detach() is used to detach any state at the end of request. this can include memory related, serialization related tasks, whatever other tasks the component needs.
if you mark the field as transient, then indeed you do not have to null it out in ondetach - at least not for serialization reasons, but you still have to keep the lazy load logic for that field because if the component is loaded from storage the field will again be null. -igor On Fri, Aug 7, 2009 at 2:42 AM, Robin Sander<robin.san...@gmx.net> wrote: > > Hi, > > correct me if I'm wrong, Igor, but I thought detach() is used to keep the > model memory footprint low > *between requests* and Serialization is a total different story. > If I mark a field as transient I don't have to nullify it in detach(). > For example using a IDataProvider for pagination: > If I set a (transient) field to null after every request I have to > initialize it before every request too, > sounds inefficient to me. To re-initialize a transient field I would use > readObject(ObjectInputStream in) > instead. > If I'm right the following comment in IDetachable is misleading: > > /** > * Detaches model after use. This is generally used to null out > transient references that can be > * re-attached later. > */ > void detach(); > > What am I missing? > > Robin. > > > > On 06.08.2009, at 21:45, Igor Vaynberg wrote: > >> yep, lazy init is the way to do things. also helps to mark those >> fields as transient as an additional safeguard. >> >> -igor >> >> On Thu, Aug 6, 2009 at 12:22 AM, Gabi Kaltman<gkalt...@yahoo.com> wrote: >>> >>> Hi, >>> >>> I'm very young on the Wicket planet, so please excuse my simple question >>> related to DataView/IDataProvider >>> >>> My configuration: >>> 1. I use a DataView (MyDataView) >>> 2. I added a PageNavigator to MyDataView >>> 3. I defined a IDataProvider attached to MyDataView (MyDataProvider) >>> 4. MyDataProvider has a not-serializable field (MyField) >>> 5. MyField is used in the method MyDataProvider.size() >>> 6. I use Wicket 1.4.0 >>> >>> What I do: >>> 1. In the method MyDataProvider.detach() , I nullify MyField (MyField = >>> null) >>> >>> What happens: >>> 1. When I navigate through pages, I get a NPE in MyDataProvider.size() as >>> MyField became null >>> >>> How I fixed it: >>> 1. I overrode in MyDataView the method getDataProvider(). Didn't work. I >>> noticed that this method is never invoked >>> 2. I tested again null in MyDataProvider.size(). If MyField is null, I >>> just reinitialize it. It works >>> >>> My question is if this solution is the optimal one, or there is a better >>> one? >>> >>> Thanks, >>> kaltman >>> >>> >>> >>> >> >> --------------------------------------------------------------------- >> 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
