i didnt say you have to have a different object. I just say dont keep persistent objects in memory between requests. Use detachable for that.
The only exception i guess is when you create a new object that isnt persisted yet to the db and you have some kind of wizard to fill it up. On Sun, Mar 1, 2009 at 14:56, Willis Blackburn <wbo...@panix.com> wrote: > Let's say you have a Java object with 20 fields that's mapped to a database > using Hibernate. I don't see that there's much difference in terms of > memory utilization between using that object as the model and creating a > separate object with 20 fields to use as the model. Following the principle > of not repeating yourself, I'd say that everything else being equal, it > makes more sense to use the persistent object. Of course there will always > be fields that you don't want to be set directly from the form, but you can > use Brill's strategy of wrapping the persistent object in another object > that just contains the fields for which you want to implement some extra > logic. > > There's a subtle difference between having the model reload the persistent > object every time and just keeping a hard reference to it that is worth > mentioning. If you keep a hard reference to the persistent object, and > you're using Hibernate's version or timestamp feature, and you actually > merge the object back into the session rather than copy the fields to a > newly-loaded object, then Hibernate will be able to detect cases in which > the user is trying to save edits to a stale version of the object. This > isn't always useful, but it might be, depending on your requirements. > > W > > > > > On Mar 1, 2009, at 5:09 AM, Johan Compagner wrote: > > You shouldnt put that object directly in a CPM, but have a loadabled >> detachable model in between. Because now you probably have that hib >> object in the page between requests >> >> On 28/02/2009, Stephen Swinsburg <s.swinsb...@lancaster.ac.uk> wrote: >> >>> Hi all, >>> >>> I'm after your thoughts on the following method. >>> >>> Suppose there is a wicket form with some fields that can map directly >>> to a simple Hibernate object, and hence a db table. Is it safe to >>> simply wrap this object in a CompoundPropertyModel and use it as the >>> backing model for the form? >>> Then in the onSubmit method, calling a method to get the object from >>> the form's model and saving it via Hibernate. >>> >>> This does work fine, I'm just after any pitfalls that might happen >>> down the track. Very simple form here. >>> >>> thanks. >>> S >>> >>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org >>> For additional commands, e-mail: users-h...@wicket.apache.org >>> >>> >>> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org >> For additional commands, e-mail: users-h...@wicket.apache.org >> >> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org > For additional commands, e-mail: users-h...@wicket.apache.org > >
