Re: [weld-dev] Maintenance release
On 10 Jan 2010, at 21:36, Mark Struberg wrote:
Hi Gavin!
A few random observations from a non-native english speaker, so beg your pardon if I got
something wrong ;)
Clarifying the 'Context' lifespan:
I think it is currently not clear what a Context instance represents.
While the wording in the default scope lifecycle section (6.7) suggests that there are n
(multiple) Context objects for a specific Scope annotation [1] (e.g. one SessionContext
instance for each session), the system eventing section (11.5.2) [2] only allows adding a
single Context for a Scope annotation (kind of a Context-Facade?).
[1] 6.7.2
The session context is shared between all servlet requests that occur
_in_the_same_HTTP_session (->another session gets another session context?). The
session context is destroyed when the HTTPSession times out, after all
HttpSessionListeners have been called, and at the very end of any request in which
invalidate() was called, after all filters and ServletRequestListeners have been called
(->again backs the n-contexts theory).
I think you are inserting the word "instance" into these sentences in your head
when you read them - if you re read 6.7.2 "The session context is provided by a
built-in context object" you can see the spec does differentiate between the concept
of the "session context" (multiple contexts per application instance) and the
"context object for the session" (one instance per application instance).
Perhaps there is a way to clean up the language to make it clearer that there is expected
to only be one context object instance?
[2] 11.5.2
AfterBeanDiscovery#addContext() registers a custom Context object with the container.
(-> no way to add a 'ContextFactory')
While this doesn't make much difference for our built in scopes (e.g. OWB currently
implements the n-context strategy with a ContextFactory while weld seems to use 1
SessionContext instance, isn't?) it may make a difference for portable extensions. And
it is really confusing for people who only want to write an extension providing a Context
for a custom scope.
So how do you implement addContext() in OWB? Surely it is tricky as it involves cloning
the object?