On 10 June 2014 10:52, Erik de Hair <e...@pocos.nl> wrote: > Hi Dan, > > That's not the answer I hoped for ;-) > > sorry bout that!
> It looks like the ViewModels only work with persisted entities. Is that > correct? > > Not exactly. A view model can hold references to any data; that's what the MementoService is for. Our Google Summer of Coder (Dileepa) has written a view model that wraps some JSON representing a gmail obtained via a web service, for example. Fundamentally a view model just has the ability to marshall itself to/from a string. We use that string as its OID, which appears in the URL. When we next interact with the view model, Isis recreates the view model from that OID. What the view model does with its string is up to it. > What I try to accomplish right now (as a work around) is to return a > ViewModel from an action with the posted data from the action put into that > viewmodel and than call some actions on that viewmodel. If it is possible > to return a fresh viewmodel every time I return from an action, it looks a > bit like a wizard. At least I can build some data model in memory and > persist this model when ready. Should that be possible? > > Yup, that's the best we can offer for now. > I will elaborate my wishes in the ticket you raised. > > Wat is the use of a @NotPersistable-entity like described in [1]? > > It was a way of saying that an object can never be persisted, ie a domain constraint. But when using JDO objectstore it is somewhat redundant (or at least not fully implemented), because we delegate the responsibility for doing persistence to JDO/DN. When Isis 2.0 comes along, some of these older annotations might end up being deprecated/removed. Cheers Dan > Thanks, > Erik > > [1] > http://isis.apache.org/more-advanced-topics/how-to-07-040-How-to-specify-that-an-object-should-not-be-persisted.html > > > On 06/09/2014 07:59 AM, Dan Haywood wrote: > > Hi Erik, > Short answer is that we don't really (properly) support this. And we > should. > > I agree that @NotPersistable is confusing and its not clear what to use; > the right solution would be to implement a view model (currently: implement > the ViewModel interface), and then - optionally - write a custom > ComponentFactory for the Wicket viewer to render the wizard appropriately. > > But the snag even with the above is that (currently) view models are > immutable; they support actions but their properties cannot be edited. > > I can see the way forward on this; I don't think it's difficult, but it > will require a change in core and probably the wicket viewer also. > > If you want then raise a ticket for this requirement, and sketch how you'd > like it to work. > > Cheers > Dan > > > > On 6 June 2014 17:40, Erik de Hair <e...@pocos.nl><mailto:e...@pocos.nl> > wrote: > > > > Ok, I've found the @NotPersistable annotation but don't know how to use > this. I get an error message saying the object is not persistent. Extended > my entity from AbstractDomainObject later, but that doesn't help. > > Erik > > On 06/06/2014 04:07 PM, Erik de Hair wrote: > > Hi, > > Is it in some way possible to create a wizard like form or open an action > with an action? I tried to return a not yet persisted object from an action > and hoped I could edit some properties and add some elements to collections > of the object before persisting it to the database... > > Thanks, > Erik > > > > > > > > > >
