Hallo,
thank you again: now I got it!
I needed examples :-)
> Well, if you can mark each entity with whether it's persistent or not,
Yes.
> you could do this:
>
> public void addToManyTarget(Object obj, ...)
> {
> if obj.isNonpersistent()
> {
> nonpersistentSet.add(obj);
> }
> else
> {
> super.addToManyTarget(obj, ....);
> }
> }
>
> public List getList()
> {
> List list = new ArrayList(super.getList())
> list.addObjects(nonPersistentSet);
> }
This defines me "persistent -> (non)persistent".
> Things get more complicated if you want to have reverse relationships
> set for your non-persistent objects. I have implemented a
> non-persistent object DAO using the Cayenne api for testing and
> development. It's not pretty, but it can be done.
Do you mean that "nonpersistent -> (non)persistent" will be complicated?
Why? I can do the following:
public void addToManyTarget(Object obj, ...)
{ if(this.isNonpersistent()) {
allObjects.add(obj);
} else {
if obj.isNonpersistent() {
nonpersistentSet.add(obj);
} else {
super.addToManyTarget(obj, ....);
}
}
}
Would this work?
> And that's not going to handle what happens if you try to do a query
> on object sets that are both persistent and non-persistent.
I will not get the references in the nonpersistent-object-list, right?
Another question: How does cayenne hold objects in memory?
As a normal reference, as WeakReference or even as PhantomReference?
Peter.
