Hi Marcin,
I've already looked at localObject() and it's not good.
Here's why ?
You have a data object : dataObjectInContext1
You modify a property : dataObjectInContext1.setName("the new name");
You copy it to the second dataContext and modify it's persistenceState
dataObjectInContext2=
context2.localObject(dataObjectInContext1.getObjectId(),
dataObjectInContext1);
dataObjectInContext2.setPersistenceState(PersistenceState.MODIFIED);
Everything is ok till now but here is the problem :
dataObjectInContext2.commitChanges();
Nothing will be written to the database because context2 did not track
changes of dataObjectInContext2.
That's why i'm not using localObject().
Is there a way that dataObjectInContext2 will be committed using
localObject() ?
I'm using Cayenne 1.2
Jonathan.
Marcin Skladaniec wrote:
Hello Jonathan
Please take a closer look on the localObject() method.
Straight from javadocs :
"Returns an object local to this DataContext and matching the
ObjectId. If prototype is not null, local object is refreshed with the
prototype values.
In case you pass a non-null second parameter, you are responsible for
setting correct persistence state of the returned local object, as
generally there is no way for Cayenne to determine the resulting local
object state."
If you have still problems please mention what version of cayenne are
you using.
Marcin
-------------------------->
ish
http://www.ish.com.au
Level 1, 30 Wilson Street Newtown 2042 Australia
phone +61 2 9550 5001 fax +61 2 9550 4001
On 28/08/2006, at 6:33 AM, Jonathan Bélisle wrote:
Hi, maybe someone can help me here.
I'm trying to copy a dataObject to another dataContext while keeping
it's modified state so that it will be correctly committed to the db
by the second dataContext.
Let say we have an entity with an attribute Name and a relationship
Category.
The object 1000001 exist in the db and has a Name and a Category
//Create the dataContext
DataContext dc1= DataContext.createDataContext();
DataContext dc2= DataContext.createDataContext();
//Get object from db. Modify the name.
Animal from= (Animal) DataObjectUtils.objectForPK(dc1, new
ObjectId("Animal", "animalId", 1000001));
from.setName("XXX" + new SecureRandom().nextInt());
//Get local object to dc2
//I cannot use dc2.localObject(from.getObjectId(), from);
//because the dc2 won't see the modification made in dc1.
Animal to= (Animal) dc2.localObject(from.getObjectId(), null);
dc2.getObjectStore().resolveHollow(to);
//Copy the attributes from object1 to object2 String attName;
ObjAttribute objAttribute;
ObjEntity objEntity=
from.getObjectContext().getEntityResolver().lookupObjEntity(to);
Iterator attributes = objEntity.getAttributes().iterator();
while (attributes.hasNext()) {
objAttribute = (ObjAttribute) attributes.next();
attName= objAttribute.getName();
to.writeProperty(attName, from.readPropertyDirectly(attName));
}
dc2.commitChanges();
System.out.println(from);
System.out.println(to);
Everything is committed correctly to the db but the object from has
now a Category = null
The problem is after the dc2.commitChanges() and
it comes from
org.objectstyle.cayenne.event.EventManager.DispatchThread.run() witch
is firing an event to set the relationship Category to null.
I don't know why it is doing that.
I am doing something wrong ? Is it a bug in cayenne ?
And i need context synchronization so turning it off is not an option.
I really need help on this one, can someone help me ?
Jonathan
