The base class provided no behavior, just method signatures. The second
> key thing for me is in this area. AC is more like a definition, where
> as MC is a running instance of that definition. Since these are
> different, it shows that MC doesn't inherit the use-case of the parent AC.
> Third issue I have with extending is that AC is meant to be implemented
> by developers to create custom contexts. Developers aren't intended to
> implement MC. The container should provide these instances, since they
> are intended only for built in contexts. We allow developers who
> implement AC to control their activation, as a result we've already
> provided a means to disassociate a custom AC from any thread.
> I want to get others opinions on whether these reasons make sense and if
> they guide to the same conclusion about not extending AC. For what its
> worth, I've shown these classes to some of my own developers to get
> their feedback, who have had to do things like quartz integration or
> responding to netty requests and activate contexts. The concerns I
> raise are based on questions they've asked me.
> cdi-dev mailing list
> cdi-dev at lists.jboss.org
> Note that for all code provided on this list, the provider licenses the code under the Apache License, Version 2 (http://www.apache.org/licenses/LICENSE-2.0.html). For all other ideas provided on this list, the provider waives all patent and other intellectual property rights inherent in such information.
More information about the cdi-dev