In general, you should not pass references to components to other pages. That section on anonymous inner classes is telling you that when you create an anonymous inner class and pass it to another page, you will inadvertently be passing a reference to the outer class, which is typically a page. This builds up memory and you will get a OOM. Passing models between pages is absolutely fine - as long as you're not accidentally passing a bunch of other stuff with it (including large domain objects - which should be detached by using a detachable model). The page linked to even says that you will often pass models between pages.
-- Jeremy Thomerson http://www.wickettraining.com On Sun, May 16, 2010 at 11:05 PM, Rik van der Kleij <rikvdkl...@gmail.com>wrote: > Hi Bernard and Mike, > > According to > https://cwiki.apache.org/WICKET/best-practices-and-gotchas.html#BestPracticesandGotchas-AnonymousInnerclassessharing > models could eventually lead to Out of memory error. > > Holding a page reference in an instance field that points to another page > looks the same but it is doesn't seems to be a problem. What's the > difference? > > Regards, > Rik > > > On 16 mei 2010, at 04:39, Michael O'Cleirigh wrote: > > > Hello, > > > > I'm not sure on the answer to your question about the anonymous inner > class but in general sharing models between pages can be a bad idea. > > > > The memory issues comes into play if the IModel is like Model and the > contained object is not transient (it is serialized as part of the page). > > > > While Pages are serialized each page is serialized independently so on > page reload the IModel from the first page is no longer the same object > instance as the IModel from the second page. At deserialization time the > page1.model.getObject().equals page2.model.getObject() but > page1.model.getObject() != page2.model.getObject(); so any changes to either > model are not shared between then. > > > > This is not a problem if the model is loadable since the memory of the > page it is contained in doesn't matter as the value is loaded from the > backend db or some other independent data source like the httpsession, or > with wicketApplication. > > > > You can see the same effect if you try and share a model between a panel > and a ModelWindow that uses a PageCreator > > > > Hope this helps, > > > > Mike > >> Hi, > >> > >> Can someone explain me why it is a memory issue when an instance of an > anonymous IModel class is passed to another page to be shared, but it seems > to be no problem when a page reference is passed to another page and is put > in an instance field (for example to be used in a button to navigate back to > previous page)? > >> > >> Many thanks. > >> > >> Regards, > >> Rik > >> > >> > >> > >> --------------------------------------------------------------------- > >> 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 > >
