Not that I know of. Although googling "Wicket pagereference" will give you a discussion thread on it. Basically, just replace "private Page previousPage" with "private PageReference previousPage".
-- Jeremy Thomerson http://www.wickettraining.com On Mon, May 17, 2010 at 12:35 PM, Zilvinas Vilutis <[email protected]>wrote: > Are there any patterns described how to use PageReference efficiently? > > > Žilvinas Vilutis > > Mobile: (+370) 652 38353 > E-mail: [email protected] > > > On Mon, May 17, 2010 at 9:55 AM, Jeremy Thomerson < > [email protected] > > wrote: > > > You should use PageReference (Page#getPageReference()). > > > > -- > > Jeremy Thomerson > > http://www.wickettraining.com > > > > > > > > On Sun, May 16, 2010 at 11:52 PM, Rik van der Kleij < > [email protected] > > >wrote: > > > > > Hi Jeremy, > > > > > > So an instance field inside a page that points to another page is also > > > something you should avoid? In our application we using this pattern a > > lot > > > (for going back to previous page) but it never seems to be any problem. > > So > > > probably because our pages don't consume a lot of memory. > > > > > > Regards, > > > Rik > > > > > > On 17 mei 2010, at 06:13, Jeremy Thomerson wrote: > > > > > > > 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 < > > > [email protected]>wrote: > > > > > > > >> Hi Bernard and Mike, > > > >> > > > >> According to > > > >> > > > > > > https://cwiki.apache.org/WICKET/best-practices-and-gotchas.html#BestPracticesandGotchas-AnonymousInnerclassessharingmodelscouldeventually > 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: [email protected] > > > >>>> For additional commands, e-mail: [email protected] > > > >>>> > > > >>>> > > > >>> > > > >>> > > > >>> > --------------------------------------------------------------------- > > > >>> To unsubscribe, e-mail: [email protected] > > > >>> For additional commands, e-mail: [email protected] > > > >>> > > > >> > > > >> > > > >> > --------------------------------------------------------------------- > > > >> To unsubscribe, e-mail: [email protected] > > > >> For additional commands, e-mail: [email protected] > > > >> > > > >> > > > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: [email protected] > > > For additional commands, e-mail: [email protected] > > > > > > > > >
