Obtain relationship target objects of a DataObject

[Andreas Hartmann <an...@apache.org>]

Hi everyone,

I'd like to write some generic code to replace the set of related 
objects of a DataObject with a different set of objects. But I can't 
figure out how to get the list of the target objects.

Here's some naiive code to illustrate what I'd like to achieve:


final List<DataObject> oldObjects = (List<DataObject>) 
object.readProperty(name);

for (final DataObject targetObj : oldObjects) {
     object.removeToManyTarget(name, targetObj, true);
}

for (final DataObject targetObj : newObjects) {
     object.addToManyTarget(name, targetObj, true);
}


But apparently object.readProperty(…) doesn't return a list of the 
existing target objects.

What would be the correct way to do this?

Thanks a lot in advance!

-- Andreas


-- 
Andreas Hartmann, CTO
BeCompany GmbH
http://www.becompany.ch
Tel.: +41 (0) 43 818 57 01

Re: Obtain relationship target objects of a DataObject

[Andreas Hartmann <an...@apache.org>]

Hi Andrus,

thanks for your reply!

Andrus Adamchik schrieb:
> On Sep 21, 2009, at 12:49 AM, Andreas Hartmann wrote:
> 
>> But apparently object.readProperty(…) doesn't return a list of the 
>> existing target objects.
> 
> It does and the code looks correct to me. Doublecheck that "name" 
> corresponds to a property mapped as to-many relationship.

Apparently it was a concurrent list access issue. If I wrap the list in 
a new array list before iterating, it works:

final List<DataObject> oldObjects
   = new ArrayList<DataObject>((List<DataObject>) 
object.readProperty(name));


So it's not a Cayenne issue; sorry for the noise.

-- Andreas


-- 
Andreas Hartmann, CTO
BeCompany GmbH
http://www.becompany.ch
Tel.: +41 (0) 43 818 57 01

Re: Obtain relationship target objects of a DataObject

[Andrus Adamchik <an...@objectstyle.org>]

On Sep 21, 2009, at 12:49 AM, Andreas Hartmann wrote:

> But apparently object.readProperty(…) doesn't return a list of the  
> existing target objects.

It does and the code looks correct to me. Doublecheck that "name"  
corresponds to a property mapped as to-many relationship.

Andrus