Thanks for the example.
You can fix this as follows:
//@ViewModel
@XmlRootElement
public class SimpleViewModel {
private SimpleObjectDTO filter;
...
}
The issue, is that @ViewModel will only serialize out the state of scalar
value types (strings, dates etc). The SimpleObjectDTO, being a reference
type, is ignored. It's confusing, because it looks like the value of the
filter (SimpleObjectDTO) has been set and serialized correctly, however I
think you would find that just refreshing the SimpleObjectViewModel causes
its state to get lost once more.
Changing @ViewModel to @XmlRootElement causes the entire graph of objects'
state, including SimpleObjectDTO, to be captured.
~~~
Another way to check this: without making the above change, alter the
SimpleObjectViewModel.layout.xml so that you have the regular title, by
adding <domainObject/>, eg:
<bs3:row>
<bs3:col span="11" unreferencedActions="true">
<domainObject/>
...
</bs3:row>
Then, do the following:
- call filter action, set a value for the name of the SimpleObjectDTO
filter, eg "Foo"
- the click on the "ViewModel" title
- now inspect the property of SimpleObjectDTO filter... it will be null.
Change @ViewModel to @XmlRootElement, and it should be retained
HTH
Dan
On 27 November 2016 at 00:27, Hector Fabio Meza <
[email protected]> wrote:
> Hi, Dan,
>
> Thank you for your suggestions. Im using the @ViewModel annotation on the
> ViewModel. The DTO I´m trying to use as a filter is annotated with
> @DomainObject(nature=Nature.VIEW_MODEL) and javax.xml annotations.
>
> After doing some more tests, I think the problem is not in the model´s
> state, since the viewer shows the correct value for the properties. Now I
> suspect my problem has to do with the point of the lifecycle where methods
> are called.
>
> I´ve included a link to a SimpleObjects app where I added a simplified
> case of my ViewModel (SimpleViewModel.java). It is intended to be a single
> entry point for an entity, so it has an action that returns a collection
> with all entities, a "create" action that allows the user to create a new
> SimpleObject and a "filter" action that asks the user for a "name" and
> stores it in thje model´s DTO.
>
> The problem is that when I try to access the DTO´s fields in the list
> action, it shows all attributes as null while the Viewer does show me the
> value I entered.
>
> I think maybe the getObjects method is being called before the model´s
> state has been recreated?
>
> ---------------------------------------------
>
>
> private SimpleObjectDTO filter;
>
> public SimpleViewModel filter(
> final @ParameterLayout(named = "Name") @Parameter(optionality
> = Optionality.OPTIONAL) String name) {
>
> filter = new SimpleObjectDTO();
>
> filter.setName(name);
>
> filter.setDoFilter(true);
>
> return this;
> }
>
> public List<SimpleObject> getObjects() {
> System.out.println("filter : " + filter);
>
> return simpleObjects.listAll();
>
> }
>
> filter : SimpleDTO [name=null, doFilter=false]
> 19:23:29,147 [Native qtp1615535645-20 DEBUG] SELECT
> 'domainapp.dom.simple.SimpleObject' AS
> "NUCLEUS_TYPE","A0"."name","A0"."notes","A0"."id","A0"."version" FROM
> "simple"."SimpleObject" "A0"
>
> ----------------------------------------------
>
> https://www.dropbox.com/s/xiot10oskfpn5vm/SimpleViewModel.zip?dl=0
>
>
> El 2016-11-26 13:00, Dan Haywood escribió:
>
> Hi Hector,
>
> There are a couple of different ways to write view models, and they have
> different capabilities. At some point I anticipate we'll deprecate
> some/most of these... we are where we are.
>
> What's common about all the view models is that the view model's state is
> converted into the object's OID: this is visible in the URL of the object
> (either in Wicket viewer or REST API). When the view model is next
> interacted with, then the framework recreates the view model from that OID,
> then invokes the action/property edit.
>
> Which state is extracted into the OID/used to rehydrate the view model
> subsequenty varies by implementation:
>
> - if your code implements ViewModel interface, then you have full control
> (the viewModelInit and viewModelMemento methods are basically reciprocals
> of each other)
>
> - if your code is annotated with @ViewModel or with
> @DomainObject(nature=VIEW_MODEL | EXTERNAL_ENTITY | INMEMORY_ENTITY),
> then the framework will use the state of any properties of the domain
> object; however collections are ignored
>
> - if your code is annotated with @XmlRootElement, then we use JAXB to
> serialize the entire object graph; in practice this means both properties
> and collections, ignoring fields annotated with @XmlTransient. Any
> references to entities are converted to bookmarks, assuming that those
> entities are themselves annotated with @XmlJavaTypeAdapter(
> PersistentEntityAdapter.class)
>
> Hopefully that's enough for you to figure out what's going on. But if
> not, perhaps you could post some code or, even better, create a simple
> example app that demonstrates the issue.
>
> Cheers
> Dan
>
>
>
>
>
> --
>
> *Hector Fabio Meza*
> *R&D Lead smartools*
> (57) 300 2254455 <%2857%29%20300%206815404>
> Skype: hectorf.meza
> www.smartools.com.co
>
>
