Re: WicketRuntimeException: Attempted to set property value on a null object

2012-12-01 Thread Sven Meier 

Ah, silly Hibernate ;).

AFAICS sooner or later a Wicket component will have to write a value 
into the embedded address, so obviously it has to be there.
You can of course build a specialized model doing some magic here, but 
at the moment I don't know how that might look like.


Sven

On 12/01/2012 12:43 AM, Andrew Geery wrote:

The problem with doing that is that Hibernate detects that as a change
(a null object is not the same as an empty object) and does a database
update (see some of the comments on this:
https://issues.jboss.org/browse/HIBERNATE-50).

Andrew

On Fri, Nov 30, 2012 at 5:59 PM, Sven Meier s...@meiers.net wrote:

d

-
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

WicketRuntimeException: Attempted to set property value on a null object

2012-11-30 Thread Andrew Geery 
I have a Person Hibernate/JPA entity with an @Embedded address object in it:

@Entity
public class Person {
...
  @Embedded
  private Address address;
...
}

I have a Panel with a Form for editing the Address
(EditAddressFormPanel) and a panel for editing the Person which uses
the Panel for editing (EditPersonFormPanel).

public class EditPersonFormPanel extends Panel {

  public EditPersonFormPanel(String cid, IModelPerson model) {
super(cid, model);
// create the person form
Form form = ...
// add the address form panel to it
form.add(new EditAddressFormPanel(address, new
PropertyModelAddress(model, address));
...
  }

}

This works if the Person.address field is not null.  However, because
of the way that JPA works, the address field will be null if all of
the fields in the class are null.  For example, if a Person object was
persisted without an initial address (i.e., address = null).  When
this happens, 
org.apache.wicket.model.AbstractPropertyModel.getInnermostModelOrObject()
returns null and I ultimately get a WicketRuntimeException: Attempted
to set property value on a null object in PropertyResolver.setValue
because the object is null.

My question is how to deal this this correctly at the model level.  I
think IModel.setObject should create a new object if the incoming
object is null and IModel.getObject should return null if no fields
are set on the object to match how JPA/Hibernate handles this.

How do other people handle this problem?  Is there a good model to
extend from (maybe something like IWrapModel)?  Any examples?

Thanks
Andrew

PS I'm already using EntityModels
(http://wicketinaction.com/2008/09/building-a-smart-entitymodel/)

-
To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org
For additional commands, e-mail: users-h...@wicket.apache.org

Re: WicketRuntimeException: Attempted to set property value on a null object

2012-11-30 Thread Sven Meier 

Why not handle this in your domain objects already?

@Entity
public class Person {
...
  @Embedded
  private Address address;
...

  public Address getAddress() {
if (address == null) {
  address = new Address();
}

return address;
  }
}
 


Sven

On 11/30/2012 11:49 PM, Andrew Geery wrote:

I have a Person Hibernate/JPA entity with an @Embedded address object in it:

@Entity
public class Person {
...
   @Embedded
   private Address address;
...
}

I have a Panel with a Form for editing the Address
(EditAddressFormPanel) and a panel for editing the Person which uses
the Panel for editing (EditPersonFormPanel).

public class EditPersonFormPanel extends Panel {

   public EditPersonFormPanel(String cid, IModelPerson model) {
 super(cid, model);
 // create the person form
 Form form = ...
 // add the address form panel to it
 form.add(new EditAddressFormPanel(address, new
PropertyModelAddress(model, address));
 ...
   }

}

This works if the Person.address field is not null.  However, because
of the way that JPA works, the address field will be null if all of
the fields in the class are null.  For example, if a Person object was
persisted without an initial address (i.e., address = null).  When
this happens, 
org.apache.wicket.model.AbstractPropertyModel.getInnermostModelOrObject()
returns null and I ultimately get a WicketRuntimeException: Attempted
to set property value on a null object in PropertyResolver.setValue
because the object is null.

My question is how to deal this this correctly at the model level.  I
think IModel.setObject should create a new object if the incoming
object is null and IModel.getObject should return null if no fields
are set on the object to match how JPA/Hibernate handles this.

How do other people handle this problem?  Is there a good model to
extend from (maybe something like IWrapModel)?  Any examples?

Thanks
Andrew

PS I'm already using EntityModels
(http://wicketinaction.com/2008/09/building-a-smart-entitymodel/)

-
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

Re: WicketRuntimeException: Attempted to set property value on a null object

2012-11-30 Thread Andrew Geery 
The problem with doing that is that Hibernate detects that as a change
(a null object is not the same as an empty object) and does a database
update (see some of the comments on this:
https://issues.jboss.org/browse/HIBERNATE-50).

Andrew

On Fri, Nov 30, 2012 at 5:59 PM, Sven Meier s...@meiers.net wrote:
 d

-
To unsubscribe, e-mail: users-unsubscr...@wicket.apache.org
For additional commands, e-mail: users-h...@wicket.apache.org