I think you're biggest problem is you haven't gotten your head wrapped around
the conversational model yet. It definitely takes time and I'd recommend that
the first thing you do is at least skim through the Seam reference
documentation in it's entirety.
That being said, I'll try to explain as best I can.
anonymous wrote : I don't understand this part at all. I know that if I stick
the edited activity back into the users collection of activites and have the
correct cascade type, that when I save the updated user, it will save the
updated activity as well.
Where you're going wrong here is you don't need to stick the activity back into
the list if it's already there. If you are using a conversationally scoped EM
(which is what my suggestions are based on) then there will only be one version
of each activity per conversation, whether that activity was retrieved through
user.getActivities or through SELECT..... That's how an EntityManager works
and it's important to understand that. So rather than the view that you
provided, what I'm talking about is the edit view where you will have values
bound like:
| Name: <h:inputText value="#{selectedActivity.name}"/>
|
When the update data model phase happens the name would be updated on the one
and only version of the selected Activity, which is managed by your
conversation scoped EM, and when the transaction is commited it will be
updated. After that anytime you access user.getActivities() you will see the
updated activity and it will be reflected in the database. Does that make more
sense?
anonymous wrote : I guess that's what I'm saying. I'm not sure I'd call it
spanning more than one conversation. In reality, user is a session scoped bean
representing the currently logged in user.
Well, since a session may contain many conversations, then your User object at
least has the capability of spanning more than one and that should be factored
in. Again, this seems to be an issue with your understanding of how
conversations, and more specifically conversation scoped EMs work. You cannot
use the @PersistenceContext annotation to specify a conversation scoped EM. It
needs to be injected using the @In annotation, and if you've configured that
correctly (see the docs on how) Seam will magically make sure that the same EM
gets injected into every bean within the same conversation.
As far as persistence units are concerned, I've never had the need to deal with
more than one on a project, but I'd imagine if I did I could create 2 Seam
managed EMs, one for each persistence context and then your example would
become:
| @In(create="true")
| EntityManager manager1;
|
| @In(create="true")
| EntityManager manager2;
|
Where manager1 and manager2 are both properly configured, conversation scoped
EMs.
Make more sense?
View the original post :
http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3983934#3983934
Reply to the post :
http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3983934
_______________________________________________
jboss-user mailing list
[email protected]
https://lists.jboss.org/mailman/listinfo/jboss-user
