[jboss-user] [JBoss Seam] - Re: HowTo: When going to a page to enter data, pull from db

[CptnKirk]

Re EJB3 Entities:
anonymous wrote : Not quite, they are only components if the have @Name (in which case they would be CONVERSATION scoped). The "preferred" way to do this is to use Home objects to manage an Entity, rather than expose it directly with @Name, and uses pages.xml for wiring. We could probably do with an example app built using Seam-gen that does a couple of simple CRUD operations
Yep, it was late, I forgot I overrode the scope on some of my entities.  However there are plenty of times where simple CRUD doesn't fit the bill.  If you're actually managing an entity, sure, use a Home.  However if you're using a form to populate an entity for another purpose, using Seam to populate a scoped entity and hand it off for further processing has advantages.  Of course the entity doesn't need to be an EJB 3 entity.  Seam does the same for POJOs.

For example I don't think I'd recommend using a Home to populate a search prototype.  For search pages, an entity with an event scoped role combined with Hibernate's Criteria API + Example criterion is great.

In general if I'm not doing CRUD I prefer to decouple the entity population and the controller doing the work.  Prior to Seam I had to populate #{someController.entity.value1}.  Now that I can simply work with #{entity.value1} means I have some additional flexibility.

What would be really great would be to put out a Seam cookbook.  About @Unwrap, Pete is right, most people just want a contextual variable to go from void (not there), to initialized, and that's usually the job for @Factory.  However the managed component pattern can be useful not just for scafolding and exposing non-Seam services.  For an example you could have a managed component observe many events that happen within your system and change the underlying representation as a result of those observations.  With the managed component pattern a component can manage these actions itself and because the component is unwrapped on every access, all callers will have a consistent view.  This is a much different use than what Factories provide for.

I wasn't sure exactly what the user wanted so figured I'd lay out everything and let him choose. 

View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4039566#4039566

Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4039566