Matthew, A quick absolute way to make sure those values are serialized is to use the Java 'transient' keyword. But Wicket will be assuming that when a user hits the Back button, that it can re-constitute the page from the serialized info it has on disk, if it cannot, then yes you'll need a LoadableDetachable model that can rebuild that expensive graph when demanded but you won't need to persist it.
-R On Sun, Feb 28, 2010 at 4:37 PM, Matthew Welch <matt...@welchkin.net> wrote: > Models have been my achilles heel when it comes to Wicket. Not so much > their > explicit use, but understanding whe they data they wrap around is > serialized > or kept in session and when it's not. I was running some tests today to > experiment with just this subject. The domain object I was using in my > tests > intentionally had one field that I could, as an option, populate with > unserializable value. This made it easy for me to determine when Wicket was > trying to store the object with the page, as it would throw an exception. I > created a page with a form to create new instances of this particular > object. I initialized the form with a CompoundPropertyModel wrapped around > my domain object. When I submitted the form and saved the object to my > backend store , I received a WicketNotSerializableException. I was > initially > surprised by this, but after a few moments I realized (and correct me if > I'm > wrong) that the model wasn't detachable and that when I saved it the > attribute I mentioned above was being populated with that unserializable > value, but wicket was trying to save the page (probably to disk) with the > model wrapped around the now unserializable object. > > I guess this isn't a big deal, but what concerns me, and the reason I was > running these tests, was that some of the objects I'm working with have > huge > data graphs attached to them. I don't want these huge objects stored in > memory or serialized with any of the pages to disk. Can a form be backed by > a detachable model? It certainly wouldn't be a "loadable" detachable model > for new objects that are to be created as there's nothing yet to load. If > one can back a form with detachable model, does that limit anything that > you > can do with the form? >
